再生聚丙烯的洁净化和高质化应用

聚丙烯以其优异的机械性能、高的性价比和多重改性方式成为重要的通用树脂之一,这些产品废弃后产生了种类繁多和数量巨大的再生聚丙烯.通过将再生聚丙烯根据性能和来源进行分类,然后分类阐述各再生聚丙烯物料特点,结合再生聚丙烯改性方式,为高质化应用提出方向.     

贵屿电子垃圾处理对河流底泥及土壤重金属污染

以广东省汕头市贵屿镇电子垃圾处理场为对象,主要研究了电子垃圾场附近河流的底泥和农田土壤中重金属形态分布特征。结果表明,底泥中Cd、Cr、Cu、Pb、Zn质量分数分别为52.9-67.1、309-359、79.2-1485、391-449、37.5-111 mg.kg^-1;土壤中Cd、Cr、Cu、Pb、Zn的平均质量分数分别是54.1-57.1、278-320、93.5-116、382-415、46.2-68.1 mg.kg^-1。底泥和土壤中Cd、Cr、Cu、Pb均超过《土壤环境质量标准》（GB15618—1995）二级标准,其中以Cd和Cu污染最为严重。底泥及土壤中重金属的地球化学形态分布规律基本一致。重金属具有较高迁移性,重金属的迁移性为Cd〉Cr〉Pb〉Zn〉Cu。     

Thermal cracking of waste printed wiring boards for mechanical recycling by using residual steam preprocessing

Mechanical waste-processing methods, which combine crushing and separation processes for the recovery of valuable materials, have been widely applied in waste printed wiring board (PWB) treatment. However, both the high impact toughness and the tensile and flexural strengths of whole PWB with a laminated structure result in great energy consumption and severe abrasion of the cutters during multi-level crushing. In addition, the high temperatures occurring in continual crushing probably cause the decomposition of the polymer matrix. A thermal-crack method using residual steam as the heating medium has been developed to pre-treat waste PWBs. This treatment reduces the mechanical strength in order to improve the recovery rate of valuable materials in subsequent mechanical recycling. The changes of the PWBs’ macro-mechanical properties were studied to evaluate thermal expansion impacts associated with changes in temperature, and the dynamic dislocation micro-structures were observed to identify the fracture mechanism. The results showed that thermal cracking with steam at the temperature of 500 K can effectively attenuate the mechanical properties of waste PWBs, by reducing the impact, tensile and flexural strengths respectively, by 59.2%, 49.3% and 51.4%, compared to untreated PWB. Thermal expansion can also facilitate the separation of copper from glass fiber by reducing peel resistance by 95.4% at 500 K. It was revealed that the flexural fracture was a transverse cracking caused by concentrated stress when the heating temperature was less than 500 K, and shifted to a vertical cracking after exceeding 500 K.     

Co-fermentation of waste activated sludge with food waste for short-chain fatty acids production: effect of pH at ambient temperature

Effect of pH ranging from 4.0 to 11.0 on co-fermentation of waste activated sludge (WAS) with food waste for short-chain fatty acids (SCFAs) production at ambient temperature was investigated in this study. Experimental results showed that the addition of food waste significantly improved the performance of WAS fermentation system, which resulted in the increases of SCFAs production and substrate reduction. The SCFAs production at pH 6.0, 7.0, 8.0, and 9.0 and fermentation time of 4 d was respectively 5022.7, 6540.5, 8236.6, and 7911.7 mg COD·L^-1, whereas in the blank tests (no pH adjustment, pH 8.0 (blank test 1), no food waste addition, pH 8.0 (blank test 2), and no WAS addition (blank test 3)) it was only 1006.9, 971.1, and 1468.5 mg COD·L^-1, respectively. The composition of SCFAs at pH from 6.0 to 9.0 was also different from other conditions and propionic acid was the most prevalent SCFA, which was followed by acetic and n-butyric acids, while acetic acid was the top product under other conditions. At pH 8.0 a higher volatile suspended solids (VSS) reduction of 16.6% for the mixture of WAS and food waste than the sole WAS indicated a synergistic effect existing in fermentation system with WAS and food waste. The influence of pH on the variations of nutrient content was also studied during anaerobic fermentation of the mixture of WAS and food waste at different pH conditions. The release of NH4+-N increased with fermentation time at all pH values investigated except 4.0, 5.0 and in blank test one. The concentrations of soluble phosphorus at acidic pHs and in the blank test one were higher than those obtained at alkaline pHs. Ammonia and phosphorus need to be removed before the SCFAs-enriched fermentation liquid from WAS and food waste was used as the carbon source.     

论固体废物排放统计指标体系设计

固体废物排放统计对象应覆盖固体废物从原材料到最终处置的整个生命周期的各个环节(机构),即矿业--加工制造业--产品流通领域--用户--固体废物收运体系--固体废物中间处理厂--固体废物最终处置场.统计指标体系包括固体废物排放统计指标和排放管理指标;统计指标区分为指标、主要参数和辅助参数,既便于理解也便于管理.根据固体废物排放量和已知的固体废物资源化技术,对固体废物重新分类、统计并分类填埋,以便将来实现再利用.固体废物排放控制统计的对象主要是规模以上的污染源,实施统计的污染源的规模应当是全国统一的.     

Removal of trace elements in three horizontal sub-surface flow constructed wetlands in the Czech Republic

Between March 2006 and June 2008 removal of 34 trace elements was measured on a monthly basis at three horizontal-flow constructed wetlands in the Czech Republic designed to treat municipal wastewater. In general, the results indicated a very wide range of removal efficiencies among studied elements. The highest degree of removal (average of 90%) was found for aluminum. High average removal was also recorded for zinc (78%). Elements removed in the range of 50-75% were uranium, antimony, copper, lead, molybdenum, chromium, barium, iron and gallium. Removal of cadmium, tin, mercury, silver, selenium and nickel varied between 25 and 50%. Low retention (0-25%) was observed for vanadium, lithium, boron, cobalt and strontium. There were two elements (manganese and arsenic) for which average outflow concentrations were higher compared to inflow concentrations. Reduced manganese compounds are very soluble and therefore they are washed out under anaerobic conditions.     

城市生活垃圾综合处理系统的选择

以上海城市生活垃圾处置为对象，利用层次分析方法，选择了分选回收＋堆肥＋卫生填埋的综合处置系统，并且确定了堆肥方式应首先考虑仓式静态好氧堆肥。经过运行费比较，所选择的综合处置系统比现行的处置系统具有明显的优势。     

上海生活垃圾资源化产业的发展探讨

概述了国内外生活垃圾资源化利用的现状，对上海生活垃圾资源化利用状况和问题作了分析，探讨了垃圾资源化利用的价值和实现途径，提出了促进上海生活垃圾资源化产业发展的几点建设。     

造纸废水综合治理技术的应用研究

采用“酸化 物化 生化”组合工艺并辅以芦苇湿地处理系统对造纸废水进行综合治理。通过优化工艺条件 ,逐级削减污染负荷 ,使废水排放达到国家标准     

城市污水强化一级处理技术及发展趋势

基于经济与环保的要求，分析了城市污水强化一级处理的适用情况，指出了城市污水强化一级处理的主要工艺方法、特点、处理效果及应用，并提出了城市污水强化一级处理技术的发展趋势。