Environments

20 pages, 6507 KiB

Open AccessEditor’s ChoiceArticle

The Impact of Tourism Activity on Coastal Biodiversity: A Case Study at Praia da Cova Redonda (Algarve—Portugal)

by Leonel J. R. Nunes, Mauro A. M. Raposo and Carlos J. Pinto Gomes

Environments 2020, 7(10), 88; https://doi.org/10.3390/environments7100088 - 12 Oct 2020

Cited by 12 | Viewed by 5612

Tourism activity has a very significant weight in the world economy, even being the main activity responsible for the export of many countries, in the form of providing services to foreign citizens. In mainland Portugal, the main tourist region is the Algarve, where [...] Read more.

Tourism activity has a very significant weight in the world economy, even being the main activity responsible for the export of many countries, in the form of providing services to foreign citizens. In mainland Portugal, the main tourist region is the Algarve, where beach tourism, known as sun and sea tourism, plays a decisive role. However, this activity also has its negative impacts. In the present work, a case study was analyzed, at Praia da Cova Redonda, located in the parish of Porches, in the municipality of Lagoa. Negative impacts on land use and occupation were identified, caused by the excessive presence of people, the introduction of invasive species and the artificial filling of beaches. At the end, a set of mitigating measures are presented that aim to ensure that the exploitation of natural resources can be maintained, but in a perspective of preservation and recovery of natural resources and biodiversity. Full article

(This article belongs to the Special Issue Dynamic of Vegetation and Climate Change)

► Show Figures

Figure 1

15 pages, 753 KiB

Open AccessEditor’s ChoiceArticle

Small Environmental Actions Need of Problem-Solving Approach: Applying Project Management Tools to Beach Litter Clean-Ups

by Corrado Battisti, Gianluca Poeta, Federico Romiti and Lorenzo Picciolo

Environments 2020, 7(10), 87; https://doi.org/10.3390/environments7100087 - 11 Oct 2020

Cited by 39 | Viewed by 6309

Abstract

Clean-ups can be considered real conservation actions since beach litter may impact many ecosystem components. However, although these actions are quite easy to carry out, we think that they need to follow specific criteria and clear planning. Contrariwise, an unplanned clean-up could lead [...] Read more.

Clean-ups can be considered real conservation actions since beach litter may impact many ecosystem components. However, although these actions are quite easy to carry out, we think that they need to follow specific criteria and clear planning. Contrariwise, an unplanned clean-up could lead to counter-productive—or even harmful—consequences to the fragile dune ecosystem; e.g., excessive trampling and/or extreme sand removal. Here, we defined a road map for implementing beach clean-ups according to the logic of problem solving and project management, also adding a flow chart. More particularly, we subdivided the clean-up project into different steps as follows: context analysis, input and planning, process, monitoring (outputs and outcomes) and adaptation. Full article

(This article belongs to the Special Issue Anthropogenic Beach Litter and Impact on Habitats)

► Show Figures

Figure 1

13 pages, 5926 KiB

Open AccessEditor’s ChoiceArticle

Effect of Multiple Stresses, Organic Amendment and Compaction, on the Fate and Impact of Isoproturon in Soil

by Laure Mamy, Christian Mougin, Pierre Benoit, Sabine Houot, Agathe Brault, Nathalie Cheviron, Ghislaine Delarue, Valérie Dumeny and Laure Vieublé-Gonod

Environments 2020, 7(10), 79; https://doi.org/10.3390/environments7100079 - 29 Sep 2020

Cited by 3 | Viewed by 3242

Abstract

Organic matter decline and compaction are two major processes of soil degradation. Organic amendment is a current practice to compensate the loss of organic matter, which could in addition contribute to increase soil aggregate stability and limit compaction. Therefore, the objective of this [...] Read more.

Organic matter decline and compaction are two major processes of soil degradation. Organic amendment is a current practice to compensate the loss of organic matter, which could in addition contribute to increase soil aggregate stability and limit compaction. Therefore, the objective of this work was to study the effect of multiple physico-chemical stresses, organic amendment (compost of sewage sludge and green waste) addition and soil compaction, on the fate and impact (measured through the urease enzyme activity) of isoproturon. Compost addition and compaction did not significantly affect the fate and impact of isoproturon. The lack of effect of compost can be due to the delay between soil sampling and soil amendment. Compaction had no effect probably because the porosity reduction does not affect the habitable pore space accessible to degrading microorganisms. Nevertheless, isoproturon significantly increased the urease enzyme activity in compacted and not compacted unamended soils contrary to the amended ones. It seems that the organic amendment could act as a buffer with regards to the impact of isoproturon. The results obtained in this work suggest that, in general, the fate and impact of isoproturon in soils will not change following compaction and/or organic amendment addition, neither the corresponding risks for the environment. Full article

(This article belongs to the Special Issue Effect of the Application of Organic Waste on the Dynamics of Pesticides in Soils)

► Show Figures

Graphical abstract

32 pages, 5327 KiB

Open AccessEditor’s ChoiceArticle

Techno-Economic Assessment of CHP Systems in Wastewater Treatment Plants

by Derall M. Riley, Jiashen Tian, Gamze Güngör-Demirci, Patrick Phelan, J. Rene Villalobos and Ryan J. Milcarek

Environments 2020, 7(10), 74; https://doi.org/10.3390/environments7100074 - 26 Sep 2020

Cited by 45 | Viewed by 6885

Abstract

Wastewater treatment plant (WWTP) utilization of combined heat and power (CHP) systems allows for the efficient use of on-site biogas production, as well as increased annual savings in utility costs. In this paper, a review of biogas energy recovery options, CHP prime mover [...] Read more.

Wastewater treatment plant (WWTP) utilization of combined heat and power (CHP) systems allows for the efficient use of on-site biogas production, as well as increased annual savings in utility costs. In this paper, a review of biogas energy recovery options, CHP prime mover technologies, and the costs associated with biogas cleaning give a broad summary of the current state of CHP technology in WWTPs. Even though there are six different prime mover technologies, the main ones currently being implemented in WWTPs are micro turbines, fuel cells and reciprocating engines. Different prime movers offer varying efficiencies, installation costs, and biogas impurity (H₂S, siloxanes, HCl) tolerances. To evaluate the long-term savings capabilities, a techno-economic assessment of a CHP installation at a case study WWTP shows the payback, annual savings, and initial costs associated with the installation of a CHP system. In this case, a study a payback of 5.7 years and a net present value of USD 709,000 can be achieved when the WWTP generates over 2,000,000 m³ of biogas per year and utilizes over 36,000 GJ of natural gas per year. Full article

(This article belongs to the Special Issue Pollution Prevention/Environmental Sustainability for Industry)

► Show Figures

Figure 1

30 pages, 3321 KiB

Open AccessEditor’s ChoiceReview

The Way of Macroplastic through the Environment

by Simone Lechthaler, Kryss Waldschläger, Georg Stauch and Holger Schüttrumpf

Environments 2020, 7(10), 73; https://doi.org/10.3390/environments7100073 - 24 Sep 2020

Cited by 73 | Viewed by 12934

Abstract

With the focus on microplastic in current research, macroplastic is often not further considered. Thus, this review paper is the first to analyse the entry paths, accumulation zones, and sinks of macroplastic in the aquatic, terrestrial, and atmospheric environment by presenting transport paths [...] Read more.

With the focus on microplastic in current research, macroplastic is often not further considered. Thus, this review paper is the first to analyse the entry paths, accumulation zones, and sinks of macroplastic in the aquatic, terrestrial, and atmospheric environment by presenting transport paths and concentrations in the environment as well as related risks. This is done by applying the Source–Pathway–Receptor model on macroplastic in the environment. Based on this model, the life cycle of macroplastic is structurally described, and knowledge gaps are identified. Hence, current research aspects on macroplastic as well as a sound delimitation between macro- and microplastic that can be applied to future research are indicated. The results can be used as basic information for further research and show a qualitative assessment of the impact of macroplastic that ends up in the environment and accumulates there. Furthermore, the applied model allows for the first time a quantitative and structured approach to macroplastic in the environment. Full article

(This article belongs to the Special Issue Bioplastics in the Environment)

► Show Figures

Graphical abstract

9 pages, 12596 KiB

Open AccessEditor’s ChoiceCommunication

Performance of a Woodchip Bioreactor for the Treatment of Nitrate-Laden Agricultural Drainage Water in Northeastern Germany

by Lennart Gosch, Haojie Liu and Bernd Lennartz

Environments 2020, 7(9), 71; https://doi.org/10.3390/environments7090071 - 15 Sep 2020

Cited by 13 | Viewed by 3895

Abstract

Reactive barriers, such as denitrifying bioreactors, have been identified as a clean-up option for nutrient-laden agriculture runoff. Here we tested a 20 m long, 3.75 m wide and 2.2 m deep woodchip bioreactor receiving tile drainage water from a 5.2 ha field site, [...] Read more.

Reactive barriers, such as denitrifying bioreactors, have been identified as a clean-up option for nutrient-laden agriculture runoff. Here we tested a 20 m long, 3.75 m wide and 2.2 m deep woodchip bioreactor receiving tile drainage water from a 5.2 ha field site, aiming at testing the hydraulic functioning of a dual-inlet system and quantifying its impact on nutrient loads (nitrogen, reactive phosphorus, organic carbon) in a region with a drainage season taking place in the hydrological winter (November to April). The hydraulic conditions in the dual-inlet bioreactor system developed differently than expected; asymmetric flow rates led to long average hydraulic retention times and a highly dispersed residence time distribution, which was revealed by a bromide tracer test. With a nitrate load reduction of 51 to 90% over three drainage seasons, the woodchip bioreactor proved at the same time to be very effective under the winter conditions of northeastern Germany. The bioreactor turned from an orthophosphate source in the first year of operation into an orthophosphate sink in the second and third year, which was not expected because of anoxic conditions (favorable for denitrification) prevailing within the woodchips. Besides an efficient nutrient retention, the woodchip bioreactor contributed to the total organic carbon load of receiving waters, which impairs the overall positive role of bioreactors within intensively agriculturally used landscapes. We consider this promising low-maintenance biotechnology particularly suitable for single drainage pipes with high discharge and high nitrate concentrations. Full article

(This article belongs to the Special Issue Treatment Wetlands)

► Show Figures

Figure 1

14 pages, 1434 KiB

Open AccessEditor’s ChoiceArticle

Monitoring Arsenic Species Content in Seaweeds Produced off the Southern Coast of Korea and Its Risk Assessment

by Min-hyuk Kim, Junseob Kim, Chang-Hyun Noh, Seogyeong Choi, Yong-Sung Joo and Kwang-Won Lee

Environments 2020, 7(9), 68; https://doi.org/10.3390/environments7090068 - 03 Sep 2020

Cited by 17 | Viewed by 4825

Abstract

Seaweed, a popular seafood in South Korea, has abundant dietary fiber and minerals. The toxicity of arsenic compounds is known to be related to their chemical speciation, and inorganic arsenic (iAs) is more detrimental than other species. Due to the different toxicities of [...] Read more.

Seaweed, a popular seafood in South Korea, has abundant dietary fiber and minerals. The toxicity of arsenic compounds is known to be related to their chemical speciation, and inorganic arsenic (iAs) is more detrimental than other species. Due to the different toxicities of the various chemical forms, speciation analysis is important for evaluating arsenic exposure. In this study, total arsenic (tAs) and six arsenic species (arsenite, arsenate, monomethylarsonic acid, dimethylarsinic acid, arsenobetaine, and arsenocholine) were analyzed in 180 seaweed samples. Although there were differences between seaweed species, the concentration of tAs was detected at levels ranging from 1 to 100 µg/g, and the distribution of six arsenic species differed depending on the seaweed species. No correlation between the concentration of iAs and tAs was found in most seaweed species. Through statistical clustering, hijiki and gulfweed were seen to be the seaweeds with the highest ratios of iAs to tAs. Using the iAs concentration data from the arsenic speciation analysis, a risk assessment of seaweed intake in South Korea was conducted. The margin of exposure values showed no meaningful risk for the general population, but low levels of risk were identified for seaweed consumers, with high intakes of gulfweed and hijiki. Full article

(This article belongs to the Special Issue Metal Speciation/Fractionation in Different Phases of the Marine Environment)

► Show Figures

Graphical abstract

12 pages, 3502 KiB

Open AccessEditor’s ChoiceArticle

Assessment of Non-Anthropogenic Addition of Uric Acid to a Water Treatment Wetlands

by Joseph Welch, Vanessa Simmons, Eduardo Meléndez, Mark Sees, Yolanda Gold and Emily C. Heider

Environments 2020, 7(8), 60; https://doi.org/10.3390/environments7080060 - 05 Aug 2020

Cited by 3 | Viewed by 3615

Abstract

Artificial water-treatment wetlands can reduce nitrogen and phosphorous nutrient concentrations in wastewater effluent to improve water quality and decrease eutrophication in natural waters. The Orlando Easterly Wetlands (OEW) is an engineered wetland that polishes 57 million liters of wastewater per day, lowering the [...] Read more.

Artificial water-treatment wetlands can reduce nitrogen and phosphorous nutrient concentrations in wastewater effluent to improve water quality and decrease eutrophication in natural waters. The Orlando Easterly Wetlands (OEW) is an engineered wetland that polishes 57 million liters of wastewater per day, lowering the total nitrogen and phosphorous concentrations through biological, physical, and chemical processes. In addition to purifying the water, the wetlands provide habitat for avian, mammalian, reptilian and macroinvertebrate species. Previous research has shown that avian species affect the eutrophication of agricultural reservoirs near their roost. The research herein quantifies uric acid in avian and reptilian excretory product and tracks its concentration profile throughout the OEW over a seven-month period. This measure of the non-anthropogenic contribution to nitrogen within the park includes winter months when large numbers of migratory birds occupy the wetland. The enzymatic decomposition of uric acid and the subsequent fluorimetric analysis were used to quantify uric acid throughout the flow train of the OEW. High concentrations of 2–4 mg/L uric acid were found in the influent, but drastically declined to concentrations below 0.2 mg/L in the effluent. Full article

(This article belongs to the Special Issue Treatment Wetlands)

► Show Figures

Graphical abstract

19 pages, 1564 KiB

Open AccessEditor’s ChoiceArticle

From Boiling to Frozen? The Rise and Fall of International Tourism to Iceland in the Era of Overtourism

by Anna Dóra Sæþórsdóttir, C. Michael Hall and Margrét Wendt

Environments 2020, 7(8), 59; https://doi.org/10.3390/environments7080059 - 03 Aug 2020

Cited by 24 | Viewed by 11614

Abstract

Overtourism has emerged as a common concept to describe the perceived negative impacts that large numbers of tourists can have on destinations. Iceland is one of the destinations which has been most associated with the concept of overtourism. Tourism in Iceland grew rapidly [...] Read more.

Overtourism has emerged as a common concept to describe the perceived negative impacts that large numbers of tourists can have on destinations. Iceland is one of the destinations which has been most associated with the concept of overtourism. Tourism in Iceland grew rapidly from 2010 to 2019, much higher than in most other countries, with Iceland reaching a ranking as high as thirteenth on a list of countries with the highest ratio of tourists per inhabitant. The increase in visitors to the country has had various impacts on Iceland’s economy, society and environment. This paper provides an overview of the different ways in which overtourism has revealed itself at a national level in Iceland. The implications of supposed overtourism are shown to be complex, with management responses limited by their relative focus. Full article

► Show Figures

Figure 1

14 pages, 6312 KiB

Open AccessEditor’s ChoiceReview

Fire as a Selection Agent for the Dissemination of Invasive Species: Case Study on the Evolution of Forest Coverage

by Leonel J. R. Nunes, Mauro A. M. Raposo, Catarina I. R. Meireles, Carlos J. Pinto Gomes and Nuno M. C. Almeida Ribeiro

Environments 2020, 7(8), 57; https://doi.org/10.3390/environments7080057 - 31 Jul 2020

Cited by 10 | Viewed by 3785

Abstract

Climate change has enhanced the occurrence of rural fires, since changes in the hydrological cycle have led to the occurrence of increasingly long and frequent periods of drought. This recurrence of rural fires in Portugal, in turn, has led to the successive elimination [...] Read more.

Climate change has enhanced the occurrence of rural fires, since changes in the hydrological cycle have led to the occurrence of increasingly long and frequent periods of drought. This recurrence of rural fires in Portugal, in turn, has led to the successive elimination of vast areas traditionally occupied by native species or species of economic interest, which are being successively replaced by new species with invasive behavior. Among these, Acacia dealbata stands out for its dispersion capacity and for the area it has already occupied. In the present work, which reviews the evolution of forest cover over the last 18,000 years in the Serra da Estrela Natural Park, we intend to demonstrate that fire acts as a species selection agent and that it enhances the development of heliophile and pyrophyte species. For this purpose, an area of the municipality of Seia was selected, more specifically Casal do Rei, where the development of Acacia dealbata forests is monitored. In the end, it was concluded that, in fact, by analyzing the ages of the specimens present in these populations, fire acts as a selection agent by freeing up the space previously occupied by other species, opening the way for the growth of heliophiles and pyrophytes invasive species while enhancing their germination. Full article

(This article belongs to the Special Issue Landscape Ecological and Social–Ecological Approaches in Agro-Ecological System)

► Show Figures

Figure 1

16 pages, 3149 KiB

Open AccessEditor’s ChoiceArticle

Alleviation of Cadmium Adverse Effects by Improving Nutrients Uptake in Bitter Gourd through Cadmium Tolerant Rhizobacteria

by Muhammad Zafar-ul-Hye, Muhammad Naeem, Subhan Danish, Shah Fahad, Rahul Datta, Mazhar Abbas, Ashfaq Ahmad Rahi, Martin Brtnicky, Jiří Holátko, Zahid Hassan Tarar and Muhammad Nasir

Environments 2020, 7(8), 54; https://doi.org/10.3390/environments7080054 - 26 Jul 2020

Cited by 77 | Viewed by 5791

Abstract

Cadmium is acute toxicity inducing heavy metal that significantly decreases the yield of crops. Due to high water solubility, it reaches the plant tissue and disturbs the uptake of macronutrients. Low uptake of nutrients in the presence of cadmium is a well-documented fact [...] Read more.

Cadmium is acute toxicity inducing heavy metal that significantly decreases the yield of crops. Due to high water solubility, it reaches the plant tissue and disturbs the uptake of macronutrients. Low uptake of nutrients in the presence of cadmium is a well-documented fact due to its antagonistic relationship with those nutrients, i.e., potassium. Furthermore, cadmium stressed plant produced a higher amount of endogenous stress ethylene, which induced negative effects on yield. However, inoculation of 1-amino cyclopropane-1-carboxylate deaminase (ACCD), producing plant growth promoting rhizobacteria (PGPR), can catabolize this stress ethylene and immobilized heavy metals to mitigate cadmium adverse effects. We conducted a study to examine the influence of ACCD PGPR on nutrients uptake and yield of bitter gourd under cadmium toxicity. Cadmium tolerant PGPRs, i.e., Stenotrophomonas maltophilia and Agrobacterium fabrum were inoculated solely and in combination with recommended nitrogen, phosphorus, and potassium fertilizers (RNPKF) applied under different concentration of soil cadmium (2 and 5 mg kg⁻¹ soil). Results showed that A. fabrum with RNPKF showed significant positive response towards an increase in the number of bitter gourds per plant (34% and 68%), fruit length (19% and 29%), bitter gourd yield (26.5% and 21.1%), N (48% and 56%), and K (72% and 55%) concentration from the control at different concentrations of soil cadmium (2 and 5 mg kg⁻¹ soil), respectively. In conclusion, we suggest that A. fabrum with RNPKF can more efficaciously enhance N, K, and yield of bitter gourd under cadmium toxicity. Full article

(This article belongs to the Special Issue Soil Contamination by Heavy Metals and Metalloids)

► Show Figures

Figure 1

8 pages, 1881 KiB

Open AccessEditor’s ChoiceArticle

Decontaminating Terrestrial Oil Spills: A Comparative Assessment of Dog Fur, Human Hair, Peat Moss and Polypropylene Sorbents

by Megan L. Murray, Soeren M. Poulsen and Brad R. Murray

Environments 2020, 7(7), 52; https://doi.org/10.3390/environments7070052 - 08 Jul 2020

Cited by 12 | Viewed by 17299

Abstract

Terrestrial oil spills have severe and continuing consequences for human communities and the natural environment. Sorbent materials are considered to be a first line of defense method for directly extracting oil from spills and preventing further contaminant spread, but little is known on [...] Read more.

Terrestrial oil spills have severe and continuing consequences for human communities and the natural environment. Sorbent materials are considered to be a first line of defense method for directly extracting oil from spills and preventing further contaminant spread, but little is known on the performance of sorbent products in terrestrial environments. Dog fur and human hair sorbent products were compared to peat moss and polypropylene sorbent to examine their relative effectiveness in adsorbing crude oil from different terrestrial surfaces. Crude oil spills were simulated using standardized microcosm experiments, and contaminant adsorbency was measured as percentage of crude oil removed from the original spilled quantity. Sustainable-origin absorbents made from dog fur and human hair were equally effective to polypropylene in extracting crude oil from non- and semi-porous land surfaces, with recycled dog fur products and loose-form hair showing a slight advantage over other sorbent types. In a sandy terrestrial environment, polypropylene sorbent was significantly better at adsorbing spilled crude oil than all other tested products. Full article

(This article belongs to the Special Issue Pollution Prevention/Environmental Sustainability for Industry)

► Show Figures

Figure 1

13 pages, 1507 KiB

Open AccessEditor’s ChoiceArticle

UV Light-Irradiated Photocatalytic Degradation of Coffee Processing Wastewater Using TiO₂ as a Catalyst

by Gurudev Sujatha, Subramaniam Shanthakumar and Fulvia Chiampo

Environments 2020, 7(6), 47; https://doi.org/10.3390/environments7060047 - 19 Jun 2020

Cited by 46 | Viewed by 6752

Abstract

The coffee industry generates a significant amount of wastewater that is rich in organic loads and is highly acidic. The present study investigates the potential of the heterogeneous photocatalytic oxidation process to reduce the pollutant load in coffee processing wastewater. The experimental runs [...] Read more.

The coffee industry generates a significant amount of wastewater that is rich in organic loads and is highly acidic. The present study investigates the potential of the heterogeneous photocatalytic oxidation process to reduce the pollutant load in coffee processing wastewater. The experimental runs were conducted to evaluate the effect of operative parameters such as pH, catalyst dosage, intensity of UV light irradiation, and addition of oxidant on Chemical Oxygen Demand (COD) and colour reduction. Significant results for COD and colour removal, 67%, and 70% respectively, were achieved at a pH of 4 with titanium dioxide (TiO₂), and a catalyst dosage of 500 mg/L, using four ultraviolet-C (UV-C) lamps of 16 W each. With the addition of hydrogen peroxide (H₂O₂) as an oxidant, the removal efficiency increased to 84% and 75% for COD and colour, respectively. Finally, the best results obtained by photocatalytic degradation using UV light were compared to those using solar light. Based on the investigation, it was inferred that the pollutant removal efficiency in coffee pulping wastewater was also considerably high under sunlight. These findings may have relevance in terms of application in countries where coffee processing is carried out and where sunlight irradiance is usually strong: the technique could be exploited to decrease the pollutant content of this wastewater sustainably. Full article

(This article belongs to the Special Issue Emerging Technologies for Advanced Water Purification)

► Show Figures

Figure 1

15 pages, 1756 KiB

Open AccessEditor’s ChoiceArticle

Biogas Production from Food Residues—The Role of Trace Metals and Co-Digestion with Primary Sludge

by Moshe Habagil, Alexander Keucken and Ilona Sárvári Horváth

Environments 2020, 7(6), 42; https://doi.org/10.3390/environments7060042 - 29 May 2020

Cited by 29 | Viewed by 5418

Abstract

The majority of municipal Wastewater Treatment Plants (WWTPs) in Sweden produce biogas from sewage sludge. In order to increase the methane production, co-digestion of internal sludge with Organic Fraction of Municipal Solid Waste (OFMSW) might be feasible in the future. The objective of [...] Read more.

The majority of municipal Wastewater Treatment Plants (WWTPs) in Sweden produce biogas from sewage sludge. In order to increase the methane production, co-digestion of internal sludge with Organic Fraction of Municipal Solid Waste (OFMSW) might be feasible in the future. The objective of this study was therefore to find a beneficial solution for the utilization of OFMSW at the WWTP in Varberg, Sweden. The effects of co-digesting primary sludge (PS) and OFMSW collected in the municipality, in different mixing ratios, were investigated by semi-continuous anaerobic digestion assays. Furthermore, the effects of the addition of a commercial trace elements mixture solution (CTES), available on the market in Sweden, were also examined. Co-digestion of OFMSW and PS resulted in specific methane yields of 404, 392, and 375 NmL CH₄/g volatile solids (VS), obtained during semi-continuous operations of 301, 357 and 385 days, for the reactors fed with OMFSW:PS ratio of 4:1, 3:1, and 1:1, and at maximum organic loading rates (OLRs) achieved of 4.0, 4.0 and 5.0 gVS/L/d, respectively. Furthermore, mono-digestion of OFMSW failed already at OLR of 1.0 gVS/L/d, however, an OLR of 4.0 gVS/L/d could be achieved with addition of 14 µL/g VS Commercial Trace Element Solutions (CTES) leading to 363 mL CH₄/g VS methane production. These experiments were running during 411 days. Hence, higher process efficiency was obtained when using co-digestion of OFMSW and PS compared to that of OFMSW in mono-digestion. Co-digestion is a more feasible option where a balanced Carbon/Nitrogen (C/N) ratio and nutrient supply can be maintained. Full article

(This article belongs to the Special Issue Wastewater and Solid Waste Treatment)

► Show Figures

Figure 1

18 pages, 317 KiB

Open AccessEditor’s ChoiceArticle

Plastic Pollution in Soils: Governance Approaches to Foster Soil Health and Closed Nutrient Cycles

by Jessica Stubenrauch and Felix Ekardt

Environments 2020, 7(5), 38; https://doi.org/10.3390/environments7050038 - 20 May 2020

Cited by 24 | Viewed by 13596

Abstract

Plastic pollution in soils pose a major threat to soil health and soil fertility that are directly linked to food security and human health. In contrast to marine plastic pollution, this ubiquitous problem is thus far scientifically poorly understood and policy approaches that [...] Read more.

Plastic pollution in soils pose a major threat to soil health and soil fertility that are directly linked to food security and human health. In contrast to marine plastic pollution, this ubiquitous problem is thus far scientifically poorly understood and policy approaches that tackle plastic pollution in soils comprehensively do not exist. In this article, we apply a qualitative governance analysis to assess the effectiveness of existing policy instruments to avoid harmful plastic pollution in (agricultural) soils against the background of international environmental agreements. In particular, environmental and fertiliser legislation relevant to soil protection in the European Union and in Germany are assessed. Regulatory weaknesses and gaps of the respective legislation are identified, and proposals for enhanced command-and-control provisions developed. However, the legal analysis furthermore shows that plastic pollution ecologically is also a problem of quantity, which is difficult to solve exclusively through command-and-control legislation. Instead, comprehensive quantity-control instruments to phase out fossil fuels (worldwide and in all sectors) as required by climate protection law can be effective approaches to tackle plastic pollution in environmental media like agricultural soils as well. Full article

16 pages, 2247 KiB

Open AccessEditor’s ChoiceArticle

Control of Invasive Forest Species through the Creation of a Value Chain: Acacia dealbata Biomass Recovery

by Leonel J.R. Nunes, Mauro A.M. Raposo, Catarina I.R. Meireles, Carlos J. Pinto Gomes and Nuno M.C. Almeida Ribeiro

Environments 2020, 7(5), 39; https://doi.org/10.3390/environments7050039 - 20 May 2020

Cited by 28 | Viewed by 4142

Abstract

In Portugal, some species are now considered invasive by law and have proliferated in recent years. Among these, Acacia dealbata stands out. This work investigated the behavior of this species, in order to characterize and evaluate its potential as raw material for biomass [...] Read more.

In Portugal, some species are now considered invasive by law and have proliferated in recent years. Among these, Acacia dealbata stands out. This work investigated the behavior of this species, in order to characterize and evaluate its potential as raw material for biomass pellets production, while controlling its proliferation. It was found that A. dealbata has a large capacity for raw material supply, as cutting 2 ha resulted in about 140 tons of biomass. Thus, the attribution of a market value for this material could result in a reduction in the area occupied by the invasive species, once the demand for it increases, causing a pressure over the resource. This pressure on the species must be duly followed by other control measures, such as reducing the population and mitigating its proliferation. Laboratory tests have shown that both the raw material and the finished product are similar to those obtained with other species normally used for biomass pellet production, such as Pinus pinaster and Eucalyptus globulus. Thus, it can be concluded that there is a high potential for this species in the production of biomass pellets for energy, and that this may be an important contribution to controlling the proliferation of this invasive species. Full article

► Show Figures

Figure 1

13 pages, 2646 KiB

Open AccessEditor’s ChoiceArticle

Vehicular Emission: Estimate of Air Pollutants to Guide Local Political Choices. A Case Study

by Sergio Mazza, Donatella Aiello, Anastasia Macario and Pierantonio De Luca

Environments 2020, 7(5), 37; https://doi.org/10.3390/environments7050037 - 16 May 2020

Cited by 16 | Viewed by 6654

Abstract

The aim of this case study was to show how, with the use of software, is it possible to carry out a preventive screening of vehicular emissions. Moreover, thanks to this preliminary analysis, some areas that are potentially polluted can be identified in [...] Read more.

The aim of this case study was to show how, with the use of software, is it possible to carry out a preventive screening of vehicular emissions. Moreover, thanks to this preliminary analysis, some areas that are potentially polluted can be identified in advance and suitable samplings on small-scale on them would help to verify the effectiveness of policies that can be adopted for the reduction of pollution. To this end, this paper reports a case study on vehicle traffic pollution in Calabria, a region in the south of Italy. We used the methodology called Corinair (Coordination Information AIR), developed by the EEA (European Environment Agency) and uses the software Copert4 (Computer Program to calculate Emission from Road Traffic). The total emissions per area were analyzed and the emissions for particular pollutants per unit area (km²) and per citizen were considered. The obsolete vehicles determined a substantial impact on the local atmospheric pollution. It was demonstrated how it is possible to substantially reduce the pollution of an area by adopting policies that encourage, for example, through tax concessions, the replacement of old cars of private citizens. Full article

(This article belongs to the Special Issue Environmental Monitoring of Pollutants)

► Show Figures

Figure 1

15 pages, 2645 KiB

Open AccessEditor’s ChoiceArticle

Life Cycle Assessment of Community-Based Sewer Mining: Integrated Heat Recovery and Fit-For-Purpose Water Reuse

by Ludwig Paul B. Cabling, Yumi Kobayashi, Evan G. R. Davies, Nicholas J. Ashbolt and Yang Liu

Environments 2020, 7(5), 36; https://doi.org/10.3390/environments7050036 - 14 May 2020

Cited by 5 | Viewed by 4760

Abstract

Municipal sewage contains significant embedded resources in the form of chemical and thermal energy. Recent developments in sustainable technology have pushed for the integration of resource recovery from household wastewater to achieve net zero energy consumption and carbon-neutral communities. Sewage heat recovery and [...] Read more.

Municipal sewage contains significant embedded resources in the form of chemical and thermal energy. Recent developments in sustainable technology have pushed for the integration of resource recovery from household wastewater to achieve net zero energy consumption and carbon-neutral communities. Sewage heat recovery and fit-for-purpose water reuse are options to optimize the resource recovery potential of municipal wastewater. This study presents a comparative life cycle assessment (LCA) focused on global warming potential (GWP), eutrophication potential (EUP), and human health carcinogenic potential (HHCP) of an integrated sewage heat recovery and water reuse system for a hypothetical community of 30,000 people. Conventional space and water heating components generally demonstrated the highest GWP contribution between the different system components evaluated. Sewage-heat-recovery-based district heating offered better environmental performance overall. Lower impact contributions were demonstrated by scenarios with a membrane bioreactor (MBR) and chlorination prior to water reuse applications compared to scenarios that use more traditional water and wastewater treatment technologies and discharge. The LCA findings show that integrating MBR wastewater treatment and water reuse into a district heating schema could provide additional environmental savings at a community scale. Full article

(This article belongs to the Special Issue Water and Energy Consumption in Urban Water Cycles)

► Show Figures

Figure 1

23 pages, 3864 KiB

Open AccessEditor’s ChoiceArticle

Long-Term Environmental Monitoring in an Arctic Lake Polluted by Metals under Climate Change

by Elena M. Zubova, Nikolay A. Kashulin, Vladimir A. Dauvalter, Dmitry B. Denisov, Svetlana A. Valkova, Oksana I. Vandysh, Zakhar I. Slukovskii, Peter M. Terentyev and Alexander A. Cherepanov

Environments 2020, 7(5), 34; https://doi.org/10.3390/environments7050034 - 29 Apr 2020

Cited by 20 | Viewed by 4412

Abstract

Lake Kuetsjarvi (in the lower reaches of the Pasvik River, Murmansk Region, Russia) in the border area between Russia and Norway, is one of the most polluted water reservoirs in the European Arctic. The operation of the Pechenganikel Smelter located on its shores [...] Read more.

Lake Kuetsjarvi (in the lower reaches of the Pasvik River, Murmansk Region, Russia) in the border area between Russia and Norway, is one of the most polluted water reservoirs in the European Arctic. The operation of the Pechenganikel Smelter located on its shores has led to the extremely high concentrations of heavy metals observed in the waters and sediments of the lake. Long-term comprehensive studies of the ecosystem of Lake Kuetsjarvi have made it possible to identify the response of its components to the global and regional change in the environment and climate as a whole, resulting in increased water toxicity and eutrophication, reduction in the number of stenobiont species of aquatic organisms against the background of an increase in the number of eurybiontic and invasive species. Modern communities of Lake Kuetsjarvi are the result of a combination of long-term changes in the abiotic environment and biotic interactions. Heavy-metal pollution of Lake Kuetsjarvi, observed since the 1930s, has led to the formation of a community that is resistant to this type of impact and supports large populations of adapted species. Adaptations of communities to the dynamics of the environmental conditions that their members are exposed to include changes in the species composition, quantitative indicators, ratios between individual taxonomic groups, and the population structure. The development of sympatric forms that differ in the ecological niches they occupy, morphology, and life cycle strategies, including the transition to a short-cycle survival strategy, allows whitefish to remain the dominant species and maintain high population numbers. Unlike the organismal level, responses to medium-term environmental changes on the population and community level are less specific and characterized by stronger inertia. Full article

► Show Figures

Figure 1

18 pages, 1147 KiB

Open AccessEditor’s ChoiceArticle

The Spatial and Temporal Variability of the Effects of Agricultural Practices on the Environment

by Rosa Maria Fanelli

Environments 2020, 7(4), 33; https://doi.org/10.3390/environments7040033 - 15 Apr 2020

Cited by 20 | Viewed by 5398

Abstract

It is widely known that agricultural practices can alter natural ecosystems, both from a qualitative and quantitative point of view. Indeed, over the years, the intensification of production through excessive or inappropriate use of pesticides and fertilisers in the agricultural sector has had [...] Read more.

It is widely known that agricultural practices can alter natural ecosystems, both from a qualitative and quantitative point of view. Indeed, over the years, the intensification of production through excessive or inappropriate use of pesticides and fertilisers in the agricultural sector has had a negative impact on natural resources. This negative environment impact has had both minor and major consequences for the natural resources present in the different areas of the European Union (EU). This variability depends mainly on the different agricultural training of farmers and on their ability to practise sustainable agriculture. Hence, with a specific set of agri-environmental indicators provided by the Eurostat database, this paper analyses the spatial and temporal variation of the agricultural land-use practices and the related environmental effects in EU countries. In pursuit of this aim, descriptive statistics and multivariate analysis (factor analysis and hierarchical cluster analysis) were adopted to determine the similarities/dissimilarities between the different types of agricultural production in the EU and the dominant dimensions of agricultural production and activities there in terms of their impact of natural resources in order to identify “homogeneity” among member states. The main contribution of this paper lies, above all, in the fact that the classification of these countries in four agro-ecosystems, with similar use of energy, pollution factors, and natural resources, could be useful as a tool for policymakers. Importantly, it could help them to define different incentives that could encourage farmers to adopt more sustainable agricultural production methods. Full article

► Show Figures

Figure 1

28 pages, 2014 KiB

Open AccessEditor’s ChoiceReview

Microplastic Contamination in Freshwater Environments: A Review, Focusing on Interactions with Sediments and Benthic Organisms

by Arianna Bellasi, Gilberto Binda, Andrea Pozzi, Silvia Galafassi, Pietro Volta and Roberta Bettinetti

Environments 2020, 7(4), 30; https://doi.org/10.3390/environments7040030 - 12 Apr 2020

Cited by 225 | Viewed by 16187

Abstract

Plastic is one of the most commonly produced and used materials in the world due to its outstanding features. However, the worldwide use of plastics and poor waste management have led to negative impacts on ecosystems. Plastic degradation in the environment leads to [...] Read more.

Plastic is one of the most commonly produced and used materials in the world due to its outstanding features. However, the worldwide use of plastics and poor waste management have led to negative impacts on ecosystems. Plastic degradation in the environment leads to the generation of plastic particles with a size of <5 mm, which are defined as microplastics (MPs). These represent a global concern due to their wide dispersion in water environments and unclear potential ecotoxicological effects. Different studies have been performed with the aim of evaluating the presence and impacts of MPs in the marine environment. However, the presence of MPs in freshwater systems is still poorly investigated, making data retrieval a difficult task. The purpose of this review is to identify the main aspects concerning MPs pollution sources in lakes and rivers, with a focus on freshwater sediments as a site of accumulation and as the habitat of benthic organisms, which are key components of food webs and play a fundamental role in energy/contaminant transfer processes, but are still poorly considered. Through this review, the sources and fate of MPs in freshwater are analysed, ecotoxicological studies focused on sediments and benthic fauna are exposed, the most frequently used sampling and analysis strategies are reported, and future trends of MPs analysis in this field are proposed. Full article

(This article belongs to the Special Issue Feature Papers in Environments in 2020)

► Show Figures

Figure 1

20 pages, 1838 KiB

Open AccessEditor’s ChoiceReview

Effects of Mixtures of Engineered Nanoparticles and Metallic Pollutants on Aquatic Organisms

by Mengting Li, Wei Liu and Vera I. Slaveykova

Environments 2020, 7(4), 27; https://doi.org/10.3390/environments7040027 - 01 Apr 2020

Cited by 32 | Viewed by 5875

Abstract

In aquatic environment, engineered nanoparticles (ENPs) are present as complex mixtures with other pollutants, such as trace metals, which could result in synergism, additivity or antagonism of their combined effects. Despite the fact that the toxicity and environmental risk of the ENPs have [...] Read more.

In aquatic environment, engineered nanoparticles (ENPs) are present as complex mixtures with other pollutants, such as trace metals, which could result in synergism, additivity or antagonism of their combined effects. Despite the fact that the toxicity and environmental risk of the ENPs have received extensive attention in the recent years, the interactions of ENPs with other pollutants and the consequent effects on aquatic organisms represent an important challenge in (nano)ecotoxicology. The present review provides an overview of the state-of-the-art and critically discusses the existing knowledge on combined effects of mixtures of ENPs and metallic pollutants on aquatic organisms. The specific emphasis is on the adsorption of metallic pollutants on metal-containing ENPs, transformation and bioavailability of ENPs and metallic pollutants in mixtures. Antagonistic, additive and synergistic effects observed in aquatic organisms co-exposed to ENPs and metallic pollutants are discussed in the case of “particle-proof” and “particle-ingestive” organisms. This knowledge is important in developing efficient strategies for sound environmental impact assessment of mixture exposure in complex environments. Full article

(This article belongs to the Special Issue New Insights into Impacts of Toxic Metals in Aquatic Environments)

► Show Figures

Figure 1

12 pages, 1375 KiB

Open AccessEditor’s ChoiceArticle

Adsorption Characteristics of Spent Coffee Grounds as an Alternative Adsorbent for Cadmium in Solution

by Min-Suk Kim and Jeong-Gyu Kim

Environments 2020, 7(4), 24; https://doi.org/10.3390/environments7040024 - 27 Mar 2020

Cited by 41 | Viewed by 7007

Abstract

The present study was conducted to ascertain the potential of spent coffee grounds (SCGs) as an alternative adsorbent for the removal of cadmium (Cd) from aqueous solutions. Therefore, Cd adsorption batch tests, using SCGs that had not undergone any chemical pretreatment, were conducted [...] Read more.

The present study was conducted to ascertain the potential of spent coffee grounds (SCGs) as an alternative adsorbent for the removal of cadmium (Cd) from aqueous solutions. Therefore, Cd adsorption batch tests, using SCGs that had not undergone any chemical pretreatment, were conducted using Cd solutions with a wide concentration range (i.e., 0.1–120 mM) under various adsorption conditions, e.g., ion strength, pH, and solid/solution ratio. For comparison, zeolite, as a well-known common representative adsorbent, was included to determine the adsorption efficiency. The adsorption capacity of the SCGs increased with the decreasing ionic strength of the test solution from 200 to 0 mM of Ca(NO₃)₂ and the increasing solid:solution ratio from 1:4 to 1:400. The most significant factor influencing the adsorption capacity of the SCGs was the pH of the test solution, with increases in the adsorption capacity as the initial solution pH was increased from 2 to 10. However, the rate for Cd removal remained constant, at 71.19%, when the initial solution pH was between 4 and 8 due to the buffer capacity of SCGs. The obtained data were fitted with the Freundlich, Langmuir, and Dubinin-Radushkevich isotherm models. The Langmuir isotherm provided the best correlation for Cd adsorption onto SCGs (R² = 0.96) and zeolite (R² = 0.92), and the maximum Cd adsorption capacity of the SCGs was 19.32 mg g^-1, which was higher than that of zeolite (13.91 mg g⁻¹). These results mean that the SCGs can be utilized as alternative low-cost biosorbents to replace conventional adsorption materials. Full article

► Show Figures

Figure 1

15 pages, 4375 KiB

Open AccessEditor’s ChoiceArticle

Experimental Procedure for Fifth Generation (5G) Electromagnetic Field (EMF) Measurement and Maximum Power Extrapolation for Human Exposure Assessment

by Daniele Franci, Stefano Coltellacci, Enrico Grillo, Settimio Pavoncello, Tommaso Aureli, Rossana Cintoli and Marco Donald Migliore

Environments 2020, 7(3), 22; https://doi.org/10.3390/environments7030022 - 17 Mar 2020

Cited by 34 | Viewed by 8329

Abstract

The fifth generation (5G) technology has been conceived to cover multiple usage scenarios from enhanced mobile broadband to ultra-reliable low-latency communications (URLLC) to massive machine type communications. However, the implementation of this new technology is causing increasing concern over the possible impact on [...] Read more.

The fifth generation (5G) technology has been conceived to cover multiple usage scenarios from enhanced mobile broadband to ultra-reliable low-latency communications (URLLC) to massive machine type communications. However, the implementation of this new technology is causing increasing concern over the possible impact on health and safety arising from exposure to electromagnetic field radiated by 5G systems, making imperative the development of accurate electromagnetic field (EMF) measurement techniques and protocols. Measurement techniques used to assess the compliance with EMF exposure limits are object to international regulation. The basic principle of the assessment is to measure the power received from a constant radio frequency source, typically a pilot signal, and to apply a proper extrapolation factor. This kind of approach is standardized for 2G, 3G, and 4G technologies, but is still under investigation for 5G technology. Indeed, the use of flexible numerologies and advanced Time Division Duplexing (TDD) and spatial multiplexing techniques, such as beam sweeping and Massive Multiple Input Multiple Output (MIMO), requires the definition of new procedures and protocols for EMF measurement of 5G signals. In this paper a procedure for an accurate estimation of the instant maximum power received from a 5G source is proposed. The extrapolation technique is based on the introduction of proper factors that take into account the effect of the TDD and of the sweep beam in the measured value of the 5G signal level. Preliminary experimental investigation, based on code domain measurement of appropriate broadcast channels, and carried out in a controlled environment are reported, confirming the effectiveness of the proposed approach. Full article

(This article belongs to the Special Issue Physical Agents: Measurement Methods, Modelling and Mitigations)

► Show Figures

Figure 1

22 pages, 1591 KiB

Open AccessEditor’s ChoiceArticle

Towards Forest Landscape Restoration Programs in the Philippines: Evidence from Logged Forests and Mixed-Species Plantations

by Rizza Karen Veridiano, Jobst Michael Schröder, Renezita Come, Angelica Baldos and Sven Günter

Environments 2020, 7(3), 20; https://doi.org/10.3390/environments7030020 - 05 Mar 2020

Cited by 10 | Viewed by 9069

Abstract

With only 7.01 million hectares of remaining forested areas in the Philippines, there is an urgency to protect these areas, while also implementing restoration strategies to increase forest cover and improve forest functionality. In this study, we assess how the so called “rainforestation” [...] Read more.

With only 7.01 million hectares of remaining forested areas in the Philippines, there is an urgency to protect these areas, while also implementing restoration strategies to increase forest cover and improve forest functionality. In this study, we assess how the so called “rainforestation” approach, attempts to implement close-to-nature restoration strategies in humid tropic areas. One of the main objectives of the “rainforestation” approach as a form of a mixed-species plantation is the rehabilitation of structural and floristic integrity similar to natural conditions. We compared study areas located in the provinces of Leyte and Southern Leyte composed of logged forests (temporary plots), with logged forests on a permanent research plot and with mixed-species plantations. Basal area, carbon stocks, volume and biological diversity between study areas were calculated and compared, both for static and dynamic data. Results from the static data indicate that carbon stocks (89.30 t ha⁻¹) and volume (262.56 m³ ha⁻¹) of the mixed-species plantations (“rainforestation” approach) is significantly lower than that of the logged forests. However, when it comes to the capacity of the study areas for potential increments, the mixed-species plantations are not significantly different on basal area increment (0.99 m² ha⁻¹ yr⁻¹), carbon stock increment (3.67 t ha⁻¹ yr⁻¹) and total volume increment (10.47 m³ ha⁻¹ yr⁻¹) as compared to the logged forests’ capacity (basal area—1.08 m² ha⁻¹ yr⁻¹, carbon—4.06 t ha⁻¹ yr⁻¹ and total volume—11.98 m³ ha⁻¹ yr⁻¹). The species composition was only partly comparable to logged forests of the region, but overall tree species richness is high in comparison to classical plantation approaches. Previously logged forests are able to recover fast reaching surprisingly high values of carbon stocks and potential commercial timber volume. Our study indicates that “rainforestation” cannot fully replace the functionality of natural forests, but can provide a surprisingly multifunctional tool for landscape restoration, providing both timber and non-timber ecosystem services. Full article

► Show Figures

Figure 1

17 pages, 3376 KiB

Open AccessEditor’s ChoiceArticle

Port Noise and Complaints in the North Tyrrhenian Sea and Framework for Remediation

by Matteo Bolognese, Francesco Fidecaro, Diego Palazzuoli and Gaetano Licitra

Environments 2020, 7(2), 17; https://doi.org/10.3390/environments7020017 - 24 Feb 2020

Cited by 34 | Viewed by 5351

Abstract

Compared to the other relevant noise sources such as railways, roads, and airplanes, the regulation regarding port noise is lagging behind. The absence of specific laws is likely one of the main causes of the increasingly high number of complaints reported by the [...] Read more.

Compared to the other relevant noise sources such as railways, roads, and airplanes, the regulation regarding port noise is lagging behind. The absence of specific laws is likely one of the main causes of the increasingly high number of complaints reported by the citizens living nearby the ports. At the same time, scientific literature concerning the impact of port noise and its mitigation is not so widespread and only a few studies are available at the moment. However, the volume of maritime traffic has increased in the last years and consequently, Port Authorities are required to assess the impact of port operations on the city soundscape without using specific directives or guidelines. In this context, the INTERREG Maritime programme projects RUMBLE, MON ACUMEN, and REPORT aim to fill this gap, by investigating the state-of-the-art of port noise in the north Tyrrhenian sea and developing helpful instruments. Data were collected via a survey sent to the Port Authorities, local environmental protection agencies and universities involved in the projects. The survey was focused on monitoring systems, previous measurement campaigns, noise maps, and citizens’ complaints already taken. The results confirmed both a lack of awareness among residents and authorities and the absence of actions aimed at reducing port noise. In this framework, the difficulties encountered by the Port Authorities in managing the ports sustainably are highlighted. An underestimation of citizens’ exposure to noise in port areas could be expected. Full article

(This article belongs to the Special Issue Physical Agents: Measurement Methods, Modelling and Mitigations)

► Show Figures

Figure 1

17 pages, 1082 KiB

Open AccessEditor’s ChoiceReview

Cyanobacteria: Review of Current Potentials and Applications

by Zahra Zahra, Da Hyun Choo, Heayyean Lee and Amna Parveen

Environments 2020, 7(2), 13; https://doi.org/10.3390/environments7020013 - 12 Feb 2020

Cited by 103 | Viewed by 27097

Abstract

Continual increases in the human population and growing concerns related to the energy crisis, food security, disease outbreaks, global warming, and other environmental issues require a sustainable solution from nature. One of the promising resources is cyanobacteria, also known as blue-green algae. They [...] Read more.

Continual increases in the human population and growing concerns related to the energy crisis, food security, disease outbreaks, global warming, and other environmental issues require a sustainable solution from nature. One of the promising resources is cyanobacteria, also known as blue-green algae. They require simple ingredients to grow and possess a relatively simple genome. Cyanobacteria are known to produce a wide variety of bioactive compounds. In addition, cyanobacteria’s remarkable growth rate enables its potential use in a wide range of applications in the fields of bioenergy, biotechnology, natural products, medicine, agriculture, and the environment. In this review, we have summarized the potential applications of cyanobacteria in different areas of science and development, especially related to their use in producing biofuels and other valuable co-products. We have also discussed the challenges that hinder such development at an industrial level and ways to overcome such obstacles. Full article

(This article belongs to the Special Issue Deployment of Green Technologies for Sustainable Environment)

► Show Figures

Figure 1

16 pages, 1488 KiB

Open AccessEditor’s ChoiceArticle

In Situ Acoustic Treatment of Anaerobic Digesters to Improve Biogas Yields

by John Loughrin, Stacy Antle, Karamat Sistani and Nanh Lovanh

Environments 2020, 7(2), 11; https://doi.org/10.3390/environments7020011 - 08 Feb 2020

Cited by 6 | Viewed by 6772

Abstract

Sound has the potential to increase biogas yields and enhance wastewater degradation in anaerobic digesters. To assess this potential, two pilot-scale digestion systems were operated, with one exposed to sound at less than 10 kHz and with one acting as a control. Sounds [...] Read more.

Sound has the potential to increase biogas yields and enhance wastewater degradation in anaerobic digesters. To assess this potential, two pilot-scale digestion systems were operated, with one exposed to sound at less than 10 kHz and with one acting as a control. Sounds used were sine waves, broadband noise, and orchestral compositions. Weekly biogas production from sound-treated digesters was 18,900 L, more than twice that of the control digester. The sound-treated digesters were primarily exposed to orchestral compositions, because this made cavitational events easier to identify and because harmonic and amplitude shifts in music seem to induce more cavitation. Background recordings from the sound-treated digester were louder and had more cavitational events than those of the control digester, which we ascribe to enhanced microbial growth and the resulting accelerated sludge breakdown. Acoustic cavitation, vibrational energy imparted to wastewater and sludge, and mixing due to a release of bubbles from the sludge may all act in concert to accelerate wastewater degradation and boost biogas production. Full article

(This article belongs to the Special Issue Wastewater and Solid Waste Treatment)

► Show Figures

Graphical abstract

31 pages, 1510 KiB

Open AccessEditor’s ChoiceArticle

Solar UV Irradiance in a Changing Climate: Trends in Europe and the Significance of Spectral Monitoring in Italy

by Ilias Fountoulakis, Henri Diémoz, Anna-Maria Siani, Gudrun Laschewski, Gianluca Filippa, Antti Arola, Alkiviadis F. Bais, Hugo De Backer, Kaisa Lakkala, Ann R. Webb, Veerle De Bock, Tomi Karppinen, Katerina Garane, John Kapsomenakis, Maria-Elissavet Koukouli and Christos S. Zerefos

Environments 2020, 7(1), 1; https://doi.org/10.3390/environments7010001 - 18 Dec 2019

Cited by 30 | Viewed by 8981

Abstract

Review of the existing bibliography shows that the direction and magnitude of the long-term trends of UV irradiance, and their main drivers, vary significantly throughout Europe. Analysis of total ozone and spectral UV data recorded at four European stations during 1996–2017 reveals that [...] Read more.

Review of the existing bibliography shows that the direction and magnitude of the long-term trends of UV irradiance, and their main drivers, vary significantly throughout Europe. Analysis of total ozone and spectral UV data recorded at four European stations during 1996–2017 reveals that long-term changes in UV are mainly driven by changes in aerosols, cloudiness, and surface albedo, while changes in total ozone play a less significant role. The variability of UV irradiance is large throughout Italy due to the complex topography and large latitudinal extension of the country. Analysis of the spectral UV records of the urban site of Rome, and the alpine site of Aosta reveals that differences between the two sites follow the annual cycle of the differences in cloudiness and surface albedo. Comparisons between the noon UV index measured at the ground at the same stations and the corresponding estimates from the Deutscher Wetterdienst (DWD) forecast model and the ozone monitoring instrument (OMI)/Aura observations reveal differences of up to 6 units between individual measurements, which are likely due to the different spatial resolution of the different datasets, and average differences of 0.5–1 unit, possibly related to the use of climatological surface albedo and aerosol optical properties in the retrieval algorithms. Full article

(This article belongs to the Special Issue Physical Agents: Measurement Methods, Modelling and Mitigations)

► Show Figures

Graphical abstract

15 pages, 3239 KiB

Open AccessEditor’s ChoiceArticle

Tourism Industry’s Vulnerability upon Risk of Flooding: The Aquis Querquennis Complex

by Noelia Araújo Vila, Diego R. Toubes and Jose Antonio Fraiz Brea

Environments 2019, 6(12), 122; https://doi.org/10.3390/environments6120122 - 28 Nov 2019

Cited by 4 | Viewed by 10014

Abstract

Thermal baths are the main touristic attraction of Ourense (Galicia, Spain). Therefore, protecting and potentializing the resources related to this type of tourism is essential for the province. Most of these resources are located by the banks or nearby rivers, which makes them [...] Read more.

Thermal baths are the main touristic attraction of Ourense (Galicia, Spain). Therefore, protecting and potentializing the resources related to this type of tourism is essential for the province. Most of these resources are located by the banks or nearby rivers, which makes them particularly susceptible to flooding, a very common phenomenon throughout the province. In this context, vulnerability analysis, and particularly flooding damage evaluation, are of utmost importance to this area. Considering this scenario, the present study consists of a preliminary analysis of a historical-heritage tourism resource’s vulnerability to flooding. To this end, the study examines the visitation patterns to the Aquis Querquennis complex (Bande, Ourense, Spain), which is located by the banks of the As Conchas reservoir, and the water levels of said reservoir. The complex is a touristic resource with great historical value. Apart from the thermal baths, it encompasses a military campsite and a hostel. The Roman complex attracts a constant tourist flow, which has a positive socioeconomic impact to the area. The analysis showed that there is a correlation between the number of visits and flooding patterns. Increased levels of water are a hinderance for those willing to access the attraction. Consequently, there is a negative relationship between water level and number of visitors. Full article

► Show Figures

Figure 1

13 pages, 1821 KiB

Open AccessEditor’s ChoiceArticle

Workers with Active Implantable Medical Devices Exposed to EMF: In Vitro Test for the Risk Assessment

by Eugenio Mattei, Giovanni Calcagnini, Federica Censi, Iole Pinto, Andrea Bogi and Rosaria Falsaperla

Environments 2019, 6(11), 119; https://doi.org/10.3390/environments6110119 - 15 Nov 2019

Cited by 5 | Viewed by 5529

Abstract

The occupational health and safety framework identifies workers with an active implantable medical device (AIMD), such as a pacemaker (PM) or an implantable defibrillator (ICD), as a particularly sensitive risk group that must be protected against the dangers caused by the interference of [...] Read more.

The occupational health and safety framework identifies workers with an active implantable medical device (AIMD), such as a pacemaker (PM) or an implantable defibrillator (ICD), as a particularly sensitive risk group that must be protected against the dangers caused by the interference of electromagnetic field (EMF). In this paper, we describe the results of in vitro testing/measurements performed according to the EN50527-2-1:2016 standard, for the risk assessment of employees with a PM exposed to three EMF sources: (1) An electrosurgical unit (ESU); (2) a transcranial stimulator (TMS); and (3) an arc welder. The ESU did not affect the PM behavior in any of the configurations tested. For the TMS and the arc welder, interference phenomena were observed in limited experimental configurations, corresponding to the maximum magnetic field coupling between the EMF source and the implant. The in vitro measurements presented can be considered an example of how the specific risk assessment for a worker with a PM can be performed, according to one of the methodologies proposed in the EN50527-2-1:2016, and can be used as scientific evidence and literature data for future risk assessments on the same EMF sources. Full article

(This article belongs to the Special Issue Physical Agents: Measurement Methods, Modelling and Mitigations)

► Show Figures

Figure 1

12 pages, 1845 KiB

Open AccessEditor’s ChoiceArticle

Impact of Zirconium on Freshwater Periphytic Microorganisms

by Doose Caroline, Morin Soizic, Vedrenne Jacky and Fortin Claude

Environments 2019, 6(10), 111; https://doi.org/10.3390/environments6100111 - 01 Oct 2019

Cited by 4 | Viewed by 5948

Abstract

The majority of studies on biofilms have focused on autotrophic and bacterial taxa, without considering the potential effects on biofilm grazers. In this work, we investigated the effects of realistic environmental concentrations of zirconium (Zr) on periphyton algal growth and micromeiofauna biodiversity. Glass [...] Read more.

The majority of studies on biofilms have focused on autotrophic and bacterial taxa, without considering the potential effects on biofilm grazers. In this work, we investigated the effects of realistic environmental concentrations of zirconium (Zr) on periphyton algal growth and micromeiofauna biodiversity. Glass slides were submerged in a pond for four weeks to colonize biofilms and exposed for four weeks in aquaria to targeted Zr concentrations of 0, 1, and 10 nM, which were monitored over time (average measured concentrations were 0.2 ± 0.1, 0.5 ± 0.3, and 2.9 ± 0.3 nM Zr). The four-week exposure to the highest concentration (3 nM) affected the micromeiofauna structure of biofilms and modified the autotrophic biofilm structure by increasing the proportion of green algae and decreasing the abundance of cyanobacteria and brown algae. Rotifers and the ciliate Aspidisca cicada appeared to be the most sensitive organisms among the observed micromeiofauna. A toxic effect of Zr on rotifers could explain such results. Indirect effects, such as reduced food availability given the reduced algal growth in the presence of Zr, could also play a role in the changes of micromeiofauna community structure. These results are among the few published data on the effects of Zr. Full article

(This article belongs to the Special Issue New Insights into Impacts of Toxic Metals in Aquatic Environments)

► Show Figures

Graphical abstract

17 pages, 2789 KiB

Open AccessEditor’s ChoiceArticle

Diatom Deformities and Tolerance to Cadmium Contamination in Four Species

by Sandra Kim Tiam, Isabelle Lavoie, Fengjie Liu, Paul B. Hamilton and Claude Fortin

Environments 2019, 6(9), 102; https://doi.org/10.3390/environments6090102 - 02 Sep 2019

Cited by 4 | Viewed by 6115

Abstract

The relative tolerance of four diatoms (Nitzschia palea, Pinnularia mesolepta, Mayamaea atomus, and Gomphonema truncatum) to Cd was evaluated, including their proneness to deformities, and the severity of the abnormalities in relation to Cd concentration. The indirect effect [...] Read more.

The relative tolerance of four diatoms (Nitzschia palea, Pinnularia mesolepta, Mayamaea atomus, and Gomphonema truncatum) to Cd was evaluated, including their proneness to deformities, and the severity of the abnormalities in relation to Cd concentration. The indirect effect of Cd on photosynthetic capacities was assessed during a short time exposure experiment using a dose-response approach to evaluate the relative tolerance of the four diatom species. The EC₂₅ were 9 (3, 23), 606 (348, 926), 1179 (1015, 1349) and 2394 (1890, 2896) µg/L for P. mesolepta, G. truncatum, N. palea, and M. atomus respectively. P. mesolepta was by far the most Cd sensitive species while M. atomus was the most tolerant. In addition, diatoms were exposed to a single concentration of Cd comparable to a heavily contaminated environment for a longer duration to evaluate the effect of Cd on growth kinetics and the deformities induced. N. palea, P. mesolepta, and M. atomus were able to grow when cultivated with Cd while G. truncatum was not. Cadmium strongly affected the effective quantum yield in G. truncatum (4.8 ± 5.9% of the control) and P. mesolepta cultures (29.2 ± 6.9% of the control). The effects were moderate for N. palea (88.3 ± 0.7% of the control) and no impact was observed for M. atomus. The results from the two approaches were in accordance since they identified N. palea and M. atomus as the two most tolerant species to Cd, while P. mesolepta and G. truncatum were the most sensitive. The microscopy analyses revealed that P. mesolepta was more impacted by Cd than N. palea and M. atomus considering both the quantity of abnormal cells and the severity of the deformities. Overall, this research shows that not all deformities can be considered equal for a water quality bio-assessment. The work highlights a need to take into account metal-tolerance/sensitivity of the species and the severity of the deformities. Full article

(This article belongs to the Special Issue Aquatic Microbial Ecotoxicology)

► Show Figures

Figure 1

12 pages, 5430 KiB

Open AccessEditor’s ChoiceArticle

Is a Land Use Regression Model Capable of Predicting the Cleanest Route to School?

by Luca Boniardi, Evi Dons, Laura Campo, Martine Van Poppel, Luc Int Panis and Silvia Fustinoni

Environments 2019, 6(8), 90; https://doi.org/10.3390/environments6080090 - 30 Jul 2019

Cited by 16 | Viewed by 7920

Abstract

Land Use Regression (LUR) modeling is a widely used technique to model the spatial variability of air pollutants in epidemiology. In this study, we explore whether a LUR model can predict home-to-school commuting exposure to black carbon (BC). During January and February 2019, [...] Read more.

Land Use Regression (LUR) modeling is a widely used technique to model the spatial variability of air pollutants in epidemiology. In this study, we explore whether a LUR model can predict home-to-school commuting exposure to black carbon (BC). During January and February 2019, 43 children walking to school were involved in a personal monitoring campaign measuring exposure to BC and tracking their home-to-school routes. At the same time, a previously developed LUR model for the study area was applied to estimate BC exposure on points along the route. Personal BC exposure varied widely with mean ± SD of 9003 ± 4864 ng/m3. The comparison between the two methods showed good agreement (Pearson’s r = 0.74, Lin’s Concordance Correlation Coefficient = 0.6), suggesting that LUR estimates are capable of catching differences among routes and predicting the cleanest route. However, the model tends to underestimate absolute concentrations by 29% on average. A LUR model can be useful in predicting personal exposure and can help urban planners in Milan to build a healthier city for schoolchildren by promoting less polluted home-to-school routes. Full article

(This article belongs to the Special Issue Air Quality Assessment for Environmental Policy Support: Sources, Emissions, Exposures and Health Impacts)

► Show Figures

Figure 1

12 pages, 3599 KiB

Open AccessEditor’s ChoiceArticle

Potential of Urban Densification to Mitigate the Effects of Heat Island in Vienna, Austria

by Milena Vuckovic, Wolfgang Loibl, Tanja Tötzer and Romana Stollnberger

Environments 2019, 6(7), 82; https://doi.org/10.3390/environments6070082 - 10 Jul 2019

Cited by 16 | Viewed by 7534

Abstract

Global increase of urban population has brought about a growing demand for more dwelling space, resulting in various negative impacts, such as accelerated urbanization, urban sprawl and higher carbon footprints. To cope with these growth dynamics, city authorities are urged to consider alternative [...] Read more.

Global increase of urban population has brought about a growing demand for more dwelling space, resulting in various negative impacts, such as accelerated urbanization, urban sprawl and higher carbon footprints. To cope with these growth dynamics, city authorities are urged to consider alternative planning strategies aiming at mitigating the negative implications of urbanization. In this context, the present contribution investigates the potential of urban densification to mitigate the heat island effects and to improve outdoor thermal conditions. Focusing on a quite densely urbanized district in Vienna, Austria, we carried out a set of simulations of urban microclimate for pre- and post-densification scenarios using the parametric modelling environment Rhinoceros 3D and a set of built-in algorithms in the Rhino’s plug-in Grasshopper. The study was conducted for a hot summer period. The results revealed a notable solar shielding effect of newly introduced vertical extensions of existing buildings, promoting temperature decrease and improved thermal conditions within more shaded urban canyons and courtyards. However, a slight warming effect was noted during the night-time due to the higher thermal storage and lower sky view factor. Full article

(This article belongs to the Special Issue Adaptation Measures for Urban Heat Island)

► Show Figures

Figure 1

18 pages, 726 KiB

Open AccessEditor’s ChoiceArticle

Ecological Health Index: A Short Term Monitoring Method for Land Managers to Assess Grazing Lands Ecological Health

by Sutie Xu, Jason Rowntree, Pablo Borrelli, Jennifer Hodbod and Matt R. Raven

Environments 2019, 6(6), 67; https://doi.org/10.3390/environments6060067 - 10 Jun 2019

Cited by 7 | Viewed by 9714

Abstract

Grazing lands should be monitored to ensure their productivity and the preservation of ecosystem services. The study objective was to investigate the effectiveness of an Ecological Health Index (EHI) for assessing ecosystem ecological health in grazing lands. The EHI was developed by synthesizing [...] Read more.

Grazing lands should be monitored to ensure their productivity and the preservation of ecosystem services. The study objective was to investigate the effectiveness of an Ecological Health Index (EHI) for assessing ecosystem ecological health in grazing lands. The EHI was developed by synthesizing existing vegetation and soil cover indicators. We implemented long-term transects at 44 farms from two ecological regions in Patagonia, the Humid Magellan Steppe (HMS) (n = 24) and Subandean Grasslands (SG) (n = 20), to collect data on established quantifiable vegetative and soil measurements and the EHI. Using known quantifiable measures, the HMS had numerically greater species richness compared to SG. Similarly, the average percentage of total live vegetation was more favorable in HMS. Correlating the EHI with these known quantifiable measures demonstrated positive correlations with species richness, the percentage of total live vegetation and carrying capacity and was negatively correlations with bare ground. These results suggest that EHI could be a useful method to detect the ecological health and productivity in grazing lands. Overall, we conclude that EHI is an effective short-term monitoring approach that ranchers could implement annually to monitor grazing lands and determine the impacts of ranch decision-making on important ecosystem indicators. Full article

(This article belongs to the Special Issue Agricultural Ecosystem Services)

► Show Figures

Figure 1

12 pages, 997 KiB

Open AccessEditor’s ChoiceArticle

Fertilizer Efficacy of Poultry Litter Ash Blended with Lime or Gypsum as Fillers

by Philip J. Bauer, Ariel A. Szogi and Paul D. Shumaker

Environments 2019, 6(5), 50; https://doi.org/10.3390/environments6050050 - 01 May 2019

Cited by 14 | Viewed by 5973

Abstract

Ash from power plants that incinerate poultry litter has fertilizer value, but research is lacking on optimal land application methodologies. Experiments were conducted to evaluate calcitic lime and flue gas desulfurization gypsum (FGDG) as potential fillers for poultry litter ash land applications. The [...] Read more.

Ash from power plants that incinerate poultry litter has fertilizer value, but research is lacking on optimal land application methodologies. Experiments were conducted to evaluate calcitic lime and flue gas desulfurization gypsum (FGDG) as potential fillers for poultry litter ash land applications. The ash had phosphorus (P) and potassium (K) contents of 68 and 59 g kg⁻¹, respectively. Soil extractable P and K were measured in an incubation pot study, comparing calcitic lime to FGDG at filler/ash ratios of 1:3, 1:2, 1:1, 2:1, and 3:1. After one month, soils were sampled and annual ryegrass (Lolium multiflorum Lam.) seeds were planted to investigate how plant growth and uptake of P and K were influenced by the fillers. Application of ash alone or with fillers increased soil extractable P and K levels above unamended controls by 100% and 70%, respectively. Filler materials did not affect biomass or P and K concentration of the ryegrass. A field study with a commercial spinner disc fertilizer applicator was conducted to compare application uniformity of ash alone and filler/ash blends. Overall, test data suggested that uniform distribution of ash alone or with fillers is feasible in field applications using a commercial fertilizer spreader. Full article

(This article belongs to the Special Issue Innovative Animal Manure Management for Environmental Protection, Improved Soil Fertility and Crop Production)

► Show Figures

Figure 1

10 pages, 1273 KiB

Open AccessEditor’s ChoiceArticle

Aeration to Improve Biogas Production by Recalcitrant Feedstock

by John Loughrin and Nanh Lovanh

Environments 2019, 6(4), 44; https://doi.org/10.3390/environments6040044 - 11 Apr 2019

Cited by 12 | Viewed by 5532

Abstract

Digestion of wastes to produce biogas is complicated by poor degradation of feedstocks. Research has shown that waste digestion can be enhanced by the addition of low levels of aeration without harming the microbes responsible for methane production. This research has been done [...] Read more.

Digestion of wastes to produce biogas is complicated by poor degradation of feedstocks. Research has shown that waste digestion can be enhanced by the addition of low levels of aeration without harming the microbes responsible for methane production. This research has been done at small scales and without provision to retain the aeration in the digestate. In this paper, low levels of aeration were provided to poultry litter slurry through a sub-surface manifold that retained air in the sludge. Digestate (133 L) was supplied 0, 200, 800, or 2000 mL/day air in 200 mL increments throughout the day via a manifold with a volume of 380 mL. Digesters were fed 400 g of poultry litter once weekly until day 84 and then 600 g thereafter. Aeration at 200 and 800 mL/day increased biogas production by 14 and 73% compared to anaerobic digestion while aeration at 2000 mL/day decreased biogas production by 19%. Biogas quality was similar in all digesters albeit carbon dioxide and methane were lowest in the 2000 mL/day treatment. Increasing feed to 600 g/week decreased gas production without affecting biogas quality. Degradation of wood disks placed within the digesters was enhanced by aeration. Full article

(This article belongs to the Special Issue Innovative Animal Manure Management for Environmental Protection, Improved Soil Fertility and Crop Production)

► Show Figures

Figure 1

13 pages, 1365 KiB

Open AccessEditor’s ChoiceArticle

Application of Gas-Permeable Membranes For-Semi-Continuous Ammonia Recovery from Swine Manure

by Berta Riaño, Beatriz Molinuevo-Salces, Matías B. Vanotti and María Cruz García-González

Environments 2019, 6(3), 32; https://doi.org/10.3390/environments6030032 - 06 Mar 2019

Cited by 31 | Viewed by 6059

Abstract

Gas-permeable membrane technology is a new strategy to minimize ammonia losses from manure, reducing pollution and recovering N in the form of an ammonium salt fertilizer. In this work, a new operational configuration to recover N using the gas-permeable membrane technology from swine [...] Read more.

Gas-permeable membrane technology is a new strategy to minimize ammonia losses from manure, reducing pollution and recovering N in the form of an ammonium salt fertilizer. In this work, a new operational configuration to recover N using the gas-permeable membrane technology from swine manure was tested in a semi-continuous mode. It treated swine manure with a total ammonia nitrogen (TAN) concentration of 3451 mg L⁻¹. The system was operated with low aeration rate (to raise pH), and with hydraulic retention times (HRT) of seven days (Period I) and five days (Period II) that provided total ammonia nitrogen loading rate (ALR) treatments of 491 and 696 mg TAN per L of reactor per day, respectively. Results showed a uniform TAN recovery rate of 27 g per m² of membrane surface per day regardless of the ALR applied and the manure TAN concentration in the reactor. TAN removal reached 79% for Period I and 56% for Period II, with 90% of recovery by the membrane in both periods. Water capture in the acidic solution was also uniform during the experimental period. An increase in temperature of 3 °C of the acidic solution relative to the wastewater reduced 34% the osmotic distillation and water dilution of the product. These results suggested that the gas-permeable membrane technology operating in a semi-continuous mode has a great potential for TAN recovery from manure. Full article

(This article belongs to the Special Issue Innovative Animal Manure Management for Environmental Protection, Improved Soil Fertility and Crop Production)

► Show Figures

Graphical abstract

19 pages, 9626 KiB

Open AccessEditor’s ChoiceReview

Recent Developments in Sonic Crystals as Barriers for Road Traffic Noise Mitigation

by Luca Fredianelli, Lara Ginevra Del Pizzo and Gaetano Licitra

Environments 2019, 6(2), 14; https://doi.org/10.3390/environments6020014 - 30 Jan 2019

Cited by 66 | Viewed by 8029

Abstract

Noise barriers are the most widespread solution to mitigate noise produced by the continuous growth of vehicular traffic, thus reducing the large number of people exposed to it and avoiding unpleasant effects on health. However, conventional noise barriers present the well-known issues related [...] Read more.

Noise barriers are the most widespread solution to mitigate noise produced by the continuous growth of vehicular traffic, thus reducing the large number of people exposed to it and avoiding unpleasant effects on health. However, conventional noise barriers present the well-known issues related to the diffraction at the edges which reduces the net insertion loss, to the reflection of sound energy in the opposite direction, and to the complaints of citizens due to the reduction of field of view, natural light, and air flow. In order to avoid these shortcomings and maximize noise abatement, recent research has moved toward the development of sonic crystals as noise barriers. A previous review found in the literature was focused on the theoretical aspects of the propagation of sound through crystals. The present work on the other hand reviews the latest studies concerning the practical application of sonic crystal as noise barriers, especially for road traffic noise mitigation. The paper explores and compares the latest developments reported in the scientific literature, focused on integrating Bragg’s law properties with other mitigation effects such as hollow scatterers, wooden or recycled materials, or porous coating. These solutions could increase the insertion loss and frequency band gap, while inserting the noise mitigation action in a green and circular economy. The pros and cons of sonic crystal barriers will also be discussed, with the aim of finding the best solution that is actually viable, as well as stimulating future research on the aspects requiring improvement. Full article

(This article belongs to the Special Issue New Solutions Mitigating Environmental Noise Pollution)

► Show Figures

Figure 1

13 pages, 1811 KiB

Open AccessEditor’s ChoiceArticle

Vinasse Treatment within the Sugarcane-Ethanol Industry Using Ozone Combined with Anaerobic and Aerobic Microbial Processes

by Cristiano E. R. Reis, Heitor B. S. Bento, Thiago M. Alves, Ana K. F. Carvalho and Heizir F. De Castro

Environments 2019, 6(1), 5; https://doi.org/10.3390/environments6010005 - 07 Jan 2019

Cited by 34 | Viewed by 7579

Abstract

The production of ethanol from sugarcane or molasses generates vinasse, a residue rich in organic matter and minerals. Vinasse is often used in fertilization and irrigation practices, which may be linked to negative environmental outcomes if excess is applied. Herein, we introduce a [...] Read more.

The production of ethanol from sugarcane or molasses generates vinasse, a residue rich in organic matter and minerals. Vinasse is often used in fertilization and irrigation practices, which may be linked to negative environmental outcomes if excess is applied. Herein, we introduce a novel alternative to the treatment of vinasse promoting the reduction in Chemical Oxygen Demand (COD) levels, phenolic compounds, and its mineral content through the coupling of ozone treatment, anaerobic digestion, and the aerobic growth of fungi. The ozone treatment is able to remove about 30% of the total COD, and deplete the concentration of phenolic compounds, while anaerobic digestion produces biogas and generates vinasse digestate, which is less biorecalcitrant than raw vinasse. The aerobic fungal growth generates oleaginous fungal biomass and promotes over 80% of Kjeldahl-Nitrogen in the vinasse. If vinasse were treated following the sequence of anaerobic digestion, aerobic fungal growth, and ozone treatment, the effluent would have about 95% of the COD decreased, complete removal of phenolic compounds, and over 80% of Kjeldahl-Nitrogen. Full article

(This article belongs to the Special Issue Advanced Oxidation Applications)

► Show Figures

Graphical abstract

13 pages, 578 KiB

Open AccessEditor’s ChoiceArticle

Speech Identification and Comprehension in the Urban Soundscape

by Letizia Marchegiani, Xenofon Fafoutis and Sahar Abbaspour

Environments 2018, 5(5), 56; https://doi.org/10.3390/environments5050056 - 07 May 2018

Cited by 4 | Viewed by 4477

Abstract

Urban environments are characterised by the presence of copious and unstructured noise. This noise continuously challenges speech intelligibility both in normal-hearing and hearing-impaired individuals. In this paper, we investigate the impact of urban noise, such as traffic, on speech identification and, more generally, [...] Read more.

Urban environments are characterised by the presence of copious and unstructured noise. This noise continuously challenges speech intelligibility both in normal-hearing and hearing-impaired individuals. In this paper, we investigate the impact of urban noise, such as traffic, on speech identification and, more generally, speech understanding. With this purpose, we perform listening experiments to evaluate the ability of individuals with normal hearing to detect words and interpret conversational speech in the presence of urban noise (e.g., street drilling, traffic jams). Our experiments confirm previous findings in different acoustic environments and demonstrate that speech identification is influenced by the similarity between the target speech and the masking noise also in urban scenarios. More specifically, we propose the use of the structural similarity index to quantify this similarity. Our analysis confirms that speech identification is more successful in presence of noise with tempo-spectral characteristics different from speech. Moreover, our results show that speech comprehension is not as challenging as word identification in urban sound environments that are characterised by the presence of severe noise. Indeed, our experiments demonstrate that speech comprehension can be fairly successful even in acoustic scenes where the ability to identify speech is highly reduced. Full article

(This article belongs to the Special Issue Sound Environments)

► Show Figures

Figure 1

2263 KiB

Open AccessEditor’s ChoiceArticle

Audio-Visual Preferences and Tranquillity Ratings in Urban Areas

by Luca Cassina, Luca Fredianelli, Irene Menichini, Claudia Chiari and Gaetano Licitra

Environments 2018, 5(1), 1; https://doi.org/10.3390/environments5010001 - 22 Dec 2017

Cited by 49 | Viewed by 6344

Abstract

During a survey related to acoustic and visual perception of users of urban areas, 614 people have been interviewed in Pisa (Italy). The work aims to identify and quantify the effects of parameters influencing the perception of tranquillity in order to understand the [...] Read more.

During a survey related to acoustic and visual perception of users of urban areas, 614 people have been interviewed in Pisa (Italy). The work aims to identify and quantify the effects of parameters influencing the perception of tranquillity in order to understand the soundscape and to propose a method based on the perception of tranquillity for the detection of quiet areas within urban ones. A linear model that predicts the tranquillity perceived in different environments, based on their visual and acoustic characteristics, is proposed. Users were interviewed by operators inside the areas, using a direct approach of standardized questionnaires and oral questions. Simultaneous noise measurements and soundwalks have been performed, together with visual registrations. The linear model obtained predicts the perceived tranquillity based on the statistical level L_A10 (A-weighted noise level exceeded for 10% of the measurement time) the sound sources and visual elements. The perceived tranquillity results negatively correlated to L_A10 and to the presence of sound sources or negative visual elements. The presence of beneficial sound sources is positively correlated to the perceived tranquillity. However, the effect of the noise level is regulated by environmental characteristics. Perceived tranquillity is proposed as an indicator to identify quiet areas in the urban environment, according to European Directive 49/2002/EC. The obtained model identifies the areas that would get a higher tranquillity value than a fixed threshold value and therefore would be perceived as quiet. The model can be used as a cost-benefit analysis support tool to identify the best solution between the reduction of noise levels and the regeneration of urban areas, referring to the tranquillity perceived by the users. Full article

(This article belongs to the Special Issue Sound Environments)

► Show Figures

Figure 1

Journal Menu

Journal Browser

Editor’s Choice Articles

Further Information

Guidelines

MDPI Initiatives

Follow MDPI