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21 pages, 4525 KiB

Open AccessArticle

Effect of UV_C and UV_A Photocatalytic Processes on Tetracycline Removal Using CuS-Coated Magnetic Activated Carbon Nanocomposite: A Comparative Study

by Negin Nasseh, Rasoul Khosravi, Narjes sadat Mazari Moghaddam and Shahabaldin Rezania

Int. J. Environ. Res. Public Health 2021, 18(21), 11163; https://doi.org/10.3390/ijerph182111163 - 24 Oct 2021

Cited by 6 | Viewed by 1870

Abstract

In this study, we synthesized a novel MAC nanocomposite using almond’s green hull coated with CuS. The whole set of experiments have been conducted inside a batch (discontinuous reactor system) at room temperature. The effectiveness of different parameters in tetracycline removal pH (3, [...] Read more.

In this study, we synthesized a novel MAC nanocomposite using almond’s green hull coated with CuS. The whole set of experiments have been conducted inside a batch (discontinuous reactor system) at room temperature. The effectiveness of different parameters in tetracycline removal pH (3, 5, 7, and 9), pollutant concentration (5–100 mg/L), nanocomposite dosage (0.025–1 g/L), and contact time (5–60 min) using newly synthesized nanocomposite were investigated. Based on the results, in the optimal conditions of pH = 9, nanocomposite dosage of 1 g/L, pollutant concentration of 20 mg/L, contact time of 60 min, and room temperature, 95% removal efficiency was obtained. In MAC/CuS/UV_C process, the removal of COD and TOC were 76.89% and 566.84% respectively meanwhile, these values in MAC/CuS/UV_A process were 74.19% and 62.11%, respectively. The results of nanocomposite stability and magnetic recovery illustrated that the removal efficiency was reduced by 1.5% in the presence of UV_C and 5% in the presence of UV_A lights during all six cycles. Therefore, this nanocomposite was highly capable of recycling and reuse. It can be concluded that considering the high potential of the synthesized nanocomposite, the photocatalytic efficiency of the MAC/CuS/UV_C process in tetracycline synthesis was higher than MAC/CuS/UV_A process. Full article

(This article belongs to the Special Issue State-of-the-Art Environmental Science and Technology)

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11 pages, 2245 KiB

Open AccessArticle

Evaluation of the Bioaerosol Inactivation Ability of Chitosan-Coated Antimicrobial Filters

by Ying-Fang Hsu, Chi-Yu Chuang and Shinhao Yang

Int. J. Environ. Res. Public Health 2021, 18(13), 7183; https://doi.org/10.3390/ijerph18137183 - 05 Jul 2021

Cited by 5 | Viewed by 2082

Abstract

This work considers the enhancement of indoor bioaerosol removal efficiency by liquid coating of the antimicrobial agent chitosan onto polypropylene fibrous filters (CCFs). Escherichia coli (E. coli) and Bacillus subtilis (B. subtilis) were chosen as the tested bioaerosols. The [...] Read more.

This work considers the enhancement of indoor bioaerosol removal efficiency by liquid coating of the antimicrobial agent chitosan onto polypropylene fibrous filters (CCFs). Escherichia coli (E. coli) and Bacillus subtilis (B. subtilis) were chosen as the tested bioaerosols. The results revealed that 2.5% (w/w) of CCFs have significantly higher bioaerosol survival capability (23% and 34% of E. coli and B. subtilis, respectively), compared to an untreated filter (65% and 64% for E. coli and B. subtilis, respectively). Increasing face velocity and relative humidity during operating CCFs could reduce the bioaerosol removal capability. The regression analysis of the experimental findings demonstrated that the higher coating concentration of chitosan had the most positive influence on bioaerosol removal, while the face velocity and relative humidity had a negative influence, but a milder effect was observed (R² = 0.83 and 0.81 for E. coli and B. subtilis bioaerosols, respectively). A CCF-loaded air-cleaning device was tested in a real indoor environment and resulted in 80.1% bioaerosol removal within 3 h of operating, which suggests that the chitosan-coated filter has the potential for further application in improving indoor air quality in the future. Full article

(This article belongs to the Special Issue State-of-the-Art Environmental Science and Technology)

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13 pages, 2379 KiB

Open AccessArticle

Purification Efficiency of Three Combinations of Native Aquatic Macrophytes in Artificial Wastewater in Autumn

by Lei Xu, Siyu Chen, Ping Zhuang, Dongsheng Xie, Xiaoling Yu, Dongming Liu, Zhian Li, Xinsheng Qin, Faguo Wang and Fuwu Xing

Int. J. Environ. Res. Public Health 2021, 18(11), 6162; https://doi.org/10.3390/ijerph18116162 - 07 Jun 2021

Cited by 5 | Viewed by 2339

Abstract

Water pollution caused by excessive nutrient and biological invasion is increasingly widespread in China, which can lead to problems with drinking water as well as serious damage to the ecosystem if not be properly treated. Aquatic plant restoration (phytoremediation) has become a promising [...] Read more.

Water pollution caused by excessive nutrient and biological invasion is increasingly widespread in China, which can lead to problems with drinking water as well as serious damage to the ecosystem if not be properly treated. Aquatic plant restoration (phytoremediation) has become a promising and increasingly popular solution. In this study, eight native species of low-temperature-tolerant aquatic macrophytes were chosen to construct three combinations of aquatic macrophytes to study their purification efficiency on eutrophic water in large open tanks during autumn in Guangzhou City. The total nitrogen (TN) removal rates of group A (Vallisneria natans + Ludwigia adscendens + Monochoria vaginalis + Saururus chinensis), group B (V. natans + Ipomoea aquatica + Acorus calamus + Typha orientalis), and group C (V. natans + L. adscendens + Schoenoplectus juncoides + T. orientalis) were 79.10%, 46.39%, and 67.46%, respectively. The total phosphorus (TP) removal rates were 89.39%, 88.37%, and 91.96% in groups A, B, and C, respectively, while the chemical oxygen demand (COD) removal rates were 93.91%, 96.48%, and 92.78%, respectively. In the control group (CK), the removal rates of TN, TP, and COD were 70.42%, 86.59%, and 87.94%, respectively. The overall removal rates of TN, TP, and COD in the plant groups were only slightly higher than that in CK group, which did not show a significant advantage. This may be related to the leaf decay of some aquatic plants during the experiment, whereby the decay of V. natans was the most obvious. The results suggest that a proper amount of plant residue will not lead to a significant deterioration of water quality. Full article

(This article belongs to the Special Issue State-of-the-Art Environmental Science and Technology)

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16 pages, 3003 KiB

Open AccessArticle

Using Spatial Pattern Analysis to Explore the Relationship between Vulnerability and Resilience to Natural Hazards

by Chien-Hao Sung and Shyue-Cherng Liaw

Int. J. Environ. Res. Public Health 2021, 18(11), 5634; https://doi.org/10.3390/ijerph18115634 - 25 May 2021

Cited by 10 | Viewed by 2603

Abstract

This research aims to explore the spatial pattern of vulnerability and resilience to natural hazards in northeastern Taiwan. We apply the spatially explicit resilience-vulnerability model (SERV) to quantify the vulnerability and resilience to natural hazards, including flood and debris flow events, which are [...] Read more.

This research aims to explore the spatial pattern of vulnerability and resilience to natural hazards in northeastern Taiwan. We apply the spatially explicit resilience-vulnerability model (SERV) to quantify the vulnerability and resilience to natural hazards, including flood and debris flow events, which are the most common natural hazards in our case study area due to the topography and precipitation features. In order to provide a concise result, we apply the principal component analysis (PCA) to aggregate the correlated variables. Moreover, we use the spatial autocorrelation analysis to analyze the spatial pattern and spatial difference. We also adopt the geographically weighted regression (GWR) to validate the effectiveness of SERV. The result of GWR shows that SERV is valid and unbiased. Moreover, the result of spatial autocorrelation analysis shows that the mountain areas are extremely vulnerable and lack enough resilience. In contrast, the urban regions in plain areas show low vulnerability and high resilience. The spatial difference between the mountain and plain areas is significant. The topography is the most significant factor for the spatial difference. The high elevation and steep slopes in mountain areas are significant obstacles for socioeconomic development. This situation causes consequences of high vulnerability and low resilience. The other regions, the urban regions in the plain areas, have favorable topography for socioeconomic development. Eventually, it forms a scenario of low vulnerability and high resilience. Full article

(This article belongs to the Special Issue State-of-the-Art Environmental Science and Technology)

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16 pages, 2243 KiB

Open AccessArticle

Soil Contamination Assessments from Drilling Fluids and Produced Water Using Combined Field and Laboratory Investigations: A Case Study of Arkansas, USA

by Joshua Swigart, Joonghyeok Heo and Duane Wolf

Int. J. Environ. Res. Public Health 2021, 18(5), 2421; https://doi.org/10.3390/ijerph18052421 - 02 Mar 2021

Cited by 6 | Viewed by 2359

Abstract

Rotary drilling for oil and natural gas uses drilling fluid for lubrication of the bit, to seal off unstable shale layers, and floating out rock cuttings. Drilling fluid is a water–clay chemical mixture. Produced water is a water–sand chemical mixture. Land farming is [...] Read more.

Rotary drilling for oil and natural gas uses drilling fluid for lubrication of the bit, to seal off unstable shale layers, and floating out rock cuttings. Drilling fluid is a water–clay chemical mixture. Produced water is a water–sand chemical mixture. Land farming is a common disposal technique of drilling fluid and produced water. In the land farming process, amendments of fluid are repeatedly applied to the soil surface. Plant growth and soil chemical properties may be altered by additions of drilling fluid, because of alkalinity, salinity, trace elements, and petroleum residue contained in waste. The objective of this study was to determine the change in soil pH, electrical conductivity (EC), total nitrogen and carbon, and extractable nutrient levels following the land application of drilling fluid and produced water. The study was a comparison of three plots with similar soil properties and conditions. The three study plots had various levels of drilling fluid and produced water applications. The data show a major difference from field-to-field for EC, Na, and Cl levels. The EC and salt levels increased with additional applications of drilling fluid and produced water. The percent total nitrogen values and plant available P levels were very low in all fields. High EC and salt values, coupled with low N and P levels, would be detrimental to plant growth and development. To successfully vegetate this land-farm site, application of N and P fertilizer would be required. This study help to give a better understanding of practical ways to land-farm drilling fluid and produced water in a fashion that both minimizes environmental issues and is economically feasible in Arkansas. Thus, this research will provide important information for soil contamination management and contributes on understanding of the responses of soil properties to drilling fluid and produced water in the future. Full article

(This article belongs to the Special Issue State-of-the-Art Environmental Science and Technology)

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18 pages, 25895 KiB

Open AccessArticle

Synthesis of Nano-Magnetite from Industrial Mill Chips for the Application of Boron Removal: Characterization and Adsorption Efficacy

by Mohammed Umar Abba, Hasfalina Che Man, Raba’ah Syahidah Azis, Aida Isma Idris, Muhammad Hazwan Hamzah and Mohammed Abdulsalam

Int. J. Environ. Res. Public Health 2021, 18(4), 1400; https://doi.org/10.3390/ijerph18041400 - 03 Feb 2021

Cited by 13 | Viewed by 2567

Abstract

The present study synthesized nano-magnetite (Fe₃O₄) from milled steel chips using the high energy ball milling (HEBM) method, characterized it, and then utilized it as a sorbent to remediate boron concentration at various pH (4–9), dosages (0.1–0.5 g), contact [...] Read more.

The present study synthesized nano-magnetite (Fe₃O₄) from milled steel chips using the high energy ball milling (HEBM) method, characterized it, and then utilized it as a sorbent to remediate boron concentration at various pH (4–9), dosages (0.1–0.5 g), contact times (20–240 min), and initial concentrations (10–100 mg/L). The nano-sorbents were characterized based on SEM structure, elemental composition (EDX), surface area analysis (BET), crystallinity (XRD), and functional group analysis (FTIR). The highest adsorption capacity of 8.44 mg/g with removal efficiency of 84% was attained at pH 8, 0.5 g dosage, contact time of 180 min, and 50 mg/L initial concentration. The experimental data fit best with the pseudo-second-order kinetic model with R² of 0.998, while the Freundlich adsorption isotherm describes the adsorption process with an R² value of 0.9464. A regeneration efficiency of 47% was attained even after five cycles of reusability studies. This efficiency implies that the nano-magnetite has the potential for sustainable industrial application. Full article

(This article belongs to the Special Issue State-of-the-Art Environmental Science and Technology)

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20 pages, 4519 KiB

Open AccessArticle

Adsorption of Methylene Blue Dye by Calix[6]Arene-Modified Lead Sulphide (Pbs): Optimisation Using Response Surface Methodology

by Nor Zida Rosly, Abdul Halim Abdullah, Mazliana Ahmad Kamarudin, Siti Efliza Ashari and Shahrul Ainliah Alang Ahmad

Int. J. Environ. Res. Public Health 2021, 18(2), 397; https://doi.org/10.3390/ijerph18020397 - 06 Jan 2021

Cited by 28 | Viewed by 3920

Abstract

Lead sulphide (PbS) modified with calix[6]arene was synthesised as an alternative and regenerative adsorbent for the adsorption of methylene blue (MB) dye. The prepared calix[6]arene-modified PbS was characterised via Fourier-transform infrared spectroscopy, field emission scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The response [...] Read more.

Lead sulphide (PbS) modified with calix[6]arene was synthesised as an alternative and regenerative adsorbent for the adsorption of methylene blue (MB) dye. The prepared calix[6]arene-modified PbS was characterised via Fourier-transform infrared spectroscopy, field emission scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The response surface methodology (RSM) based on the central composite design (CCD) was employed to identify the most significant factors, such as the initial concentration, adsorbent dosage, pH, and temperature, and to optimise the effects of the factors on the adsorptive efficiency as its response. The optimised initial concentration, adsorbent dosage, pH, and temperature were 20.00 mg/L initial concentration, 44.00 mg calix[6]arene-modified PbS, pH 6, and a temperature of 31.00 °C. A good correlation between the values and well-fitted model was observed. The adsorption performance was evaluated based on the percentage removal of MB dye from the water system. The adsorption isotherm best fit the Langmuir isotherm model, and the adsorption rate was followed by a pseudo-second-order kinetic model, a single layer chemical adsorption with a maximum adsorption capacity (q_max) of 5.495 mg/g. Full article

(This article belongs to the Special Issue State-of-the-Art Environmental Science and Technology)

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11 pages, 2931 KiB

Open AccessArticle

An Innovative in Situ Monitoring of Sulfate Reduction within a Wastewater Biofilm by H₂S and SO₄²⁻ Microsensors

by Hong Liu, Xun Liu and Ning Ding

Int. J. Environ. Res. Public Health 2020, 17(6), 2023; https://doi.org/10.3390/ijerph17062023 - 19 Mar 2020

Cited by 3 | Viewed by 2602

Abstract

Microelectrodes can be used to obtain chemical profiles within biofilm microenvironments. For example, sulfate (SO₄²⁻) and hydrogen sulfide (H₂S) microelectrodes can be used to study sulfate reduction activity in this context. However, there is no SO₄²⁻ [...] Read more.

Microelectrodes can be used to obtain chemical profiles within biofilm microenvironments. For example, sulfate (SO₄²⁻) and hydrogen sulfide (H₂S) microelectrodes can be used to study sulfate reduction activity in this context. However, there is no SO₄²⁻ microelectrode available for studying sulfate reduction in biofilms. In this study, SO₄²⁻ and H₂S microelectrodes were fabricated and applied in the measurement of a wastewater membrane-aerated biofilm (MAB) to investigate the in situ sulfate reduction activity. Both the SO₄²⁻ and H₂S microelectrodes with a tip diameter of around 20 micrometers were successfully developed and displayed satisfying selectivity to SO₄²⁻ and H₂S, respectively. The Nernstian slopes of calibration curves of the fabricated SO₄²⁻ electrodes were close to −28.1 mV/decade, and the R² values were greater than 98%. Within the selected concentration range from 10⁻⁵ M (0.96 mg/L) to 10⁻² M (960 mg/L), the response of the SO₄²⁻ microelectrode was log-linearly related to its concentration. The successfully fabricated SO₄²⁻ microelectrode was combined with the existing H₂S microelectrode and applied on an environmental wastewater biofilm sample to investigate the sulfate reduction activity within it. The H₂S and SO₄²⁻ microelectrodes showed stable responses and good performance, and the decrease of SO₄²⁻ with an accompanying increased of H₂S within the biofilm indicated the in situ sulfate reduction activity. The application of combined SO₄²⁻ and H₂S microelectrodes in wastewater biofilms could amend the current understanding of sulfate reduction and sulfur oxidation within environmental biofilms based on only H₂S microelectrodes. Full article

(This article belongs to the Special Issue State-of-the-Art Environmental Science and Technology)

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12 pages, 1552 KiB

Open AccessArticle

Assessment of Microbiological Quality and Mycotoxin in Dried Chili by Morphological Identification, Molecular Detection, and Chromatography Analysis

by Rachma Wikandari, Inggrid Chrisanti Mayningsih, Maura Dania Permata Sari, Fiametta Ayu Purwandari, Widiastuti Setyaningsih, Endang Sutriswati Rahayu and Mohammad J. Taherzadeh

Int. J. Environ. Res. Public Health 2020, 17(6), 1847; https://doi.org/10.3390/ijerph17061847 - 12 Mar 2020

Cited by 22 | Viewed by 4941

Abstract

The growing interest in spicy foods leads to the global demand for spices, particularly dried chili. This study aimed to assay both aflatoxin (AFs) and ochratoxin A (OTA) contamination using an integrative method of morphological identification, molecular detection, and chromatography analysis on dried [...] Read more.

The growing interest in spicy foods leads to the global demand for spices, particularly dried chili. This study aimed to assay both aflatoxin (AFs) and ochratoxin A (OTA) contamination using an integrative method of morphological identification, molecular detection, and chromatography analysis on dried chili provided from traditional and modern markets in Indonesia. The results showed that total fungal infection ranged from 1-408 × 10³ CFU/g. Eighty percent of the chili obtained from both the traditional and the modern markets were infected by Aspergillus spp., in which 50% of the infections were identified as A. parasiticus and A. flavus. A complete set of targeted genes involved in AF production and OTA were detected in two isolates of A. flavus and one isolate of A. carbonarius, respectively. The levels of AFs B₁, B₂, and OTA in the contaminated dried chilies were in the range of 39.3–139.5 µg/kg, 2.6–33.3 µg/kg, and 23.7–84.6 µg/kg, respectively. In contrast, no AFs G₁ and G₂ were detected. This study showed that the fungal infection of Indonesian dried chili occurs both in the field and during storage; thus, it is suggested to implement good agricultural and handling processes. Full article

(This article belongs to the Special Issue State-of-the-Art Environmental Science and Technology)

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Review

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22 pages, 3253 KiB

Open AccessReview

Reductive Defluorination and Mechanochemical Decomposition of Per- and Polyfluoroalkyl Substances (PFASs): From Present Knowledge to Future Remediation Concepts

by Philipp Roesch, Christian Vogel and Franz-Georg Simon

Int. J. Environ. Res. Public Health 2020, 17(19), 7242; https://doi.org/10.3390/ijerph17197242 - 03 Oct 2020

Cited by 14 | Viewed by 5993

Abstract

Over the past two decades, per- and polyfluoroalkyl substances (PFASs) have emerged as worldwide environmental contaminants, calling out for sophisticated treatment, decomposition and remediation strategies. In order to mineralize PFAS pollutants, the incineration of contaminated material is a state-of-the-art process, but more cost-effective [...] Read more.

Over the past two decades, per- and polyfluoroalkyl substances (PFASs) have emerged as worldwide environmental contaminants, calling out for sophisticated treatment, decomposition and remediation strategies. In order to mineralize PFAS pollutants, the incineration of contaminated material is a state-of-the-art process, but more cost-effective and sustainable technologies are inevitable for the future. Within this review, various methods for the reductive defluorination of PFASs were inspected. In addition to this, the role of mechanochemistry is highlighted with regard to its major potential in reductive defluorination reactions and degradation of pollutants. In order to get a comprehensive understanding of the involved reactions, their mechanistic pathways are pointed out. Comparisons between existing PFAS decomposition reactions and reductive approaches are discussed in detail, regarding their applicability in possible remediation processes. This article provides a solid overview of the most recent research methods and offers guidelines for future research directions. Full article

(This article belongs to the Special Issue State-of-the-Art Environmental Science and Technology)

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12 pages, 1676 KiB

Open AccessReview

Performance of Exoelectrogenic Bacteria Used in Microbial Desalination Cell Technology

by Li Guang, Desmond Ato Koomson, Huang Jingyu, David Ewusi-Mensah and Nicholas Miwornunyuie

Int. J. Environ. Res. Public Health 2020, 17(3), 1121; https://doi.org/10.3390/ijerph17031121 - 10 Feb 2020

Cited by 67 | Viewed by 6748

Abstract

The tri-functional purpose of Microbial Desalination Cell (MDC) has shown a great promise in our current scarcity of water, an increase in water pollution and the high cost of electricity production. As a biological system, the baseline force that drives its performance is [...] Read more.

The tri-functional purpose of Microbial Desalination Cell (MDC) has shown a great promise in our current scarcity of water, an increase in water pollution and the high cost of electricity production. As a biological system, the baseline force that drives its performance is the presence of exoelectrogens in the anode chamber. Their presence in the anodic chamber of MDC systems enables the treatment of water, desalination of seawater, and the production of electrical energy. This study reviews the characteristics of exoelectrogens, as a driving force in MDC and examines factors which influence their growth and the performance efficiency of MDC systems. It also addresses the efficiency of mixed cultures with certain predominant species as compared to pure cultures used in MDC systems. Furthermore, the study suggests the need to genetically modify certain predominant strains in mixed cultures to enhance their performance in COD removal, desalination and power output and the integration of MDC with other technologies for cost-effective processes. Full article

(This article belongs to the Special Issue State-of-the-Art Environmental Science and Technology)

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