A quantitative estimate of potential aluminium recovery from incineration bottom ashes

The recovery of ferrous and non ferrous metals from the bottom ashes is a common practice in the most part of Europe, both for the environmental advantages of their recycle and to avoid problems of swelling and expansion that metals can cause when bottom ashes are reused in concrete production or in road construction. This paper focuses on metal recovery from bottom ashes produced in Municipal Solid Waste (MSW) incinerators, with a particular focus on aluminium. A forecasting model was developed in order to evaluate the quantity of aluminium scraps recoverable from the bottom ashes. The model was applied to the Italian situation but its validity can be extended to other countries. Focusing on Italy, by applying conventional technologies for the separation of non-ferrous metals, the amount of aluminium potentially recoverable from bottom ashes is estimated in the range from 16,500 to 21,000 tonnes at the year 2015, and from 19,000 to 28,500 tonnes at 2020.     

Household organic waste composting using bins with different types of passive aeration

The objective of this study was to study the performances of six 200-L polyethylene bins, each with different design for passive aeration to organic wastes composting. Food scraps and dry leaves (1.6 kg) were added to each bin once a day until the bin was full. Temperatures at the middle portion were measured daily. The compost from each bin was taken once a week for 120 days for analysis of C, N, volatile solids, and a germination index once a week for 120 days. After 120 days, the compost sample from each bin was taken to determine the mass reduction, size distribution, CEC, N, P and K values. The results showed that the temperatures inside the bins were in the ranges of 24 °C-57 °C. The composts in all bins were found to be stable at around 56-91 days. The wastes decayed fastest in bins with lateral and vertical systems of natural ventilation. It took about two months to stabilize the organic wastes, with a 59-62% decrease of mass. The C/N ratio, CEC, N, P, and K values of the final composts were 14.8-16.0, 66-68 cmol/kg, and 1.26-1.50% N, 0.52-0.56% P₂O₅ and 1.66-1.92% K₂O, respectively.     

Overview of non-hazardous solid waste in the small island state of Mauritius

In Mauritius, solid waste disposal has been a cause for concern since the 1980s. Currently, there is no segregation of waste and some 1200 tonnes of solid waste are generated daily by the 1.24 million inhabitants of the island. As processes such as recycling and composting are still in their infancy stage, most of the waste generated have to be disposed of at the sole landfill. The solid waste management practices of 1980s and early 1990s are no longer compatible with the changing composition and quantity of wastes now generated. As a result, there is an urgency to review the whole waste management system and come forward with sustainable solutions.This paper presents an overview of the disposal of non-hazardous solid waste in Mauritius and provides recommendations for improving the current disposal system.     

The influence of collection facility attributes on household collection rates of electronic waste: The case of televisions and computer monitors

In the US, household electronic waste collected for recycling is primarily by voluntary drop-off at designated collection facilities. This study examines the influence of specific collection facility attributes (recycling fees charged, number of days open, and driving distance) on the household collection rate of e-waste in the US state of Maine. Data were collected for household computer monitor and television collection for 92 municipal waste transfer facilities representing 30% of the state's population for one year. Results suggest that recycling fees are negatively correlated with the number of televisions and computer monitors collected; furthermore, the more frequently facilities were open, the more televisions and computer monitors were collected per capita. The distance from the facility had no correlation, which prompted an analysis of whether the existence of a curbside collection system in the municipality was influential. Results show a negative correlation between computer monitor and television collection and a municipality having recycling (but not e-waste) curbside collection. Based on the results of this study, policymakers may be able to increase the collection rate of household e-waste by eliminating or lowering recycling fees, expanding collection days and hours to increase convenience, and/or considering curbside collection of e-waste.     

Management of urban solid waste: Vermicomposting a sustainable option

Solid waste management is a worldwide problem and it is becoming more and more complicated day by day due to rise in population, industrialization as well as changes in our life style. Presently most of the waste generated is either disposed of in an open dump in developing countries or in landfills in the developed ones. Landfilling as well as open dumping requires lot of land mass and could also result in several environmental problems. Land application of urban/municipal solid waste (MSW) can be carried out as it is rich in organic matter and contains significant amount of recyclable plant nutrients. The presence of heavy metals and different toxics substances restricts its land use without processing. Vermicomposting of MSW, prior to land application may be a sustainable waste management option, as the vermicast obtained at the end of vermicomposting process is rich in plant nutrients and is devoid of pathogenic organism. Utilization of vermicast produced from urban/municipal solid waste in agriculture will facilitate in growth of countries economy by lowering the consumption of inorganic fertilizer and avoiding land degradation problem. Vermicomposting of urban/MSW can be an excellent practice, as it will be helpful in recycling valuable plant nutrients. This review deals with various aspects of vermicomposting of MSW.     

有机废气治理技术的研究进展

有机废气治理问题是当前废气处理的难点问题之一。本文首先介绍了几类传统有机废气处理技术的发展现状,包括吸附法、吸收法、催化氧化法、生物处理法等。对这几类有机废气治理技术的应用机理、适用范围以及现存问题进行了综合地比较与分析。最后,对于近年来出现的几类新型有机废气处理技术,如膜分离法、光催化氧化法、综合处理法的发展前景进行了一定的展望并列举了几类新技术的工程应用实例。     

基于主成分分析模型的核设施放射性废物管理评价研究

针对核设施放射性废物管理问题,采用主成分分析方法直观定量地研究了大亚湾、岭澳、田湾、秦山等各核电厂单位装机容量（MW）三废年度实际排放值或产生量,揭示了核设施放射性废物管理评价指标数据间的相关性和差异性,识别出了核设施放射性废物管理评价指标数据的主要成分;分析结果基本上反映了各核电厂放射性废物管理状况,主成分分析得分以秦山核电站第一期核电厂最高,其他依次为田湾核电厂、秦山核电站第二期核电厂、岭澳核电厂、大亚湾核电厂,秦山核电站第三期核电厂最低,即秦山核电站第三期核电厂在核设施放射性废物管理最优,大亚湾核电厂次之。辅助核设施放射性废物管理作出快速分析与决策,以提高检测能力和监管能力,具有很好地应用价值。     

我国电子废弃物处理产业现状与前景探讨

电子废弃物处理产业是伴随我国近年来社会经济快速发展而产生的一个新兴产业。本文分析了电子废弃物的经济价值、处理技术和产业政策,并对我国电子废弃物处理产业的现状与前景进行了探讨。     

多晶硅切割液废液的回收与利用

结合工程实际,介绍了太阳能产业用多晶硅片切割过程中产生的割液废液的处理工艺及回收工艺,并分析了它的投资成本和经济效益。