Waste Management & Research: The Journal for a Sustainable Circular Economy

Home composting (HC) is recognized by both local and national Governments for its contribution to reducing household waste disposal in landfill. However, the quantitative impact of HC on the diversion of household waste from landfill is uncertain. An overview of key results is presented from a 3-year research programme on HC in the West London area of Runnymede Borough Council (RBC), Surrey, UK. The amount of biodegradable household waste diverted from landfill disposal by HC was measured in a 2-year monitoring study involving 64 homeowners. The total average annual waste input to a standard 290 L HC bin was approximately 370 kg per household. The average relative mass inputs of kitchen, paper and garden waste were 29, 2 and 69%, respectively. A survey of the study area indicated that approximately 20% of households were engaged in HC and, based on inputs to HC bins, this corresponded to an overall recycling/diversion rate equivalent to 20% of household biodegradable waste. Temperature and gas composition measurements indicated organic matter decomposition by HC was aerobic and only traces of CH₄ were occasionally detected. A field trial examined the end-use of composted products for the growth of Petunia grandiflora. Flower production increased with home-produced composts in comparison with peat-amended or untreated control soil. Compost chemical composition, bioaerosol emissions and vector attraction were also investigated.

In the urban—rural fringe of the Bangkok Metropolitan Region, rapid urbanization is creating a land-use mixture of agricultural fields and residential areas. To develop appropriate policies to enhance recycling of municipal solid waste (MSW), current MSW management was investigated in the oboto (local administrative district) of Bang Maenang in Nonthaburi Province, adjoining Bangkok. The authors conducted a structural interview survey with waste-related organizations and local residents, analysed household waste generation, and performed global positioning system (GPS) tracking of municipal garbage trucks. It was found that MSW was collected and treated by local government, private-sector entities, and the local community separately. Lack of integrated management of these entities complicated waste flow in the study area, and some residences were not served by MSW collection. Organic waste, such as kitchen garbage and yard waste, accounted for a large proportion of waste generation but was underutilized. Through GPS/GIS analysis, the waste collection rate of the generated waste amount was estimated to be 45.5— 51.1% of total generation.

The study examined the determinants of willingness-to-pay for private solid waste disposal systems by urban households in Ibadan, Nigeria. A multistage random sampling technique was used to select 552 households for the study. Data obtained from survey were analysed using a logit model-based contingent valuation. Evidence from the logit model indicated that seven variables had significant influence on the households’ willingness-to-pay. Of these, income and asset owned were positive and significant at P < 0.01 but amount of willingness-to-pay and firm services were negative and significant at P < 0.01. Education and occupation were positive and significant at the P < 0.05 level while age was negative and significant at P < 0.10. The implication is that households have certain socio-economic characteristics, which influence their willingness-to-pay for solid waste disposal. The study recommends government intervention in a variety of forms such as encouraging public—private participation in solid waste disposal, an aggressive environmental clean-up campaign, decentralization of Waste Management Boards and privatization of some aspects of waste management to ameliorate solid waste problems and improve health.

The aim of this investigation was to determine odorous compounds in the air over the landfill sites in France and Poland. Air samples were collected by passive and dynamic methods of preconcentration analytes and analysed by GC-MS and GC-FID. The coupling µTD-µGC-MS was also used for on-site analysis of odorous compounds. The achieved results indicated that the concentrations of odorants in the air varied and strongly depended on the sampling site. The highest concentrations were observed at the points situated near biogas wells and above the fresh waste layer. The concentrations were influenced by landfill activities such as failures of the landfill gas collection system, heavy truck traffic, machinery operations and compacting fresh waste.

Coal fly ashes (CFA) are generated in large amounts worldwide. Current combustion technologies allow the burning of fuels with high sulfur content such as petroleum coke, generating non-CFA, such as petroleum coke fly ash (PCFA), mainly from fluidized bed combustion processes. The disposal of CFA and PCFA fly ashes can have severe impacts in the environment such as a potential groundwater contamination by the leaching of heavy metals and/or particulate matter emissions; making it necessary to treat or reuse them. At present CFA are utilized in several applications fields such as cement and concrete production, agriculture and soil stabilization. However, their reuse is restricted by the quality parameters of the end-product or requirements defined by the production process. Therefore, secondary material markets can use a limited amount of CFA, which implies the necessity of new markets for the unused CFA. Some potential future utilization options reviewed herein are zeolite synthesis and valuable metals extraction. In comparison to CFA, PCFA are characterized by a high Ca content, suggesting a possible use as neutralizers of acid wastewaters from mining operations, opening a new potential application area for PCFA that could solve contamination problems in emergent and mining countries such as Chile. However, this potential application may be limited by PCFA heavy metals leaching, mainly V and Ni, which are present in PCFA in high concentrations.

In an era of global warming, rising energy costs and increasing volumes of wastes destined for landfills and incinerators, communities should set up environmentally sustainable services that are cost-effective for their citizens and revenue generators for municipalities. A win-win garbage collection and kerbside recycling program established more than eight years ago in a small rural community in Ohio, US is still going strong. It is offering a relatively inexpensive way for waste disposal by providing an incentive-based and highly participatory kerbside recycling and at the same time bringing in substantial franchise fees for the municipal coffers. Unlike garbage contracts in most communities that are designed for only residential waste collection, this program extends disposal and recycling services to non-residential establishments. It picks up hard-to-dispose household furniture, appliances and other bulky items without additional costs to the residents. By being creative and assessing local political and socio-economic milieu, public officials can implement a comprehensive service package for taking care of their community throwaways. However, before establishing such programs in partnership with a private firm, city administrators must understand the intricacies of bid specifications customized for municipal wastes and recyclable materials.

Across India, all small and large urban local bodies (ULB) alike are grappling with the problem of municipal solid waste (MSW), which has reached critical dimensions because of, among others, rapidly increasing quantities and complex characteristics, inadequate regulation, lack of awareness, concern and cooperation on the part of the urban residents, limited resources for collection, transport and safe disposal, and limited expertise on the part of the ULBs. A number of ULBs have attempted to address the two-fold constraint of resources and land by setting up treatment plants under the premise of generating revenue and reducing liability of safe disposal. Over the last three decades, under the paradigms of converting ‘waste to energy’ and ‘waste to wealth’ various technologies have been tried out, however time and again it is seen that irrespective of the technology, MSW treatment plants run in to difficulties and/or close down. The issues do not pertain just to technology but are systemic and encompass project development, feedstock delivery system including quality and quantity, climate, high life-cycle costs, low value realization on outputs and adverse environmental and social impacts. With such a wide range of risk factors, experience has shown that the probability of manifestation of any one of them or a combination thereof at one or the other stages of the project is quite high. Investment in a mixed MSW treatment plant therefore can not deliver positive financial returns, rather it can become a non-performing asset without even guaranteeing the desired environmental and public health benefits. This paper therefore argues for the adoption of a robust, elastic and most forgiving option of sanitary landfill as a dependable and safe disposal system for MSW.

We present the development stage of the sanitary landfills in Brazil in the context of urban solid residue management, demonstrating the necessity and importance of the employment of economic models. In the article, a cost estimate model is proposed as the basis for studies to be applied by sector management, including the city council, companies, consultants and engineers, contributing to the choice of new areas, public bids, municipal consortia and private public partnerships.