有机氯农药在东方白鹳组织里的浓度

对越冬迁徙期间中途停留在天津北大港的野生鸟类-东方白鹳（Ciconia boyciana）体内肌肉、肝脏、心脏、胃和脾中∑OCPs浓度进行了检测.各组织中检出的∑OCPs平均浓度（浓度范围,以脂重计）在心脏中最高,为955.30ng/g（88.65～4102.577ng/g）,次之为肝脏,平均浓度为465.55ng/g（37.96～1476.17ng/g）,再次之为胃、脾和肌肉,浓度分别为251.64ng/g（102.88～354.61ng/g）、176.5ng/g（158.72～194.50ng/g）和143.96ng/g（10.90～800.51ng/g）.在肝脏和心脏中∑DDTs和浓度高于∑HCHs,在其它组织中则相反.与其它研究相比,本研究所检测鸟体内有机氯浓度较低,表明这批东方白鹳并尚未受到环境中OCPs的严重污染.     

连云港潮滩表层沉积物中有机氯农药残留特征与风险评估

利用GC-ECD检测了连云港地区绣针河口、临洪河口、灌河口北和灌河口南等4个潮滩断面表层沉积物中DDTs和HCHs含量及组成成分.结果表明,连云港潮滩沉积物中有机氯农药的含量在2.15—24.84 ng.g-1之间,均值为9.09 ng.g-1.其中DDTs的含量在1.11—11.74 ng.g-1之间,均值为3.72 ng.g-1,HCHs的含量在0.38—20.17 ng.g-1之间,均值为5.36 ng.g-1.4个断面有机氯农药含量的顺序是临洪河口>绣针河口>灌河口北>灌河口南.连云港潮滩沉积物中HCHs主要来源于早期林丹在土壤中的残留,灌河口有新的DDT污染源输入.总有机碳是影响绣针河口和临洪河口潮滩有机氯农药分布的主要因素.以风险低值(ERL)为评价基准,沉积物中有机氯农药的最大风险商达到7.43,连云港潮滩有机氯农药存在着一定的潜在生态风险.     

辽河和太湖沉积物中PAHs和OCPs的分布特征及风险评估

于2009年6月分别采集辽河和太湖表层沉积物样品,测定了多环芳烃(PAHs)和有机氯农药(OCPs)的含量.结果表明,辽河表层沉积物中∑PAHs含量(干重)为120.8~22120ng/g,平均值为3281ng/g,处于较高的水平;太湖∑PAHs的含量为256.6~1709ng/g,平均值为829.0ng/g,处于中等水平.两采样区的PAHs以4环和5~6环为主,荧蒽含量最高,PAHs主要因热解产生.辽河和太湖表层沉积物中OCPs的含量均处于较低水平,且均以β-HCH为主.利用相平衡分配法建立了15种PAHs和8种OCPs的沉积物基准值,对沉积物中PAHs和OCPs进行了生态风险评估,结果显示辽河流域的浑河段均有∑PAHs、∑DDTs和∑HCHs超标点位,具有较大的生态风险;太湖流域未发现超标点位,沉积物中各类污染物中含量均未超过基准值,生态风险较小.     

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.     

有机微污染物在污水处理过程中的变化研究

多环芳烃等有毒有机微污染物对污水处理综合指标BOD、COD和TOC等的贡献极小,但危害却很大.采用固相萃取的前处理方法和GC/MS、GC/μECD的分析方法,针对北京市某污水处理厂的总泵进水、二沉出水以及混凝沉淀出水中有机氯农药、多环芳烃和酚类的浓度进行分析.研究结果表明,在不同处理工艺段中,有机氯农药、多环芳烃和酚类的质量浓度分别为nd～10、nd～835、nd～3 248 μg/L.所有检出化合物均未超出中国污水与地表水相应标准限值,其中多环芳烃和酚残留水平较高,应为重点监测对象.这些污染物多数能够在二级处理过程中得到有效去除,但混凝沉淀并没有显著地进一步去除效果.     

有机氯农药在湖北省菜地土壤中的污染研究

采集了湖北省武汉、宜昌、襄阳地区的45个菜地土壤样品,测定其中11种有机氯农药的残留量,并对其残留特征和污染来源进行了研究分析。结果表明,所有土壤样品中均检出有机氯农药,但大多数点位的污染物含量均低于相关标准限值,通过数据统计和因子分析法得出p,p’-DDT、p,p’-DDE为主要污染物。计算特征比值后发现,该地区滴滴涕污染可能源于传统工业滴滴涕和三氯杀螨醇的混合源,既有早期污染也有新污染的输入,六六六污染主要源于林丹,氯丹残留主要源于早期污染。     

胶州湾岩心柱状沉积物中有机氯农药的气相色谱法测定

采用气相色谱法(GC)测定了胶州湾中部岩心柱状沉积物中10种常见的有机氯农药,发现狄氏剂、p,p'-DDT、异狄氏剂和β-666等4种是该海域主要的有机氯农药污染物.其中狄氏剂和p,p'-DDT的检出率为100%,其余2种分别为44%和67%.10种有机氯农药在样品中的总含量为(4.2～121.8)×10-12(干重).调查站位上4种主要的有机氯农药在柱状沉积物中的垂直分布特征为表层至20～22 cm层位其含量随深度的增加而增大;在22 cm以深层位,∑OCPs迅速降低,可能与深层沉积物中的氧化-还原条件以及微生物作用等环境因素引起的降解速率增大有关.     

Distribution and bioaccumulation of organochlorine pesticides in surface sediments and benthic organisms from Taihu Lake, China

The spatial distribution and bioaccumulation of organochlorine pesticides (OCPs) in surface sediments and benthic organisms from Taihu Lake were studied. OCPs were detected in all sediment samples with total concentrations ranging from 4.22 to 461 ng g⁻¹ dry weight (dw). The ratios of certain metabolites to their parent compounds indicated there are still new inputs of parent DDT (dichlorodiphenyltrichloroethane) to Taihu Lake, while the highest residues of HCHs (hexachlorocyclohexanes) mainly came from earlier usage and fresh γ-HCH (lindane). No positive correlation was found between the distribution of OCPs and organic matter contents in sediments. Concentrations of OCPs and lipids in typical large benthic organisms, Bellamya aeruginosa (B. aeruginosa) and Corbicula fluminea (C. fluminea), increased with body weight. HCHs, DDTs, chlordanes and heptachlors were the dominant compounds detected in organisms and C. fluminea accumulated much more OCP than B. aeruginosa. Higher values of biota-sediment accumulation factor (BSAF) were detected in C. fluminea, which was both affected by biological characteristics of the organisms and physicochemical properties of the compounds.     

Concentrations and characteristics of organochlorine pesticides in aquatic biota from Qiantang River in China

The Qiantang River is a typical river flowing through an agricultural area in China. It was studied in 2006 for its aquatic biota quality by determining 13 organochlorine pesticides (OCPs) in the edible parts of crabs, clams, shrimp, fish, aquatic plants, as well as water and sediments collected from seven sites along its upper reaches all the way downstream. The levels of all insecticides were in the range of 17+/-13 (water plants), 35+/-36 (shrimp), 32+/-14 (crabs), 39+/-21 (clams), 47+/-35 (fish) ng/g wet weight (ww) and in the range of 2936+/-2356 (water plants), 5827+/-6013 (shrimp), 2102+/-966 (crabs), 1859+/-1018 (clams), 3624+/-11331 (fish) ng/g lipid. DDT and its metabolites were the predominant contaminants in most biota. A linear relationship was observed between the log bio-concentration factor (BCF) and log octanol-water partition coefficients (Kow) for fish, clams and shrimp. Composition analyses in various environmental media indicated a recent usage of lindane and dicofol into the river.     

鼠李糖脂对林丹-重金属复合污染土壤的同步淋洗效果研究

选取典型有机氯农药林丹及典型重金属Pb、Cd为目标污染物,以模拟污染土壤为对象,考察了鼠李糖脂对林丹/重金属的增溶/配合作用及其影响因素,同时分析了淋洗前后土壤重金属的形态变化,并深入研究了鼠李糖脂对林丹-重金属复合污染土壤的淋洗效果.结果表明,林丹溶解度随鼠李糖脂浓度及离子强度的提高显著增大,但随pH(5.0~10.0)的提高而逐渐降低.鼠李糖脂对Pb的配合能力大于Cd,两种重金属的配合浓度随鼠李糖脂浓度的增加而增加;pH提高对Pb的配合有抑制作用,而对Cd有所促进.鼠李糖脂在土壤上的吸附符合线性等温吸附.当鼠李糖脂浓度高于5000 mg·L-1时,其对3种污染物的淋洗开始有显著效果;当鼠李糖脂浓度为40000 mg·L-1时,其对林丹、Pb及Cd的去除率分别达到76.9%、18.0%和100%,且pH为7.0时淋洗效果最好.同时,鼠李糖脂对不同形态Pb和Cd的去除能力有差异,其中,对可交换态重金属的去除最为有效.