4种石油化工污染物对15种水生动物急性毒性效应

采用１５种试验生物测试了硫氰酸钠、二甲基甲酰胺、乙腈和丙烯腈等４种石油化工废水中常见污染物对水生生物的急性毒性．结果表明，４种石油化合物对１５种水生动物的ρ（ＬＣ５０）［或ρ（ＥＣ５０）］分别为４．２２～１６９１ｍｇ／Ｌ，２４００～２２６１９ｍｇ／Ｌ，４３４６～１６１９４ｍｇ／Ｌ和５．１６～１９．６４ｍｇ／Ｌ，说明丙烯腈为高毒污染物，乙腈和硫氰酸钠为中等毒性的污染物，而二甲基甲酰胺为低毒污染物；８种鱼类对试验污染物的敏感性基本接近，因而常用的毒性试验用鱼（鲢鱼和鲤鱼）可以较好地代表我国主要的淡水鱼类；中华大蟾蜍、黑斑蛙、盐水卤虫、摇蚊幼虫、折叠萝卜螺和霍甫氏水丝蚓等可以用来作为常用水生态毒理学试验生物的补充，以满足对污染物进行某些特殊的水生态毒理学研究和生物监测时的需要．

Sources of Particular Pollutants inAmbient Air at a Petrochemical Enterprise

The study on source apportionment of particular pollutants in ambient air at a petrochemical enterprise is the ba-sis of the control over air pollution. Through analyzing particular pollutants in the samples collected from one petrochemi- cal enterprise in northwestern China, the sources of particular pollutants were discussed. The test results showed that con- centrations of particular pollutants in different sites were remarkably different. Results showed that the sampling sites with higher concentrations of particular pollutants, including toluene, xylenes, NH3 and H2S, were located at the boundary of the petrochemical enterprise. Instead, the concentrations of NMHC in the ambient air sampling sites were higher than those at the boundary of the petrochemical enterprise. The sampling sites with higher concentrations of particular pollutants were located in the area that was close to the petrochemical enterprise. The results obtained from the Pearson correlation co- efficients analyses, the factor analyses, and x^2-tests of the particular pollutants had revealed that NH3, H2S, toluene and xylenes at all sampling sites came from the same source, while NMHC might come from some other sources besides the petrochemical enterprise.

Microbial community study in a petrochemical industry wastewater treatment system by PCR-DGGE

To improve the efficiency of petrochemical wastewater purification, the relationship between bacterial community structure and pollutants loading/degrading rates in A/O process for petrochemical wastewater treatment was investigated by denaturing gradient gel eleetrophoresis （DGGE） of the 16S rRNA gene fragments amplified by polymerase chain reaction （PCR）. Results show that while the influent COD and NH4^＋ -N concentrations are 425.92 -560 mg/L and 64 - 100 mg/L respectively, the corresponding average concentrations of the effluent are 160 mg/L and 55 mg/L, which are 1. 6 and 3.6 times more than the national standards respectively. It demonstrates that the performance of pollutants removal process is inefficient. The analysis of PCR-DGGE profile indicates that the bacterial community structure of the activated sludge in A/O system is species-rich but unstable, and the highest and the lowest similarity coefficients are 36% and 6. 25% respectively, which shows that remarkable community structure evolution exists in the system. The variation of bacterial community structure and pollutants loading influences the removal efficiency of pollutants obviously, and relatively stable com- munity structure leads to the stable operational performance of biological wastewater treatment system.

Analysis of petroleum hydrocarbons in mangrove sediments of Red Sea of Yemen

A field work has been carried out to identify the occurrence of oil and oil products pollution in mangrove sediment from Red Sea of Yemen. The concentration of total petroleum hydrocarbons is from 700ng/g at Kamaran Island station to 400 ng/g at Al-Hodiedah station, and the total organic carbon (TOC) in samples ranges from 0.07% at Dhubab station to 0.03% at Kamaran Island station. This pollution is as a result of localized oil pollution and/or heavy ship traffic in the Red Sea and Gulf of Aden.

Magnetite/Reduced Graphene Oxide Nanocomposites： One Step Solvothermal Synthesis and Use as a Novel Platform for Removal of Dye Pollutants

A simple one step solvothermal strategy using non-toxic and cost-effective precursors has been developed to prepare magnetite/reduced graphene oxide （MRGO） nanocomposites for removal of dye pollutants. Taking advantage of the combined benefits of graphene and magnetic nanoparticles, these MRGO nanocomposites exhibit excellent removal efficiency （over 91% for rhodamine B and over 94% for malachite green） and rapid separation from aqueous solution by an external magnetic field. Interestingly, the performance of the MRGO composites is strongly dependent on both the loading of Fe304 and the pH value. In addition, the adsorption behavior of this new adsorbent fits well with the Freundlich isotherm and the pseudo-second-order kinetic model. In further applications, real samples--including industrial waste water and lake water--have been treated using the MRGO composites. All the results demonstrate that the MRGO composites are effective adsorbents for removal of dye pollutants and thus could provide a new platform for dye decontamination.