Recycling

10 pages, 4191 KiB

Open AccessArticle

Valorization of Municipal Waterworks Sludge to Produce Ceramic Floor Tiles

by Lara Pessin Rodrigues and José Nilson França De Holanda

Recycling 2018, 3(1), 10; https://doi.org/10.3390/recycling3010010 - 17 Mar 2018

Cited by 8 | Viewed by 4449

In municipal waterworks large amounts of waste in the form of sludge have to be discarded. This investigation focuses on the processing of ceramic floor tiles incorporated with a municipal waterworks sludge. Four floor tile formulations containing up to 10 wt. % of [...] Read more.

In municipal waterworks large amounts of waste in the form of sludge have to be discarded. This investigation focuses on the processing of ceramic floor tiles incorporated with a municipal waterworks sludge. Four floor tile formulations containing up to 10 wt. % of the municipal waterworks sludge were prepared in order to replace the kaolin. The floor tile processing route consisted of dry powder granulation, uniaxial pressing, and firing between 1190 and 1250 °C using a fast-firing cycle (<60 min). The densification behavior and technological properties of the floor tile pieces as function of the sludge addition and firing temperature were determined. The development of the microstructure was followed by XRD and SEM/EDS. The results show that the replacement of kaolin with municipal waterworks sludge, in the range up to 10 wt. %, allows the production of ceramic floor tiles (group BIb and group BIIa, ISO 13006 Standard) at lower firing temperatures. These results suggest a new possibility of valorization of municipal waterworks sludge in order to bring economic and environmental benefits. Full article

(This article belongs to the Special Issue Water Recovery Recycling and Resilience)

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19 pages, 2446 KiB

Open AccessFeature PaperReview

The Potential of Tree Fruit Stone and Seed Wastes in Greece as Sources of Bioactive Ingredients

by Stella A. Ordoudi, Christina Bakirtzi and Maria Z. Tsimidou

Recycling 2018, 3(1), 9; https://doi.org/10.3390/recycling3010009 - 05 Mar 2018

Cited by 27 | Viewed by 8999

Abstract

The inedible part (stones, husks, kernels, seeds) of the tree fruits that are currently processed in various regions of Greece constitutes a huge portion of the fruit processing solid waste that remains underexploited. In this review, the existing scientific background for the composition [...] Read more.

The inedible part (stones, husks, kernels, seeds) of the tree fruits that are currently processed in various regions of Greece constitutes a huge portion of the fruit processing solid waste that remains underexploited. In this review, the existing scientific background for the composition and content of fruit stone and seed in bioactive ingredients is highlighted for olives, stone fruits and citrus fruits that represent the economically most important tree crop products of the country. The content of bioactive compounds may vary considerably depending on the quality of the raw material and the treatment during processing. However, both the hydrophilic and the lipophilic fractions of the seeds contain significant amounts of the primary and the secondary plant metabolites. Among them, phytosterols and several types of polyphenols, but also squalene, tocopherols and some other terpenoids with a unique structure are of particular importance for the utilization and valorization of stones and seeds. Official and scholar records about the current management practices are also presented to highlight the dynamics of the Greek fruit sector. Prospects for the regionalization of fruit seed wastes, in line with EU-promoted Research and Innovation Strategies (RIS) for Smart Specialization are critically discussed. Full article

(This article belongs to the Special Issue Food Waste – Strategies to Reuse and Prevention)

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11 pages, 5002 KiB

Open AccessReview

Mechanical Processing of GFRP Waste into Large-Sized Pieces for Use in Concrete

by Ardavan Yazdanbakhsh, Lawrence C. Bank and Yuan Tian

Recycling 2018, 3(1), 8; https://doi.org/10.3390/recycling3010008 - 15 Feb 2018

Cited by 30 | Viewed by 6943

Abstract

Recycling glass fiber reinforced polymer (GFRP) composite materials has been proven to be challenging due to their high mechanical performance and high resistance to harsh chemical and thermal conditions. This work discusses the efforts made in the past to mechanically process GFRP waste [...] Read more.

Recycling glass fiber reinforced polymer (GFRP) composite materials has been proven to be challenging due to their high mechanical performance and high resistance to harsh chemical and thermal conditions. This work discusses the efforts made in the past to mechanically process GFRP waste materials by cutting them into large-sized (cm scale) pieces, as opposed to pulverization, for use in concrete mixtures. These pieces can be classified into two main categories—coarse aggregate and discrete reinforcement, here referred to as “needles.” The results from all the studies show that using GFRP coarse aggregate leads to significant reductions in the compressive strength and tensile strength of concrete. However, GFRP needles lead to sizable increases in the energy absorption capacity of concrete. In addition, if the glass fibers are longitudinally aligned within the needles, these elements can substantially increase the tensile strength of concrete. Processing GFRP waste into needles requires less energy and time than that for producing GFRP coarse aggregate. Also, compared to pulverized GFRP waste, which consists of broken and separate particles of glass and resin that at best can be used as low-quality fillers, GFRP needles are high strength composite elements. Full article

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22 pages, 1256 KiB

Open AccessArticle

Material Implications of Rural Electrification—A Methodological Framework to Assess In-Use Stocks of Off-Grid Solar Products and EEE in Rural Households in Bangladesh

by Alexander Batteiger and Vera Susanne Rotter

Recycling 2018, 3(1), 7; https://doi.org/10.3390/recycling3010007 - 07 Feb 2018

Cited by 3 | Viewed by 5979

Abstract

“Universal access to electricity” is proclaimed as the seventh sustainable development goal (SDG 7) of the United Nations (UN) Sustainable Development Goals list. The achievement of this goal will result in a rapid diffusion of energy technologies that would in turn increase materials [...] Read more.

“Universal access to electricity” is proclaimed as the seventh sustainable development goal (SDG 7) of the United Nations (UN) Sustainable Development Goals list. The achievement of this goal will result in a rapid diffusion of energy technologies that would in turn increase materials stocks, subsequently increase the raw material demand as well as the arising waste flows. This study describes a methodological framework to assess in-use stocks of off-grid solar products and electrical and electronic equipment (EEE) for rural communities in developing countries. The methodology is based on energy-access data. Furthermore, the specifics of the characteristics of off-grid solar products are discussed. The methodology is applied to rural Bangladesh and its solar home system (SHS) program. By the end of 2016, around 4.1 million SHSs were installed. This type of access to electricity has a significant impact on the in-use stocks, as households add the comparatively heavy SHSs to their in-use stocks. In-use stocks of EEE, in general, are low. Off-grid solar products are lighter than standard EEE, and fewer products types are available. These findings will help to better understand material stocks and future waste flows in the given context and will support the adaption of recycling infrastructures. Full article

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22 pages, 4217 KiB

Open AccessArticle

Sustainable Airport Waste Management: The Case of Kansai International Airport

by Glenn Baxter, Panarat Srisaeng and Graham Wild

Recycling 2018, 3(1), 6; https://doi.org/10.3390/recycling3010006 - 03 Feb 2018

Cited by 27 | Viewed by 20969

Abstract

The global air transport industry is predicted to continue its rapid growth. A by-product of air transport operations, however, is the substantial volumes of waste generated at airports. To mitigate the environmental impact of waste and to comply with regulatory requirements, airports are [...] Read more.

The global air transport industry is predicted to continue its rapid growth. A by-product of air transport operations, however, is the substantial volumes of waste generated at airports. To mitigate the environmental impact of waste and to comply with regulatory requirements, airports are increasingly implementing sustainable waste management policies and systems. Using an in-depth case study research design, this study has examined waste management at Kansai International Airport from 2002 to 2015. Throughout its history the airport has implemented world best practices to achieve its goal of being an eco-friendly airport. The qualitative data gathered for the study were analysed using document analysis. The quantitative data were analysed using t-tests. Statistically significant results were found in the reduction in waste per passenger and aircraft movement (for total waste, incinerated waste, and landfill waste). In addition, a statistically significant increase in the proportion of waste recycled, and a decrease in the proportion of waste sent to landfill was observed. As such, quantitatively speaking, Kansai International Airport has shown significant waste management improvements. The study concludes that Kansai Airport’s waste management approaches and policies can be transferred to other airport facilities. This would greatly improve sustainability across airports, globally. Full article

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11 pages, 1459 KiB

Open AccessArticle

Procedural Information and Behavioral Control: Longitudinal Analysis of the Intention-Behavior Gap in the Context of Recycling

by Sonny Rosenthal

Recycling 2018, 3(1), 5; https://doi.org/10.3390/recycling3010005 - 22 Jan 2018

Cited by 40 | Viewed by 9605

Abstract

The theory of planned behavior states that individuals act on their intentions, especially when they have behavioral control. The current study examines how seeking recycling-related procedural information—i.e., information about how and where to recycle—is related to behavioral control. Hypothesis testing used hierarchical ordinary [...] Read more.

The theory of planned behavior states that individuals act on their intentions, especially when they have behavioral control. The current study examines how seeking recycling-related procedural information—i.e., information about how and where to recycle—is related to behavioral control. Hypothesis testing used hierarchical ordinary least squares regression analysis of longitudinal data from 553 survey respondents. Results supported seven hypotheses. Most notably, procedural information seeking both mediated and moderated the relationship between intention and behavior. Further, the moderation effect was itself mediated by behavioral control. The argument for this mediated moderation is that information seeking enhances behavioral control, and it is primarily behavioral control that moderates the relationship between intention and behavior. These results have implications for the theory of planned behavior and, more generally, for how individuals use information to support their behaviors. Full article

(This article belongs to the Special Issue Waste Management Education and Promotion)

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12 pages, 1093 KiB

Open AccessArticle

Social Acceptance for Reclaimed Water Use: A Case Study in Bengaluru

by Chaya Ravishankar, Sunil Nautiyal and Manasi Seshaiah

Recycling 2018, 3(1), 4; https://doi.org/10.3390/recycling3010004 - 20 Jan 2018

Cited by 26 | Viewed by 6455

Abstract

The main source of water to the peri-urban areas of Bengaluru is groundwater. Access to groundwater is through tankers, private borewells, Bruhat Bengaluru MahanagaraPalike (Urban Local Body) borewells, and public stand posts. All modes other than tankers provide water to the community free [...] Read more.

The main source of water to the peri-urban areas of Bengaluru is groundwater. Access to groundwater is through tankers, private borewells, Bruhat Bengaluru MahanagaraPalike (Urban Local Body) borewells, and public stand posts. All modes other than tankers provide water to the community free of charge. Reclaimed water from sewage treatment plants (STPs) is in use by industries and some gated communities and multistoried apartments for toilet flushing and landscaping. For individual households in peri-urban areas of Bengaluru, it could be an additional water source replacing expensive water supply through tankers; reducing demand for groundwater (a finite resource); improving the sanitation system by providing drainage systems and preventing groundwater contamination from black and grey water. Consequently, this research paper investigates the willingness of residents in peri-urban areas of Bengaluru to use reclaimed water for non-potable end uses. To investigate residents’ willingness and key motivations for the use of reclaimed water, a survey of residents in the peri-urban ward of Bellandur was conducted. In this region, the sewerage board had prepared a media advertisement to create awareness of—and to sell—reclaimed water to other users, including local residents. This advertisement was shown to respondents, asking if they were willing to accept and buy the reclaimed water at 15 Indian Rupees (INR) per kiloliter. Sixty-seven percent of residents who were household owners were willing to buy reclaimed water, 20% were concerned about hygiene, and 33% of respondents lacked trust in the public agency with respect to water quality standards. The study concludes that public awareness from key stakeholders is essential for the reuse of reclaimed water. It also recommends stringent regulation by levying fees for groundwater extraction in addition to making reclaimed water readily available and supplied free of charge to the consumers. In addition, the quality of reclaimed water should meet international standards to gain the confidence of the people. Full article

(This article belongs to the Special Issue Water Recovery Recycling and Resilience)

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11 pages, 9305 KiB

Open AccessArticle

Concepts for Reusing Composite Materials from Decommissioned Wind Turbine Blades in Affordable Housing

by Lawrence C. Bank, Franco R. Arias, Ardavan Yazdanbakhsh, T. Russell Gentry, Tristan Al-Haddad, Jian-Fei Chen and Ruth Morrow

Recycling 2018, 3(1), 3; https://doi.org/10.3390/recycling3010003 - 17 Jan 2018

Cited by 60 | Viewed by 12966

Abstract

The very rapid growth in wind energy technology in the last 15 years has led to a rapid growth in the amount of non-biodegradable, thermosetting fiber reinforced polymer (FRP) composite materials used in wind turbine blades. This paper discusses conceptual architectural and structural [...] Read more.

The very rapid growth in wind energy technology in the last 15 years has led to a rapid growth in the amount of non-biodegradable, thermosetting fiber reinforced polymer (FRP) composite materials used in wind turbine blades. This paper discusses conceptual architectural and structural options for recycling these blades by reusing parts of wind turbine blades in new or retrofitted housing projects. It focuses on large-sized FRP pieces that can be salvaged from the turbine blades and can potentially be useful in infrastructure projects where harsh environmental conditions (water and high humidity) exist. Since reuse design should be for specific regional locations and architectural characteristics the designs presented in this paper are for the coastal regions of the Yucatan province in Mexico on the Gulf of Mexico where low-quality masonry block informal housing is vulnerable to severe hurricanes and flooding. To demonstrate the concept a prototype 100 m long wind blade model developed by Sandia National Laboratories is used to show how a wind blade can be broken down into parts, thus making it possible to envision architectural applications for the different wind blade segments for housing applications. Full article

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2 pages, 279 KiB

Open AccessEditorial

Acknowledgement to Reviewers of Recycling in 2017

by Recycling Editorial Office

Recycling 2018, 3(1), 2; https://doi.org/10.3390/recycling3010002 - 09 Jan 2018

Cited by 1 | Viewed by 2606

Abstract

Peer review is an essential part in the publication process, ensuring that Recycling maintains high quality standards for its published papers. In 2017, a total of 24 papers were published in the journal.[...] Full article

2899 KiB

Open AccessReview

Recycling of Polymer-Based Multilayer Packaging: A Review

by Katharina Kaiser, Markus Schmid and Martin Schlummer

Recycling 2018, 3(1), 1; https://doi.org/10.3390/recycling3010001 - 22 Dec 2017

Cited by 261 | Viewed by 58124

Abstract

Polymer-based multilayer packaging materials are commonly used in order to combine the respective performance of different polymers. By this approach, the tailored functionality of packaging concepts is created to sufficiently protect sensitive food products and thus obtain extended shelf life. However, because of [...] Read more.

Polymer-based multilayer packaging materials are commonly used in order to combine the respective performance of different polymers. By this approach, the tailored functionality of packaging concepts is created to sufficiently protect sensitive food products and thus obtain extended shelf life. However, because of their poor recyclability, most multilayers are usually incinerated or landfilled, counteracting the efforts towards a circular economy and crude oil independency. This review depicts the current state of the European multilayer packaging market and sketches the current end-of-life situation of postconsumer multilayer packaging waste in Germany. In the main section, a general overview of the state of research about material recycling of different multilayer packaging systems is provided. It is divided into two subsections, whereby one describes methods to achieve a separation of the different components, either by delamination or the selective dissolution–reprecipitation technique, and the other describes methods to achieve recycling by compatibilization of nonmiscible polymer types. While compatibilization methods and the technique of dissolution–reprecipitation are already extensively studied, the delamination of packaging has not been investigated systematically. All the presented options are able to recycle multilayer packaging, but also have drawbacks like a limited scope or a high expenditure of energy. Full article

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Recycling, Volume 3, Issue 1 (March 2018) – 10 articles

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