电子废弃物拆解厂排放多溴联苯醚和重金属的吸入性健康风险评估

以江苏某典型正规电子废弃物拆解厂为研究对象,在实测排放源数据的基础上,采用Calpuff大气扩散模式模拟其排放的多溴联苯醚(PBDEs)和重金属Pb、Cd大气浓度的区域与局部空间分布,进而对所排放PBDEs、Pb和Cd导致的健康风险进行评估.研究结果表明:在气象条件最为不利的情景下,污染物在东北、西南方向污染物扩散行为显著.PBDEs、Pb和Cd在区域空间范围的大气浓度最大值分别为3×10~(-6)、8.6×10~(-5)和3.6×10~(-6)μg·m~(-3),而局部范围的浓度则会高出一个数量级;其中BDE-209对于PBDEs的大气浓度贡献可达77%.在局部范围内,以HQ表达的PBDEs和Pb健康风险数值均在10~(-3)以下,非致癌健康风险极低;BDE-209和Cd的终生致癌风险最大值为1.10×10~(-12)与6.32×10~(-7),致癌风险可以忽略.该评估表明,正规操作的电子废弃物拆解厂的大气污染物不会对公共健康造成不可控风险.     

VOC气体检测仪在进口废塑料检验中的应用

针对挥发性有机化合物(VOC)气体在现实中的危害,对废物原料检验的标准进行了探讨,对废物原料检验中如何进行VOC检测进行分析并提出建议。     

工业贮池防腐材料及其施工性能

总结了常用的工业贮池防腐蚀处理方法、防腐蚀材料的性能及施工过程和要点,比较了玻璃钢衬里、玻璃鳞片与乙烯基酯树脂混合衬里和耐酸块材砌筑等防腐蚀处理工艺的工艺条件,并介绍了玻璃钢衬里工艺中所用树脂的类型及性能.     

Co-gasification of wood and polyethylene with the aim of CO and H2 production

This article describes the gasification of polyethylene–wood mixtures to form syngas (H₂ and CO) with the aim of feedstock recycling via direct fermentation of syngas to ethanol. The aim was to determine the effects of four process parameters on process properties that give insight into the efficiency of gasification in general, and particularly into the optimum gasification conditions for the production of ethanol by fermentation of producer gas. Gasification experiments (fluidized bed, 800°–950°C) were done under different conditions to optimize the composition of syngas suitable for fermentation purposes. The data obtained were used for statistical analysis and modeling. In this way, the effect of each parameter on the process properties was determined and the model was used to predict the optimum gasification conditions. The parameters varied during the experiment were gasification temperature, equivalence ratio, the ratio of plastic to wood in the feed, and the amount of steam added to the process. The response models obtained proved to be statistically significant in the experimental domain. The optimum gasification conditions for maximization of carbon monoxide and hydrogen production were identified. The conditions are: temperature 900°C, equivalence ratio 0.15, amount of plastic in the feed 0.11 g/g feed, and amount of steam added 0.42 g/g feed. These optimum conditions are at the edge of the present experimental domain. The maximum combined CO and H₂ efficiency was 42%, and for the maximum yield of CO and H₂ it is necessary to minimize the polyethylene content, minimize the added steam and the equivalence ratio, and maximize temperature.     

我国报废汽车回收拆解企业发展的关键问题研究

报废汽车回收拆解具有巨大的经济、环境和社会效益。我国报废汽车回收拆解企业正面临极佳的发展环境,但目前存在着诸多问题,需要进行转型升级。提出报废汽车回收拆解企业转型升级过程中存在的若干关键问题,即回收阶段中的报废汽车量预测、回收模式选择、报废汽车回收网络构建;拆解阶段中的拆解工艺选择、拆解设备选择;产品销售阶段中的产品分类及市场分析、销售模式确定及销售网络构建、产品定价等问题,并对这些问题进行分析,提供解决方法和措施。     

Mechanical performance of woodfibre–waste plastic composite materials

Plastic products used for packaging are often discarded after a single use resulting in an inexhaustible supply of waste polymeric materials. The stiffness and strength of polymeric materials have been known to improve with the addition of lignocellulosic fibres available in abundance in nature. Hence, composite materials containing natural fibres and waste plastics would result in the reduction of solid wastes and the use of cheap, renewable resources. Composite specimens, consisting of waste plastics obtained from a Kerbside collection (high density polyethylene (HDPE) waste, Janitorial waste, Kerbside waste I and Kerbside waste II) and Pinus radiata woodfibres (medium density fibres (MDF)), have been produced through melt blending and injection moulding. The effects of fibre content, matrix type and interfacial bonding on the tensile and flexural properties of these composite materials have been determined through extensive testing at various conditions. The mechanical properties of these composites at room temperature and humidity depend on the amount of woodfibres, the mechanical properties of the waste plastics used and the presence of a suitable coupling agent. The tensile strengths of MDF/waste plastic composites do not generally change with fibre content except for 40% MDF/HDPE waste and 40% MDF/Kerbside waste II (plus 1% Epolene™) composites, where the tensile strengths increase by about 25% compared to those of the corresponding waste plastics. Flexural strengths of MDF/waste plastic composites increase with the addition of medium density fibres with the exception of MDF/Kerbside waste I composites. The tensile and flexural moduli of MDF/waste plastic composites mostly increase with increasing fibre content.     

Effect of the composting substrate on biodegradation of solid materials under controlled composting conditions

Biodegradability under composting conditions is assessed by test methods, such as ASTM D 5338-92, based on the measurement of CO₂ released by test materials when mixed with mature compost and maintained in a controlled composting environment. However, in real composting, biodegradation occurs in fresh waste. To clarify this point, the biodegradation of paper and of a starch-based biodegradable thermoplastic material, Mater-Bi ZI01U, was followed by measuring the weight loss of samples introduced either into a mature compost or into a synthetic waste. The weight loss in mature compost was higher at the beginning but tended to decrease; in synthetic waste a first lag phase was followed by an exponential phase. Complete degradation of paper was noticed simultaneously in the two substrates (after 25 days). The bulkier Mater-Bi samples were fully degraded after 20 days in fresh waste, but after 45 days in mature compost. Therefore, the test methods using mature compost as a substrate can possibly underestimate the biodegradation rate occurring in fresh waste, i.e., in real composting plants, and have to be considered as conservative test methods. The test procedure described in this paper seems very suitable as a screening method to verify the compostability of plastic materials in a composting environment.     

纸类和塑料类生活垃圾共热解交互作用的热重研究

采用热重实验方法对纸张和不同塑料共热解的协同作用进行了研究。实验结果表明:纸巾和不同种类塑料共热解时,会产生不同程度的交互作用,与线性加权实验结果相比,偏离程度由大到小依次为PVC>PP>PS>HDPE>LDPE>塑胶。其中,纸巾/PVC的偏离高达58.4%;纸巾和LDPE、HDPE,以及塑胶的交互作用则可以忽略不计。纸巾/PVC、纸巾/PP、纸巾/PS共热解的交互作用分别发生在纸巾、PP、PS的热解阶段,这3种组分相应的热解特征参数及动力学参数发生了变化,需要修正。     

塑料对农田生态系的污染及其防治

农田生态系的塑料污染主要来源于：（１）工业废弃物的排放，（２）城市生活垃圾，（３）农用塑料薄膜残余物。塑料对我国农田生态系的污染状况相当普遍，个别地区由于农田残膜量大幅度增加或城市生活垃圾直接进入农田给农业带来了一场空前的“白色灾害”，成为影响农业生产的主要污染问题之一。土壤耕层中的塑料可严重影响作物根系的生长发育及土壤中水肥的运移，而使作物减产。此外，塑料中各种添加剂尤其是酞酸酯类增塑剂对作物的生长有明显影响，这种影响随作物生长时期和品种不同而异。为了防治塑料对农田生态系的污染，应该大力研制各类可降解性塑料制品，并推广应用到实际生产中去，注重废弃塑料的回收，使其再生资源化。     

废旧塑料的综合利用

近年来 ,治理“白色污染”、消灭“白色公害”已成为全球的共识 ,从废旧塑料的最终处置、直接再生利用、改性再生利用、热分解以及与其他材料复合等几个方面综述了废旧塑料的综合利用途径 ,其中废旧塑料和其他材料复合的再生利用技术有很好的发展前途 ,将成为今后研究的新热点