Effects of nature organic matters and hydrated metal oxides on the anaerobic degradation of lindane,p,p''''-DDT and HCB in sediments

IntroductionLindane ,p,p’ DDTandHCBaresemivolatileandlipophilic ,andtheyfallintotheclassofcompoundsdescribedaspersistentorganicpollutants.Moreover,thesecompoundshavebeenidentifiedaspotentendocrinedisrupters(Smith ,2 0 0 2 ;Willett,1 998;Robert,2 0 0 1 ) .Ithasbeenreportedchlorinatedorganiccompoundscanbedecomposedveryslowlyinsedimentsthroughvariousreactions(Niesl,1 990 ) .Factorsinfluencingthebiodegradationofcompoundsarevarious.Amongthem ,itwasreportedthattheeffectsofnaturalorganicmatters…     

Catalytic dechlorination of o-chlorophenol by nanoscale Pd/Fe

IntroductionTheuseofzerovalentironforthetreatmentofchlorinatedorganiccompounds (COCs )inwaterandgroundwaterhasbeenthefocusofmuchrecentresearch .Thestudieswereconcernedwithcompoundssuchascarbontetrachloride(Bradley ,1995 ) ,trichloroethene(Orth ,1996 ;Chen ,2 0 0 1)andpesticidesandrelatedcompounds(Sayles,1997;Monson ,1998;Eykholt,2 0 0 1;Dombek ,2 0 0 1) .Whenironisincontactwithalessreductivemetal,themetalcouplecanformgalvaniccells.ThishasledtothediscoveryofPd Febimetalliccomplexinwhichpal…     

工业用防锈铝合金板材的超塑性能研究

此文主要对工业牌号防锈铝合金板LF3、LF21进行了组织超塑性研究.结果表明,LF3防锈铝合金,在变形温度为470～510℃、ε_0=(5.56～11.1)×10~(-4)s~(-1)的试验条件下可实现超塑性;LF21防锈铝合金,在变形温度为510～540℃、ε_0=(5.56～8.83)×10~(-4)s~(-1)的试验条件下具有超塑性.     

Analysis and assessment of Chinese eco-environmental situation

In order to give out the correct conclusion for evaluating Chinese eco-environmental situation, in this paper, a special assessmental procedure has been used to analyse following 7 basic environmental problems: (1) Natural hazards; (2) Soil erosion; (3) Forest shrinkage and grassland degradation; (4) Water resources shortage; (5) Desertification; (6) Environmental pollution; (7) Farmland decrease. The basic strategies for improving Chinese environmental situation have been suggested.     

二溴硝基偶氮氯膦光度法测定水中微量铬

本文研究了二溴硝基偶氮氯膦与铬(Ⅲ)的显色反应.在pH为3.2的缓冲介质中,铬(Ⅲ)与二溴硝基偶氮氯膦生成1:2的配合物,其最大吸收波长为624nm,摩尔吸光系数ε=1.1×10~4L·mol~(-1)·cm~(-1)铬(Ⅲ)量在0～20μg/25ml范围内符合比尔定律.该法可用于环境水样的分析.     

Preparation of TiO_2/Ti mesh photoelectrode and properties

ＩｎｔｒｏｄｕｃｔｉｏｎＭｕｃｈｉｎｖｅｓｔｉｇａｔｉｏｎｓｓｈｏｗｅｄｔｈａｔｐｈｏｔｏｃａｔａｌｙｔｉｃｏｘｉｄａｔｉｏｎｏｆＴｉＯ2 ｐｒｏｖｉｄｅｓａｎｅｆｆｅｃｔｉｖｅｔｅｃｈｎｏｌｏｇｉｃａｌｍｅｔｈｏｄｆｏｒｔｈｅｄｅｇｒａｄａｔｉｏｎｏｆｔｈｅｏｒｇａｎｉｃｃｏｎｔａｍｉｎａｎｔｓｉｎｗａｔｅｒ(Ａｎｄｊｅｌｋａ ,2 0 0 0 ;Ｆｕｊｉｓｈｉｍａ ,1972 ;Ｈｉｄａｋａ ,1992 ;Ｋｅｓｓｅｌｍａｎ ,1997) .Ｉｎｏｒｄｅｒｔｏｏｖｅｒｃｏｍｅｔｈｅｓｈｏｒｔｃｏｍｉｎｇｓｔｈａｔｔｈｅｒｅｃｏｖ…     

天然水中Ca^2＋的双波长分光光度法测定

依据胶体颗粒与入射光有A=φε~(-2)λ~(-ε)关系,又φε~(-6)与CaC_2O_4-乙醇胶体体系中的Ca~(2+)浓度呈正相关,φ、ε分别为胶粒的粒数函数和粒径函数。选择两个测定波长λ_1和λ_2,解联立方程,计算φ和ε,由φ和ε求Ca~(2+)浓度。方法的线性范围为0～20μg/ml,最低检出浓度为0.4μg/ml。     

Landscape structure and land uese on county level in northeastern Yunnan Province of China—a case study of Huize County

1　Ｌａｎｄｓｃａｐｅｓｔｒｕｃｔｕｒｅａｎａｌｙｓｉｓ1.1　ＴｈｅｅｌｅｍｅｎｔｓｓｔｒｕｃｔｕｒｅＴｈｅｓｔｕｄｙａｒｅａ(ＨｕｉｚｅＣｏｕｎｔｙ)ｉｓｌｏｃａｔｅｄａｔ2 5°48′34″— 2 7°0 3′19″Ｎａｎｄ 10 3°0 3′47″— 10 3°54′2 7″Ｅ .ＩｔｂｅｌｏｎｇｓｔｏｔｈｅＺｈａｏｔｏｎｇａｎｄＸｕａｎｗｅｉｍｏｕｎｔａｉｎ ｐｌａｔｅａｕｒｅｇｉｏｎｗｉｔｈｓｅｍｉ ｈｕｍｉｄｅｖｅｒｇｒｅｅｎｂｒｏａｄ ｌｅａｖｅｄｆｏｒｅｓｔａｎｄｒｅｄｅａｒｔｈｏｆｎｏｒｔｈｅｒｎｓｕｂｔｒｏｐｉｃａｌＹ…     

Distributions of dimethylsulfide in the Bohai sea and Yellow Sea of China

IntroductionDimethylsulfide(CH3SCH3,DMS)isbelievedasthemostimportantvolatilesulfurcompoundreleasedfromtheseawater(Turner,1 988;Andreae ,1 990 ) .ThelatestestimationofDMSfluxfromtheoceantotheatmosphereis 2 0 7± 5 2Tg a ,accountingfor 85%ofglobalDMSsources(Watts,2 0 0 0 ) .AtmosphericDMSisinitiallyoxidizedbyOHinthedaytimeandnitrateradical(NO3)atnightasmajorsinksofDMSintheatmosphere(Andreae ,1 986;Yin ,1 990a ;Barnes ,1 996) .TheoxidationofatmosphericDMSseemstocontributelargelytot…     

Rapid ecotoxicological assessment of heavy metal combined polluted soil using canonical analysis

IntroductionElevatedconcentrationofheavymetalssuchascopperandcadmiumexistinmanyagriculturalsoilsfromminingactivities(Chen ,2 0 0 0 ;Dudka ,1 997;Lambert,1 997)andfrommanagementpracticesincludingirrigationwithsewageandutilizationofsewagesludge(Clapp ,1 994) .Onceheavymetalsenteredintosoils,regardlessthesources,theywouldnotonlybeaccumulatedbyorganisms,butalsocirculateinthefoodchain (Uhlig ,2 0 0 0 ;Barcan ,1 998) .Furthermore ,theirramificationwouldberetainedinsoilecosystemwithtoxicconcentrati…     

二氧化氯对水中流感病毒的消毒效果

通过考察MDCK细胞病变程度,研究二氧化氯(ClO₂)对水中流感病毒(包括流感病毒Ⅰ型 、流感病毒Ⅱ型和流感病毒Ⅲ型)的消毒效果.对各种试验条件,如消毒剂投加量、消毒时间 及pH值等影响因素进行了研究,并与液氯(Cl₂)消毒效果进行了对比.结果表明,ClO₂投加量为 40mg/L时,作用20min,ClO₂对试验的流感病毒具有很好的灭活效果,且在pH值为3.0～8.0的范 围内均达到很好的消毒效果.而液氯在试验的投加量、时间和pH值范围内均不能灭活流感病 毒.      

Impact of combining chlorine dioxide and chlorine on DBP formation in simulated indoor swimming pools

The main objective of this study was to assess the combined use of chlorine dioxide (ClO2) and chlorine (Cl2) on the speciation and kinetics of disinfection by-product (DBP) formation in swimming pools using synthetic pool waters prepared with a body fluid analog (BFA) and/or fresh natural water. At 1:25 (mass ratio) of ClO2 to Cl2, there was no significant reduction in the formation of trihalomethanes (THMs) and haloacetic acids (HAAs) for both BFA solution and natural water compared to the application of Cl2 alone. When the mass ratio of ClO2 to Cl2 increased to 1:1, substantial decreases in both THMs and HAAs were observed in the natural water, while there was almost no change of DBP formations in the BFA solution. Haloacetonitriles and halonitromethanes levels in both water matrices remained similar. In the presence of bromide, the overall DBP formation increased in both BFA solution and natural water. For the DBP formation kinetics, after 72 hr of contact time, very low formation of THMs and HAAs was observed for the use of ClO2 only. Compared to Cl2 control, however, applying the 1:1 mixture of ClO2/Cl2 reduced THMs by > 60% and HAAs by > 50%. Chlorite was maintained below 1.0 mg/L, while the formation of chlorate significantly increased over the reaction time. Finally, in a bench-scale indoor pool experiment, applying ClO2 and Cl2 simultaneously produced less THMs compared to Cl2 control and kept chlorite at < 0.4 mg/L, while HAAs and chlorate accumulated over 4-week operation period.     

医院污水处理中ClO_2检测方法的改进研究

本研究用R5法制取ClO2 对医院污水进行消毒处理 ,针对碘量法测定剩余ClO2 时的不足 ,通过控制溶液pH值、加入稳定剂、活化剂和掩蔽剂的方法对其进行改进 ,实现了将溶液中ClO2 、Cl2 、ClO- 2 、ClO- 3区分测定的目的。实验表明 ,改进后的检测方法能够真实准确地反映溶液中剩余的ClO2 。     

二氧化氯/活性炭催化氧化处理对硝基苯甲酸废水影响因素

以对硝基苯甲酸废水为处理对象,分别考察了活性炭投加量、二氧化氯投加量、pH值及反应时间等因素对二氧化氯/活性炭催化氧化工艺处理对硝基苯甲酸废水的影响.并在最优条件下,通过试验考证了该工艺作为高浓度对硝基苯甲酸废水的预处理手段,在去除废水中COD和提高可生化性(BOD5/COD)方面的综合效果.结果表明,采用ClO2与活性炭组成催化氧化体系,其处理COD为109印mg·L-1,的对硝基苯甲酸废水,效率比单独使用二氧化氯高10%;在废水pH值为4.1时,当活性炭投加量为200 g·L-l、反应时间30 min、二氧化氯投加量为300 mg·L-1,时,废水的COD降至7 100 mg·L-1,去除率达到35%, BOD5浓度提高到1 810 mg·L-1,废水的BOD5/COD值由原来的0.10提高到0.25,明显提高了废水的可生化性.因此,二氧化氯/活性炭催化氧化工艺是预处理高浓度对硝基苯甲酸废水的有效手段.     

二氧化氯-氯联合用于饮用水消毒的研究进展

使用单一的氯或者二氧化氯消毒剂都有一定的局限性,二氧化氯-氯联合消毒工艺是近年来消毒工艺研究的新方向,本文主要对二氧化氯-氯联合消毒工艺的特点和控制因素进行阐述。实验结果表明,二氧化氯-氯联合消毒工艺不仅能够有效地去除水样中的大肠杆菌以及其他细菌,而且联合消毒工艺能够减少消毒副产物的生成,并且有比较强的持续消毒能力。联合消毒工艺受投加比例的影响比较大,因为二氧化氯的浓度过高,衰减也相应增加,并且所产生的ClO2^-量也随之增加;而当液氯的浓度过高时,对应所产生的消毒副产物也随之增加。投加比例一般在ClO2：Cl2=1：3到1：6之间。     

饮水中非挥发性有机污染物致突变性的防治对策

针对饮水致突变物的主要成因研究了减少饮水致突变活性的措施。结果表明：进厂源水生物膜预处理,可使致突变前体物,如藻、腐殖酸、总有机碳等含量分别减少68.2％、23.9％、37.2％,使水厂加氯量减少50％,最终使所制饮水的致突变件减少30％。改革加氯消毒方法可使饮水致突变活性降低,不同消毒剂所致致突变活性顺序为Cl₂＞ClO₂Cl₂＋ClO₂＞源水,Cl₂＋ClO₂等量联合消毒优于单一加氯消毒法,既可提高所试甲型肝炎病毒、脊髓灰质炎病毒及大肠杆菌ｆ₂噬菌体的灭活效果一至数倍;又可使饮水中CHCl₃,减少91.5％－96.5％,致突变活性减少27.6％。     

二氧化氯灭活水中隐孢子虫的影响因素及机理研究

以荧光活体染色法研究了ClO2浓度、灭活时间、浊度、pH值、温度、有机物含量等,对ClO2灭活隐孢子虫效果的影响,并利用扫描电镜和蛋白质实验初步探究了灭活机理.结果显示,当pH7.0,水温为25℃,浊度为1NTU时,投加3mg/L ClO2经过120min,可以达到最适消毒效果(存活率小于1%),隐孢子虫的灭活率与ClO2投加浓度、作用时间成非线性正相关.浊度是影响ClO2灭活隐孢子虫的主要因素,浊度越低,灭活效果越佳;水温(较)低,灭活效果稍差;酸性较于碱性更适宜ClO2灭活隐孢子虫;可溶性有机物一定程度上影响ClO2的灭活效果.扫描电镜和蛋白试验表明,ClO2主要破坏其细胞表面结构,从而引起隐孢子虫死亡.     

新型消毒剂二氧化氯的开发与应用

从保护饮用水的安全与卫生出发，介绍了替代液氯和其它氯制品的新型消毒剂——二氧化氯所具有的优点，特别是可有效抑制三卤代烷（ＴＨＭＳ）的产生；讨论了二氧化氯的最佳投放方式及ＣｌＯ－２和ＣｌＯ－３等有害副产物生成的机理和控制方法     

ClO2和Cl2混合消毒剂对氯仿形成的影响

研究了ClO₂和Cl₂混合水溶液对黄腐酸、间苯二酚、间苯三酚和3,5-甲苯二酚等9种THMs前驱物在ClO₂/Cl₂各种配比、前驱物含量、反应pH、反应时间和温度等不同条件下对氯仿形成的影响.结果表明,随着ClO₂占混合消毒剂中质量分数的增加,形成氯仿量减少,在混合消毒剂中ClO₂的质量分数为25%、50%和75%时,CHCl₃生成量分别减少55%～65%,70%～86%和80%～93%;直到ClO₂占90%时,CHCl₃降低率才达到95%～99%.欲较彻底地控制氯仿的生成,ClO₂的质量分数必须大于90%.这为生产高纯ClO₂发生器以及用高纯ClO₂消毒的必要性提供了重要的科学依据.     

含氯有机污染物中氯同位素测定方法及应用进展

本文综述了四种稳定氯同位素的测定方法。重点比较了当前使用最为广泛的两种测定方法,基于CH3Cl+离子的正电离气体质谱法(PEIMS)和基于Cs2Cl+离子的正热电离质谱法(PTIMS)。论述了稳定氯同位素体系(37Cl/35Cl)在含氯有机污染物来源、迁移及转换过程中的应用研究。