Showing papers in "Resources Conservation and Recycling in 2015"

A literature review and perspectives in reverse logistics

Abstract: In recent years, reverse logistics (RL) has become a field of importance for all organizations due to growing environmental concerns, legislation, corporate social responsibility and sustainable competitiveness. RL refers to the sequence of activities required to collect the used product from the customers for the purpose of either reuse or repair or re-manufacture or recycle or dispose of it. Perusal of the literature shows that research in the field of RL is in evolving phase and issues pertaining to adoption and implementation, forecasting product returns, outsourcing, RL networks from secondary market perspective, and disposition decisions have not been reviewed extensively. This study attempts to fill the existing gap through literature review on these issues, and outline the future directions for research based on research gap analysis. Total 242 published articles were selected, categorized, analyzed, and gaps in literature were identified to suggest for future research opportunities. The review may be useful for academicians, researchers and practitioners for better understanding of RL and guidance for future research.

Extending the Theory of Planned Behavior in the context of recycling: The role of moral norms and of demographic predictors

Abstract: This paper examines how an individual's moral norms and demographic characteristics interact with the standard ‘Theory of Planned Behavior’ predictors (Attitude; Subjective Norms; and Perceived Behavioral Control (PBC)) in explaining the intention to recycle (RI). Our data originate from an empirical research of Greek citizens conducted in Autumn 2013 (N = 293). Through structural equation modeling, we find that PBC is consistently the most important predictor of RI. Moral norms have a larger effect on RI than Attitude while their influence is primarily direct. On the contrary, demographic characteristics were found to be statistically non-significant predictors of RI, similarly to Subjective Norms.

Risk analysis in green supply chain using fuzzy AHP approach: A case study

Abstract: Due to increase in customer environmental awareness, competitiveness and strict governmental policies, the approach of incorporating green supply chain management (GSCM), to conserve resources and sustainable production, is gradually becoming more imperative for organizations. However, the successful accomplishment of green supply chain (GSC) production and business activities is relatively difficult due to involvement of different risks. These risks and their respective sources have a tendency to disturb the GSC functioning, and thereby, decline in the ecological-economic performance. Therefore, identification of risks and their subsequent analysis in the GSC are very important to know and understand. The present research analyzes the risks relevant to adoption and effective implementation of GSC practices at industrial viewpoint. A two-phase research approach has been proposed and used in this study. In the first phase, six categories of risks and twenty-five specific risks, associated with the GSC, were identified. The basis of identification of the risks was literature and inputs received from experts from industries. Experts’ opinion has been collected from the officials and managers of four Indian poly product-manufacturing companies. In the second phase, the fuzzy analytic hierarchy process (fuzzy AHP), a qualitative and quantitative analysis was used to analyze the identified risks for determining of their priority of concern. The used fuzzy AHP approach is also useful in dealing with the human subjectivity and ambiguity involved in the process of risk analysis. In this research, an effort has been made to know the most important risk in GSC context, and the findings would be useful for industries in managing and reducing the consequences of the risks in GSC. The analysis of the results indicates that operational category risks are the most important risks in GSC. Sensitivity analysis is also conducted to examine the priority ranking stability.

Predicting household food waste reduction using an extended theory of planned behaviour

Abstract: Identifying the antecedents of household food waste reduction is an important step in the development of effective and efficient interventions. This prospective study tested the utility of applying an extended theory of planned behaviour (TPB) model to household food waste reduction. At baseline, participants (N = 279) completed a questionnaire designed to measure the following cognitive constructs derived from the extended TPB model: intention, attitude, subjective norm, perceived behavioural control, self-identity, anticipated regret, moral norm and descriptive norm. At follow-up, participants (N = 204) completed a questionnaire assessing their household food waste behaviour. The extended TPB model accounted for a substantial amount (64%) of the variance in intention, with attitude, subjective norm, perceived behavioural control, self-identity and anticipated regret emerging as significant linear predictors. Furthermore intention significantly predicted the likelihood that participants had reduced their household fruit and vegetable waste at follow-up; however, the amount of variance in behaviour accounted for by the TPB model was relatively small (5%). Results demonstrate the utility of applying an extended theory of planned behaviour model to predict motivation and – to a lesser extent – behaviour, in the context of household fruit and vegetable waste reduction.

Overview and description of technologies for recovering phosphorus from municipal wastewater

Abstract: Over the past years, numerous technologies have been developed to recover phosphorus (P) from waste streams to repair currently broken nutrient cycles. These developments were largely triggered by environmental considerations (sustainability, resource efficiency), concerns regarding the finite and geopolitically concentrated deposits of raw phosphate ore, and phosphate price increases. Municipal wastewater is a promising and viable source to recover P in larger quantities, to re-establish a circular economy and therefore increase net use efficiency. This work compiles the latest knowledge on approaches to recover P from municipal wastewater and related waste flows with a specific focus on the existing well-developed wastewater management infrastructure, available in significant parts of Europe (e.g., secondary treated effluent, digester supernatant, sewage sludge, sewage sludge ash). About 50 technologies were identified at various levels of development (industrial-, full-, pilot- and laboratory scale). The current selection of P recovery processes is broad and ranges from simple precipitation of dissolved P to complex multi-step approaches, and only a few of these displayed potential for full-scale implementation. They are discussed with regard to their technical principles, process parameters, recovery efficiency, resource demand, possible effects on wastewater treatment, waste flows, and fate of pollutants. We also evaluated them with respect to their rates of P removal from wastewater and their access points of P recovery. For selected technologies, material flow models are presented to facilitate the understanding of even complex processes. This work serves as a basis for future integrated comparative assessments of selected recovery approaches according to technical, environmental and economic criteria.

Household recycling knowledge, attitudes and practices towards solid waste management

Abstract: A questionnaire survey consisting of 2400 householders was performed on Abadan residents to evaluate their knowledge, attitudes, and practices (KAP) towards solid waste (SW) reduction, source separation and recycling, collection and willingness to pay (WTP) for SW services. The study has also covered the relationship between demographic variables and KAP towards SW management. The data analyzed suggests that the studied community had a very positive attitude to take part in SW source separation and recycling plans. However, the respondents not only showed low intimate knowledge of different steps of SW management, but were also weak to take practices about these steps. The KAP of SW source separation and recycling was influenced by demographic factors of age, education level, gender and occupation. It was further found that education level and occupation were two significant factors affecting residents’ WTP (χ2 = 24.083, p-value

Reusing wastewater to cope with water scarcity: Economic, social and environmental considerations for decision-making

Abstract: Wastewater reuse has been recognized as an encouraging solution to cope with the problem of water scarcity around the globe. Adopting Integrated Water Resources Management principles will ensure that the implementation of wastewater reuse projects will take into account all the various types of affected stakeholders, accounting in addition for the external costs and benefits derived from the reuse decision. The objective of this paper is to analyze the economic, social and environmental aspects surrounding the concept of wastewater reuse in order to assist policy-makers and managers on the implementation of economic instruments for decision-making. This study proposes a methodological framework for conducting cost-benefit analysis, which is later exemplified by the Yarqon Recycling Project case study in Israel. In this case study application, 3 different scenarios (“pessimistic”, “base-case” and “optimistic”) with a range of parameters values, were used to estimate the most relevant internal and external costs and benefits. Additionally, the most influential parameters were identified using a sensitivity analysis that included both Monte Carlo simulations and the standardized regression coefficients method. For the “base-case” scenario, the net present value obtained was approximately $4.83 million. Although the feasibility of the project is demonstrated, the sensitivity analysis results were less favorable (likelihood of obtaining a positive result was only 64.28%), being the external recreational costs derived from irrigating with reclaimed wastewater the most influential parameter. The results of this analysis led to the conclusion that including the relevant externalities might have a strong impact on the economic feasibility of the wastewater reuse projects. The proposed methodological framework aims to guide decision-makers in evaluating their success with respect to Integrated Water Resources Management in economic terms.

Use of recycled construction and demolition materials in geotechnical applications: A review

Abstract: The proper use of natural resources is one of the fundamental pillars of sustainable development imposed on modern societies. A more effective and efficient use of natural resources, as well as the mitigation of environmental impacts induced by their extraction could be achieved if proper management and recycling policies of Construction and Demolition (C&D) wastes were implemented. The valorisation of wastes in the construction industry is needed and is a way toward sustainability. This paper provides a literature review on studies related to the valorisation of Construction and Demolition (C&D) materials in geotechnical engineering applications, with an emphasis on their use as recycled aggregates in base layers of roadway infrastructures and as filling material for geosynthetic reinforced structures. Specifications that should be followed when these materials are used in such projects are also summarised. With this review it is intended to promote the use of recycled C&D materials, showing that research carried out all over the world has demonstrated their good performance in general.

Phosphorus use efficiency and management in agriculture

Abstract: Phosphorus (P) is an essential element for all life, is essential for global food security, and is a limited, nonrenewable global resource, making its efficient use vitally important. There is a commonly held belief that P fertilizer is very inefficient because P recovery by crops in the year it is applied is often only 10-15%. The residual fertilizer P not recovered by the crop is believed to be permanently tied-up or “fixed” in the soil in forms not available to plants. However, field experiments do not support that view. The behavior of inorganic P in fertilizer when applied to the soil can be explained as contained in four pools of varying availability to plants based on its accessibility to plant roots and its extractability by soil test reagents. Phosphorus use efficiency can be assessed in several ways, but the “balance” method (i.e. partial nutrient balance) calculated as a P removal-to-input ratio and expressed as a percent best reflects the behavior of fertilizer P in soils and supports the concept of P transfer and availability within the four pools discussed. When determined by the balance method, P recovery is often in the range of 50-70% or even higher. Improving fertilizer P use and effectiveness is achievable through the implementation of fertilizer best management practices within the context of 4Rs—application of the right nutrient source, applied at the right rate, right time, and in the right place.

Factors affecting consumers’ choices concerning sustainable packaging during product purchase and recycling

Abstract: The interest in sustainable (environmentally friendly) packaging has started to increase in comparison with regular packaging. To date, research has focused on how to increase the sustainability of packaging through the use of eco-design tools, and there has been only limited investigation of the relationship between sustainable packaging and consumer behavior during the purchase and recycling stages of the packaging life cycle. The present study examines the factors that influence consumers’ product purchasing behavior and their recycling behavior with respect to sustainable packaging. Data from an online survey of 215 respondents in Portugal was used to test several hypotheses by comparing two groups of consumers: one group that places importance on environmentally friendly packaging and another that regards such packaging as unimportant in product purchase decisions. The results obtained show that gender, environmental awareness, concerns about societal opinions, a positive attitude towards green purchasing, and the perception of consumer actions are factors that differentiate the two groups of consumers. The findings should prove of use to public decision-makers, companies producing packaging, and marketers. However, features such as price are still needed to alter the behavior of consumers with respect to encouraging the use of sustainable packaging. In the near future, the study should be spread to a national scale to extend the findings of the present study, and to explore further aspects of consumer pro-environmental behavior with respect to sustainable packaging, including how the relationship between product and packaging may influence consumer behavior.

Compost from organic solid waste: Quality assessment and European regulations for its sustainable use

Abstract: Composting represents the most common option to recover material from the organic fraction of municipal solid waste, due to the possibility to use compost as a fertilizer. To this end the assessment of compost quality needs to be adequately enforced in national regulations. This work aims at reviewing European regulations regarding compost quality, in order to identify the most common parameters used to define compost characteristics as fertilizer. It was found that the majority of European States requires the fulfilment of specific criteria, but a lack of uniformity in regulations and guidelines can be observed. In particular the approach to the evaluation of stability and maturity, which account for compost safe use on soils, shows great heterogeneity throughout Europe. As stability and maturity go hand in hand, the proper characterization of compost toxicity should rely on the determination of both parameters. The results of an annual monitoring of compost under the Italian regulation highlighted, indeed, that the evaluation of the germination index can provide only partial information on the product maturity but not reliable operating indication on compost inhibitory properties.

Waste minimisation through deconstruction: A BIM based Deconstructability Assessment Score (BIM-DAS)

Abstract: The overall aim of this study is to develop a Building Information Modelling based Deconstructability Assessment Score (BIM-DAS) for determining the extent to which a building could be deconstructed right from the design stage. To achieve this, a review of extant literature was carried out to identify critical design principles influencing effectual building deconstruction and key features for assessing the performance of Design for Deconstruction (DfD). Thereafter, these key features were used to develop BIM-DAS using mathematical modelling approach based on efficient material requirement planning. BIM-DAS was later tested using case study design and the results show that the major contributing factors to DfD are use of prefabricated assemblies and demountable connections. The results of the evaluation demonstrate the practicality of BIM-DAS as an indicator to measure the deconstructability of building designs. This could provide a design requirement benchmark for effective building deconstruction. This research work will benefit all stakeholders in the construction industry especially those interested in designing for deconstruction. The eventual incorporation of BIM-DAS into existing BIM software will provide a basis for the comparison of deconstructability of building models during design.

Greenhouse gas emission factors for recycling of source-segregated waste materials

Abstract: A key challenge for the waste management sector is to maximise resource efficiency whilst simultaneously reducing its greenhouse gas (GHG) emissions. For stakeholders to better understand the GHG impacts of their waste management activities and identify emissions reduction opportunities, they need to be able to quantify the GHG impacts of material recycling. Whilst previous studies have been undertaken to develop GHG emission factors (EF) for materials recycling, they are generally insufficient to support decision-making due to a lack of transparency or comprehensiveness in the range of materials considered. In this study, we present for the first time a comprehensive, scientifically robust, fully transparent, and clearly documented series of GHG EFs for the recycling of a wide range of source-segregated materials. EFs were derived from a series of partial life cycle assessments (LCA) performed as far as possible in accordance with the ISO 14040 standard. With the exceptions of soil, plasterboard, and paint, the recycling of source-segregated materials resulted in net GHG savings. The majority of calculated GHG EFs were within the range of data presented in the literature. The quality of secondary data used was assessed, with the results highlighting the dearth of high quality life cycle inventory (LCI) data on material reprocessing and primary production currently available. Overall, the results highlight the important contribution that effective source-segregated materials recycling can have in reducing the GHG impacts of waste management.

Comparative life cycle assessment of asphalt pavements using reclaimed asphalt, warm mix technology and cold in-place recycling

Abstract: In this work the environmental sustainability of asphalt pavement is analyzed, from material production and maintenance strategy point of view. The work consists of an analysis of the life cycle of 1 km of road pavement and includes all stages of the life cycle: from extraction of virgin materials to end of life. Three types of pavements are compared, among which one produced with virgin materials and traditional technologies in plant, which is used as a reference, and two in which the use of Reclaimed Asphalt Pavement (RAP) and Warm Mix Asphalt (WMA) technology are combined. Also the implementation of the practice of Cold In-Place Recycling (CIR) at the end of life is considered from an environmental point of view: after the first 15 years of life the comparison is made between traditional recycling in plant and CIR. The impacts are evaluated using different methods. Decrease in environmental impacts are found for the options that combine the use of RAP and WMA reaching up to a percentage of reduction of 12% for CO2eq, 15% for energy consumptions, 15% for water used during the lifecycle, and 10–15% for the three macro-categories of damage evaluated in the ReCiPe endpoint method. Additional reductions could be achieved by applying also CIR technology especially for greenhouse gas emissions (−9%).

Waste effectiveness of the construction industry: Understanding the impediments and requisites for improvements

Abstract: Construction industry contributes a large portion of waste to landfill, which in turns results in environmental pollution and CO2 emission. Despite the adoption of several waste management strategies, waste reduction to landfill continues seeming an insurmountable challenge. This paper explores factors impeding the effectiveness of existing waste management strategies, as well as strategies for reducing waste intensiveness of the construction industry. Drawing on series of semi structured focus group discussions with experts from the UK leading construction companies, this paper combines phenomenological approach with a critical review and analysis of extant literatures. Five broad categories of factors and practices are responsible for ineffectiveness of construction and demolition waste management strategies, which subsequently results in waste intensiveness of the industry. These include end of pipe treatment of waste, externality and incompatibility of waste management tools with design tools, atomism of waste management strategies, perceived or unexpected high cost of waste management, and culture of waste behaviour within the industry. To reduce waste intensiveness of the construction industry, the study suggests that six factors are requisites. These are tackling of waste at design stage, whole life waste consideration, compliance of waste management solutions with BIM, cheaper cost of waste management practice, increased stringency of waste management legislation and fiscal policies, and research and enlightenment. The proposed strategies are not only important for achieving low waste construction projects, they are important for reducing waste intensiveness of the construction. Implementation of the suggested measures would drive waste management practices within the construction industry.

Agriculture biomass in India: Part 1. Estimation and characterization

Abstract: Biomass residues or wastes generated in the agricultural sector represent a source of potentially sustainable feedstock for bio-refineries. The strategy toward such a bio-based economy will only succeed if enough biomass and adequate qualities can be provided not only to produce bioenergy but also to fulfil the food security and health requirements of the growing population. In India, the majority of the biomass generated come from agriculture sector. It is therefore important to have a reliable estimate of the biomass, biowaste and agro-residue generated to define policies for their valorization as well as identifying technologies which could be used for such purpose. Herein we present an assessment of the amounts and availability of biomass residues/wastes generated in the Indian agriculture sector for organized use as a biorefinery feedstock, for data collected up to the year 2010. A compilation of some relevant physicochemical characteristics of the residues is also included.

Recycling indium from waste LCDs: A review

Abstract: As one of the most widely used scarce metals located at the column of IIIA in the periodic table, indium has drawn more and more attention due to its semiconductor and optoelectronic performance While the reduction of indium minerals, as one of secondary resources, the amount of waste liquid crystal display (LCD) has been accumulated considerably Indium tin oxide (ITO) film which is the main functional fraction of LCD has consumed more than 70% of the indium production worldwide Therefore, it is necessary to recycle indium from waste LCDs Some researches have been done for proper treatment to recycle indium from waste LCD which is a primary part of waste electric and electronic equipment (WEEE) In this paper, the main characteristics of indium and the waste management status of end-of-life LCDs are introduced And we mainly focus on the highly developed single recycling and reusing techniques In addition, several combined recycling processes are evaluated Furthermore, on the foundation of techniques and processes mentioned above, the promising related single techniques and the improvements on whole treatment process of waste LCDs are suggested

Carbon footprint of supermarket food waste

Abstract: Food waste is a major problem in modern society and carries considerable social, economic and environmental costs. Food production causes greenhouse gas emissions along the entire food supply chain and wasting food means that those emissions are produced in vain. There is consensus that food waste has to be reduced. For example, the EU and some of its member countries have set concrete targets to reduce the amount of waste. However, in order to achieve the overall goal of a more sustainable economy, not only quantitative but also environmental indicators have to be considered when pursuing waste reduction goals. This study analysed the discrepancies between the waste quantity and wastage carbon footprint (CF) profiles of perishable food products wasted in Swedish supermarkets. The wastage CF, defined as the product CF from cradle up to and including delivery to the retailer times the amount of the product wasted at the store, was calculated for products in the meat, deli, cheese, dairy and fruit & vegetable departments of six Swedish supermarkets. The CF from cradle to retailer of the various products was determined based on existing life cycle assessment (LCA) literature. Emissions due to production and transportation were considered. Data on wasted mass of the products in the period 2010–2012 was provided by the Swedish retail chain Willys. Data on bread waste are mainly held by the bakeries, and were thus not included in the study. Over a three-year period, 1570 t of fresh food (excluding bread) were wasted in the six supermarkets. The associated total wastage CF was 2500 t CO 2 e. The fruit & vegetable department contributed 85% of the wasted mass and 46% of the total wastage CF. The meat department contributed 3.5% of the wasted mass, while it accounted for 29% of the total wastage CF. The wastage CF of each department tended to be highly concentrated in certain products and thus halving the waste of the top three products in each department could save more than 25 t CO 2 e per store and year.

Reverse logistics system design for the waste of electrical and electronic equipment (WEEE) in Turkey

Abstract: Depending on the high consumption in the world, the amount of waste increases. One of the critical waste types to be handled is the electrical and electronic waste (WEEE). The recovery of WEEE is very important both from environmental and economic aspects and has become mandatory in most of the countries in the world. Reverse logistics which is mainly the backward flows of used products from consumers to producers is an important stage while constructing a recovery system. The network structure of reverse logistics system plays an important role in the total cost of the recovery system. These structures mainly include the locations of facilities and the flows between the related points. With this study, a reverse logistics system is designed for WEEE in Turkey which is one of the fast developing countries in the world. Ten scenarios are taken into account regarding different collection rates via a mixed integer linear programming model. Different types of storage sites and recycling facilities are considered within the model differing from the existing studies. The optimum locations of storage sites and recycling facilities are obtained for each scenario satisfying the minimum recycling rates stated by the European Union directive for each product category.

Community participation in household solid waste reduction in Surabaya, Indonesia

Abstract: The goal of this study was to examine the community participation in household solid waste (HSW) reduction and the influencing factors in eastern Surabaya. The research was conducted in three districts, namely Sukolilo, Rungkut, and Tenggilis Mejoyo. The HSW sampling for SW composition analysis was performed over eight consecutive days. Survey concerning community involvement in HSW reduction was conducted in 300 households using stratified random sampling technique. The questionnaires were distributed during HSW sampling for generation rate and composition measurements. Results of this study showed that average HSW generation rate in eastern Surabaya was 0.33 kg/capita/day. The HSW composition was dominated by food waste (64.19%), followed by plastics (10.79%), paper (9.24%) and used diapers (6.97%). The socio-economic characteristics had less influence than the supporting factors on sorting, recycling and composting activities. This study suggested four strategies to support the community participation on HSW reduction in eastern Surabaya. These strategies were: to intensify the HSW reduction training programs; to intensify the information dissemination through mass media and campaign; to increase the number of environmental cadres; and to optimize the existence of waste bank and its function.

Stochastic reverse logistics network design for waste of electrical and electronic equipment

Abstract: In recent years, Reverse Logistics has received increasing attentions in supply chain management area. The reasons such as political, economic, green image and social responsibility etc. force firms to develop strategies to their current systems. The aim of this study is to propose a generic Reverse Logistics Network Design model under return quantity, sorting ratio (quality), and transportation cost uncertainties. We present a generic multi-echelon, multi-product and capacity constrained two stage stochastic programing model to take into consideration uncertainties in Reverse Logistics Network Design for a third party waste of electrical and electronic equipment recycling companies to maximize profit. We validated developed model by applying to a real world case study for waste of electrical and electronic equipment recycling firm in Turkey. Sample average approximation method was used to solve the model. Results show that the developed two stage stochastic programming model provides acceptable solutions to make efficient decisions under quantity, quality and transportation cost uncertainties.

Evaluation of rainwater harvesting in Portugal: Application to single-family residences

Abstract: Because water is a key at-risk resource, improved water management is essential. In terms of quantity, the two major alternatives in water management can be grouped into: (i) improving efficiency in water use; and (ii) exploring alternative water sources. Rainwater harvesting (RWH) is one of the most promising alternative water sources, since rainwater can easily be collected and used without significant treatment for non-potable purposes. However, the economical viability of these systems is not always assured. This paper examines the most relevant technical and economical issues in designing domestic RWH systems, evaluating the technical feasibility and economical viability of this technology in the particular weather and water use in Portugal. The evaluation is performed for a single-family residence, where the water use pattern was monitored. The precipitation pattern is characterized for two locations in Portugal, Porto and Almada, since they represent two different scenarios for RWH. The RWH and water savings efficiency were assessed and payback period estimated for both cities. It was found that, for an optimum rainwater tank, the water savings potential are similar for both locations, despite the differences in the average annual precipitation. A simple rule for estimating the optimum tank capacity for single-family households in Portugal is proposed. A sensitivity analysis shows an important influence of water fees on the economical viability of RWH systems in single-family houses in Portugal, namely when compared to changes in the consumption pattern.

Toward a systematized framework for resource efficiency indicators

Abstract: The transition toward resource efficient production and consumption patterns is currently one of the main challenges in engineering, environmental science and especially in governmental policies. This transition has led to a proliferation of meanings related to the resource efficiency concept, resulting in a wide variety of indicators. In this paper, we propose a systematized framework in which resource efficiency indicators can be structured and comprehensively positioned. The aim is to provide a proper understanding of the scope and limitations of particular existing resource efficiency indicators in order to assist policy makers and the scientific community in the application and further development of indicators. This framework covers all different resource use-related aspects evaluated in existing approaches, including simple accounting of resource extraction and use; environmental impact assessment due to resource extraction and use; accounting and environmental impact assessment of specific processes and of full supply chains; analyses at micro-scale and macro-scale; and analysis of both natural resources versus waste-as-resources. To illustrate the potential application of the framework, a set of currently used indicators was selected, whereupon these indicators were structured and evaluated within the framework.

Social impact assessment of informal recycling of electronic ICT waste in Pakistan using UNEP SETAC guidelines

Abstract: New and improved Information and Communication Technology (ICT) is being produced every day. With every new product on the market, an older product becomes obsolete. These obsolete products are being added to the world's fastest growing waste stream, ICT electronic waste (e-waste). This is formally recycled in developed countries, stockpiled, landfilled or shipped to developing countries, such as Pakistan, here it is recycled informally through crude processes (e.g. manual dismantling, burning, dumping and dipping in acids to extract gold and other precious metals). This study assessed the social impacts of informal e-waste recycling in Pakistan using data obtained in a detailed on-site inventory of the processes directly involved in informal e-waste recycling. The inventory and assessment were conducted according to United Nations Environmental Programme (UNEP) guidelines on Social Life Cycle Assessment (SLCA). The results presented in this paper fill an important data gap and can be integrated with data on other stages of ICT product lifecycle to produce a full SLCA of such products.

Green supply chain management and firms’ performance: Understanding potential relationships and the role of green sourcing and some other green practices

Abstract: This study examines how the adoption of green supply chain management (GSCM) practices, including green sources, affects environmental and operational performance indicators. A multiple-case study was conducted using large Brazilian firms that have achieved particular success in their sectors and that occupy high positions in important rankings of corporate sustainability. The results of the study indicate that the GSCM practice of “internal environmental management” has the greatest positive effect on environmental performance indicators, and that the GSCM practice of “cooperation with customers” has the greatest positive effect on operational performance indicators. Thus, if a company aims to improve environmental performance (EP), it may create procedures and programs based on the environmental management system and adopt cleaner production initiatives. If a company intends to improve its operational performance (OP), it may respond to audits, improve information exchange between companies and clients and build research and development (R&D) areas to promote environmental innovation.

Improving waste management in construction projects: An Australian study

Abstract: Construction waste generation has been identified as one of the major issues in the construction industry due to its direct impacts on the environment as well as the efficiency of the construction industry. As the industry cannot continue to practice if the environmental resources on which it depends are depleted, the significance of waste management needs to be understood in order to encourage stakeholders to achieve related goals. Therefore, this research aims to determine effective approaches to eliminate and/or minimise waste generation in construction projects. Mixed methods were adopted by combining qualitative and quantitative research approaches. Interviews and a questionnaire survey were conducted as the primary data collection methods. The findings reveal twenty six critical solutions for waste management. Five factors of solutions for waste management were extracted from the exploratory factor analysis. These factors were: team building and supervision; strategic guidelines in waste management; proper design and documentation; innovation in waste management decisions; and lifecycle management. The evidence from this study suggests that both technologies and attitudinal approaches require improvement to eliminate/minimise waste generation in construction projects. Similarly, attention should be paid to being mindful of the environmental effects of waste generation and avoiding waste generation as early as possible in construction projects.

Comparative life cycle assessment of concrete road pavements using industrial by-products as alternative materials

Abstract: The construction industry is a major consumer of natural resources and a major contributor to CO2 emissions. As increasing attention is paid to sustainability and resource preservation, current construction practices need to be assessed in terms of environmental performance as well. Currently, the decision making process for pavement construction in Greece is largely based on initial cost, excluding use and maintenance costs as well as environmental performance. Therefore, the use of concrete road pavements is very limited, despite possible technical and financial benefits. In the present paper, a comparative life cycle assessment was carried out for six different concrete road pavements. The parameters for the comparative LCA were three types of binders; a pozzolanic Portland cement, a new hydraulic road binder and a mixed-type binder consisting of Portland cement and fly ash, as well as two different aggregates; crushed limestone and steel slag. Construction, use and maintenance and end-of-life recycling for a period of 40 years were considered for the life cycle assessment. Results show that concrete road pavements with high volume of alternative materials can reduce CO2-eq emissions to a great extent compared to ordinary concrete pavements and, thus, significantly improve their environmental footprint. The transportation distance sensitivity analysis showed that substituting cement with fly ash is environmentally beneficial even when fly ash is transported over long distances, while the emissions from the use of alternative aggregates in concrete are reduced only in limited geographical areas.

Biogas digestate marketing: Qualitative insights into the supply side

Abstract: Managing digestate output and developing a market for the product is a serious challenge for the biogas industry. Without effective strategies for sustainable management, the large volume of digestate produced by biogas plants may cripple the industry and its potential. Through interviews with diverse biogas stakeholders, we examine current approaches to digestate marketing to identify factors that support and those that inhibit its success. We find that marketing to regions with a nutrient demand or into the non-agricultural sector holds promise. Upgraded digestate products offer increased marketability due to their higher nutrient content and lower water content. Fertilizer and soil manufacturers, farmers, horticulturists and private customers all represent markets for digestate. Current disposal prices range from negative to strongly positive, depending on the regional nutrient availability, agricultural structure, season, feedstock and degree of upgrading. Marketers agree that concealing the biogas origin of digestate products is still necessary to avoid negative perceptions by customers. One implication of this is the need for better understanding by marketers of consumer concerns and preferences, and for better education of consumers regarding the safety and benefits of digestate. Overall, we find that opportunities for digestate marketing remain largely unexploited and marketing strategies remain immature. Our findings should prove helpful to current and future digestate marketers.

Benchmarking construction waste management performance using big data

Abstract: The waste generation rate (WGR) is usually used as a key performance indicator (KPI) to benchmark construction waste management (CWM) performance, with a view to improving the performance continuously. However, existing researches, for different reasons, only investigated a relatively small amount of construction projects, whose WGRs cannot be confidently accepted as KPIs. This study develops a set of more reliable KPIs/WGRs using an available big dataset on CWM in Hong Kong. By mining the 2,212,026 waste disposal records generated from 5764 projects in two consecutive years of 2011 and 2012, the WGRs/KPIs are revisited and refined. Demolition is found the most wasteful works. New building, and maintenance and renovation (M&R) works individually produce the least waste amount but by accumulating all M&R works, their contribution to the total amount of construction waste could be phenomenal. Based on the more reliable WGRs from the big data, CWM performance benchmarks for different categories of projects are set up. A contractor can benchmark its CWM performance against its counterparts or its past performance as ‘Good’, ‘Average’, and ‘Not-so-good’, and thus identify better CWM practices that induce superior performance. Based on the benchmarks, the government may consider setting up a WGR-step toll system to encourage those ‘Not-so-good’ contractors to perform well in the future, and initiate incentives to the companies conducting ‘Good’ projects to spur better CWM performance. Overall, the WGRs derived from the big data and more robust analyses provide a very powerful and handy tool for CWM.

Polymer recycling codes for distributed manufacturing with 3-D printers

Abstract: With the aggressive cost reductions for 3-D printing made available by the open-source self-replicating rapid prototypers (RepRaps) the economic advantage of custom distributed manufacturing has become substantial. In addition, the number of free designs is growing exponentially and the development and commercialization of the recyclebot (plastic extruders that fabricate 3-D printing filament from recycled or virgin materials) have greatly improved the material selection available for prosumer 3-D printer operators. These trends indicate that more individuals will manufacturer their own polymer products, however, there is a risk that an even larger fraction of polymer waste will not be recycled because it has not been coded. The current limited resin identification code available in the U.S. similarly restricts closing the loop on less popular polymers, which could hamper the environmental impact benefits of distributed manufacturing. This paper provides a solution for this challenge by (1) developing a recycling code model based off of the resin identification codes developed in China that is capable of expansion as more complex 3-D printing materials are introduced, (2) creating OpenSCAD scripts based on (1) to be used to print resin identification codes into products, (3) demonstrating the use of this functionality in a selection of products and polymer materials, and (4) outlining the software and policy tools necessary to make this application possible for widespread adoption. Overall the results showed that a far larger resin code identification system can be adopted in the U.S. to expand distributed recycling of polymers and manufacturing of plastic-based 3-D printed products.