土壤及果树中HCH和DDT残留及分布规律研究

采用索氏提取、弗罗里土固相微萃取小柱净化结合GC-ECD测定了苹果园土壤和果树样品中4种六六六(HCH)和4种滴滴涕(DDT)的残留量,并对果树的根、枝、叶中HCH和DDT的分布规律进行了研究。实验结果表明,土壤和果树样品中均有HCH和DDT检出。土壤样品中两类农药的含量分别在0.51～3.97ng/g和1.46～15.55ng/g之间,其中β-HCH是六六六残留的主体,滴滴涕类的含量以p,p'-DDT为最高,并且(DDE+DDD)/DDT<1表明近期果园中有新的DDT输入。果树样品中,HCH和DDT的残留量分别在0.22～2.01ng/g和0.38～6.08ng/g之间,都要低于相应土壤中有机氯农药的浓度。果树中总OCPs的含量在4.88～17.94ng/g之间,是土壤和大气中OCPs污染共同作用的结果。根部的OCPs的含量明显高于枝和叶,其分布规律为根>叶>枝,这主要取决于根、枝、叶各组织的结构以及农药的理化性质。     

Organochlorine pesticides in soils under different land usage in the Taihu Lake region, China

A field study was conducted in the Taihu Lake region, China in 2004 to reveal the organochlorine pesticide concentrations in soils after the ban of these substances in the year 1983. Thirteen organochlorine pesticides (OCPs) were analyzed in soils from paddy field, tree land and fallow land. Total organochlorine pesticide residues were higher in agricultural soils than in uncultivated fallow land soils. Among all the pesticides, ΣDDX (DDD, DDE and DDT) had the highest concentration for all the soil samples, ranging from 3.10 ng/g to 166.55 ng/g with a mean value of 57.04 ng/g and followed by ΣHCH, ranging from 0.73 ng/g to 60.97 ng/g with a mean value of 24.06 ng/g. Dieldrin, endrin, HCB and α-endosulfan were also found in soils with less than 15 ng/g. Ratios of p,p'-(DDD DDE)/DDT in soils under three land usages were: paddy field ＞ tree land ＞ fallow land, indicating that land usage inlfuenced the degradation of DDT in soils. Ratios of p,p'-(DDD DDE)/DDT ＞1, showing aged residues of DDTs in soils of the Taihu Lake region. The results were discussed with data from a former study that showed very low actual concentrations of HCH and DDT in soils in the Taihu Lake region, but according to the chemical half-lives and their concentrations in soils in 1980s, the concentration of DDT in soils seemed to be underestimated. In any case our data show that the ban on the use of HCH and DDT resulted in a tremendous reduction of these pesticide residues in soils, but there are still high amounts of pesticide residues in soils, which need more remediation processes.     

漓江桂林市区段表层沉积物有机氯农药分布特征

对漓江桂林市区段沉积物中有机氯农药分析结果表明,沉积物中总OCPs为0.94~56.68ng/g(平均值13.77ng/g),在国内处于中等水平.上游蚂蝗洲附近和下游瓦窑受有机氯农药污染最为严重,中游河段污染较轻.18种检出的有机氯农药中,六氯苯含量最高,其次为HCHs,这与当地使用历史有关.(DDE＋DDD)/DDT比值(平均值为2.79)表明DDT降解比较完全,DDE/DDD比值说明沉积物降解主要发生在厌氧条件下.同分异构体比例分析说明漓江市区河段HCH类农药以历史残留为主,而蚂蝗洲附近有大量林丹输入,需引起相关部门重视.     

北京地区松叶中有机卤素污染物的研究

利用中子活化分析(NAA)技术测定了北京市不同“功能区”松叶中可萃取有机卤素污染物(EOX)的含量,结果表明,化工工业区松叶中可萃取有机氯(EOCl)含量高达40mg/g(干重),钢铁工业区的松叶含量最低(12mg/g).松叶中EOCl、可萃取有机溴(EOBr)、碘(EOI)含量顺序为EOCl>>EOBr>EOI, EOCl在总EOX中占到了97%以上.在EOCl中,有机氯农药仅占0.2%～1.9%,松叶中绝大多数EOCl为未知的.4个城市“功能区”中EOCl含量顺序为化工工业区>交通枢纽地带>居民区>钢铁工业区.城区大气中有机氯污染物主要来自化学工业和交通污染.城区松叶中EOCl的含量远高于偏远山区的样品,但两地样品中EOBr、EOI的含量无显著差异.     

官厅水库周边土壤中有机氯农药残留的统计分布特征

采用气相色谱(GC ECD)分析方法测定了官厅水库周边地区土壤样品中HCH、DDT、七氯、艾氏剂等多种有机氯农药的含量,采用数理统计方法研究了不同土地利用类型、不同采样方位与土壤中有机氯农药含量的关系.结果表明,官厅水库周边地区土壤中总HCH含量为0～19 63ng g-1(中位数0 50ng·g-1),总DDT含量为0～176 01ng·g-1(中位数4 42ng·g-1).其它几种有机氯农药的含量未检出.不同的土地利用类型土壤中HCH和DDT的含量均有显著性差异,不同的官厅水库方位对土壤中HCH和DDT的含量不造成显著影响.     

杭州湾滨岸潮滩表层沉积物中有机氯农药的分布特征

运用气相色谱-电子捕获(GC-ECD)法对杭州湾滨岸潮滩表层沉积物样品中的有机氯农药(OCPs)进行了定量分析.结果表明,沉积物中有机氯农药(OCPs)总含量在2.38～17.71 ng·g-1(以干重计,下同)之间,其中,六六六类(HCH)农药含量在0·33～8·75 ng·g-1之间,滴滴涕类农药(DDT)含量在0...     

珠江干流河口水体有机氯农药的研究

参考美国EPA标准对珠江干流河口表层水样颗粒相和溶解相有机氯农药进行定量分析,并对有机氯农药的含量及分布进行探讨,结果显示,洪季、枯季水体中有机氯农药总量(颗粒相和溶解相)分别是9.7～26.3ng/L、41.7～122.5ng/L;洪季、枯季HCHs总量分别为5.8～20.6ng/L、13.8～99.7ng/L, DDTs总量分别是0.52～1.13ng/L、5.85～9.53ng/L,其它有机氯农药总量分别为3.36～8.51ng/L、17.5～61.5ng/L.珠江干流河口水体的DDT/(DDE+DDD)比值向口门方向有逐渐递增趋势,表明沿程(特别是东江网河区)不断有浓度相对较高的DDT输入或仍有新使用的DDT农药进入珠江干流水体.     

DDTs在海河干流市区段沉积物/水间迁移行为研究

于2007年8月~2008年3月对海河干流表层水和沉积物中滴滴涕(DDTs)污染状况进行了采样调查.结果表明,海河干流水体DDTs含量为6.88~78.82 ng/L(均值28.54 ng/L),表层沉积物中DDTs含量为5.82~45.5 ng/g(均值21.55 ng/g),表层水和表层沉积物中DDTs主要成分分别为p,p-′DDT和p,p-′DDE.利用稳态非平衡逸度模型计算了p,p-′DDT在海河干流沉积物/水间迁移和分布,模型结果用现场实测浓度进行验证,计算值与实测值吻合很好.模型参数灵敏度分析进一步表明,生物降解速率常数、污染物在悬浮颗粒物/水间分配系数以及水体颗粒物沉降通量是影响p,p-′DDT在沉积物/水间迁移过程的主要因素.     

太湖沉积物中有机氯农药的残留特征及风险评估

分析了太湖沉积物中的有机氯农药残留情况,发现DDT及其代谢产物、HCH的异构体、艾氏剂、狄氏剂、六氯苯、七氯等在几乎所有的样品中均被检出.其中β-HCH、p,p'-DDE和六氯苯的残留水平最高,平均值分别达到6.572ng/g、1.432ng/g和2.158ng/g(干重),沉积物的HCHs含量明显高于DDTs.有机氯农药的主要来源为地表径流入湖、大气沉降和工业污水排放.数据表明太湖沉积物的HCHs、DDTs比报道的中国江河沉积物高,但低于海湾沉积物.根据海洋风险评估值进行对比,太湖沉积物中有机氯农药的生态风险较低.     

府河和白洋淀沉积物中DDTs的分布特征和风险评估

利用气相色谱-质谱(GC-MS)检测了府河和白洋淀共计19个表层沉积物样品中的w(DDTs)及其分布特征. 结果表明,w(DDTs)为1.74～51.33 ng/g (以干质量计),平均值为11.01 ng/g,其分布特征呈现从府河到白洋淀逐渐递减的趋势. 与国内其他地区沉积物相比,府河和白洋淀地区DDTs的污染处于中等偏低的水平. 在所有沉积物样品中,p,p′-DDT所占比例较大,是最主要的异构体. 大部分样品中w(DDD)/w(DDE)大于1,而w(DDT)/w(DDE+DDD)小于1,说明研究区DDT处于厌氧环境条件,且没有新的DDT输入. 该地区DDTs主要来源于农田土壤侵蚀及工业废水排放. 潜在风险评估表明,府河和白洋淀的表层沉积物中DDTs对周围环境具有一定的影响,应引起相关部门的重视.      

太湖梅梁湾沉积物中有机氯农药的残留现状

采用GC/ECD分析了梅梁湾沉积物中有机氯农药的残留现状.所测样品中有机氯农药总浓度为1.78～64.74ng/g,其中,HCHs、DDTs在几乎所有采样点都有检出,含量分别是0.23～1.81ng/g、1.78～63.08ng/g.HCHs中,α-HCH与γ-HCH残留水平相当,未检出β-HCH.DDTs中p,p'DDE残留水平较高.数据表明有机氯农药中HCHs可能有新的污染源输入,DDTs在多数采样点发生好氧生物降解,与国内不同水体表层沉积物中HCHs、DDTs的含量相比,梅梁湾沉积物中有机氯农药含量较低.     

Application of sewage sludge and intermittent aeration strategy to the bioremediation of DDT-and HCH-contaminated soil

Adding organic amendments to stimulate the biodegradation of pesticides is a subject of ongoing interest. The effect of sewage sludge on the bioremediation of dichlorodiphenyltrichloroethane（DDT） and hexachlorocyclohexane（HCH） contaminated soil was investigated in bench scale experiments,and intermittent aeration strategy was also used in this study to form an anaerobic–aerobic cycle. Bioremediation of DDT and HCH was enhanced with the addition of sewage sludge and the intermittent aeration. The removal rates of HCH and DDT were raised by 16.8%–80.8% in 10 days. Sewage sludge increased the organic carbon content from 6.2 to218 g/kg,and it could also introduce efficient degradation microbes to soil,including Pseudomonas sp.,Bacillus sp. and Sphingomonas sp. The unaerated phase enhanced the anaerobic dechlorination of DDT and HCH,and anaerobic removal rates of β-HCH,o,p′-DDT and p,p′-DDT accounted for more than 50% of the total removal rates,but the content of α-HCH declined more in the aerobic phase.     

Levels, distributions, and source identification of organochlorine pesticides in the topsoils in Northeastern China

Seventeen topsoil samples (9 urban, 4 suburban, 3 rural and 1 background) were collected in/around Harbin, a typical city in northeast of China, to measure concentration levels of organocholrine pesticides (OCPs) in topsoil of Northeastern China in 2006. Hexachlorohexanes (HCH), dichlorodiphenyltrichloroethane (DDT), and hexachlorobenzene (HCB) were detected in soil samples with mean concentrations (in pg/g dry weight (dw)) of 7120, 5425, and 1039, respectively. The mean concentrations for other OCPs were very low, 4.8 pg/g dw for chlordane and 3.3 pg/g dw for endosulfan. Source identification analysis reveals that all OCPs found in soil samples were due to historical use of these chemicals or from other source regions through long- and short-range atmospheric transport. DDT was mainly used in the rural sites, whereas the sources of HCB, chlordane and endosulfan were mainly in the urban area. HCH was found almost equally in both urban and rural area. Soil concentrations of all detected OCPs, except HCHs, in and around Harbin were much lower than those in the southeast of China, which is expected since the use of these OCPs in the former was much lower than that in the latter, however higher HCH concentrations in and around Harbin than those found in most places of the Southeast China is not expected. It is suggested that high HCH concentration in soil of Northeast China was most likely due to long-range atmospheric transport (LRAT) from Southeast China and the cold condensation process.     

丹江口水库库边降雨径流中有机氯农药赋存及风险评价

在南水北调中线源头区丹江口水库典型区域,根据不同土地利用类型修建了5组径流场来收集径流,研究了降雨径流水相及颗粒相中有机氯农药的分布特征及来源,并对其进行了风险评价.采用GC/MS对降雨径流中美国EPA优先控制的20种有机氯农药(OCPs)进行了检测分析.结果表明,径流颗粒物中有α-HCH和DDE两种有机氯农药检测出,而水相中仅有α-HCH一种有机氯农药检测出,不同利用类型土地径流颗粒物中OCPs含量的基本趋势为: 耕地(137.35ng/g)>果园(43.74ng/g) >山林(26.89ng/g),水相中OCPs含量的基本趋势为:耕地(1.94ng/L) >果园(1.90ng/L)>山林(1.19ng/L),说明耕地和果园受人为污染的影响,这和当地的开发情况也非常符合;同种土地利用类型径流中OCPs含量的基本趋势为: 10~15°耕地>5~10°耕地>0~5°耕地,由此可知,径流中OCPs含量随坡度的增加而增加,可能是由于坡度增大径流量也随之增大,降雨冲刷对土壤中有机氯农药的影响较大.对降雨径流中α-HCH和DDE进行源解析,α-HCH可能来自早期残留,部分也可能来自大气沉降;而DDE可能源之早期施用的DDT农药在好氧条件下分解产物.     

Gridded inventories of historical usage for selected organochlorine pesticides in Heilongjiang River Basin, China

Introduction O rganochlorine pesticides (O C Ps) is a com m on nam e of a group of pesticides consisting of benzene and chlorine. Som e of O C Ps belong to persistent organic pollutants (PO Ps) that are sem i-volatile, bioaccum ulative, persistent and toxic (V allack et al., 1998; Jones and de V oogt, 1999). O CPs are ubiquitous pollutants due to their long-range transport potential. These chem icals have even been found in rem ote areas like the A rctic (M acdonald etal., 2000; A M A …     

某农药厂废弃场地六六六和滴滴涕污染分布特征及风险评价

研究了某农药厂废弃场地土壤中六六六（α,β,γ,δ-HCH）和滴滴涕（p,p＇-DDT,o,p＇-DDT,p,p＇-DDD,p,p＇-DDE）的污染分布特征,并对其进行了风险评价.从该场地72个点位的0～400 cm深度土壤中共采集了232个样品,分析表明六六六残留含量为2.6～80 130μg/kg,滴滴涕残留含量为...     

长江口南岸水体SPM和表层沉积物中OCPs的赋存

利用GC-ECD对长江口南岸14个采样点水体悬浮颗粒物(SPM)及表层沉积物进行了有机氯农药(OCPs)的测定,分析了其中HCHs和DDTs的赋存水平和形态分布.研究表明,OCPs的含量水平有DDTs>HCHs的趋势;悬浮物中污染物浓度高于表层沉积物.悬浮物中HCHs污染水平分布在6.24～14.75ng/g,平均值为12.27ng/g;DDTs的污染水平为3.36～25.66ng/g,平均值为16.37ng/g.而表层沉积物中HCHs含量为1.19～8.22ng/g,平均值5.92ng/g;DDTs的含量水平为4.96～14.94ng/g,平均值为8.92ng/g.研究区内OCPs的含量低于ER-M值,对环境生物具有潜在的危害性.