Sound management of brominated flame retarded (BFR) plastics from electronic wastes: State of the art and options in Nigeria

Management of flame retarded plastics from waste electrical and electronic equipment (WEEE) has been posing a major challenge to waste management experts because of the potential environmental contamination issues especially the formation of polybrominated-dioxins and -furans (PBDD/F) during processing. In Nigeria, large quantities of electronic waste (e-waste) are currently being managed—a significant quantity of which is imported illegally as secondhand electronics. As much as 75% of these illegal imports are never reused but are rather discarded. These waste electronic devices are mostly older equipment that contains brominated flame retardants (BFRs) such as penta-brominated diphenyl ethers (PBDEs), and polybrominated biphenyls (PBBs) which are presently banned in Europe under the EU WEEE and RoHS Directives. Risk assessment studies found both to be persistent, bio-accumulative and toxic. The present management practices for waste plastics from WEEE in Nigeria, such as open burning and disposal at open dumps, creates potential for serious environmental pollution. This paper reviews the options in the environmentally sound management of waste plastics from electronic wastes. Options available include mechanical recycling, reprocessing into chemicals (chemical feedstock recycling) and energy recovery. The Creasolv^® and Centrevap^® processes, which are the outcome of the extensive research at achieving sound management of waste plastics from WEEE in Europe, are also reviewed. These are solvent-based methods of removing BFRs and they presently offer the best commercial and environmental option in the sound management of waste BFR-containing plastics. Because these developments have not been commercialized, WEEE and WEEE plastics are still being exported to developing countries. The industrial application of these processes and the development of eco-friendlier alternative flame retardants will help assure sound management of WEEE plastics.     

Effects of planned expansion of waste incineration in the Swedish district heating systems

Recent targets for reduced amounts of waste to landfills in Sweden will result in a large increase in waste incineration with recovery of energy, used primarily for district heating. The aim of this study is to investigate what changes in the usage of other fuels and technologies for district heat production would be caused by this increase. A questionnaire was sent out to the largest district heating companies, and simulations in an energy systems model were carried out. The analysis shows that increased waste incineration reduces the demand for other fuels, especially biomass, for district heat production. The effects include reductions in operating hours as well as the avoidance or postponement of investments in new plants for district heat production. Increased waste incineration will also lead to a greater use of district heating in Sweden.     

生物反应器填埋场渗滤液及其处理对策

根据垃圾的降解和稳定机理分析了生物反应器填埋场渗滤液的动态变化规律,并对其处理对策进行了探讨。生物反应器填埋场前期产生的渗滤液可全部回灌,后期再根据实际情况排放处理部分过量的渗滤液。在对渗滤液水量和水质全面直观认识后,再对生物反应器填埋场渗滤液处理工艺进行针对性的选择和设计,并宜采用物化法处理方式。     

玻璃生产企业废水综合利用的可行性探讨

本文分析了玻璃生产企业废水的来源,并从耀华玻璃集团实施的废水治理项目的实际出发,阐述了废水经过治理后综合利用的途径,实现废水的零排放,减少环境污染,节约水资源。     

交流电凝聚技术及其在油田污水处理方面的应用研究

交流电凝聚（ACE）技术能有效地从稳定的悬浮液和乳浊液中凝聚并分离出固相、重金属和油。电压缩和电絮凝促进凝结、快速沉淀及脱水,且不使用昂贵的高分子电解质和化学药品,也不需使用复杂且易于被超细微粒堵塞的过滤系统。木文介绍了ACE技术的初步原理及其在国外油田污水处理方面的应用,并与传统的污水净化方法进行了比较。     

Non-conventional gas phase remediation of volatile halogenated compounds by dehydrated bacteria

Traditional biological removal processes are limited by the low solubility of halogenated compounds in aqueous media. A new technology appears very suitable for the remediation of these volatile organic compounds (VOCs). Solid/gas bio-catalysis applied in VOC remediation can transform halogenated compounds directly in the gas phase using dehydrated cells as a bio-catalyst.     

Present status of the recycling of waste electrical and electronic equipment in Korea

In Korea due to rapid economical growth followed by urbanisation, breakage of large traditional families into small nuclear families, continuous changes in equipment features and capabilities causes tremendous increase in sale of new electrical and electronic equipment (EEE) and decrease in sale of used EEE. Subsequently, the ever-increasing quantity of waste electrical and electronic equipment (WEEE) has become a serious social problem and threat to the environment. Therefore, the gradual increase in the generation of WEEE intensifies the interest for recycling to conserve the resources and protect the environment. In view of the above, a review has been made related to the present status of the recycling of waste electrical and electronic equipment in Korea. This paper describes the present status of generation and recycling of waste electrical and electronic equipment, namely TVs, refrigerators, washing machines, air conditioners, personal computers and mobile phones in Korea. The commercial processes and the status of developing new technologies for the recycling of metallic values from waste printed circuit boards (PCBs) is also described briefly. Since 1998, three recycling centers are in full operation to recycle WEEE such as refrigerators, washing machines and air conditioners, having the total capacity of 880,000 units/year. All waste TVs are recently recycled on commission basis by several private recycling plants. The recycling of waste personal computers and mobile phones is insignificant in comparison with the amount of estimated obsolete those. Korea has adopted and enforced the extended producer responsibility (EPR) system. Korea is making consistent efforts to improve the recycling rate to the standards indicated in the EU directives for WEEE. Especially environmentally friendly and energy-saving technologies are being developed to recycle metal values from PCBs of WEEE.     

钻井废水的处理

本文针对钻井废水的处理,综述了现有的处理方法、处理药剂以及处理装置,并对钻井废水的处理、排放提出了一些意见和建议。     

Building partnerships — the Ohio Materials Exchange

This paper discusses a method by which individuals working in government, private business, not-for-profit and educational organizations developed a collaborative statewide program involving the exchange of materials from manufacturers, commercial business and not-for-profit organizations in Ohio.