氯苯驯化活性污泥对同类有机物的好氧降解性比较研究

利用测定微生物呼吸耗氧量的方法,对氯苯类中的５种优先污染物：氯苯,邻,间,对－二氯苯１,２,４－三氯苯,用接种活性污泥和经氯苯驯化的污泥地它们的生物降解性能进行了测试。实验结果表明,用未经驯化的污泥,５种氯苯皆存在的抑制作用,抑制作用的大小和抑制时间的长短氯代程度和浓度的影响,用氯苯将此污泥驯化后,该污染不仅表现出对苯具有降解能力,而且也表现出邻二氯苯,间二氯苯等同类有机物的共代谢降解能力,经分析     

民勤盆地水资源承载力指标体系及评估

水资源是民勤盆地社会经济发展最主要的限制因子,水资源承载力研究对民勤盆地实现可持续发展具有重要意义。论文采用定性和定量相结合的方法,从水资源承载力的定义、内涵、影响因素出发,结合民勤盆地的生态环境特点、社会经济发展状况,构建了由对象层指标和影响层指标组成、能够对水资源承载力进行测度和评价的指标体系。依据各指标的含义,利用可得数据初步估算、预测了民勤盆地2001、2010和2020年的水资源承载力,并对计算结果进行了简要评价。     

Biodegradation of indole by a newly isolated Cupriavidus sp. SHE

Indole, a typical nitrogen heterocyclic aromatic pollutant, is extensively spread in industrial wastewater. Microbial degradation has been proven to be a feasible approach to remove indole, whereas the microbial resources are fairly limited. A bacterial strain designated as SHE was isolated and found to be an efficient indole degrader. It was identified as Cupriavidus sp. according to 16S rRNA gene analysis. Strain SHE could utilize indole as the sole carbon source and almost completely degrade 100 mg/L of indole within 24 hr. It still harbored relatively high indole degradation capacity within pH 4–9 and temperature 25°C–35°C. Experiments also showed that some heavy metals such as Mn^2 +, Pb^2 + and Co^2 + did not pose severe inhibition on indole degradation. Based on high performance liquid chromatography–mass spectrum analysis, isatin was identified as a minor intermediate during the process of indole biodegradation. A major yellow product with m/z 265.0605 (C₁₅H₈N₂O₃) was generated and accumulated, suggesting a novel indole conversion pathway existed. Genome analysis of strain SHE indicated that there existed a rich set of oxidoreductases, which might be the key reason for the efficient degradation of indole. The robust degradation ability of strain SHE makes it a promising candidate for the treatment of indole containing wastewater.     

Analysis of parental strain DNA fragments existing in GEMs-Fhhh

There were 6 target DNA fragments of the three parental strains existing in the cell of GEMs( genetically engineered microorganism strain) Fhhh measured in this research by PCR(polymerase chain reaction). The determination showed that GEMs Fhhh contained all the 6 target DNA fragments, mnpl, mnp2, lipl, lip2, FLOI and 16S rDNA, and had the molecular genetic stability. Meanwhile the PCR production of each parental strain could only had its target DNA fragments and was different from each other. It may illustrate that the technique of the inter-kingdom protoplast fusion for the construction of GEMs Fhhh through the process of intercellular gene recombination could be used as a reliable bioengineefing technique to create the soecific functional stain for the nollution control.     

组合指数在环境混合物联合毒性研究中的初步应用

化学品在实际环境中总是以组分繁杂多变的混合物形式存在,其混合物的毒性评估与预测一直是环境毒理学研究重点。在环境毒理学领域,浓度加和(concentration addition,CA)及独立作用(independent action,IA)是评估与预测化学混合物联合毒性的经典模型,一般认为CA适用于作用模式相似的混合物体系而IA适用于作用模式相异的混合物体系,但如何使用CA与IA一直存在争议。组合指数(combination index,CI)是在半数效应方程基础上发展起来的不依赖于作用模式的用于混合物联合毒性评估的混合物毒性指数,具有坚实的理论基础,不仅能定性地评估毒理学相互作用,也能定量地评估相互作用的大小,已在药物组合研究中得以广泛应用,近年来已引起环境毒理学研究者兴趣。本文就组合指数及药物组合应用、进入环境毒理学领域、与CA及IA的关系、存在的问题等几个方面进行评述,以期推进CI在化学混合物毒性评估与预测领域中的应用。     

36种典型除草剂对绿藻的毒性研究

近年来,农药对生态系统的初级生产者——藻类的毒性及其生态毒理学研究引起了国内外学者的广泛关注。除草剂在生产中广泛应用,对藻类的毒性作用最强,其毒性效应远高于杀虫剂和杀菌剂。论文选择市场上具有典型代表性的36种除草剂原药,分析解读除草剂在国内的登记情况,以及在作物、旱田和水田的使用情况;明晰对藻类生长抑制急性毒性效应。结果表明:1)除草剂的作用方式和化学类别对绿藻毒性影响显著;对于抑制植物细胞分裂和作用于植物叶绿体的除草剂对绿藻毒性均较高,以人工合成植物生长素为代表的除草剂对绿藻毒性均较低;2)相同作用方式,不同化学类别的除草剂,对单一绿藻的毒性差异明显。在水稻上获得登记的除草剂对藻类毒性整体低于在旱田获得登记的除草剂对藻类的毒性。开展多种农药对水生生态毒性的研究,为农药的合理安全使用、农药在淡水环境中的生态效应评价以及保护淡水生态系统提供科学依据。     

北京地区一次尘暴过程的来源

本文根据卫星云图分析以及对尘暴气溶胶和尘暴路径地区表层土的元素组分分析,进一步讨论了1980年4月18日出现在北京地区上空强尘暴的来源。结果表明,这次强尘暴的来源是比较复杂的,它不只是来源于某一单一地区,而是由尘暴起源地区及其移动路径地区的沙土微粒经大风输送到高空并进行混合,然后随着大风移动而造成的。     

环境中全氟有机物的毒性、检测分析及降解

自全氟有机物广泛使用50多年以来,已经在世界范围内发现一定浓度的全氟有机物,各国研究人员针对该类物质特别是全氟辛酸(PFOA)、全氟辛烷基磺酸(PFOS)进行了一定的研究.介绍了该类物质的污染现状,阐述了全氟有机物的毒性、检测分析技术及降解技术,在此基础上提出了今后的研究方向.     

Effects of copper(II) and copper oxides on THMs formation in copper pipe

Little is known about how the growth of trihalomethanes (THMs) in drinking water is affected in copper pipe. The formation of THMs and chlorine consumption in copper pipe under stagnant flow conditions were investigated. Experiments for the same water held in glass bottles were performed for comparison. Results showed that although THMs levels firstly increased in the presence of chlorine in copper pipe, faster decay of chlorine as compared to the glass bottle affected the rate of THMs formation. The analysis of water phase was supplemented by surface analysis of corrosion scales using X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM) and energy dispersive spectroscopy (EDX). The results showed the scales on the pipe surface mainly consisted of Cu₂O, CuO and Cu(OH)₂ or CuCO₃. Designed experiments confirmed that the fast depletion of chlorine in copper pipe was mainly due to effect of Cu₂O, CuO in corrosion scales on copper pipe. Although copper(II) and copper oxides showed effect on THMs formation, the rapid consumption of chlorine due to copper oxide made THM levels lower than that in glass bottles after 4 h. The transformations of CF, DCBM and CDBM to BF were accelerated in the presence of copper(II), cupric oxide and cuprous oxide. The effect of pH on THMs formation was influenced by effect of pH on corrosion of copper pipe. When pH was below 7, THMs levels in copper pipe was higher as compared to glass bottle, but lower when pH was above 7.     

活性焦对水中汞的吸附性能

采用活性焦作为吸附剂,通过静态吸附实验,研究了活性焦对水中汞的吸附特性,并初步探讨了其吸附机理。活性焦对汞的吸附可用拟二级动力学模型描述;在pH为5时能达到对Hg(Ⅱ)的最大吸附容量,在不同离子强度下均能保证对Hg(Ⅱ)有较高的去除率;据Langmuir吸附等温线模型计算出活性焦对Hg(Ⅱ)的饱和吸附容量可达412.1 mg/g。结合红外光谱、Zeta电位测试的结果,可推测活性焦对Hg的吸附过程是物理吸附和化学吸附综合作用的结果。活性焦是一种成本低、效果显著且稳定的吸附剂,有望在含汞废水处理中发挥重要作用。