Emerging pollutants: impact on environment,management, and challenges

Environmental Science and Pollution Research -     

垃圾渗沥液中氨氮的电化学氧化

针对目前国内外垃圾渗沥液处理中存在的问题,采用电化学氧化与上流式厌氧污泥床（UASB）相结合,研究建立了对香港垃圾渗沥液的二步法处理工艺．本文着重探讨了电化学间接氧化去除渗沥液中氨氮的反应机制及主要影响因素,并通过实验找出了最佳的操作条件：入水初始 pH值为9.0;流速为0.01－0.10cm/s;CI加入量2000mg/L;电流密度 32.3mA/cm²．在此条件下,经过 6h电解后,UASB反应器出水中NH_－N和COD的去除率分别达到100％和87％．对该电化学氧化过程的运行成本进行了评估．     

Ökotoxikologie am Beispiel der Rheinverschmutzung durch den Chemie-Unf all bei Sandoz in Basel

A fire at a chemical manufacturing plant at Schweizerhalle (near Basel) in November 1986 and the subsequent release of toxic agrochemicals into the Rhine river is taken as a basis to discuss some problems and needs in ecotoxicological research. Especially serious is the lack of knowledge about chronic effects of mixtures of chemicals to individuals and whole ecosystems. There is an urgent need for generally applicable principles and concepts. A discussion of the relationship between toxic effects to fish, exposure time, and concentration provides some hints about the direction towards which research should proceed. Finally, eight theses pertaining to ecotoxicology summarize what can be learned from the analysis of a chemical spill.     

Use and validation of novel snow samplers for hydrophobic, semi-volatile organic compounds (SVOCs)

Two novel gas-tight snow samplers (snow-can and snow-tube) are presented and the performance of the snow-can in a field trial was assessed. The methodology for the sampling, extraction and analysis of persistent organic pollutants (POPs) are detailed. These samplers allow the various components of a snow sample to be analysed separately; these included the meltwater (MW), particulate matter (GFF) and vapour in the headspace (HS). Snow samples collected on the Punta Indren glacier in the Italian Alps revealed the occurrence of polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs) and organochlorine pesticides (OC). Replicate samples of the same snow type were undertaken as a test of sampling precision. Relative standard deviations (RSDs) for SigmaPCBs and SigmaPAHs were approximately 30% and approximately 35% respectively. The lowest precision was found for the particle-laden snow, notably for the heavier PCB homologues. For the chlorinated compounds, the pesticides lindane and endosulfan-I had the highest levels in snow, with mean concentrations of 402 and 103 pgl(-1) (snow meltwater) respectively. The vapour present in the headspace (HS) comprised a minor component of a collected sample for all compounds, but HS concentrations for three lighter PAHs gave good agreement with those calculated based on their dimensionless Henry's law constants. This suggests that volatilisation during melting of aged snow-can be reasonably predicted with knowledge of the temperature-dependent Henry's law constant.