电子废物拆解区典型用地土壤重金属分布特征

以广东清远的电子废物拆解区为研究对象,采集了遗留拆解场地,水稻田,蔬菜地,旱地和林地等5种用地类型土壤,分析了土壤基本理化指标和重金属含量.结果表明,各重金属元素含量高低总体呈现出：拆解场地 > 蔬菜地 > 水稻田 > 旱地 > 林地的趋势.其中,拆解场地的As、Cd、Cu、Hg、Pb和Zn均超过《土壤环境质量标准》（GB 15618–1995）二级标准,超标倍数最高的为Cd、Cu、Pb和Zn.蔬菜地和水稻田也出现不同程度的Cd和Cu超标,但林地与旱地的各元素含量均接近于背景值.在垂向分布上,受拆解活动直接影响的拆解场地中,各重金属含量随深度而显著递减,呈现出明显的表聚特征;而电子废物拆解活动影响较小的林地和旱地变化趋势不明显.冗余分析结果表明,研究区域土壤中重金属的迁移主要受土壤pH值、有机质和总磷的共同影响.各重金属元素的潜在生态危害风险程度处于轻微至极强,其中Cd和Cu的危害指数最高;各用地类型土壤的综合生态风险指数介于93（林地）~4750（拆解场地）,平均为1187,属于很强的风险水平.本研究的结果可为政府部门科学开展电子废物拆解综合整治和土地管理提供基础信息.     

环境保护公信体系构架和建设的探索

本文对环境保护的公信体系建设进行了探索。首先，对环境保护公信体系的概念作出了解释；其次，对环境保护公信体系的建设内容、建设框架做出了思考；最后，在对环境保护公信体系的建设方法方面，结合电子政务系统的优势，探索了建立电子环境保护公信体系平台的可能性。     

电子垃圾拆解区及其周边大气中得克隆的污染和呼吸暴露研究

添加型高氯代阻燃剂得克隆(dechlorane plus,DP)因为在环境中表现出普遍存在性、持久性、生物富集性、长距离迁移性和毒性,近年来迅速引起各国环境科学家的关注和重视。DP广泛应用于电线电缆等电子产品塑料中,粗放式电子垃圾拆解活动已被证实是环境中DP的重要污染来源之一。为探讨电子垃圾拆解区及其周边地区大气中DP的污染特征、呼吸暴露剂量和影响因素,对典型电子垃圾拆解区贵屿(GY)及其周边地区陈店(CD)和对照市区(广州市天河区,TH)进行大气采样和DP分析,并运用Monte Carlo模拟计算其日呼吸摄入剂量,同时对暴露参数进行了灵敏度分析。结果表明:受当地粗放式电子垃圾拆解活动的影响,GY大气中的DP平均浓度(范围)高达(1 119±1 021)pg·m-3(410~3 381 pg·m-3),远高于CD(52.2±30.2,20.9~102 pg·m-3)和TH(5.04±2.73,0.967~9.43 pg·m-3);受GY大气污染扩散迁移的影响,CD大气中的DP浓度也显著高于TH(t-test,P=0.006);GY大气中反式DP的比例(fanti)与DP商业品(fanti=0.70)无显著差异(t-test,P=0.08),这与其存在本地排放源一致,而TH大气中的fanti显著低于DP商业品(t-test,P=0.000);3个地区居民的DP日均呼吸摄入剂量(pg·kg-1·d-1)分别为:GY成人1 888,儿童1 912;CD成人60.9,儿童62.8;TH成人5.16,儿童5.25;呼吸速率是DP日呼吸摄入剂量的主要贡献因子,其次为大气中的DP浓度和体重,体重对于儿童的影响远高于成人。上述研究结果表明GY及其周边地区居民均处于较高DP呼吸暴露风险中。     

1,2-二氯乙烷自然衰减过程中模拟饱和含水层的氧化还原条件变化

为研究自然条件下饱和含水层中1,2-DCA(1,2-二氯乙烷)的自然衰减过程及该过程中含水层氧化还原环境的变化特征,利用室内连续水流土柱模拟饱和含水层,研究生物降解作用对1,2-DCA自然衰减的贡献以及饱和含水层环境条件的动态变化规律. 初始ρ(1,2-DCA)为50 mg/L,模拟地下水流速为450 μL/min,模拟试验连续进行30 d,分别监测ρ(1,2-DCA)和水环境指标. 结果表明,1,2-DCA自然衰减的一级速率常数为0.068 9 d-1,其中生物降解作用的贡献率为6.34%. 1,2-DCA自然衰减过程中,NO₃-首先充当生物降解的电子受体,随后Fe3+、SO₄2-依次发生反应,土柱内部不同高度出现了氧化还原分带,分别是硫酸盐还原带、铁盐还原带、硝酸盐还原带.      

Fate of metals contained in waste electrical and electronic equipment in a municipal waste treatment process

In Japan, waste electrical and electronic equipment (WEEE) that is not covered by the recycling laws are treated as municipal solid waste. A part of common metals are recovered during the treatment; however, other metals are rarely recovered and their destinations are not clear. This study investigated the distribution ratios and substance flows of 55 metals contained in WEEE during municipal waste treatment using shredding and separation techniques at a Japanese municipal waste treatment plant. The results revealed that more than half of Cu and most of Al contained in WEEE end up in landfills or dissipate under the current municipal waste treatment system. Among the other metals contained in WEEE, at least 70% of the mass was distributed to the small-grain fraction through the shredding and separation and is to be landfilled. Most kinds of metals were concentrated several fold in the small-grain fraction through the process and therefore the small-grain fraction may be a next target for recovery of metals in terms of both metal content and amount. Separate collection and pre-sorting of small digital products can work as effective way for reducing precious metals and less common metals to be landfilled to some extent; however, much of the total masses of those metals would still end up in landfills and it is also important to consider how to recover and utilize metals contained in other WEEE such as audio/video equipment.     

废手机面板焚烧产物研究

以废手机面板为试验材料,利用热重分析仪(TGA)研究热处理失重特征,同时利用气相色谱仪-质谱仪联用(GC-MS)对管式炉试验系统焚烧产物进行分析. 结果表明:废手机面板焚烧失重温度为128.3～558.1 ℃,最大失重温度为357.4 ℃;焚烧废手机面板导致面板组成材料液晶、偏光片和取向剂等发生化学反应,焚烧产物除CO₂外,还含有醛、酮、联苯酚、苯胺等芳香族化合物和少量的苯并吡喃、萘、菲、吡啶等多环芳烃(PAHs). 由于焚烧产物中绝大多数是有毒有害物质,部分可致癌,故废手机面板不宜焚烧处理,如与其他固体废物混合焚烧,必须采取相应的污染控制措施.      

Electronic labelling in recycling of manufactured articles

The concept of a recycling system aiming at the recovery of resources from manufactured articles is proposed. The system integrates electronic labels for product identification and internet for global data exchange. A prototype for the recycling of electric motors has been developed, which implements a condition-based recycling decision system to automatically select the environmentally and economically appropriate recycling strategy, thereby opening a potential market for second-hand motors and creating a profitable recycling process itself. The project has been designed to evaluate the feasibility of electronic identification applied on a large number of motors and to validate the system in real field conditions.     

International aspects of recycling of electrical and electronic equipment: material circulation in the East Asian region

This article examines the present circumstances of recycling of end-of-life electrical and electronic equipment discarded in Japan from the domestic and international viewpoints of material circulation. It is pointed out that some of the discarded items are absorbed into an invisible flow by informal economic activities, being exported in the form of secondhand equipment and secondary materials. Since the equipment has a pollution potential as well as a resource potential, it is anticipated that the pollution potential may possibly be realized if the equipment is mishandled at recycling plants in developing countries. To reduce the invisible flow as much as possible and to reduce the pollution potential from diffusion in developing countries, a policy tool such as extended producer responsibility should be applied to retailers of the equipment, as well as to producers.     

我国废钢铁市场的发展前景及废钢电子交易推荐标准

随着我国钢铁工业高速发展和国家对节能减排的高度重视,废钢铁资源的应用倍受业内关注。对我国废钢供需市场的规模、现状及发展前景进行分析和预测,并对我国废钢电子交易推荐标准进行详细介绍,指出作为大宗商品交易发展方向的电子交易模式,是我国废钢贸易的发展趋势,有利于废钢市场有序健康发展。     

电子废弃物的机械物理回收过程

电子产品数量及更新速度的提高,导致电子废弃物产生量的增长。电子废弃物中既含有有害成分,又含有大量可回收利用的有价值成分。在分析电子废弃物性质的基础上,阐述了电子废弃物的回收方法与过程。机械物理过程是根据电子废弃物的性质提出的一种回收有价值材料的过程。机械物理回收过程如筛选、形状分选、磁力分选和涡流分选已经在回收工业中被广泛使用。