废塑料再生地农田土壤邻苯二甲酸酯污染特征

为了解废旧塑料再生行业对周边农田土壤环境的影响,在莱州沙河镇废旧塑料再生基地内部及周边区域采集22个农田土壤样品,文章利用高效液相色谱法对样品中6种邻苯二甲酸酯含量(PAEs)进行了检测,并对其污染特征及健康风险进行了分析。结果表明,基地农田土壤中6种PAEs总量介于4.63～15.59 mg/kg之间,邻苯二甲酸二甲酯(DMP)、邻苯二甲酸二丁酯(DBP)、邻苯二甲酸丁基苄基酯(BBP)、邻苯二甲酸二(2-乙基)己酯(DEHP)检出率均为100%;DEHP、DBP和BBP是主要的PAEs,分别占∑_6PAEs的32.96%、30.55%和26.73%。基地内部农田土壤中PAEs含量显著高于外部区域,总体表现为与基地的距离越远,农田土壤中PAEs含量越低。健康风险评估表明,成人和儿童对PAEs的暴露风险主要通过饮食途径,部分采样点BBP、DEHP和DnOP的非致癌风险值>1,存在非致癌风险;成人和儿童通过饮食途径对BBP和DEHP暴露的致癌风险值超过EPA推荐的致癌水平,应引起一定的重视。     

城郊农田土壤多环芳烃污染特征及风险评价

为明确城郊农田土壤多环芳烃（PAHs）的污染特征,按照网格布点法在南京城郊采集29个样点,测定了15种PAHs的含量.结果表明,二氢苊（Ace）均未检出,农田土壤PAHs含量为24.49~750.04 μg ·kg^-1,均值为226.64 μg ·kg^-1;高环PAHs与总PAHs空间分布类似,农田土壤PAHs主要以高环PAHs为主.相关性分析结果表明,农田土壤PAHs与有机质（SOM）、pH、阳离子交换量（CEC）和全氮（TN）无显著相关性,容重（ρ_b）与低环PAHs极显著相关.源解析结果表明,农田土壤PAHs主要来源为燃烧源和石油源的混合源.CSI指数结果表明,农田土壤PAHs不存在生态风险.健康风险评价结果表明,农田土壤PAHs对儿童和成人不存在潜在致癌风险,主要暴露途径是：皮肤接触>摄食>呼吸吸入.     

山东省农田土壤多环芳烃的污染特征及源解析

2015年7月采集山东省农田表层土壤,采用高效液相色谱紫外/荧光检测器串联方法对美国环保署优先控制的16种多环芳烃（PAHs）进行检测,分析了其含量和组成特点,比较了种植粮食作物的大田土壤和蔬菜大棚土壤、点源污染和非点源污染大田土壤中PAHs的差异,采用比值法和正定矩阵因子模型对PAHs来源进行解析,并评价了其风险.结果表明,16种PAHs总含量（∑16PAHs）范围为111.5~2744.1 ng·g^-1,均值为556.3 ng·g^-1,与国内其他地区的农田土壤污染水平相比处于中等水平.组成上,苊、芴、荧蒽的比例较高,而茚并（1,2,3-cd）芘的比例较低.点源污染大田土壤中∑16PAHs含量和7种致癌PAHs的比例均显著高于非点源污染大田;蔬菜大棚土壤与附近的大田土壤相比,∑16PAHs含量没有显著差异,且均是3~4环PAHs比例较高.山东省农田土壤中的PAHs主要来自于燃烧源,其中燃煤和生物质燃烧占42.7%,交通产生的石油燃烧占19.3%,此外炼焦排放占22.8%,石油污染占15.2%.风险评估表明,山东省非点源污染大田土壤和蔬菜大棚土壤中总毒性当量含量均未超过加拿大土壤环境质量标准,但部分点源污染大田土壤超标,具有潜在的风险.     

宁东能源化工基地核心区表层土壤中多环芳烃的空间分布特征、源解析及风险评价

为了解宁东能源化工基地核心区表层土壤多环芳烃的污染现状,按网格布点法在宁东能源化工基地核心区采集了146个代表性表层土壤样品,分析了16种优控多环芳烃（PAHs）的含量.结果表明,16种优控PAHs均检出,表层土壤中ΣPAHs含量介于ND~123.12mg·kg^-1之间,平均值为10.19mg·kg^-1;空间上存在3个PAHs高含量区,为研究区的西北部、西南部以及东部,且不同PAHs区域分异性显著;源解析表明宁东基地PAHs污染为混合源,石油污染、燃煤、交通污染及汽油源对ΣPAHs的贡献分别为39.4%、33.3%、19.2%和8.1%;质量基准与质量标准法生态风险评价表明,该区域PAHs产生的生态影响较小,出现负面生态效应的可能性较低;健康风险评价结果表明,该区域土壤PAHs对于不同年龄段的人群不存在潜在的致癌风险,主要的暴露途径是皮肤接触 > 误食 > 呼吸吸入.     

黄淮平原农田土壤中多环芳烃的分布、风险及来源

对227个黄淮平原农田表层土壤样品中16种多环芳烃(PAHs)含量进行了调查,并对其致癌风险和来源等进行了分析.结果表明,有15种PAHs被普遍检出,各单体检出率在23.3%~100%之间(苊烯未检出).土壤中PAHs总量(∑PAHs15)为33.44~1246μg/kg,平均值为152.4±166.2μg/kg,且以4环及4环以上PAHs为主,其中16.7%的样品中PAHs含量达到了污染水平(>200μg/kg),与国内外其他地区相比,黄淮平原农田土壤中PAHs含量处于相对较低水平.黄淮平原农田土壤7种致癌性PAHs毒性当量浓度(TEQBap)占总毒性当量浓度的98.27%,其中苯并(a)芘(Bap)潜在致癌风险最大.同分异构体比值法和主成分分析结果表明黄淮平原农田土壤中PAHs的主要来源是汽油、柴油高温燃烧、以及煤和秸秆燃烧.相关性分析表明有机质含量与∑PAHs15及PAHs单体含量具有显著相关性,表明有机质是影响PAHs在土壤中含量、空间分布及归趋的一个重要因素.     

广州市土壤多环芳烃污染特征及风险评估

为全面研究广州市土壤多环芳烃（PAHs）污染特征,采集广州市222个表层土壤样品进行分析,利用效应区间低/中值法（ERL/ERM）和（BaP）毒性当量法评价土壤PAHs污染生态风险状况,终生癌症风险增量模型评价土壤PAHs污染健康风险状况,特征化合物比值法和PMF模型对PAHs来源进行解析.结果表明,广州市表层土壤ω（∑16PAHs）为38~11 115 μg·kg^-1,平均值为526 μg·kg^-1,16种多环芳烃单体均为强变异;广州存在潜在生态风险,个别采样点的PAHs污染已存在较大的生态风险,整体处于轻度污染的状态;基于健康风险评价结果表明,成年和儿童的总致癌风险的贡献率都呈现为：皮肤接触 > 误食土壤 > 呼吸摄入,儿童的健康风险大于成年,健康风险总体处于可接受范围;源解析表明广州市土壤PAHs的主要来源为：煤炭源（37.1%） > 柴油源（32%） > 炼焦源 （17.3%） > 交通排放、生物质燃烧和石化产品挥发的混合源（13.6%）,整体土壤PAHs来源属于混合源.研究结果丰富了对广州市表层土壤PAHs污染特征的认识,有助于推动土壤污染防治行动的开展.     

唐山某焦化厂污染区地表水PAHs污染特征及风险评价

焦化行业产生的环境污染问题一直倍受关注,尤其是在中国唐山等焦化企业聚集地.为探讨唐山地区焦化厂周围地表水中多环芳烃（Polycyclic Aromatic Hydrocarbons,PAHs）的污染特征并对其进行风险评价,选取该地区某典型焦化厂,通过对其周围水样的采集与检测,解析了该焦化厂周边地表水中PAHs的组成特征、生态风险商值及（非）致癌风险指数,并对模型参数进行了敏感性分析.结果显示,区域内地表水体中∑₁₆PAHs平均含量为0.757 μg·L^-1,以低分子量蒽（Anthracene,Ant）和高分子量荧蒽（Fluoranthene,Flt）为主,其中,Ant为距离焦化厂较远水体的特征污染物,而焦化厂内部及外围水体则以Flt为特征污染物.生态风险评价表明,∑PAHs在研究区大部分地表水中存在较高生态风险.健康风险评价表明,整体上女性承受的（非）致癌风险高于男性;皮肤暴露产生了一定的（非）致癌风险,且其非致癌风险指数呈现出随年龄增加而上升的趋势.敏感性分析显示,体重、暴露频率、每日饮用水摄入量等参数在模型中对各个暴露途径均有较高影响,需要在风险评价中加强关注.该研究有利于推动对焦化场地地表水PAHs污染的治理与防控,也为进一步探索焦化场地PAHs污染和迁移特征提供了理论基础.     

银川市农田土壤中多环芳烃污染及风险评价

为准确了解银川市农田土壤中多环芳烃的污染状况、空间分布特征及其生态风险,文章采集银川市农田表层土壤样品共91个,采用高效液相色谱法检测了样品中16种多环芳烃(PAHs)含量,分析其污染特征及空间分布状况,对PAHs来源进行分析,并对土壤中PAHs潜在的生态风险和健康风险进行了评价。结果表明：土壤中∑PAHs含量在ND～1 517.37μg/kg之间,平均值为241.49μg/kg,16种PAHs单体变异系数均大于1,区域分异显著;未污染、轻度污染、中度污染和重度污染的样品分别占到样品总数的60.44%、32.97%、2.19%和4.40%;16种PAHs单体的空间分布差异较大,东南部和西南部含量较高;源解析结果显示银川市农田土壤中PAHs的主要来源为煤、化石燃料等的高温燃烧以及汽车尾气排放和汽油源;生态风险评价结果显示,PAHs毒性当量范围为0～1.1×10³μg/kg,平均值为52.04μg/kg,整体潜在生态风险较低,但部分样品具有较高的生态风险;健康风险评价结果显示,非致癌风险均在可接受的标准范围,但是有7个样品的BaP致癌风险超过美国环境保护局推荐的致癌水...     

典型岩溶区土壤和地下水中多环芳烃的分布特征及健康风险研究

以重庆市典型岩溶槽谷为研究区,采集其地下河流域内的土壤和地下水样品,分析了16种优控多环芳烃（PAHs）的含量、时空分布特征及致癌、非致癌健康风险.结果表明,土壤和地下水在不同样点间的PAHs含量及健康风险差异明显,与国内外其它地区相比,青木关和南山流域内土壤和地下水PAHs的污染水平较低,两地下河流域内土壤PAHs的组成以高环为主,地下水中则以低环为主,土壤PAHs的健康风险值为5.53×10^-8~4.57×10^-7,整体处于低致癌风险水平,其中,二苯并[a,h]蒽（DahA）的致癌风险最高,贡献率达80%以上;地下水PAHs的健康风险值为5.83×10^-8~1.32×10^-6,经口摄入途径的致癌风险水平较高.南山地下水样点间健康风险值波动比较大,受点源污染影响明显,其地下水的健康风险已超过可接受水平（1.0×10^-6）.     

南昌市扬尘PM2.5中多环芳烃的来源解析及健康风险评价

为了解南昌市道路扬尘和土壤风沙尘PM_2.5中多环芳烃（PAHs）的来源和健康风险,利用颗粒物再悬浮系统采集PM_2.5样品,测定了PM_2.5中16种优先控制的多环芳烃的含量.结果表明,南昌市道路扬尘PM_2.5中ΣPAHs含量范围为48.85~166.16μg·kg^-1,平均值为（114.22±39.95）μg·kg^-1,土壤风沙尘PM_2.5中ΣPAHs含量范围为31.05~62.92μg·kg^-1,平均值为（40.79±9.39）μg·kg^-1.道路尘和土壤风沙尘PM_2.5中的PAHs都是以4~5环组分为主.主成分分析/多元线性回归分析结果表明,南昌市道路扬尘PM_2.5中PAHs的来源包括机动车的排放和燃煤源与石油泄漏,贡献率分别为51.7%和48.3%,总估计值与实际值的线性拟合有很好的一致性.对于儿童和成年男性,不同暴露途径的PAHs致癌风险值从大到小依次是皮肤接触 > 摄食 > 呼吸吸入,而成年女性则表现为摄食 > 皮肤接触 > 呼吸吸入.各暴露途径中,PAHs对成人的致癌风险均高于儿童.所有人群中,PAHs的总致癌风险值均低于美国EPA推荐的致癌风险阈值10^-6,没有致癌风险.     

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.     

Potential of plant polyphenol oxidases in the decolorization and removal of textile and non-textile dyes

In this study an effort has been made to use plant polyphenol oxidases; potato （Solanum tuberosum） and brinjal （Solanum melongena）, for the treatment of various important dyes used in textile and other industries. The ammonium sulphate fractionated enzyme preparations were used to treat a number of dyes under various experimental conditions. Majority of the treated dyes were maximally decolorized at pH 3.0. Some of the dyes were quickly decolorized whereas others were marginally decolorized. The initial first hour was sufficient for the maximum decolorization of dyes. The rate of decolorization was quite slow on long treatment of dyes. Enhancement in the dye decolorization was noticed on increasing the concentration of enzymes. The complex mixtures of dyes were treated with both preparations of polyphenol oxidases in the buffers of varying pH values. Potato polyphenol oxidase was significantly more effective in decolorizing the dyes to higher extent as compared to the enzyme obtained from brinjal polyphenol oxidase. Decolorization of dyes and their mixtures, followed by the formation of an insoluble precipitate, which could be easily removed simply by centrifugation.     

Removal of heavy metals from sewage sludge by low costing chemical method and recycling in agriculture

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