废旧塑料的再生及其在制管行业中的应用

总结了再生、降解、焚烧及填埋等几种废旧塑料处置方式的特点,指出对于品种单一、老化程度低的废旧塑料应优先选择再生利用.重点介绍了废旧聚氯乙烯塑料、聚乙烯塑料、聚丙烯塑料、氯化聚氯乙烯塑料的再生及其在制管行业中的利用情况进展.     

Delineation of soil and groundwater contamination using geophysical methods at a waste disposal site in Çanakkale, Turkey

Direct current (DC) resistivity, self potential (SP) and very low frequency electromagnetic (VLF-EM) measurements are carried out to detect the spread of groundwater contamination and to locate possible pathways of leachate plumes, that resulted from an open waste disposal site of Canakkale municipality. There is no proper management of the waste disposal site in which industrial and domestic wastes were improperly dumped. Furthermore, because of the dumpsite is being located at the catchment area borders of a small creek and is being topographically at a high elevation relative to the urban area, the groundwater is expected to be hazardously contaminated. Interpretations of DC resistivity geoelectrical data showed a low resistivity zone (<5 ohm-m), which appears to be a zone, that is fully saturated with leachate from an open dumpsite. The VLF-EM and SP method, support the results of geoelectrical method relating a contaminated zone in the survey area. There is a good correlation between the geophysical investigations and the results of previously collected geochemical and hydrochemical measurements.     

Sodium and chloride accumulation in leaf, woody, and root tissue of Populus after irrigation with landfill leachate

The response of Populus to irrigation sources containing elevated levels of sodium (Na(+)) and chloride (Cl(-)) is poorly understood. We irrigated eight Populus clones with fertilized well water (control) (N, P, K) or municipal solid waste landfill leachate weekly during 2005 and 2006 in Rhinelander, Wisconsin, USA (45.6 degrees N, 89.4 degrees W). During August 2006, we tested for differences in total Na(+) and Cl(-) concentration in preplanting and harvest soils, and in leaf, woody (stems+branches), and root tissue. The leachate-irrigated soils at harvest had the greatest Na(+) and Cl(-) levels. Genotypes exhibited elevated total tree Cl(-) concentration and increased biomass (clones NC14104, NM2, NM6), elevated Cl(-) and decreased biomass (NC14018, NC14106, DM115), or mid levels of Cl(-) and biomass (NC13460, DN5). Leachate tissue concentrations were 17 (Na(+)) and four (Cl(-)) times greater than water. Sodium and Cl(-) levels were greatest in roots and leaves, respectively.     

垃圾渗滤液水质特性研究进展

垃圾渗滤液已被公认为是高风险高污染废水,对地下水与地表水具有极大的潜在危害性。由于渗滤液具有高污染、水质水量差异大、难控等特点,使得其有效处理十分棘手。近年来国内外对渗滤液的研究十分广泛,本文结合国内外渗滤液相关研究中水质特性相关部分,从渗滤液的一般特性,溶解性有机质及危险物质等方面对渗滤液水质进行阐述,有助于深入了解渗滤液水质及其变化规律,从而为渗滤液的有效处理提供理论依据。     

Natural Weathering of Polypropylene and Waste Tire Dust (PP/WTD) Blends

Three series of polypropylene and waste tire dust (PP/WTD) blends using three different WTD sizes were prepared, compression-molded and cut into dumbbells. The specimens were exposed to natural weathering in the northern part of Malaysia for a period of 6 months. The results show that at the same blend composition, blends with fine WTD size exhibit higher mechanical properties than that of blends with coarse WTD after exposure to natural weathering. Regardless of WTD size, the retention of tensile strength and elongation at break, E_b increases with the increase in WTD content. From the exposed surface morphology, it is apparent that the blends with fine WTD and WTD-rich blends were able to withstand weathering better than blends with coarse WTD and PP-rich blends. The DSC thermograms suggest that the overall drop in melting temperature (T_m) of the exposed blends decreases as the WTD content increases.     

废聚苯乙烯塑料热降解回收苯乙烯单体的研究

为了废弃物资源化利用,建立了废聚苯乙烯热降解的实验室装置,探讨了影响聚苯乙烯热降解的因素,如温度,压力,催化剂用量等,在优化条件下获得９７．６％的分解油,其中苯乙烯单体含量达５５．５％,对聚苯乙烯热降解的机理进行了初步探讨,并预测了在工业化放大情况下该工艺的经济效益。     

一次性塑料制品的替代管理策略研究

一次性塑料是指生产生活中使用一次或几乎不重复利用的塑料,约占塑料总消费量的50%,是塑料制品的重要构成部分.近年来,随着电子商务的兴起,一次性塑料的生产和消费量迅速增长.随着人们对塑料以及由此引起的微塑料污染危害的认识不断提高,国际社会对削减一次性塑料污染的呼声日益高涨,迫切需要开发可持续、环境友好的替代品以减少一次性塑料的消费量.从全球范围来看,一次性塑料制品替代主要包括非塑料材料替代和可生物降解塑料材料替代两大类.建议我国尽快完善相关立法和标准,鼓励一次性塑料制品替代并加强替代产品的质量监管;为一次性塑料制品替代提供差别化的产业政策,提高环境友好替代产品的市场竞争力,同时还应将一次性塑料制品的环境治理成本纳入其价格成本;鼓励科技创新,研发更具市场竞争力的替代材料和产品;最后,还要唤起社会公众的共同参与,主动选择替代产品并减少一次性塑料制品的使用,才能从源头上解决塑料垃圾的污染问题.      

上海与东京生活垃圾处理回收体系之比较

进入21世纪，上海提出建设循环经济型国际大都市的战略目标，其中很重要的一个领域就是要构筑高效、实用的生活垃圾处理回收体系。文章分析了上海与东京现行的生活垃圾处理回收体系的特点，并对二者进行了比较。发现上海体系存在着垃圾处理方式的简单化，垃圾分类收集形式化，废品回收无序化，对策视点局限性和管理系统封闭性等诸多缺陷。通过借鉴东京体系的成功经验，建议实施法律和经济的手段。不断改进和完善上海体系。     

美国危险废物的管理与处理处置

以危险废物的全过程管理为主线 ,阐述了美国现阶段危险废物管理的特点 ;通过介绍美国危险废物管理的重要法典《RCRA》,对美国危险废物管理体系进行全面分析 ;重点分析了对我国建立危险废物管理体系有借鉴意义的豁免制度、贮备金制度     

新型干法水泥生产线废气污染物治理技术研究

介绍了生产能力2000t·d-1的新型干法水泥生产线生产过程产生废气(主要是粉尘)的情况,针对废气排放特点,采用包含末端治理在内的综合治理措施进行治理。治理工程运行稳定,处理效果达到《水泥厂大气污染物排放标准》(GB4915-1996)Ⅲ时段二级标准和无组织排放二级标准的要求。