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.     

Comparison of China’s Environmental Impact Assessment (EIA) Law with the European Union (EU) EIA Directive

In this paper, we first review the development of China’s Environmental Impact Assessment (EIA) system in the past 30 years. Then we compare the framework and operational procedures of China’s new EIA law with those of the EU EIA Directive. We also compare public participation, as well as sanctions and control in the two EIA systems. In addition, we identify where the processes in both EIA systems are similar or different from one another. By comparison, we noted that there are at least three obvious weaknesses in China’s EIA system: (1) the application of new models for EIA legislation; (2) the improvement of EIA guidance and education; and (3) the enhancement of public participation in EIA process. Our study indicates that these three major shortcomings should be overcome and improved in China’s EIA system, when compared with the EU EIA system.     

固硫生物型煤

研究出生物型煤的生产工艺流程,对型煤和生物型煤的固硫技术进行了研究,成功试验生产出固硫性能优良的生物型煤,为中国煤能源可持续发展利用开辟了新途径。     

Uncertainty in integrated coastal zone management

Uncertainty plays a major role in Integrated Coastal Zone Management (ICZM). A large part of this uncertainty is connected to our lack of knowledge of the integrated functioning of the coastal system and to the increasing need to act in a pro-active way. Increasingly, coastal managers are forced to take decisions based on information which is surrounded by uncertainties. Different types of uncertainty can be identified and the role of uncertainty in decision making, scientific uncertainty and model uncertainty in ICZM is discussed. The issue of spatial variability, which is believed to be extremely important in ICZM and represents a primary source of complexity and uncertainty, is also briefly introduced. Some principles for complex model building are described as an approach to handle, in a balanced way, the available data, information, knowledge and experience. The practical method of sensitivity analysis is then introduced as a method for a posterior evaluation of uncertainty in simulation models. We conclude by emphasising the need for the definition of an analysis plan in order to handle model uncertainty in a balanced way during the decision making process.     

人为泥石流起动及产沙放水冲刷实验——以神府-东胜矿区为例

神府东胜矿区位于黄土高原北部干旱半旱过度地带。由于煤田的大量开采,诱发了大量的环境问题,尤以人为泥石流最为严重,本文以神府－东胜矿区人为泥石流为研究对象,采用人工放水冲刷模拟的方法,分析了坡面型和沟谷型泥石流源地松散体起动、产沙、泥石流过程的特性,所得结论为：（１）放水历时长,强度大,有利于泥石流的形成;（２）弃土石渣起动,是该区泥石流固体物质的主体;（３）沟道型泥石流放水冲刷模拟实验,便于观测石     

我区城市污水处理程度探讨

建立城市污水处理厂处理污水,是城市发展的必然趋势,而处理级别及处理后水的去向及用途是关系到环境保护和资源得到充分利用的关键,针对我区干旱缺水,灌溉农业特征及天然水域的特点,就污水处理级别排水的用途提出一些看法。     

Pb/Zn冶炼废渣中重金属的生物浸出-盐浸处理

利用中温嗜热菌对某铅锌冶炼废渣进行生物浸出盐浸处理研究,并根据国家固体废物浸出毒性方法(HJ/T299-2007)对盐浸后余渣进行毒性分析。研究结果表明,在pH 1.5、温度65℃、矿浆浓度5%的优化条件下生物浸出3 d后,废渣中Cu、In、Ga和Zn的浸出率分别达到了91.5%、91.8%、84.9%和93.4%;盐浸生物浸出渣,其浸出液中Ag、Pb浓度分别为7.6和247.5 mg/L,可从废渣中有效回收Cu、In、Ga、Zn、Ag和Pb。生物浸出盐浸处理后余渣约为原渣量的70%;毒性分析浸出液中重金属元素Ag、As、Cd、Cu、Pb和Zn浓度分别为2～3.5、2～3、0.3～0.5、30～50、2～4、20～60 mg/L,低于国家危险废物鉴别标准(GB5085.3-2007)。根据试验结果,提出了针对冶炼废渣资源化、减量化、无害化的生物浸出盐浸联用工艺。     

基于网络层次分析法的石油化工设施安全风险评估

为评估石油化工设施的安全风险,提出了一种基于网络层次分析法的安全风险评估模型.在构建石油化工设施安全风险网络层次分析模型的基础上,采用Saaty标度法对安全风险参数进行量化,利用SD软件对安全风险参数进行排序.仿真结果表明,网络层次分析法考虑了安全风险参数之间的相互作用和相互影响,能改进基于线性组合关系的递阶层次分析模...     

物理场水处理器的应用与分类研究

笔者在物理场水处理器的组成结均和作用原理的基础上,依据相关国家行业标准,将其分成了三大类,并对各类物理场水处理器作了简要的说明。其中,重点阐述了电子式水处理器的分类、命名、原理、组成结构及选用安装要求等。     

武汉市冬季重污染过程中PM2.5组分特征与区域来源解析

随着《大气污染防治行动计划》和《打赢蓝天保卫战三年行动计划》的相继实施,在高强度的污染治理下,中东部地区PM_2.5污染改善效果显著。为探讨在PM_2.5浓度不断降低的背景下,仍时有发生的武汉冬季重污染过程的成因及特征,以2020年12月武汉地区一次长达10 d的重污染过程为例,利用多种观测数据和嵌套网格空气质量预报模式系统(NAQPMS)分析污染过程中PM_2.5的化学组分特征和区域贡献等。结果表明:污染日二次无机盐SNA (SO₄^2-、NO₃^-和NH₄⁺)和碳质组分(EC和OC)在PM_2.5中的占比高(分别为78%和18%),NO₃^-的占比从清洁日的36%上升到污染日的46%,是污染过程中占比最高的化学组分。污染期间,NO₃^-和SO₄^2-的浓度比为2.9~6.1,因此二次无机盐的主要来源可能是移动源;OC和EC的浓度比为3.0~9.8,因此碳质组分的主要来源可能是燃煤源。污染期间主要有河南-孝感-武汉和安徽-黄冈-武汉2条污染传输带,污染物传输以武汉周边城市的近距离输送为主,随着污染程度加重,武汉本地及武汉城市圈的区域贡献增加。重度污染天是静稳天气下持续的偏弱东风和西北风输送的污染气团在不易扩散的天气条件下累积形成的。