北京市场淡水鱼中七氯和环氧七氯含量及分布

测定了北京市场上4种淡水鱼(草鱼、鲤鱼、鲫鱼和鳙鱼)的不同器官或组织(鱼脑、鱼泡、肝脏和肌肉)中w(七氯)和w(环氧七氯),分析了其分布特征及人体暴露健康风险. 结果表明:①w(七氯)平均值为(0.09±0.14) ng/g,范围为nd～0.82　ng/g;w(环氧七氯)平均值为(0.02±0.02) ng/g,范围为nd～0.14　ng/g,比国内外相关文献的研究结果的量级低. ②不同鱼种间w(七氯)和w(环氧七氯)均无显著差异;不同器官或组织间,鱼泡中w(七氯)显著高于鱼脑、肝脏和肌肉,w(环氧七氯)在四者间无显著差异. ③经对数变换,w(七氯)和w(环氧七氯)与脂含量有一定的相关性. ④鱼体中w(七氯)远低于联合国粮食与农业组织、世界卫生组织(1993)规定的浓度要求,食用时存在较小的健康风险.      

多溴联苯醚在市场鲫鱼体内分布和食鱼暴露量

利用气质联用仪(GC-NCI-MS)方法定量分析了台州路桥区河流野生鲫鱼肌肉、菜市场养殖鲫鱼肌肉、肝脏、脑、心脏和卵组织中多溴联苯醚(polybrominated diphenyl ethers,PBDEs)的含量及分布特征,并且评估了当地人通过食鱼的PBDEs暴露量.结果表明,电子垃圾拆解点附近河流鲫鱼肌肉中PBDEs含量显著高于没有明显PBDEs污染源的菜场养殖鲫鱼;PBDEs在养殖鲫鱼组织中分布不均,心脏组织中ΣPBDEs含量最高,均值为18.82 ng·g-1(湿重),卵组织中最低,均值为1.97ng·g-1.菜场养殖鲫鱼各组织中PBDEs同系物分布模式相似,BDE-47是最主要同系物,比例均值大于50%,其次是BDE-183(约20%),再次BDE-99和-153;河鱼肌肉组织中PBDEs同系物与养殖鲫鱼不尽相同,河鱼肌肉组织中主要同系物是BDE-47、-153和-99.这些结果可能暗示了来自上游的简单电子垃圾拆解行为是河流鲫鱼中较高PBDEs含量的一个污染来源.台州居民通过食用河流鲫鱼途径的PBDEs日均暴露量约为29.0 ng,稍微高于其他地区.     

血吸虫病疫区鱼体器官中氯苯化合物的污染特征

采用GC/MS技术对典型血吸虫病疫区3种(共68尾)具有代表性鱼体的肌肉、性腺、脑、肾脏和肝脏等器官进行分析.实验发现各鱼体组织器官样品中二氯苯和六氯苯为优势污染物,分析其来源发现研究区域六氯苯主要来源为当地施用的五氯酚类杀螺剂,二氯苯来源为六氯苯降解和当地居民日常生活用品.同时发现该地区鱼体不同器官内CBs(chlorobenzenes,CBs)含量有所差异,肌肉中CBs几何均值的含量(脂肪重,下同)范围为2 731.50~7 811.23 ng·g~(-1),性腺含量范围为2 557.89~4 640.05 ng·g~(-1),脑中含量范围为2 423.18~3 329.61 ng·g~(-1),肾脏中含量范围为1 628.05~4 667.76 ng·g~(-1),肝脏中含量范围为704.92~1 086.96 ng·g~(-1).实验结果与国内外相关研究报道值比较,显示该区域鱼体各器官中二氯苯和六氯苯含量处于较高污染水平,应引起重视.     

四溴双酚A在5种巢湖鱼类体内的组织分布与生物浓缩因子研究

利用SPE-HPLC法,分析了四溴双酚A（TBBPA）在巢湖5种经济鱼类体内的组织分布及生物浓缩因子.结果表明,TBBPA在5种鱼体内的平均含量（以干重计）为4.70～11.20 ng.g-1,高低排序为白鱼〉白鲢〉鳙鱼〉鲤鱼〉长吻鮠.不同器官中,白鱼、鳙鱼、鲤鱼和长吻鮠的肾脏中TBBPA含量最高,其次为肝脏和鳃,腹部和背部组织含量较低,无显著脂肪蓄积效应.白鲢体内肝脏的TBBPA含量最高,肾脏和鳃次之.对白鱼各组织中TBBPA含量与体重间的相关关系分析表明,肝脏、肾脏和鳃中TBBPA浓度随体重的增加而增大,而背部、腹部无显著相关关系.同时测得巢湖水体中TBBPA平均浓度为0.52μg.L-1,计算得到5种鱼的生物浓缩因子为9.56～22.64,表明TBBPA在巢湖鱼体中的浓缩效应不显著.     

巢湖水体和水产品中多环芳烃的含量与健康风险

利用GC-MS测定了巢湖水体15个样品及9种主要水产品中16种优控多环芳烃(PAHs)的含量,并用美国环保局(USEPA)推荐的健康风险评价模型估算了巢湖地区居民由于饮水、洗澡及食用水产品造成的PAHs暴露量.在此基础上,利用概率风险评价和蒙特卡罗模拟方法分析了巢湖水体与水产品中PAHs的健康风险及其不确定性.研究结果表明,巢湖水体中16种优控PAHs总含量(PAH16)范围为95.63～370.13ng·L-1,平均为(170.72 ±70.79) ng·L-1,BaP当量浓度(Bapeq)为(1.43±0.79) ng·L-1;水产品中PAH16的干重含量范围为129.33 ～575.31 ng·g-1,均值为(320.93±147.50) ng·g-1,BaP当量浓度为(4.67±6.68) ng·g-1.巢湖地区居民由于饮水和洗浴造成的PAH16暴露量分别为(5.76±2.39)×10-3 ng·kg-1·d-1和(25.08±10.40)×10-3 ng·kg-1·d-1,城镇与农村居民食用水产品造成的PAH16暴露量分别为(190.86±84.17) ng· kg-1· d-1和(75.88±33.47) ng·kg-1·d-1;水产品食用是巢湖地区居民PAHs暴露的主要途径.洗浴和饮水造成的PAH16暴露风险分别为(6.33±4.70)×10-9 a-1和(4.32±2.47) ×10-7 a-1,城镇与农村居民食用水产品造成的PAH16暴露风险分别为(3.17±3.79)×10-5 a-1和(1.25±1.50) ×10-5 a-1;居民食用水产的PAH16暴露风险高于USEPA建议的可接受风险(1.0×10-6 a-1),存在一定的致癌风险.水产品食用风险的不确定度较高,Bap当量浓度是影响风险评估不确定性的主要因素.     

血吸虫病疫区水生生物体内氯苯化合物的污染特征与潜在风险

采用GC/MS技术对典型血吸虫病疫区不同水期采集的1种软体生物和5种鱼体肌肉进行分析.实验发现3类二氯苯和六氯苯(HCB)为优势污染物.ΣCBs在软体生物肌肉中几何均值(以脂肪质量计,下同)为11 947 ng·g-1;在鱼体肌肉中范围为1 851~8 159 ng·g-1,鱼体ΣCBs最高浓度出现在鲶鱼体内,最低浓度出现在鲫鱼体内;实验结果与国内外相关文献报道值比较,显示该区域软体生物体内HCB含量与其他区域相当;鱼体肌肉中HCB含量则处于较高污染水平.癌症风险评价结果表明因软体生物和鱼类摄入HCB而带来的风险分别为1.49×10-7和3.73~21.1×10-7,说明研究区域水生生物中因HCB污染引起的癌症风险处于可接受水平.     

汞在小浪底水库的赋存形态及其时空变化

为了解小浪底水库汞的赋存状况,采用冷原子荧光光谱法测定了小浪底水库水体、表层沉积物、沉积物间隙水以及鱼类肌肉样品中的总汞,采用乙基化衍生-气相色谱-原子荧光法测定了上述样品中的甲基汞,进而分析了小浪底水库鱼体中汞的富集状况.结果表明,小浪底水库水体中丰、枯水期总汞浓度分别为0.71~1.42 ng·L-1和0.90~2.49 ng·L-1,均符合国家地表水环境质量标准(GB 3838-2002)一类水汞浓度标准限值,水样中未检出甲基汞.丰、枯水期沉积物中总汞浓度分别为51.74~90.42 ng·g-1和95.66~172.52 ng·g-1,甲基汞浓度分别为0.09~0.26 ng·g-1和0.18~0.39 ng·g-1,甲基汞浓度较低,这可能与水体底层溶解氧浓度较高以及沉积物中有机碳浓度较低有关.丰、枯水期沉积物间隙水总汞浓度分别为4.27~9.49 ng·L-1和5.46~41.04 ng·L-1,甲基汞浓度分别为0.09~0.99 ng·L-1和0.07~1.01 ng·L-1,间隙水中总汞和甲基汞浓度明显高于上覆水体,与水体间存在汞浓度梯度,可能存在从沉积物间隙水向水体中的扩散.鱼体肌肉总汞浓度在43.47~304.98 ng·g-1之间,甲基汞浓度为10.77~265.23 ng·g-1,甲基汞低于食品安全国家标准规定的污染物限量(GB 2762-2012)(非肉食性鱼500 ng·g-1和肉食性鱼1 000 ng·g-1).水库鱼体总汞的生物富集系数分别为鳙鱼1.3×105,梭鱼9.3×104,鲫鱼4.7×104,白条5.0×104,黄颡鱼1.7×105,弓鱼3.9×104.     

深圳大鹏湾海域表层沉积物和生物体中多环芳烃残留及其风险评价

为了研究深圳大鹏湾海域沉积物和生物体中多环芳烃的污染状况,2011年10月在大鹏湾采集表层沉积物及鱼类、虾类和贝类等生物样品,采用气相色谱-质谱法(GC-MS)分析了16种优先控制多环芳烃(PAHs)的含量.结果表明,大鹏湾海域表层沉积物和生物样品中PAHs总量范围分别为216.56~1 314.92 ng·g-1(干重,下同)和70.88~251.90 ng·g-1(湿重,下同);生物样品按平均含量计,鱼类最高(171.52 ng·g-1),贝类次之(134.75 ng·g-1),虾类最低(123.35 ng·g-1).与全球其他海域相比,大鹏湾海域表层沉积物和生物体PAHs污染处于中等水平.沉积物中PAHs的组成以4环为主,来源分析表明该海域PAHs污染主要来源于化石燃料燃烧源和石油污染源的共同输入.生物体中PAHs主要为2~3环PAHs,这与其生活习性和污染物的生物可利用性等因素有关.风险评价表明,大鹏湾表层沉积物中的PAHs在一定程度上可能会对该海域生物产生不利影响;生物样品PAHs的苯并(a)芘等效浓度值相对较高,长期食用这些水产品可能会有潜在的健康风险.     

电子垃圾拆解区污染池塘中鱼类多氯联苯及其代谢产物的组织分配及暴露风险

对一受电子垃圾污染池塘内两种鱼类(鲮鱼和乌鳢)体内各组织中多氯联苯(PCBs)及其甲磺基代谢产物(Me SO2-PCBs)进行了分析.鲮鱼和乌鳢体内各组织中总PCBs(ΣPCBs)的平均含量分别为560~10 462 ng·g-1和580~50 492ng·g-1(湿重),两种鱼体内肝脏中的PCBs含量均高于其他组织.PCBs在鱼体组织内的分布与不同组织的脂肪含量有关.鲮鱼和乌鳢体内各组织中ΣMe SO2-PCBs的平均含量分别为0.44~53 ng·g-1和1.86~132 ng·g-1,这一浓度水平比之前国外报道的最高浓度高1个数量级.除PCB149外,鲮鱼体内手性PCB单体的EF值与沉积物相比存在下降趋势;而在乌鳢体内则正相反,在鲮鱼体内已下降的EF值在乌鳢体内则出现回升,有些单体的EF值甚至高于沉积物.这一结果可能表明PCBs在两种鱼体内的手性选择性代谢特征正好相反.鱼体内高含量的ΣPCBs和ΣMe SO2-PCBs对当地居民具有较高的暴露风险,因此,限制这些鱼类在市场的流通对于降低当地居民健康风险具有重要意义.     

广东典型海水养殖区沉积物及鱼体中磺胺类药物的残留及其对人体的健康风险评价

采用高效液相色谱-紫外检测器(HPLC-UV)分析了广东沿海大亚湾和阳江两个典型海水养殖区中沉积物以及7种养殖鱼类肌肉和肝脏组织中磺胺嘧啶(SDZ)、磺胺二甲嘧啶(SM2)和磺胺甲基异噁唑(SMX)的残留量,并依据药品最高残留量(MRL)值和每日允许摄入量(ADI)值对海水养殖鱼类中磺胺类抗生素污染进行人体健康风险评价.结果表明,在所有沉积物样品中都能检出磺胺类抗生素.含量(干重)范围为:2.1~35.2 ng·g-1,检出率大小顺序为SDZ(85.7%)>SM2(71.4%)>SMX(28.6%).大亚湾养殖区磺胺药物在沉积物和鱼类样品中的检出频率大于阳江养殖区.3种磺胺类药物在鱼肝脏组织中的含量显著高于在肌肉组织中的含量(P<0.05).SDZ、SM2和SMX在鱼体肌肉组织中的含量(湿重)范围分别为11.6~37.9、16.3~27.8和4.9~20.0 ng·g-1.3种磺胺类药物的平均日摄入量范围为3.37~36.72 ng·kg-1,仅占食用肉类ADI的最高限值(50μg·kg-1)的0.007%~0.073%(<1%ADI),健康风险为可以忽略,膳食安全性高.     

Evaluation of phytoextracting cadmium and lead by sunflower, ricinus, alfalfa and mustard in hydroponic culture

Soil contaminated with heavy metals cadmium(Cd)and lead(Pb)is hard to be remediated.Phytoremediation may be a feasible method to remove toxic metals from soil,but there are few suitable plants which can hyperaccumulate metals.In this study,Cd and Pb accumulation by four plants including sunflower(Helianthus annuus L.),mustard(Brassica juncea L.),alfalfa(Medicago sativa L.), ricinus(Ricinus communis L.)in hydroponic cultures was compared.Results showed that these plants could phytocxtract heavy metals, the ability of accumulation differed with species,concentrations and categories of heavy metals.Values of BCF(bioconcentration factor)and TF(translocation factor)indicated that four species had dissimilar abilities of phytoextraction and transportation of heavy metals.Changes on the biomass of plants,pH and Eh at different treatments revealed that these four plants had distinct responses to Cd and Pb in cultures.Measurements should be taken to improve the phytoremediation of sites contaminated with heavy metals,such as pH and Eh regulations,and so forth.     

Oxidation of As(Ⅲ) by potassium permanganate

The oxidation of As(Ⅲ) with potassium permanganate was studied under conditions including pH, initial As(Ⅲ) concentration and dosage of Mn(Ⅶ). The results have shown that potassium permanganate was an effective agent for oxidizing of As(Ⅲ) in a wide pH range. The pH value of tested water was not a significant factor affecting the oxidation of As(Ⅲ) by Mn(Ⅶ). Although theoretical redox analyses suggest that Mn(Ⅶ) should have better performance in oxidization of As(Ⅲ) within lower pH ranges, the experimental results show that the oxidation efficiencies of As(Ⅲ) under basic and acidic conditions were similar, which may be due to the adsorption of As(Ⅲ) on the Mn(OH)2 and MnO2 resulting from the oxidation of As(Ⅲ).     

Distribution and ecological effect of mercury in Laogang landfill, Shanghai, China

Laogang landfill near Shanghai is the largest landfill in China, and receives about 10000 t of daily garbage per day, Samples of topsoil and plants were analyzed to evaluate mercury pollution from the landfill. For topsoil samples, there were significant correlations among total mercury （HgT）, combinative mercury （Hgc） and gaseous mercury （HgG）, and content of total organic carbon （TOC）, but, no significantly relationship was found between Hg content and filling time. Hg content changes in vertical profiles with time showed that the average Hgv of profiles 1992, 1996, and 2000 was similar, but their average HgG was quite different. HgT was significantly correlated with Hgc in profile 1992 and 2000, and Hgv was significantly correlated with Hg6 in profile 1996. HgG/Hgv ratio in profile samples decreased in the order of （HgG,/HgT）1992〉（HgG/HgT）1996〉〉（HgG/HgT）2000. A simple outline of Hg release in landfill could be drawn： with increasing of filling time, degradation undergoes different biodegradation, accordingly, gaseous mercury goes through small, more, and small proportion to total mercury. Distribution of Hg in plants was inhomogeneous, following the order of leaf〉root〉stem. The highest value of leaf may be associated with higher atmospheric Hg from landfill. Ligneous plants （e.g. Phyllostachys glanca, Prunus salicina and Ligustrum lucidum） are capable of enriching more Hg than herbaceous plants.     

EDTA-enhanced phytoremediation of lead contaminated soil by Bidens maximowicziana

Phytoremediation is a potential cleanup technology for the removal of heavy metals from contaminated soils.Bidens maximowicziana is a new Pb hyperaccumulator,which not only has remarkable tolerance to Pb but also extraordinary accumulation capacity for Pb.The maximum Pb concentration was 1509.3 mg/kg in roots and 2164.7 mg/kg in overground tissues.The Pb distribution order in the B. maximowicziana was:leaf>stem>root.The effect of amendments on phytoremediation was also studied.The mobility of soil Pb and the Pb concentrations in plants were both increased by EDTA application.Compared with CK(control check),EDTA application promoted translocation of Pb to overground parts of the plant.The Pb concentrations in overground parts of plants was increased from 24.23-680.56 mg/kg to 29.07-1905.57 mg/kg.This research demonstrated that B.maximowicziana appeared to be suitable for phytoremediation of Pb contaminated soil,especially,combination with EDTA.     

Decomposition of alachlor by ozonation and its mechanism

Decomposition and corresponding mechanism of alachlor, an endocrine disruptor in water by ozonation were investigated. Results showed that alachlor could not be completely mineralized by ozone alone. Many intermediates and final products were formed during the process, including aromatic compounds, aliphatic carboxylic acids, and inorganic ions. In evoluting these products, some of them with weak polarity were qualitatively identified by GC-MS. The information of inorganic ions suggested that the dechlorination was the first and the fastest step in the ozonation of alachlor.     

Enzymatic oxidation of aqueous pentachlorophenol

The influence of the nonionic surfactant Tween 80 on pentachlorophenol （PCP） oxidation catalyzed by horseradish peroxidase was studied. The surfactant was tested at concentrations below and above its critical micelle concentration （CMC）. Enhancement of PCP removal was observed at sub-CMCs. The presence of Tween 80 in the reaction mixture reduced enzyme inactivation which occurred through a combination of free radical attack and sorption by precipitated products. A simple first-order model was able to simulate time profiles for enzyme inactivation in the presence or absence of Tween 80. At supra-CMCs, the surfactant caused noticeable reductions in PCP removal, presumably through micelle partitioning of PCP which precluded the hydrophobic PCP molecule from interacting with the enzyme.     

Chlorobenzenes in waterweeds from the Xijiang River （Guangdong section） of the Pearl River

The Xijiang River is the major source of water for about 4.5 millions of urban population and 28.7 millions of rural population. The water quality is very important for the health of the rural population. The concentration and distribution of chlorobenzenes (CBs) in both water and waterweeds collected from 4 stations in the Xijiang River (Gangdong section) of the Pearl River in April and November were determined. The result showed that nearly every congener of CBs was detected. The total contents of CBs (∑CBs) in the river water ranged from 111.1 to 360.0 ng/L in April and from 151.9 to 481.7 ng/L in November, respectively. The pollution level of CBs in the water in April was higher than that in November. The contents of ∑ CBs in waterweeds ranged from 13.53×102 μg/g to 38.27×102μg/g dry weight (dw). There was no significant difference between April and November in waterweeds. The distribution of CBs in roots, caulis, and leaves of Vallisneria spiralis L. showed different patterns. The leaves mainly contained low-molecular-weight CBs(DCBs), whereas the roots accumulated more PCBs and HCBs. The average lgBCFlip (bioconcentration factor) of CBs ranged from 0.64 to 3.57 in the waterweeds. The spatial distribution character of CBs in the Xijiang River was: Fengkai County ＜ Yunan County ＜Yun'an County ＜ Gaoyao County according to the ∑CBs, and the pollution deteriorated from the upstream to the downstream of the Xijiang River. Further analysis demonstrated that the discharge of waste containing CBs may be the main source of CBs pollution in the Xijiang River.     

Degradation of 2,4-dichlorophenol with a novel TiO2/Ti-Fe-graphite felt photoelectrocatalytic oxidation process

Degradation of 2,4-dichlorophenol(2,4-DCP)was studied in a novel three-electrode photoelectrocatalytic(PEC)integrative oxidation process,and the factors influencing the degradation rate,such as applied current,flow speed of O_2,pH,adscititious voltage and initial 2,4-DCP concentration were investigated and optimized.H_2O_2 was produced nearby cathode and Fe~(2 )continuously generated from Fe anode in solution when current and O_2 were applied,so,main reactions,H_2O_2-assisted TiO_2 PEC oxidation and E-Fenton reaction,occurred during degradation of 2,4-DCP in this integrative system.The degradation ratio of 2,4-DCP was 93% in this integrative oxidation process,while it was only 31% in E-Fenton process and 46% in H_2O_2-assisted TiO_2 PEC process.So,it revealed that the degradation of 2,4-DCP was improved greatly by photoelectrical cooperation effect.By the investigation of pH,it showed that this integrative process could work well in a wide pH range from pH 3 to pH 9.     

Effect of copper on the degradation of pesticides cypermethrin and cyhalothrin

The influence of coexisting copper (Cu) ion on the degradation of pesticides pyrethroid cypermethrin and cyhalothrin in soil and photodegradation in water system were studied.Serial concentrations of the pesticides with the addition of copper ion were spiked in the soil and incubated for a regular period of time,the analysis of the extracts from the soil was carried out using gas chromatography (GC).The photodegradation of pyrethroids in water system was conducted under UV irradiation.The effect of Cu~(2 ) on the pesticides degradation was measured with half life (t_(0.5)) of degradation.It was found that a negative correlation between the degradation of the pyrethroid pesticides in soil and Cu addition was observed.But Cu~(2 ) could accelerate photodegradation of the pyrethroids in water.The t_(0.5) for cyhalothrin extended from 6.7 to 6.8 d while for cypermethrin extended from 8.1 to 10.9 d with the presence of copper ion in soil.As for photodegradation,t_(0.5) for cyhalothrin reduced from 173.3 to 115.5 rain and for cypermethrin from 115.5 to 99.0 min.The results suggested that copper influenced the degradation of the pesticides in soil by affecting the activity of microorganisms.However, it had catalyst tendency for photodegradation in water system.The difference for the degradation efficiency of pyrethroid isomers in soil was also observed.Copper could obviously accelerate the degradation of some special isomers.     

基于综合水质标识指数和对应分析法的校园河道水质评价

以三峡大学的校园河道求索溪为研究对象,利用综合水质标识指数法确定求索溪水质类别,分析其水质时空变化规律,并利用对应分析法得出求索溪中不同监测点的主要污染因子.研究结果表明:求索溪整体的综合水质标识指数为7.423,整体水质为劣V类(地表水环境质量标准GB 3838-2002)且黑臭.从时间变化来看,求索溪4月份的水质最差,5月份次之,4、5月份所有监测点的水质都劣于V类且黑臭;8月份水质最好,水质为Ⅳ类;从空间分布来看,8个监测点综合水质标识指数均超过6.0,水质为劣V类,其中6号监测点的水质相对最好,监测点3号的水质相对最差;对应分析法得出求索溪的整体水体污染程度受总氮因子的影响最大,其次为总磷.该研究拟为求索溪及类似校园河道的水环境治理研究提供基础依据和参考.