Bromine in waste incineration partitioning and influence on metal volatilisation

INTENTION, GOAL, SCOPE, BACKGROUND: The halogen bromine is far less abundant than chlorine, but it can be found at high concentrations in special materials like flame retarded plastics. The fate and effects of Br in waste incineration are not well understood. It may have similar implications like Cl for the volatilisation of heavy metals and the formation of low volatile organic compounds. Due to its lower oxidation potential, there is a risk of formation of elementary Br2 in the offgas. OBJECTIVE: Co-combustion tests of different types of Br containing plastic waste materials (up to 22%) and MSW in the TAMARA pilot plant for waste incineration were conducted to investigate the Br partitioning and the influence of Br on metal volatilisation. METHODS: The Br inventory of the fuel mix was elevated to approx. 1 wt-%. All input and output mass flows of the furnace have been sampled and the partitioning of Cl, Br, S, and a number of heavy metals, has been calculated on the basis of closed mass balances. RESULTS AND DISCUSSION: Organically-bound Br was typically released to more than 90% into the raw gas. Elementary Br2 was detected at high Br levels. Its presence was always analysed when all SO2 in the raw gas was oxidised to SO3. Br enhances the volatilisation of metals like K, Zn, Cd, Sn, Sb, and Pb out of the fuel bed principally in the same way as Cl. The tests gave strong indication that the promoting influence of the halogens on metal volatilisation is more pronounced than that of the fuel bed temperature. The volatilised metals are condensated on the fly ashes and are discharged along with the filter ashes. CONCLUSIONS: As long as a surplus of SO2 is present in the raw gas no Br2 is formed. Although the halogen induced transfer out of the fuel bed causes high concentrations of volatile metals in the filter ashes, a recovery is not economically feasible for the time being. The volatilisation gives no rise to metal emission problems as long as efficient dedusting is achieved. RECOMMENDATION AND OUTLOOK: If there is a risk of Br2 formation, in wet scrubbing a reducing agent has to be added to the neutral scrubber for efficient abatement. Filter ashes should be disposed of in a way that enables access for recovery in the future. The exact volatilisation characteristics of the various metals have to be studied in future using specifically tailored experiments.     

与环境污染物转化相关的细菌厌氧呼吸研究动态

基于细菌呼吸理论为基础的环境有毒物质降解为环境污染治理提供了新的策略和方法,是近年来研究的热点问题.细菌呼吸是自然界中一个最基本、最重要的生物代谢过程,具有很大的灵活性和多样性,且与生态环境密切相关.在厌氧条件下,细菌利用环境中多种有毒物质作为呼吸链末端电子受体进行厌氧呼吸,在有毒物质被还原甚至降解的同时实现电子在呼吸链上的传递,形成跨膜的质子浓度电势梯度,进而转化为其生长代谢所需的能量.细菌以环境有毒物质为电子受体的厌氧呼吸不断被发现,这对于深入理解细菌呼吸的本质具有重要的理论意义,同时对于有毒物质的降解及元素的生物地球化学循环具重要的环境学意义,对于提高对地球表面有毒物质污染生物修复策略的认识具有重要的现实意义.图1表1参45     

我国电子废弃物管理与资源化对策

电子废弃物对人类环境的影响,已成为全球化的问题.通过对发达国家关于电子废弃物管理以及资源化技术的进展回顾,针对我国目前的情况提出相应的对策：制定延伸生产者责任以及有害物质的停用限期的相应法规;建立电子废弃物回收网络体系;通过国家政策和经济的扶持,尽快建立专门处理电子废弃物的机构;加快我国电子废弃物处理技术的步伐,尽快提高现有工艺及设备.     

基于PSTN网的火灾安全区域网络监控系统

随着自动电子消防报警系统的广泛使用,将现行的消防电子报警作为子系统,对其运行状况的自动统一监控和管理变得愈来愈重要。针对这种情况,笔者提出了构建区域火灾网络监控系统的新思路。即以ＰＳＴＮ（公用交换电话网）为信息传输途径,利用计算机及ＭＯＤＥＭ 卡,配合自动检测软件和通信接口技术与方法, 实现自动电子消防报警系统运行状况的监控和自动接收系统报警信号。该系统的实现,将大大提高现行消防电子报警系统的管理水平,降低火灾给人类造成的危害     

电子废弃物资源化现状及处理技术

描述了电子废弃物的产生现状，分析了电子废弃物的特点，并简要地介绍了对其资源化处理的各种方法及设备。     

废旧电器再生利用产业技术、经济和社会循环互动机制探析

废旧电器回收再生利用是开辟“城市矿山”的资源源泉。从技术、经济、社会三个层面分析其物质、价值和行为三个形态的循环机理及其互动关系，价值循环要考虑自然资源资本和环境保护与恢复的成本来分析其价值保值与增值过程；行为循环要以基于生产者责任延伸制的主体责任体系为纽带，分析其行为活动规律及其相互关系；物质循环要按照循环经济的原则考虑各种物质形态的有效转换与有机联系，以实现资源到资源的物质闭路循环。     

我国电子商务立法的必要性及措施

电子商务的快速健康发展需要完善的法制体系作保障,积极探索和研究电子商务立法问 题,加快建立具有中国特色的电子商务法律体系。对推动我国电子商务发展具有重要意义。     

电子废弃物资源化的研究与进展

探讨了电子废弃物资源化的意义,重点研究了电子废弃物中金属、塑料、玻璃的回收技术,以及国内外电子废弃物的资源再利用现状。建立有效的回收体系,最大限度地循环利用资源,使我国的电子和电器制造业及电子废弃物处理业协调发展。     

粉煤灰干法除炭技术与设备

根据最新收集的文献资料，介绍了国外典型的粉煤灰干法除炭，特别是电选除炭方面的新进展，包括其工作原理、优缺点及工业应用情况。旨在为国内相关企业提供参考。     

结合数字签名和电子图章技术实现公文认证

对于电子政务中的公文认证问题,本文借助加密和数字签名理论以及数字图像处理技术实现公文流转的安全性及公文的权威认证,使其达到了安全性和直观性的统一。