Experimental study on Cr(Ⅵ) reduction by Pseudomonas aeruginosa

Investigation on Cr( Ⅵ ) reduction was conducted using Pseudomonas aeruginosa. The study demonstrated that the Cr(Ⅵ) canbe effectively reduced to Cr( Ⅲ ) by Pseudomonas aeruginosa. The effects of the factors affecting Cr( Ⅵ ) reduction rate including carbon source type, pH, initial Cr(Ⅵ) concentration and amount of calls inoculum were thoroughly studied. Malate was found to yield maximum biotransformation, followed by succinate and glucose, with the reduction rate of 60.86%, 43. 76% and 28.86% respectively. The optimum pH for Cr( Ⅵ ) reduction was ?.0, with reduction efficiency of 61.71 % being achieved. With the increase of initial Cr(Ⅵ) concentration,the rate of Cr(Ⅵ) reduction decreased. The reduction was inhibited strongly when the initial Cr(Ⅵ) concentration increased to 157 mg/L. As the amount of cells inoculum increased, the rate of Cr( Ⅵ ) reduction also increased. The mechanism of Cr( Ⅵ ) reduction and final products were also analysed. The results suggested that the soluble enzymes appear to be responsible for Cr (Ⅵ) reduction by Pseudomonas aeruginosa, and the reduced Cr( Ⅲ ) was not precipitated in the form of Cr(OH)3.     

大气监测中对空气流量测定值的修正不容忽视

依据转子流量计基本测量原理,指出在大气监测中,对实际采样气象条件下的空气体积的测定不能简单地通过转子流量计的读数而获得,必须予以修正;对由此而产生的误差进行了分析,并给出最终修正换算式。     

大气自动监测系统在炼油厂的应用

运用日本引进的大气自动测定仪组成炼油厂的大气环境自动监测系统。运行结果表明，该系统自动化程度高，故障率低，操作简便，数据齐全，它的建立使我厂的大气环境监测上了一个新台阶．     

分光光度法快速测定化纤废水COD

本文研究了化纤生产废水经酸化絮凝处理后的废水ＣＯＤ与紫外吸光度之间的相关关系，并建立了二者之间的回归直线方程，可为快速预测处理设施的运转效果提供依据。     

简易法测定水中的微量烷基苯磺酸盐

水中微量烷基苯磺酸盐（ＡＢＳ），与结晶紫（ＣＶ）生成紫色配合物。加入聚氯乙烯软质薄片与其作用，被聚氯乙烯软片吸附、染成紫色，而紫色的深浅和水中的ＡＢＳ浓度成正比例，借此测定出ＡＢＳ的含量。     

石墨炉原子吸收法测定镉

在塞曼效应和背景石墨炉原子吸收分光光度法测量镉浓度中，使用磷酸溶液作为基体改进剂，能够提高镉对直度的稳定和分析的灵敏度。     

火焰原子吸收法测定镀镍废水中镉

本文介绍了经吡咯烷二硫代氨基甲酸铵络合，以甲基异丁基甲酮－环乙烷富集萃取，用火焰原子吸收分光光度测定镀镍废水中镉含量的实验方法，该实验抗干扰性强，灵敏度与准确度较高，且操作简便，成本低，便于推广应用。     

用络合滴定法测定电镀液中的铜

用络合滴定法测定电镀液中的铜何承英仙桃市环境监测站一、概述电镀工艺在机械工业和日常生活中应用广泛，目前用于测定铜含量的方法很多，如原子吸收、示波极谱、萃取光度法等。由于各地监测站经济尚不雄厚，购买原子吸收或示波极谱等仪器都很困难，而革取光度法操作繁琐...     

BOD快速测定方法述评

简介6种BOD快速测定方法,各种测定方法的特点,适用范围。