Formation of polychlorobiphenyls in silicone rubber

In silicone rubber crosslinked with bis(2,4-dichlorobenzoyl) peroxide (DCBP) as initiator about 0.1% of DCBP is converted into polychlorobiphenyls (PCBs). The PCB content in silicone rubber determined by high resolution gas chromatography (HRGC) after its destruction by HF is around 10 mg/kg. 29 PCB congeners were detected. Instead of the expected PCB-47, lower chlorinated congeners are predominant. Some possible pathways of their origin are presented.     

二步法腈纶生产废水的处理试验

本试验采用混凝 -A/O系统组合工艺处理二步法腈纶废水 ,该系统处理效果良好 ,出水水质符合排放标准 ,可直接排入水体。A/O系统试验装置总容积 80L ,水力停留时间 5 8— 70h ,缺氧池与好氧池的容积比为 1∶3 ,回流比 ( 2—3 )∶1,COD和BOD总去除率分别约为 84%和 98%。     

超声-过氧化氢-氧化铜组合技术催化氧化水中苯酚

研究了超声-H2O2-CuO组合技术对苯酚的降解效果。考察了苯酚初始浓度、溶液温度及鼓入空气对苯酚去除率的影响。实验结果表明，与未鼓入空气时相比，连续鼓气时苯酚的降解效果较好；初始浓度低，苯酚去除率高；溶液温度从20％上升到55％时，苯酚去除率随温度升高而增大，温度对该过程的影响主要表现为对催化剂的影响而不是对超声作用的影响。高效液相色谱分析表明，苯酚降解的中间产物主要为对苯二酚、邻苯二酚及其他有机小分子物质，最终产物为草酸、二氧化碳和水。     

光助Ce-Fe/Al2O3催化H2O2降解阳离子红GTL模拟废水

利用Ce-Fe/Al₂O₃为催化剂的非均相光Fenton体系降解阳离子红GTL模拟废水，考察了H₂O₂浓度、催化剂用量、初始pH值及不同工艺过程对降解效果的影响，通过紫外-可见漫反射光谱、红外光谱、XPS手段研究铁在反应中的价态变化。结果表明，在11 W低压汞灯照射下，非均相光Fenton体系能够有效地降解结构稳定的阳离子红GTL，在pH 6，反应温度20℃，时间90 min，Ce-Fe/Al₂O₃ 2 g/L，H₂O₂浓度340 mg/L，含50 mg/L阳离子红GTL模拟废水TOC去除率为92.40%；光Fenton反应中Fe(Ⅲ)转化为Fe(Ⅱ)。     

无锡太湖新城污水处理厂改良型A^2／O工艺的调试与运行

介绍了无锡市太湖新城污水处理厂的一期工程设计概况和所采用的改良型A^2/O脱氮除磷工艺，分析、探讨了污水处理厂的调试、培菌、试运行过程中出现的问题，并针对性地采用了一系列的解决措施。由监测数据表明，该工艺运行可靠，出水水质稳定，实现了污水处理厂的正常运行。     

倒置A2/O污水处理工艺的特点及应用实例

传统A²/O工艺在保证脱氮效果的同时除磷效果往往不佳。在充分分析传统A²/O工艺的基础上，提出了将缺氧池置于厌氧池前面，厌氧池后设置好氧池的分点进水倒置A²/O工艺。某污水厂的现场试验表明，在COD去除能力与常规A²/O工艺相当的情况下，倒置A²/O工艺的脱氮除磷功能明显优于常规A²/O工艺。     

Study of oil-water partitioning of a chemical dispersant using an acute bioassay with marine crustaceans

The toxicity of seawater dispersions of a chemical dispersant to two marine crustaceans was investigated in the presence and absence of various quantities of a non-toxic mineral oil. From the results and a physical-chemical partitioning analysis, a limiting value of the oil-water partition coefficient of the toxic compounds is deduced suggesting that essentially all of the toxic compounds in the dispersant will partition into solution in water following dispersant application to an oil spill. This conclusion simplifies interpretation and prediction of the toxic effects of a dispersed oil spill.The combined bioassay-partitioning procedure may have applications to the study of the toxicity of other complex mixtures such as industrial effluents.     

A/O工艺处理城市生活工业综合污水的耐受性研究

针对目前城市污水处理厂进水水质以生活污水为主转向以难生物处理的工业废水为主的现状,进行了A/O工艺的耐受性试验.结果表明:随着工业废水比例的增加,厌氧、好氧污泥活性都显著下降,厌氧污泥的耐受性较高;随着运行时间的延长,两类污泥的活性逐步得到不同程度的恢复;工业废水比例越高,活性恢复所需时间越长;两类污泥的协同代谢作用保证了出水效果.A/O工艺所能耐受的进水中制药废水、印染废水和生活污水的分配比(体积比)为3∶3∶4.     

Widespread contamination by tris(4-chlorophenyl)methane and tris(4-chlorophenyl)methanol in cetaceans from the North Pacific and Asian coastal waters

For understanding global distribution, transport and behavior of tris(4-chlorophenyl)methane (TCPMe) and tris(4-chlorophenyl)methanol (TCPMOH), the two newly identified microcontaminants, the present study determined their concentrations and other persistent organochlorines (OCs) in the blubber of nine species of adult male cetaceans collected from various locations in the North Pacific Ocean and coastal waters of some Asian countries, during 1985-97. Concentrations of TCPMe and TCPMOH were found to be highest in northern right whale dolphins, which may be attributable to wide distribution of this species, including some heavily polluted areas such as coastal California. Elevated residue levels of TCPMe and TCPMOH were observed in both off-shore and coastal species, suggesting widespread contamination of these compounds in the marine environment. Higher contamination of TCPMe and TCPMOH was found in cetaceans from temperate and cold waters than those from tropical regions. The latitudinal distribution of TCPMe and TCPMOH in cetaceans from the North Pacific and Asian coastal waters was similar to that of DDTs, suggesting less transportable nature of TCPMe and TCPMOH in the marine environment. Data on the occurrence of TCPMe and TCPMOH further indicated high bioaccumulation potential of these compounds, which was comparable to DDTs. Relative concentrations of TCPMe/TCPMOH in cetaceans were apparently higher than those observed in seals, suggestive of lower metabolic capacity for these compounds in cetaceans than in pinnipeds, which is similar to classic contaminants like polychlorinated biphenyls and DDTs.