中水回用在沈阳市的应用前景分析

沈阳是一个水资源严重短缺的城市,研究中水回用对缓解沈阳用水紧张和节约水资源都有积极的意义。文章研究了沈阳市中水回用的必要性、可行性、现状和制约因素,进而提出了推进沈阳中水回用的有关对策。     

化肥废水零排放工程实践

采用吹脱-A/O一体生化工艺对化肥废水进行处理,设计水量1800m3／d。进水NH3-N质量浓度为762mg／L,处理后的出水水质达到GB13458—2001《合成氨工业水污染排放标准》（中型一级）,全部回用车间作为循环冷却水,污水零排放。     

尿素深度水解废液直接回用技术应用总结

尿素生产工艺废水经过解吸、水解后,仍含有0．3％尿素和0．07％氨,采用除铁、催化、除氧并加药控制后的水质完全达到低压蒸汽锅炉用水标准。新工艺技术投入使用后,设备不腐蚀、不结垢,而且维修和运行费用低,实现了尿素工艺废水的零排放,可以在同类企业中推广应用。     

Identifying implementation gaps in water recycling policy of Beijing municipality

ABSTRACT

Due to its dry climate, growing population, and overexploited groundwater, China’s capital is plagued by water scarcity. Since the late 1980s, Beijing has adopted water reuse solutions to bring relief; today, however, the intentions of these reuse policies are often not reflected in practice. Three significant implementation gaps exist: lack of use of installed decentralized reuse systems, limited understanding of the operation of decentralized treatment plants by operators, and inadequate service of centralized reuse treatment systems. By understanding the cause, impact, and severity of these gaps, Beijing’s policymakers can work to meet existing needs via a range of municipal and national policy-driven actions.

AbbrevationBWA Beijing Water AuthorityCECEPChina Energy Conservation and Environmental Protection GroupCNY Chinese yuanIPEInstitute of Public and Environmental AffairsENGOEnvironmental non-governmental organizationMACMunicipal Action CommitteeMEEMinistry of Ecological Environment MEP Ministry of Environmental ProtectionMEPBMunicipal Bureau of Environmental ProtectionMNRMinistry of Natural ResourcesOECDOrganization for Economic Cooperation and DevelopmentO&MOperation and maintenanceSNWTPSouth-North Water Transfer ProjectSOEState-Owned Enterprise     

Assessing determinants of industrial waste reuse: The case of coal ash in the United States

Devising effective strategies to facilitate waste reuse depends on the solid understanding of reuse behaviors. However, previous studies of reuse behavior have been limited in scope, focusing mostly on household recycling behaviors or very limited types of industrial wastes. To gain a better understanding of the business reuse behaviors, this study examined the impact of various factors in technical, economic, regulatory, and behavioral categories in the case of coal ash generated in the United States. The results of fixed effect models for fly ash and bottom ash particularly showed the significance role of the behavioral factor. In both models, a proxy variable, which represents knowledge sharing among the power plants or the utility's decision-making, turned out to be statistically significant and had the largest coefficient estimates among a group of variables. This finding may imply that the characteristics of waste reuse behavior are determined more by business decision-making behaviors than by market or institutional factors. However, the role of the behavioral variable was stronger in the bottom ash models than in the fly ash models. While the reuse of bottom ash was determined primarily by the behavioral variable, fly ash reuse was determined by more diverse factors including economic and regulatory variables. This could be explained by material characteristics in relation to competing resources and the nature of reuse applications.     

Decision factors for e-waste in Northern Mexico: To waste or trade

Currently, around the globe, environmental and social problems derive from the inappropriate recycling of electronic products. Moreover, improper recycling is not the only issue to address in electronic products. Others include: energy intensity in their manufacture, employment generation related to the international trade in used electronics, and access to technology by low-income communities. Nevertheless, policies and controls created to provide socially and environmentally sound management of used electronics do not match the complexity of the system. In order to understand the e-waste system, particularly used computers, as a whole, a field study was done between 2010 and 2011 in ten Mexican cities. Ninety-five diverse stakeholders were interviewed to uncover factors regarding the decision to waste or trade still-usable computers. Structured analysis was used to create Data Flow Diagrams (DFDs) to describe the critical parts of the system. The results show that perceived value and geographical location determine the rate in which computers are disposed and the opportunities to waste or trade them, including the trade of their materials. Among businesses and other organizations, legislation has a stronger effect. Technological change is another important factor, largely driving the change in materials and new products. Designing policies responding to this diversity may prevent unforeseen problems and stimulate solutions.     

Environmental behaviour of a construction made of a mixture of hydraulic binders and air pollution control residues from municipal solid waste incineration Part 2. Simulation tests and validation of the source term modelling

The reuse of waste materials requires the development of assessment methods for the long-term release of pollutants (source term) from wastes (or materials containing wastes) in contact with water. These methods depend on the scenario conditions: characteristics of the materials (especially physical structure and composition), contact with water… The scenario studied here is a water storage reservoir for fire extinguishing. The reservoir construction is made of a mixture of hydraulic binders and air pollution control (APC) residues from municipal solid waste incinerator (MSWI). The modelling of the source term is performed in five steps ranging from the physico-chemical characterisation of the material to the validation of the proposed model by means of field simulation devices. This paper follows a first publication on source term modelling using laboratory tests which therefore concerns the comparison of the results obtained with the previously established model. The first laboratory scale simulation test aims at taking into account the role of the leachate carbonation in the leaching behaviour of the studied material. The results obtained show that air carbonation of the leachate does not fundamentally change mass transfer mechanisms of easily soluble species (especially for alkaline metals). For these species, the use of the apparent diffusional model (model proposed in the previous paper) is, therefore, at first, a satisfactory solution for the prediction of long term leaching behaviour. The field scale test enables us to validate and calibrate the release model determined on a laboratory scale basis.     

A value proposition: Resource recovery from faecal sludge—Can it be the driver for improved sanitation?

There is currently a lack of access to affordable sanitation in urban areas of Sub-Saharan Africa. This study evaluated the potential for resource recovery from innovative faecal sludge treatment processes to generate a profit that could help sustain the sanitation service chain. A total of 242 interviews were conducted in Accra, Ghana; Dakar, Senegal; and Kampala, Uganda to compare markets in different cultural and regional contexts. Products identified to have potential market value include dry sludge as a fuel for combustion, biogas from anaerobic digestion, protein derived from sludge processing as animal feed, sludge as a component in building materials, and sludge as a soil conditioner. The market demand and potential revenue varied from city to city based on factors such as sludge characteristics, existing markets, local and regional industrial sectors, subsidies, and locally available materials. Use as a soil conditioner, which has been the most common end use of treated sludge, was not as profitable as other end uses. These findings should help policy and decision makers of sanitation service provision to design financially viable management systems based on resource recovery options.