Waste separation at home: Are Japanese municipal curbside recycling policies efficient?

Recent studies have predicted that the costs and benefits of curbside recycling programs will vary considerably across municipalities. In this paper, we examine how the characteristics of municipalities are reflected in curbside recycling policies. Our analysis of Japanese municipal data reveals that municipalities implement recycling programs that fit the demographic profiles of their residents. Municipalities with a considerable number of single-recycler households tend to implement simple waste separation programs. The labor market positions of spouses have different impacts on recycling policies. We further find that the municipalities implementing comprehensive recycling programs collect plastic bottles and containers more frequently than do other municipalities. This implies that the municipalities need to take measures to effectively execute comprehensive recycling programs after implementing them.     

Moving up the waste hierarchy: Car boot sales,reuse exchange and the challenges of consumer culture to waste prevention

Moving up the waste hierarchy is a key priority for UK waste policy. Waste prevention requires policy interventions to promote reuse. The term ‘reuse exchange’ has been adopted by UK policy makers to describe a variety of second-hand trading outlets including car boot sales, charity shops and online exchange sites. As waste policy is based on tonnage diverted from disposal (or landfill), policy interventions to promote reuse exchange will be based on the weight of goods estimated to be flowing through these sites. This paper uses a combination of field survey data and scale-up estimation to quantify and characterise the weight of goods exchanged at car boot sales in England in 2012. This is estimated at 50–60 000 tonnes per annum. The paper emphasises that movement up the waste hierarchy brings waste policy into closer contact with household consumption practices. It draws on qualitative research to show that, for participants, car boot sales are not associated with waste prevention. Instead, car boot sales rely on stocks of surplus household goods and exemplify the culture of thrift, which enables more, not less, consumption. The paper shows the collision between the social values that inform thrift and the environmental values that underpin reuse; and it argues that the policy goal of enhanced recovery for reuse might best be achieved by working with consumer culture. Two ways of achieving this are suggested: interventions that make it easier for consumers to do the right thing, through promoting opportunities for the circulation of stocks of surplus goods, for example, through increasing the frequency of car boot sales; and interventions which recognise that car boot sales also generate waste, which could be recovered for reuse.     

Relating disposal-based solid waste reduction rates to recycling rates

Some states measure progress in their waste reduction programs on the basis of recycling rates, while others use disposal-based reduction rates. It is generally recognized that these two measures are conceptually distinct. Nevertheless, when informational surveys of waste reduction activities are compiled, the data are usually combined in a manner that blurs this distinction and complicates the issues involved. In this paper, these two concepts are defined in a precise manner and equations are derived which clearly depict the relationship between recycling rates and disposal-based reduction rates. Information from a national survey and the US Environmental Protection Agency is used to illustrate the concepts which are developed in the paper.     

A review on the use of waste glasses in the production of cement and concrete

The use of recycled waste glasses in Portland cement and concrete has attracted a lot of interest worldwide due to the increased disposal costs and environmental concerns. Being amorphous and containing relatively large quantities of silicon and calcium, glass is, in theory, pozzolanic or even cementitious in nature when it is finely ground. Thus, it can be used as a cement replacement in Portland cement concrete. The use of crushed glasses as aggregates for Portland cement concrete does have some negative effect on properties of the concrete; however, practicle applicability can still be produced even using 100% crushed glass as aggregates. The main concerns for the use of crushed glasses as aggregates for Portland cement concrete is the expansion and cracking caused by the glass aggregates. This paper summarizes the progresses and points out the directions for the proper uses of waste glasses in Portland cement and concrete.     

An interval-based regret-analysis method for identifying long-term municipal solid waste management policy under uncertainty

In this study, an interval-based regret-analysis (IBRA) model is developed for supporting long-term planning of municipal solid waste (MSW) management activities in the City of Changchun, the capital of Jilin Province, China. The developed IBRA model incorporates approaches of interval–parameter programming (IPP) and minimax–regret (MMR) analysis within an integer programming framework, such that uncertainties expressed as both interval values and random variables can be reflected. The IBRA can account for economic consequences under all possible scenarios associated with different system costs and risk levels without making assumptions on probabilistic distributions for random variables. A regret matrix with interval elements is generated based on a matrix of interval system costs, such that desired decision alternatives can be identified according to the interval minimax regret (IMMR) criterion. The results indicate that reasonable solutions have been generated. They can help decision makers identify the desired alternatives regarding long-term MSW management with a compromise between minimized system cost and minimized system-failure risk.     

合成树脂行业固体废物产生节点及环境管理分析

2020年9月1日修订实施的《中华人民共和国固体废物污染环境防治法》在工业固体废物管理中强化了企业自主管理,并提出全过程管理要求。合成树脂行业在我国工业领域中占有重要位置,从事生产的企业以大型石化企业为主,其有能力也有责任科学管理固体废物,以实现固体废物无害化、减量化、资源化。阐述了合成树脂行业中聚乙烯、聚丙烯和聚氯乙烯的生产工艺过程和生产环节特点,详细介绍了固体废物的产生节点、废物属性及管理措施,对所产生的固体废物进行分类梳理,总结企业固体废物处理处置措施,并针对合成树脂行业固体废物产生现状提出管理建议,以期为我国危险废物环境管理及《国家危险废物名录》动态修订提供科学依据,也为企业自主管理方式提供指导方向。     

城市生活垃圾的处理方法及应用

本文从我国城市生活垃圾的危害入手,结合当前城市生活垃圾处理现状分析,提出了几点能有效提升城市生活垃圾应用的处理方法。     

Physical and chemical characteristics of waste activated sludge treated with electric field

This study investigates the physical and chemical characteristics of sludge treated with controlled levels of electric field. The results indicated that the potential gradient and contact time strongly influenced the physical and chemical characteristics of sludge. Based on the settling velocity measurements, a potential gradient of 6 V/cm with a treatment time of 10 min is recommended as an optimal condition for improving sludge settling. For sludge disintegration, applying a higher potential gradient and a longer treatment time to the sludge are more efficient than applying lower levels. The results of the experiments presented here show that an electric field not only disintegrates sludge and destroys microbial cells but also removes and solubilizes organic substances. Possible mechanisms of electric field treatment are also discussed.     

Use of recycled plastics in wood plastic composites – A review

The use of recycled and waste thermoplastics has been recently considered for producing wood plastic composites (WPCs). They have great potential for WPCs manufacturing according to results of some limited researches. This paper presents a detailed review about some essential properties of waste and recycled plastics, important for WPCs production, and of research published on the effect of recycled plastics on the physical and mechanical properties of WPCs.