Waste Diversion Rates Research Articles

Double-Stage Anaerobic Digestion for Biohydrogen Production: A Strategy for Organic Waste Diversion and Emission Reduction in a South African Municipality

Landfilling of organic waste poses a significant environmental threat, heavily contributing to climate change. The diversion of waste is imperative, but pathways to implementing alternative waste management strategies are needed. Double-stage anaerobic digestion has been identified as a potential technique that can reduce greenhouse gas emissions and diminish the amount of waste landfilled. Still, further research is needed before its implementation at the municipal level. This paper explored the potential insertion of double-stage anaerobic digestion into the portfolio of alternative treatment methods using the case study of the eThekwini Municipality in Durban, South Africa, by proposing a source-separation waste management scheme and forecasting the organic waste generation for a 24-year timeframe until 2050. The WROSE model has been identified as the ideal tool for the analysis. A new scenario, including double-stage anaerobic digestion, has been introduced in WROSE after developing a country-specific emission factor. The technology has been assessed against similar techniques, namely anaerobic digestion and composting, according to the environmental indicators included in WROSE. Compared with the business-as-usual scenario and three other alternatives, the new scenario proved to be the second-most effective (−282% versus business-as-usual) after anaerobic digestion (−291%) in reducing climate-altering emissions, achieving analogous waste diversion rate (10.09%), landfill airspace (1,653,705 m3), and monetary savings (3.8 billion Rand) compared to composting and anaerobic digestion.

Assessing non-hazardous solid waste business characteristics of Western Canadian provinces

This study addresses a gap that exists in studying waste business characteristics and the performance of a waste management system (WMS). Temporal and spatial analyses of the WMS in four Western Canadian provinces are systematically assessed over a 16-year period. The average waste business size in Canada ranged from 13.4 to 22.1 employees per business. Jurisdictions with lower disposal rates generally have larger waste companies. An average employee handled 1098 to 1426 t of waste annually. The diversion rates tended to be higher when less waste is managed per employee, suggesting total employee count may be important to improve WMS sustainability in Canada. Waste transfer costs are substantial during the study period, totaled $1276 million annually, or about 40.7% of the total government waste spending. BC only spent an average of 2.5% of the budget on operation of recycling facilities, but has the highest waste diversion rate. Expenditure distribution alone is unable to explain BC's superior waste diversion performance. Capital expenditures have been increasing from $15.7/t to $26.2/t. In this study, a business with more full-time employees correlates well with higher operating revenues. Part time workers were more predominant in SK, and may be responsible for the subpar diversion rate and operating revenue. More research is needed to determine waste business characteristics given increasing interest in circular economy and WMS efficiency.

THE IMPACT OF LANDFILL DIVERSION ON LAND USE AND LIFESPAN: A CASE STUDY OF THE BOUGHAREB TECHNICAL LANDFILL CENTRE IN CONSTANTINE, ALGERIA

Land filling is one of the most common methods of disposing of solid waste all over the world, however, with constantly increasing waste volumes and land scarcity, waste diversion and recovery are more likely the best answer to these concerns. This research paper presents an estimation of the diversion impact on the required land area and on the lifespan of a technical landfill centre (TLC) in Constantine, Algeria. Our methodology consists in drawing up three scenarios of operation of TLC, over a period of 15 years, with each scenario, applying a different waste diversion rate, results show that: waste diversion reduces land consumption and increases the TLC's lifespan in all three scenarios but diverting for composting is the most efficient one.

Mini-review of waste sector greenhouse gas and short-lived climate pollutant emissions in Tyre Caza, Lebanon, using the Solid Waste Emissions Estimation Tool ('SWEET').

In 2020, International Solid Waste Association's (ISWA) Task Force on Closing Dumpsites completed a study of waste sector short-lived climate pollutants (SLCPs) and other greenhouse gas (GHG) emissions in Tyre Caza, Lebanon, using the Solid Waste Emissions Estimation Tool (SWEET). SWEET model runs used data on municipal solid waste (MSW) generation, collection, disposal, and diversion under existing and potential alternative management scenarios proposed in an Integrated Waste Management Plan (IWMP) for Tyre Caza. Waste sector emissions reductions exceeding 45% of baseline levels are achievable by 2030 if all dumpsites are closed and remediated, waste burning stopped, and a new sanitary landfill developed with 60% methane collection and combustion. Additional emissions reduction accrues from implementing the IWMP and upgrading existing waste treatment facilities to increase waste diversion rates from current levels (22% including informal sector recycling) to 40%. Estimates of all of Lebanon's waste sector emissions using SWEET were developed for this mini-review article using published data on the amounts of MSW collected, disposed, and diverted, with adjustments to account for indirect GHG reductions from composting and anaerobic digestion (AD). A 50% reduction in emissions from baseline levels can be achieved by 2034, if by 2025 diversion of collected wastes to recycling, composting, and AD facilities is increased from 14% to 28%, and all residual MSW is disposed in sanitary landfills with 65% methane recovery.

Buyback centres in Cape Town: the key integration point between formal and informal sectors in the waste economy of the Western Cape

South Africa’s waste diversion rate from the landfills is low (11%) and leaves room for growth in the South African recycling industry to contribute to job creation, poverty alleviation, enterprise development and economic growth. The waste economy’s value chain is multi-layered with buyback centres (BBCs) as the point of convergence for informal and formal sector actors in the recycling economy. BBCs connect the informal sector actors of the recycling economy with the more formal activities. Despite this role, BBCs have not been a focus of research. This study investigated the facilitating role of BBCs as the link between the formal and informal sectors of the waste economy—using the City of Cape Town as a case study. A concurrent mixed-method design was chosen for this study. Fifty-three BBCs were surveyed in 2018. These BBCs employed 971 people and accepted material from approximately 5500 collectors, including an estimated 3000 waste pickers—supporting as many as 15,000 people. The BBCs collectively sold 17,100 tonnes recyclables in an average month, constituting about R25.7 million in material value and a monthly landfill airspace saving of 41,800 m3. BBCs facilitate informal livelihoods and contribute directly and indirectly to the formal waste economy. Two key areas for research were identified: the evolution and business models of BBCs and a holistic analysis of the waste management system and policies of cities such as Cape Town for policies to be more supportive and inclusive of BBCs.

Investigation of waste diversion rates in the construction and demolition sector in Australia

PurposeWaste diversion rate (WDR) is a key indicator of effective waste management and circular economy. However, it has not yet been widely used in the construction and demolition waste (C&DW) sector. This study aims to promote the application of WDR as an effective measure for waste management through the investigation of the current status of C&DW diversion in the Australian construction industry.Design/methodology/approachA mixed-method approach, which combines a desk study and a case study of 12 residential projects was used in this study. Data retrieved from the National Waste Database (NWD) were used for the descriptive analysis.FindingsThe analysis of the national waste data revealed that the national average WDR in Australia is 64%. WDR varies based on material types and across the states. The analysis facilitated the forecasting of the possible future trend of waste diversion in Australia. The studied projects from two states in Australia presented slightly different results. Most of the waste stream, except mixed waste, presented above 95% of WDR in each project.Research limitations/implicationsAlthough the studied projects showed a higher recycling rate, this study claims that achieving a higher rate of recovery by diverting the waste could not be assured unless accurate estimation is carried out with reliable and verifiable data. Lack of reliable data is considered as the limitation of this study. While the scope of descriptive analysis of waste generation and diversion covers the whole country, the case study analysis is limited to the states of New South Wales and Victoria.Originality/valueThe study highlights the significance of WDR in assessing the performance of effective waste management in the C&DW sector. WDR is a comprehensive measure that takes the output of the waste life cycle into account for benchmarking waste management. The results provide a critique of the current practices of waste management and the essence of the consistent, transparent and verifiable waste data to enable accurate WDR estimation in Australia. The outcome is useful for waste managers and policymakers in developing potential waste management strategies and C&DW specific legislation for building a more ecologically sustainable industry.

Nitrogen and phosphorus flows in Ontario’s food systems

Resource scarcity, energy requirements, and environmental pollution resulting from the production and use of nitrogen (N) and phosphorus (P) fertilizer have spurred an interest in a circular approach to nutrient management. An analysis of N and P flows in Ontario’s food systems was carried out to quantify relevant flows and stocks, evaluate alternative management scenarios and identify points of loss to the environment. The results showed that mineral fertilizers accounted for 42 % of N and 90 % of P inputs to Ontario’s food systems. Of the total amount of food produced, 153 kt-N/y ± 27 % and 28 kt-P/y ± 21 % in grain and oilseed were fed to animals. About 58 % (298 kt-N/y) and 29 % (15 kt-P/y) of the annual supply of N and P were lost to the environment. Major nutrient losses were from the crop production system, through erosion, contributing 35 % (103 kt-N/y ± 10 %) and 90 % (14 kt-P/y ± 51 %) of the total N and P lost. Over half of the N and P in the waste subsystem was disposed of in landfills or incinerators, where further N losses occurred through leaching and volatilization. Ontario’s reliance on inorganic fertilizer supply could reduce by 28 kt-N/y and 9 kt-P/y if the current waste diversion rates were to increase by 30 %. No single waste management scenario could effectively circularize N and P flows in Ontario’s food system. However, investment in new technologies might help to recover nutrients from manure and wastewater treatment systems efficiently.

Coordinative Urban-Rural Solid Waste Management: A Fractional Dual-Objective Programming Model for the Regional Munifcipality of Xiamen

A linear fractional programming based solid waste management planning model was proposed and applied to support the planning of urban-rural solid waste management in Xiamen, China. The model could obtain the best system efficiency while solving the tradeoff between economic and environmental objectives. It aimed to effectively address the urban and rural solid waste management planning through minimizing the system cost and optimizing system efficiency in the developed model framework. Through the model, the optimal waste flow for each facility was obtained, and the problem of overburdened landfill in Xiamen’s urban and rural solid waste management system was solved. The solutions for waste allocation and facility capacity expansion were provided for Xiamen’s urban and rural solid waste management. The planning results showed that about 42.44 × 106 tons of waste would be diverted to other facilities from landfills over the planning period of 2018-2032, and the waste diversion rate would reach 97%, which would greatly reduce the burden on landfills. The economic efficiency of waste diversion would be 5.07 × 103 ton per 106 RMB. All the capacities of Xiamen’s urban and rural solid waste management facilities including incinerators, composting plant, and landfills should be expanded because of increasing waste production rate.

Nudging waste diversion at Western State Colorado University: application of behavioral insights

PurposeThis paper aims to test a nudge, or intervention, designed through behavioral insights at a university campus to discover cost-effective means for increasing recycling participation and methods for estimating waste removal cost savings.Design/methodology/approachA series of studies were conducted demonstrating the effectiveness of behaviorally based recycling interventions. Study locations included an academic building, a performing arts/studio arts building, a sports complex and a campus library. All locations already had robust and visible recycling programs in operation. Following an observation period, modifications were made to the locations of waste and recycling containers. Waste auditing procedures were used to quantify existing waste diversion rates, and changes to those rates following changes in choice architecture.FindingsWaste diversion rates improved and significant reductions in the proportion of recyclable materials in the trash were observed at all four study locations. Results indicate that the nudge of changing choice architecture can enhance recycling programs that are already recognized as successful. This paper also explains methods for estimating waste removal, which are important as it enables calculations of cost savings from such interventions. Finally, targeting plastic bottles to increase return on investment is recommended.Practical implicationsOther colleges and universities can apply these methods to improve existing recycling programs and realize cost savings.Originality valueThis is the first study to investigate the use of a nudge on waste management issues on a university campus. An easy-to-replicate method, which allows measuring realized cost savings, is explained.

Public Perceptions and Practices of Solid Waste Recycling in the City of Laramie in Wyoming, U.S.A.

Managing household solid waste is a growing challenge for many cities. To tackle this problem, cities are turning to recycling, which is an effective tool for solid waste management. This research seeks to understand the public perceptions and practices of recycling in the City of Laramie, Wyoming. Recycling in Laramie began in 1983 with the establishment of the Ark Recycling Center. Laramie officially started its curbside recycling services in September 2011, and in April 2012 the city declared its long-term goal to achieve a 40% diversion rate by 2030. The study involved a mail-back survey to understand the public participation landscape and the factors affecting recycling behaviors and attitudes of residents in Laramie. The quantitative results of the survey responses were used to create a civic engagement score, a recycling importance score, and recycling satisfaction and recycling behavior scores to measure residents’ perceptions of the recycling program. In addition, three key informant interviews were conducted to explore the efforts of the city, the University of Wyoming, and Ark Regional Services. The results show that more than 80% of the survey respondents indicated that environmental concern was the major motivation to recycle, which was related to a high level of recycling importance and satisfaction. The study further indicated that Laramie should develop an aggressive educational policy, incentive policies, and a Master Plan to encourage stronger public participation to meet its 40% waste diversion rate by 2030 goal.

A Waste of Space -Solutions to Ontario's Landfill Problems

Canada is one of the countries that produce hundreds of kilograms of waste per captia, a number that continues to increase steadily each year. In 2007, our country generated twice as much waste as Japan. Major cities in Ontario, such as Toronto and Ottawa, are facing issues of their landfills reaching its capacity within the next decade. I will research the waste management practices of countries that have a high waste diversion rate and analyze how these practices can be incorporated into Ontario’s regulations. The countries I will discuss the background of the practices are Sweden and Finland because of the similarities to Ontario. Each technology and method used will be analyzed, and a discussion will follow on the applicability of use in Ontario.

Environmental Sustainability through Textile Recycling

The paper examines the process of achieving environmental sustainability through recycling of textile wastes. The recycling of textile waste can serve as a means of providing solutions to many economic, environmental and social issues. Though textile recycling has old history; in recent years it has assumed prime importance due to Fast Fashion culture in western world which has resulted in over consumption of textiles and corresponding waste generation. Today waste recycling has become a multibillion industry. Innovations are being made in terms of development of sorting machines, design inputs, innovative high value products to make recycling a profitable proposition. The paper also highlights in brief the efforts being made by various agencies and stake holders to achieve the aim of present 15% textile waste diversion rate to 75% diversion.

Impacts of Pay-As-You-Throw and Other Residential Solid Waste Policy Options: Southern Maine 2007–2013

Municipal solid waste management in the U.S. began a transformation in the 1980s as a result of a U.S. Environmental Protection Agency regulation requiring the closure of municipal “dumps.” This legislation, coupled with increasing total and per capita waste, resulted in waste management receiving national attention. Maine and other states began broad efforts to reduce and wisely manage their municipal solid wastes. Many states established solid waste goals, with Maine targeting a waste diversion rate of 50 percent. Four common residential waste management programs in Maine include curbside trash collection, curbside recyclable collection, single-stream recycling, and pay-as-you-throw programs. This article provides estimated impacts from these programs. Pay-as-you-throw, curbside collection of recyclables and single-stream recycling are found to increase the percentage of recycling, while curbside trash collection is found to decrease the percentage of recycling.

Measuring waste management performance using the ‘Zero Waste Index’: the case of Adelaide, Australia

Adelaide is one of the high-consuming cities of the world that has developed and implemented a zero waste strategy to achieve optimum resource recovery from waste. Many similar cities are adopting a zero waste strategy with a key goal of 100% diversion rate of waste from landfill. This study argues that achieving a 100% diversion rate will be inadequate and does not reflect the core concept of the zero waste philosophy. In a previous study, the Zero Waste Index (ZWI) was presented as an alternative waste management performance assessment tool for zero waste management systems. The ZWI is a new indicator to measure and compare virgin material replacement by urban zero waste management systems. In addition, the ZWI quantifies energy, material and water conservation through recycling efforts rather than simply measuring waste diverted from landfills. In the current study, waste management performance in Adelaide during the years 2003–2010 is analysed using the proposed Zero Waste Index tool and thereby Adelaide's performance in waste management in 2015 and 2020 is predicted. The study indicates that waste composting is increasing significantly in Adelaide and by 2015 the amount of waste composted should be higher than that going to landfill. For this reason, the biological waste treatment infrastructure, particularly in waste composting facilities, should be stimulated in Adelaide. In addition, the study identifies that despite the zero waste strategy being in place, overall waste management performance in Adelaide may not reach the targeted zero waste goals, particularly in optimum resource recovery from waste. The projected results indicate that by 2020, if similar waste diversion rates continue, Adelaide should have reached a diversion rate of over 82% of municipal solid waste from landfill and the Zero Waste Index would then be 0.45 (around 45% material substitution from its current ZWI = 0.41 with a 72% diversion rate). The study also involved an online survey on the views of local waste experts in metropolitan Adelaide. By combining the waste performance and survey findings, the study identifies the most important priority areas for future waste management strategies in Adelaide.

Strategic municipal solid waste management: A quantitative model for Italian regions

Current economic crisis brought to light the structural deficiencies of European economy. This paper aims to improve the performances of a policy on sustainable municipal solid waste management strategies. Specifically, the attention is focused on Italian country that reports a high rate of landfilling. Waste to Energy plant is an attractive technological option in municipal solid waste, but it is a subject of intense debate. Incinerators require effective and efficient controls to avoid emissions of harmful pollutants into the air, land and water, which may influence human health and environment.To address waste management situation, this study uses a multi-objective mathematical programming. A new plan is presented to evaluate and quantify the effects of initiatives for diversion of current waste from landfill. In an attempt to better simulate realistic waste management scenarios, the amount of waste generated is not annually constant and changes are accounted in waste diversion rates. Moreover, due to the geographical characteristics of Italy, the realization of new facilities is replicated with a regional detail. In this paper economic and financial indicators are used to define the profitability of waste facilities. Moreover, a sensitivity analysis is used to test some of the initial assumptions. Once identified the efficient Waste to Energy plant, regional strategies of waste management are proposed to optimize financial and environmental benefits of the sector. The proposed waste management framework provides a concrete scheme for future research in assessing quantitatively the effectiveness of waste management.

The zero waste index: a performance measurement tool for waste management systems in a ‘zero waste city’

Waste is the symbol of inefficiency of any modern society and a representation of misallocated resources. Significant progress has been achieved in reducing waste but it varies from city to city. Currently, cities use their waste diversion rate as a tool to measure the performance of their waste management systems. However, diversion of waste from landfill does not give a holistic picture of zero waste performance. This paper conceptualises the concept of the ‘zero waste city’ and proposes a new tool to measure the performance of waste management systems called the ‘zero waste index’. The zero waste index forecasts the amount of virgin materials, energy, water and greenhouse gas emissions substituted by the resources that are recovered from waste streams. Three high consuming cities (Adelaide, San Francisco and Stockholm) were analysed using the zero waste index. The zero waste indexes in Adelaide, San Francisco and Stockholm were found to be 0.23, 0.51 and 0.17 respectively (i.e. around 23%, 51% and 17% of resources were recovered and potentially substituted for virgin materials). In addition, the zero waste index estimated the potential energy, greenhouse gas (GHG) and water savings due to resource recovery from municipal solid waste in each of the three cities. It is evident that the zero waste index is an innovative tool to assess waste management performance and materials substitution by waste management systems in different cities.

Greenhouse gas impact of dual stream and single stream collection and separation of recyclables

Over the past decade communities and municipalities have been increasingly switching their recycling systems from dual stream (DS) to single stream (SS). Accordingly, material recovery facilities (MRF) have been constructed and retrofitted in order to accommodate fully commingled input streams. This transition has been driven by a variety of factors, including a general understanding that SS tends to result in increased waste diversion rates for participating communities. This paper examines the greenhouse gas emissions, or “carbon footprint,” of recycling systems before and after the transition from DS to SS. This investigation aims to assess the environmental impact of trends in the recycling industry from a holistic perspective. In our analysis we consider several communities around the U.S. on the bases of tonnage and type of material recycled, fuel and electricity consumed in collection and separation, and avoided virgin materials consumption. By examining data from a small range of communities and MRF, we arrive at three main conclusions. First, a change from DS to SS results in approximately a 50% increase in production of recyclable commodities. Second, the net result of the DS–SS transition is approximately 710kgCO2-equiv. avoided per metric ton of collection. Third, the emissions associated with collection and MRF operation are small in comparison to avoided emissions from avoided consumption of virgin materials.

The environmental comparison of landfilling vs. incineration of MSW accounting for waste diversion

This study evaluates the environmental performance and discounted costs of the incineration and landfilling of municipal solid waste that is ready for the final disposal while accounting for existing waste diversion initiatives, using the life cycle assessment (LCA) methodology. Parameters such as changing waste generation quantities, diversion rates and waste composition were also considered. Two scenarios were assessed in this study on how to treat the waste that remains after diversion. The first scenario is the status quo, where the entire residual waste was landfilled whereas in the second scenario approximately 50% of the residual waste was incinerated while the remainder is landfilled. Electricity was produced in each scenario. Data from the City of Toronto was used to undertake this study. Results showed that the waste diversion initiatives were more effective in reducing the organic portion of the waste, in turn, reducing the net electricity production of the landfill while increasing the net electricity production of the incinerator. Therefore, the scenario that incorporated incineration performed better environmentally and contributed overall to a significant reduction in greenhouse gas emissions because of the displacement of power plant emissions; however, at a noticeably higher cost. Although landfilling proves to be the better financial option, it is for the shorter term. The landfill option would require the need of a replacement landfill much sooner. The financial and environmental effects of this expenditure have yet to be considered.

A two-stage support-vector-regression optimization model for municipal solid waste management – A case study of Beijing, China

In this study, a two-stage support-vector-regression optimization model (TSOM) is developed for the planning of municipal solid waste (MSW) management in the urban districts of Beijing, China. It represents a new effort to enhance the analysis accuracy in optimizing the MSW management system through coupling the support-vector-regression (SVR) model with an interval-parameter mixed integer linear programming (IMILP). The developed TSOM can not only predict the city's future waste generation amount, but also reflect dynamic, interactive, and uncertain characteristics of the MSW management system. Four kernel functions such as linear kernel, polynomial kernel, radial basis function, and multi-layer perception kernel are chosen based on three quantitative simulation performance criteria [i.e. prediction accuracy (PA), fitting accuracy (FA) and over all accuracy (OA)]. The SVR with polynomial kernel has accurate prediction performance for MSW generation rate, with all of the three quantitative simulation performance criteria being over 96%. Two cases are considered based on different waste management policies. The results are valuable for supporting the adjustment of the existing waste-allocation patterns to raise the city's waste diversion rate, as well as the capacity planning of waste management system to satisfy the city's increasing waste treatment/disposal demands.

RECYCLING IN MULTIFAMILY DWELLINGS: DOES CONVENIENCE MATTER?

Factors that decrease the time cost of recycling have significant positive correlations with recycling rates in multifamily dwellings (MFDs). Waste-management experts have previously used anecdotes to infer a link between convenience and waste-diversion rates in MFD recycling programs. This article confirms and quantifies that link by applying probit and double-censored tobit analysis to survey data from 214 households in Urbana, Illinois. We find a strong connection between recycling rates and the perceived presence of adequate interior space for processing recyclables, and distance to recycling bins affects container-recycling intensity. The results have implications for cost-effective design of MFD recycling programs.(JEL DI, Q2)