嘉陵江重庆段表层水体多环芳烃的污染特征

为了确定嘉陵江重庆段表层水体中多环芳烃(PAHs)的组成、来源及污染特征,于2009年8月采集了8个表层水样,利用GC-MS仪器测定了16种优先控制PAHs的浓度.结果表明,水体中16种优先控制PAHs浓度范围为467.13～987.97ng.L-1,平均浓度值为702.91 ng.L-1,水体PAHs浓度和溶解性有机碳(DOC)含量呈现明显的线性正相关.PAHs的组成以2～3环PAHs为主,占水体ΣPAHs总量的68.90%.寸滩区域水体PAHs主要来源于木材和煤的燃烧污染,朝天门区域水体PAHs主要来源于石油源,嘉陵江重庆段其他区域水体PAHs主要来源于液体石化燃料的燃烧.虽然嘉陵江重庆段整体污染水平较低,但是5个取样点的地表水苯并(a)芘(BaP)含量超过国家地表水质量标准.     

大庆市不同环境介质中多环芳烃污染特征对比及来源解析

为研究不同环境介质中多环芳烃(PAHs)污染特征的异同,对大庆市道路灰尘中多环芳烃的污染特征和来源进行研究,在2012年10月采集了大庆市区23个道路灰尘样品和4个土壤样品.使用戴安ASE300快速溶剂萃取仪提取PAHs,净化浓缩后,利用气相色谱/质谱联用仪(GC/MS)测定了美国环保署列为优先控制污染物的16种PAHs及总PAHs(ΣPAHs)的含量.结果表明,道路灰尘中ΣPAHs含量的范围为579.5~4 656.7 ng·g~(-1),平均值为1839.7 ng·g~(-1).大庆市不同功能区道路灰尘中PAHs占ΣPAHs的质量比例呈现大体相似的特征,低环(2~3环)、中环(4环)、高环(5~6环)PAHs所占比例均值分别为37.9%,37.3%和24.8%.与相关研究中大庆水体及湖泊沉积物中PAHs数据进行对比,发现大庆土壤、湖泊沉积物、湖泊和水泡水体中均为低环PAHs占绝对主导优势,其质量分数高达69.3%~99.97%.ΣPAHs含量的分布受功能区的影响并不显著,与样点周围工厂的类型密切相关.特征化合物比值法表明,研究区PAHs主要来自于石油类燃料的泄漏、石油燃料燃烧及煤炭/生物质燃烧的混合源.正定矩阵因子分解法(PMF)结果表明,研究区道路灰尘中PAHs主要来源为煤炭燃烧、石油泄漏源、工业源以及交通源,其贡献率分别为30.1%、26.9%、23.6%和19.3%,与大庆地区其他环境介质中PAHs来源不完全相同.     

松花江流域冰封期水体中多环芳烃的污染特征研究

在松花江流域的3个主要江段：嫩江、第二松花江和松花江干流,于2010年冰封期采集了21个水体样品,分析了多环芳烃的污染特征.结果表明,15种PAHs的浓度范围为23.4～85.1 ng·L-1,平均浓度为（50.3±17）ng·L-1,与我国其它地区地表水中PAHs的污染程度相当.松花江流域水体中PAHs具有明显的空间分布特征,城市下游浓度高于上游,说明沿岸城市的污水排放可能是松花江水体中PAHs的主要污染源,主成分分析表明,PAHs的主要来源是化石燃料的燃烧源.商值法生态风险评价结果显示,相对分子质量高的PAHs造成的生态风险可以忽略,相对分子质量低的PAHs对松花江水体会造成一定的危害.     

降雨期间岩溶地下河溶解态多环芳烃变化特征及来源解析

2014年6月降雨期间在重庆南山老龙洞地下河出口处进行连续采样监测,利用GC-MS定量分析地下河溶解态中16种优控多环芳烃(PAHs)的含量,研究了降雨期间地下河溶解态PAHs变化特征及来源.结果表明,地下河溶解态PAHs对降雨反应迅速,ΣPAHs出现4个峰值,有2个出现在流量上升阶段,另外两个分别出现在流量最大值处和流量下降阶段.ΣPAHs范围为101~3 624 ng·L-1,平均值578 ng·L-1,7种致癌性PAHs变化较大,含量变化为ND~336 ng·L-1,平均值31.1 ng·L-1,PAHs的组成以低环(2、3环)为主,占水体ΣPAHs的86.17%;降雨对ΣPAHs影响较大,主要表现为雨水对大气污染物的清除及地表径流对地表污染物的冲刷.降雨期间水体中PAHs主要来源于石油类产品、煤炭等化石燃料的不完全燃烧、天然成岩过程,降雨期间老龙洞地下河水体中PAHs污染大部分为中等到重污染水平.     

乌梁素海水体与沉积物中半挥发性有机物污染水平及风险评估

为研究乌梁素海水体与表层沉积物中半挥发性有机物(SVOCs)的污染特征和风险水平,对乌梁素海7个点位的水体和沉积物样品进行检测分析。结果表明：水体与沉积物中SVOCs的总浓度为449.7～691.0 ng/L及144.4～587.5μg/kg;多环芳烃(PAHs)和邻苯二甲酸酯(PAEs)是所有样品中发现的主要污染物;其他SVOCs未检测到或仅检测到微量。水体与沉积物中PAHs污染主要来自石油源及煤炭、生物质燃料燃烧混合来源;PAEs污染主要来自塑料和化工工业,以及生活垃圾;水体和沉积物中主要污染物的生态风险总体上呈低风险。从饮水和暴露接触的角度,乌梁素海呈现的健康风险水平较低。     

河北南部变电站场地土壤中PAHs含量、来源及健康风险

对河北省南部地区28座典型变电站场地土壤中16种优先控制的PAHs含量进行了检测和分析.结果表明,变电站场地土壤中PAHs总量为223.48~1681.17μg/kg,平均值为443.94mg/kg.变电站整体PAHs处于轻微污染水平.利用特征组分比值法和正定矩阵因子分解模型（PMF）分析了污染源类型及贡献率,结果表明,变电站土壤中PAHs主要是石油及其衍生产物污染源,其中生物质和煤炭燃烧等化石燃料燃烧占42.1%,石油及其衍生产物污染源（变压器油、柴油和汽油等混合源）占57.9%.健康风险评价结果表明变电站土壤中PAHs致癌风险较高,非致癌风险相对较低,被测变电站中有潜在致癌风险站点占比为11%,经口摄入和皮肤接触是致癌风险的主要暴露途径,变电站场地内PAHs的生态风险整体处于较低水平.     

河北南部变电站场地土壤中PAHs含量、来源及健康风险

对河北省南部地区28座典型变电站场地土壤中16种优先控制的PAHs含量进行了检测和分析.结果表明,变电站场地土壤中PAHs总量为223.48~1681.17μg/kg,平均值为443.94mg/kg.变电站整体PAHs处于轻微污染水平.利用特征组分比值法和正定矩阵因子分解模型（PMF）分析了污染源类型及贡献率,结果表明,变电站土壤中PAHs主要是石油及其衍生产物污染源,其中生物质和煤炭燃烧等化石燃料燃烧占42.1%,石油及其衍生产物污染源（变压器油、柴油和汽油等混合源）占57.9%.健康风险评价结果表明变电站土壤中PAHs致癌风险较高,非致癌风险相对较低,被测变电站中有潜在致癌风险站点占比为11%,经口摄入和皮肤接触是致癌风险的主要暴露途径,变电站场地内PAHs的生态风险整体处于较低水平.     

深圳市表层土壤多环芳烃污染及空间分异研究

以深圳为研究区域,选择土壤为研究对象,以多环芳烃(polycyclic aromatic hydrocarbons,PAHs)为目标物,采集表层土壤样品188个,调查样品中PAHs的赋存状态,以此为基础,分析土壤PAHs污染水平与城市化进程的关系,并初步评估深圳土壤中PAHs的生态风险.结果表明,表层土壤中的28种PAHs(Σ28PAHs)、16种美国环保署优控PAHs(Σ16PAHs)和7种致癌PAHs(Σ7CarPAHs)的含量范围分别为5~7 939 ng·g-1、2~6 745 ng·g-1和未检出~3 786 ng·g-1.8种土地利用类型中Σ16PAHs平均含量由高到低依次为:交通用地、商业用地、工业用地、农业用地、居住用地、城市绿地、果园和林地.来源分析表明,化石燃料的燃烧是建设用地和非建设用地样品Σ16PAHs的主要来源,贡献率分别为75.1%和68.2%.研究还发现高分子量PAHs浓度和城市化水平呈显著正相关关系,深圳市土壤中PAHs生态风险总体处于较低水平.     

舟山近海水体和沉积物中多环芳烃分布特征

2012年,每两个月采集1次浙江省舟山近海水样及表层沉积物样品,检测16种多环芳烃(PAHs)含量.结果表明,舟山近海水体和沉积物中PAHs均存在显著的时空差异性,水体ΣPAHs浓度范围为382.3~816.9 ng·L-1,平均值为552.5ng·L-1;沉积物ΣPAHs含量范围为1017.9~3047.1 ng·g-1,平均值为2022.4 ng·g-1.空间分布上,水体ΣPAHs最大值和最小值分别出现在小洋山和燕窝山海域,而沉积物中分别出现在小洋山和朱家尖南沙海域.时间变化上,水体ΣPAHs最大值和最小值出现在10月和6月,而沉积物中分别出现在8月和6月.PAHs污染来源主要是油类排放和木柴、煤燃烧的共同叠加作用.结合PAHs的生物阈值,利用超标系数法评价舟山近海PAHs的生态风险,结果表明,ΣPAHs存在较低几率的潜在风险,但苊单体存在较高几率的潜在风险,二氢苊和芴可能存在生态风险.对水-沉积物界面PAHs的富集研究表明,舟山近海沉积物中富集了大量PAHs,富集系数(Kd值)岱山岛大于舟山本岛,并与沉积物的PAHs含量分布一致.     

输水期间于桥水库流域水体中溶解态多环芳烃的分布特征与风险

为调查输水期于桥水库流域水中多环芳烃(PAHs)的分布特征,采用气相色谱-质谱法对该区16种US EPA优先控制的PAHs进行了分析,并对PAHs的健康风险和生态风险进行了评估.结果表明,在18个点位采集的水样中均有PAHs检出,且上游水域和库区PAHs组分和浓度均存在着显著差异.上游水域水体(除洒河大桥点位外)中的PAHs以2~3环为主,其百分比介于86%~95%,ΣPAHs浓度介于13.7~104.1 ng·L~(-1)间,其中大黑汀水库渔业养殖密集区水体中PAHs污染水平较高;库区水体中低环数和高环数PAHs含量相当,ΣPAHs浓度介于1.6~3 512.5 ng·L~(-1)间,其中库区北岸水中PAHs浓度最高.Flu/Pyr、Fla/(Fla+Pyr)比值分析表明,于桥水库流域PAHs主要来自村镇居民燃煤供暖、生物质燃烧.分别采用US EPA健康风险评价模型和Kalf等使用的商值法对PAHs的饮水致癌风险和生态风险进行了评估,结果显示,库区水体的饮水致癌风险水平超过了10-6,以及库区B[a]A、B[k]F、Bap的商值(实际浓度/最大允许参考浓度)也均大于1,说明库区水体PAHs引发的致癌风险和生态风险均应当引起重视.     

Effects of two sludge application on fractionation and phytotoxicity of zinc and copper in the soil

The potential harm of heavy metals is a primary concern in application of sludge to the agricultural land. A pot experiment was conducted to evaluate the effect of two sludges on fractionation of Zn and Cu in soil and their phytotoxicity to pakchoi. The loamy soil was mixed with 0%, 20%, 40%, 60% and 80% (by weight) of digested sewage sludge (SS) and composted sludge (SC). The additions of both sludges caused a significant raise in all fractions, resulting in that exchangeable (EXCH) and organic bound (OM) became predominance of Zn and organic bound Cu occupied the largest portion. There was more available amount of Zn and Cu in SS treatments than SC treatments. During the pot experiment, the concentration of Zn in EXCH, carbonate (CAR) and OM and Cu in EXCH and OM fractions decreased in all treatments, so their bioavailability reduced. Germination rate and plant biomass decreased when the addition rate was high and the best yield appeared in 20% mixtures at the harvest of pakchoi. The two sludges increased tissue contents of Zn and Cu especially in the SS treatments. Zn in pakchoi was not only in relationship to ΔEXCH and ΔCAR forms but also in ΔOM forms in the sludge-soil mixtures. Tissue content of Cu in pakchoi grown on SC-soils could not be predicted by ΔEXCH. These correlation rates between Zn and Cu accumulation in pakchoi and variation of different fractions increased with time, which might indicate that sludges represented stronger impacts on the plant in long-term land application.     

Intraspecific differences in effects of co-contamination of cadmium and

A hydroponic experiment was carried out to study intraspecific differences in the effects of different concentrations of cadmium (Cd)(0-10 mg/L) and arsenate (As(V)) (0-8 mg/L) on the growth parameters and accumulation of Cd and As in six wheat varieties Jing-9428, Duokang-1, Jingdong-11, Jing-411, Jingdong-8 and Zhongmai-8. The endpoints of wheat seedlings, including seed germination,biomass, root length and shoot height, decreased with increasing the Cd and As concentrations. Significant differences in seed germination, biomass, root length, shoot height and the accumulation of Cd and As were observed between the treatments and among the varieties (p ＜ 0.05). The lethal dosage 50% were about 20, 80, 60, 60, 80 and 20 mg As/L for Jing-9428, Duokang-1, Jingdong-11,Jing-411, Jingdong-8 and Zhongmai-8, respectively, and the corresponding values for Cd were about 30, 80, 20, 40, 60 and 10 mg Cd/L, respectively. Among the six varieties, Duokang-1 was found to be the most resistant to Cd and As toxicity, and Zhongmai-8 was the most sensitive to Cd and As co-contamination. The resistance of the six varieties was found dependant on the seedling uptake of Cd and As. Duokang-1 was the most suitable for cultivation in Cd and As co-contaminated soils.     

Toxic effects of acetochlor, methamidophos and their combination on nifH gene in soil

Toxic effects of two agrochemicals on nifH gene in agricultural black soil were investigated using denaturing gradient gel electrophoresis （DGGE） and sequencing approaches in a microcosm experiment. Changes of soil nifH gene diversity and composition were examined following the application of acetochlor, methamidophos and their combination. Acetochlor reduced the nifH gene diversity （both in gene richness and diversity index values） and caused changes in the nifH gene composition. The effects of acetochlor on nifH gene were strengthened as the concentration of acetochlor increased. Cluster analysis of DGGE banding patterns showed that nifH gene composition which had been affected by low concentration of acetochlor （50 mg/kg） recovered firstly. Methamidophos reduced nifH gene richness that except at 4 weeks. The medium concentration of methamidophos （150 mg/kg） caused the most apparent changes in nifH gene diversity at the first week while the high concentration of methamidophos （250 mg/kg） produced prominent effects on nifH gene diversity in the following weeks. Cluster analysis showed that minimal changes of nifH gene composition were found at 1 week and maximal changes at 4 weeks. Toxic effects of acetochlor and methamidophos combination on nifH gene were also apparent. Different nifH genes （bands） responded differently to the impact of agrochemicals： four individual bands were eliminated by the application of the agrochemicals, five bands became predominant by the stimulation of the agrochemicals, and four bands showed strong resistance to the influence of the agrochemicals. Fifteen prominent bands were partially sequenced, yielding 15 different nifH sequences, which were used for phylogenetic reconstructions. All sequences were affiliated with the alpha- and beta-proteobacteria, showing higher similarity to eight different diazotrophic genera.     

Arsenic uptake by arbuscular mycorrhizal maize （Zea mays L.） grown in an arsenic-contaminated soil with added phosphorus

The effects of arbuscular mycorrhizal (AM) fungus (Glomus mosseae) and phosphorus (P) addition (100 mg/kg soil) on arsenic (As) uptake by maize plants (Zea mays L.) from an As-contaminated soil were examined in a glasshouse experiment.Non-mycorrhizal and zero-P addition controls were included.Plant biomass and concentrations and uptake of As,P,and other nutrients,AM colonization,root lengths,and hyphal length densities were determined.The results indicated that addition of P significantly inhibited root colonization and development of extraradical mycelium.Root length and dry weight both increased markedly with mycorrhizal colonization under the zero-P treatments,but shoot and root biomass of AM plants was depressed by P application.AM fungal inoculation decreased shoot As concentrations when no P was added,and shoot and root As concentrations of AM plants increased 2.6 and 1.4 times with P addition,respectively.Shoot and root uptake of P,Mn,Cu,and Zn increased,but shoot Fe uptake decreased by 44.6%,with inoculation, when P was added.P addition reduced shoot P,Fe,Mn,Cu,and Zn uptake of AM plants,but increased root Fe and Mn uptake of the nonmycorrhizal ones.AM colonization therefore appeared to enhance plant tolerance to As in low P soil,and have some potential for the phytostabilization of As-contaminated soil,however,P application may introduce additional environmental risk by increasing soil As mobility.     

Degradation of metabolites accumulated of benzo[a]pyrene by coupling Penicillium Chrysogenum with KMnO4

Several main metabolites of benzo[a]pyrene （BaP） formed by Penicillium chrysogenum, Benzo[a]pyrene-1,6-quinone （BP 1,6- quinone）, trans-7,8-dihydroxy-7,8-dihydrobenzo[a]pyrene （BP 7,8-diol）, 3-hydroxybenzo[a]pyrene （3-OHBP）, were identified by high-performance liquid chromatography （HPLC）. The three metabolites were liable to be accumulated and were hardly further metabolized because of their toxicity to microorganisms. However, their further degradation was essential for the complete degradation of BaP. To enhance their degradation, two methods, degradation by coupling Penicillium chrysogenum with KMnO4 and degradation only by Penicillium chrysogenum, were compared; Meanwhile, the parameters of degradation in the superior method were optimized. The results showed that （1） the method of coupling Penicillium chrysogenum with KMnO4 was better and was the first method to be used in the degradation of BaP and its metabolites; （2） the metabolite, BP 1,6-quinone was the most liable to be accumulated in pure cultures; （3） the effect of degradation was the best when the concentration of KMnO4 in the cultures was 0.01% （w/v）, concentration of the three compounds was 5 mg/L and pH was 6.2. Based on the experimental results, a novel concept with regard to the bioremediation of BaP-contaminated environment was discussed, considering the influence on environmental toxicity of the accumulated metabolites.     

Impact of atrazine and nitrogen fertilizers on the sorption of chlorotoluron in soil and model sorbents

Sorption of chlorotoluron in ammonium sulfate, urea and atrazine multi-solutes system was investigated by batch experiments. The results showed application of nitrogen fertilizers to the soil could affect the behavior of chlorotoluron. At the same concentration of N, sorption of chlorotoluron decreased as the concentration of atrazine increased on the day 0 and 6 in soil, respectively. The sorption of chlorotoluron increased from 0 to 6 d when soils were preincubated with deionized water, ammonium sulfate and urea solution for 6 d. That indicated incubation time was one of the most important factors for the sorption of chlorotoluron in nitrogen fertilizers treatments. The individual sorption isotherms of chlorotoluron in rubbery polymer and silica were strictly linear in single solute system, but there were competition sorption between pesticides or between pesticides and nitrogen fertilizers. That indicated the sorption taken place by concurrent solid-phase dissolution mechanism and sorption on the interface of water-organic matter or water-mineral matter.     

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.