基于GIS和PMF模型的石嘴山市土壤多环芳烃空间分布及来源解析

随着城市化和工业化进程加速,城市土壤多环芳烃（PAHs）含量及污染状况受到广泛关注.以石嘴山市为例,分析8个城市功能区156个表层土壤（0~20 cm）样品PAHs含量的空间分布特征,运用单因子指数、内梅罗综合指数和终生癌症风险增量模型评价土壤PAHs污染状况,利用正定矩阵因子分解模型（PMF）对PAHs来源进行解析.结果表明,石嘴山市表层土壤PAHs总含量均值为489.82 ng·g^-1,除芘（Pyr）外的15种PAH单体变异系数均大于100%,属强变异;不同功能区土壤PAHs含量呈现出：交通区（1217.61 ng·g^-1） > 工业区（809.58 ng·g^-1） > 公园（273.66 ng·g^-1） > 文教区（268.18 ng·g^-1） > 商业区（240.05 ng·g^-1） > 农业区（226.81 ng·g^-1） > 医疗区（211.90 ng·g^-1） > 居民区（183.49 ng·g^-1）;内梅罗综合指数显示82.58%的样点不存在污染,轻微、轻度和中度污染占比分别为6.45%、4.52%和0.65%,5.8%的样点存在重度污染;健康风险评价结果表明,皮肤接触和误食是最主要的土壤PAHs暴露途径,其健康风险处于可接受水平;源解析表明石嘴山市土壤PAHs的主要来源为交通排放源、煤炭燃烧源、生物质/重油燃烧的混合源以及石油源,其贡献率分别为10.5%、36.6%、50.3%和2.6%,且高值大多分布在工业或煤炭生产区域.研究结果可为工业城市土壤污染研究提供参考,并对预防土壤污染、保障土壤环境质量及人体健康安全有积极作用.     

新疆典型地区植物和土壤多环芳烃污染特征、来源解析及健康风险评价

利用气相色谱-质谱法（GC-MS）测定新疆多段公路沿线和3个风景区植物和土壤中多环芳烃（PAHs）含量.结果表明,11个采样点的11个土壤样品Σ₁₆PAHs含量为18.82~2153.54 ng·g^-1,平均值为425.95 ng·g^-1,36个采样点的59个植物样品中Σ₁₆PAHs含量范围为9.93~748.30 ng·g^-1,平均值为154.11 ng·g^-1.植物样品中不同环数的PAHs平均含量高低次序为：低环（2~3环）>中环（4环）>高环（5~6环）,土壤样品不同环数的PAHs平均含量高低次序为：中环（4环）>高环（5~6环）>低环（2~3环）.特征比值法和主成分分析法分析得出,土壤中PAHs主要为燃烧和石油源,植物吸收的PAHs主要来源为木材燃烧和炼焦工业.健康风险评价结果表明,S323省道库尔勒段土壤PAHs对道路工作人员致癌风险值（CR）为1.26×10^-6,存在潜在健康风险.     

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.     

北江中上游地表水和沉积物中PAHs和PCBs污染特征和风险评估

采用气相色谱-质谱法（GC-MS）测定了北江中上游流域地表水和沉积物样品中多环芳烃（PAHs）和多氯联苯（PCBs）类污染物的含量,分析了PAHs和PCBs的污染水平和空间分布,并评估了污染物的健康风险和生态风险.结果表明,16种PAHs单体在所有水样和沉积物样品中均被检出,检出范围分别为41.82~443.04 ng·L^-1和59.58~635.73 ng·g^-1,北江中上游PAHs的污染水平为中、轻度.水中PAHs以二环芳烃和三环芳烃为主,沉积物中以三环芳烃和四环芳烃为主.在水样中检出了17种PCBs,浓度范围0.81~287.50 ng·L^-1,以六氯联苯和七氯联苯为主;沉积物中检出了8种PCBs,含量范围0.13~3.96 ng·g^-1,以五氯联苯和七氯联苯为主.整个调查区域内地表水中PAHs和PCBs的终生致癌风险指数小于10^-4,处于中、低水平;非致癌风险指数均小于1,不存在非致癌风险.采用风险商值（RQ）法对地表水中污染物进行生态风险评价,研究区域内地表水中PAHs和PCBs生态风险总体处于中低风险水平,个别点位存在重度风险的污染物单体,值得引起重视.采用沉积物质量基准法（SQGs）对沉积物中污染物进行生态风险评估,沉积物中PAHs和PCBs均处于较低的生态风险水平.     

东北小兴凯湖沉积物POPs污染特征及生态风险评价

采用GC-MS分析了小兴凯湖表层沉积物多环芳烃（PAHs）、有机氯农药（OCPs）和邻-苯二甲酸酯（PAEs）的污染特征,探讨了污染物的主要来源及生物毒性风险.结果表明：①小兴凯湖沉积物中PAHs含量范围在82.1~534.6 ng·g^-1之间,西北湖区含量较高.沉积物中OCPs和PAEs含量范围分别在4.8~50.4 ng·g^-1和33.3~401.6 ng·g^-1之间,东南湖区含量较高;②沉积物中PAHs以3~5环化合物为主（占85%以上）,主要为燃烧源,其中煤和薪柴燃烧贡献47%,汽油和柴油燃烧贡献39%,石油产品泄漏贡献14%.OCPs以六氯环己烷（HCH）为主（占78%）,主要来源于新的林丹的使用和少量工业HCHs的输入.PAEs以邻-苯二甲酸二正丁酯（DBP）和邻-苯二甲酸二（2-乙基己）酯（DEHP）为主（占94%）,生活垃圾和工农业生产为其主要来源;③小兴凯湖沉积物中PAHs、OCPs和PAEs在东北地区处于低水平污染,相比于国内其他地区的湖泊河流,总体处于低污染水平,目前无生态风险,但部分点位OCPs具有中度生态风险.     

燃煤电厂和垃圾焚烧电厂燃烧产物中卤代多环芳烃的赋存特征和毒性风险

研究了燃煤电厂和垃圾焚烧电厂燃烧产物中卤代多环芳烃（HPAHs）的赋存特征、生成机制和毒性效应.结果表明,燃煤电厂和垃圾电厂飞灰中氯代PAHs （Cl-PAHs）的含量为1.06~1.67 ng·g^-1和2.76 ng·g^-1,溴代PAHs （Br-PAHs）的含量为26.4~44.2 ng·g^-1和6.31 ng·g^-1;垃圾电厂飞灰中Cl-PAHs的含量明显高于燃煤电厂,主要是因为生活垃圾中含有大量的聚氯乙烯为代表的塑料.来自煤粉炉的飞灰中Br-PAHs和Cl-PAHs的含量明显低于循环流化床燃煤飞灰,主要是因为煤粉炉具有更高的燃烧温度和燃烧效率.燃煤电厂飞灰中主要为7-BrBaA和9-ClPhe;垃圾电厂除尘器飞灰中Br-PAHs主要为9-BrPhe和2-ClAnt.7-BrBaA和9,10-Br₂Ant在燃煤电厂除尘器飞灰的含量远高于其在底灰和脱硫石膏的含量,但摩尔质量相对较小的2-BrFle在飞灰、底灰和脱硫石膏中的含量相近.垃圾电厂除尘器飞灰经过半干法脱酸后Br-PAHs的含量减少50%以上,但是经过螯合剂稳固化作用之后飞灰中Br-PAHs的含量明显升高.Pearson相关分析结果表明,燃煤电厂不同燃烧产物的HPAHs生成机制相同,而垃圾焚烧电厂不同产物中HPAHs具有不同的生成机制,飞灰螯合化过程导致HPAHs的二次生成.垃圾电厂除尘器飞灰中HPAHs的TEQs值（10.0×10^-3 ng·g^-1）与燃煤电厂相近（8.87×10^-3~15.0×10^-3 ng·g^-1）.对于垃圾电厂不同燃烧产物,脱酸工艺能够显著去除7-BrBaA从而降低飞灰的TEQ值,而飞灰螯合化后TEQ值达到螯合前的5.4倍.燃煤电厂的飞灰因年产量较大,且总HPAHs的TEQs值相对较高,对其处理和资源化利用应考虑HPAHs带来的生态风险.     

白洋淀典型持久性有机污染物污染特征与风险评估

对白洋淀表层水体和表层沉积物中多环芳烃（PAHs）、有机氯农药（OCPs）和多溴联苯醚（PBDEs）三类典型持久性有机污染物（POPs）的污染特征进行综合调查和分析.结果表明：①白洋淀水体中PAHs、OCPs和PBDEs浓度范围分别是71.32~228.27、2.62~6.13和0~6.5 ng·L^-1;沉积物中PAHs、OCPs和PBDEs含量范围分别是163.20~861.43 ng·g^-1、2.25~6.07 ng·g^-1和230.96~1224.13 pg·g^-1.与历史数据相比,白洋淀沉积物PAHs和OCPs含量均有明显下降;与国内外湖泊相比,白洋淀沉积物中PBDEs含量处于较低水平.②水体和沉积物PAHs污染来自于油类排放和木材、煤炭燃烧的共同作用;白洋淀水体和沉积物中OCPs组成均以HCHs为主（93.76%和63.10%）,水体中HCHs主要来源于工业HCHs的降解,部分地区来源于大气的远距离传输和林丹的使用,DDTs则主要来源于历史残留.沉积物中HCHs主要来源于新的林丹使用,也有少量工业HCHs的输入,DDTs则以历史残留为主,可能部分地区存在新的DDTs输入;白洋淀水体中PBDEs组成以BDE-2为主（65.80%）,可能主要来源于大气远距离传输和高溴代联苯醚的降解,沉积物中PBDEs组成以BDE-209为主（63.82%）,主要来源为商用的十溴联苯醚.③生态风险评价结果表明,白洋淀尚无明显生态风险,但部分采样点存在生态风险的可能性,应加强监控.     

典型岩溶槽谷区不同地表覆被土壤中多环芳烃的运移特征和来源解析

为探究岩溶槽谷区土壤中多环芳烃(PAHs)的环境行为,选取典型的竹林地、灌丛地和耕地作为研究对象,运用气相色谱-质谱联用仪定量分析土壤中的PAHs.结果表明,土壤剖面中PAHs污染水平表现为竹林地(204.13 ng·g^-1)>耕地(175.47 ng·g^-1)>灌丛地(106.00 ng·g^-1),土壤质量总体良好.3种土地类型均表现为浅层土壤的PAHs含量显著高于深层土壤(p<0.05),表明岩溶区土壤对防止地下水污染具有重要意义;2~3环PAHs易运移至深层土壤,而4~6环PAHs受TOC含量的影响则主要积聚在浅层土壤,富集能力表现为灌丛地>耕地>竹林地;PAHs运移特征主要受控于有机质的吸附和水的溶解两种机制,PAHs和土壤的理化性质是影响PAHs运移的重要因素.结合同分异构体比值法和主成分分析法的源解析结果,得出研究区土壤中PAHs主要源于当地能源燃烧和交通污染,而大气沉降是重要污染途径.     

广西岩溶洞穴土壤中多环芳烃污染特征与解析

首次研究相对封闭稳定环境条件下的岩溶洞穴土壤中PAHs的污染特征及其影响因素.以广西桂林大岩洞穴为例,结果表明,在洞穴内部PAHs总量为7.22～117.29 ng·g^-1,远低于洞外土壤中的含量（51.35～235.73 ng·g^-1）,与其他地区相比,表明桂林近郊土壤PAHs污染较轻.大岩土壤中PAHs总量呈现出洞外和洞口附近明显高于洞内而洞内变化不大;洞外和洞口附近土壤中重环组芳烃含量高于轻环组（平均值69.25 ng·g^-1＞38.81 ng·g^-1）,但在洞内土壤中则相反（平均值3.93 ng·g^-1＜7.41 ng·g^-1）,说明洞内PAHs不仅来自于大气迁移过程,而且也来自于洞顶雨水淋滤作用.土壤中PAHs浓度分布表明在洞口附近存在陷阱效应、在洞穴最里端有裂隙存在.陷阱效应使洞口附近重环芳烃浓度显著高于洞外（88.19 ng·g^-1＞31.28 ng·g^-1）,而且PAH分子量与”易陷落性”呈线性相关（R²=0.49）;通过实测值推测从洞口输入的PAHs浓度约为裂隙输入的17倍.温度和分子量差异是影响PAHs在土壤中浓度分布模式的重要因素.     

珠江三角洲典型区域农业土壤中多环芳烃的含量分布特征及其污染来源

2002-10～2005-11采集珠江三角洲典型区域（东莞市、惠州市、中山市、珠海市和佛山市顺德区）的农业土壤表层样品260个,运用气相色谱-质谱方法对美国EPA优控的16种多环芳烃（PAHs）进行分析测定.结果显示,研究区农业土壤中16种PAHs含量范围在3.3～4 079.0 ng·g^-1,平均含量244.2 ng·g^-1,以3环和4环的PAHs为主;中心城区土壤中PAHs含量高于远郊区,菜地>水稻田>香蕉地>旱坡地果园地>甘蔗地.依据荧蒽/芘及2+3环与4环以上PAHs化合物分布特点,表明该区域农业土壤中PAHs主要来源于化石燃料的不完全燃烧.通过与国内外土壤中PAHs含量的对比,研究区的农业土壤受到一定程度的PAHs污染,含量处于中等水平.     

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.     

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.     

Effects of chitosan on growth of an aquatic plant (Hydrilla verticillata) in polluted waters with different chemical oxygen demands

Effects of chitosan on a submersed plant, Hydrilla verticillata, were investigated. Results indicated that H. venicillata could prevent ultrastructure phytotoxicities and oxidativereaction from polluted water with high chemical oxygen demand (COD). Superoxide dismutase (SOD) activity and malondialdehyde (MDA) contents in H. verticillata treated with 0.1% chitosan in wastewater increased with high COD (980 mg/L) and decreased with low COD (63 mg/L), respectively. Ultrastructural analysis showed that the stroma and grana of chloroplast basically remained normal. However, plant cells from the control experiment (untreated with chitosan) were vacuolated and the cell interval increased. The relict of protoplast moved to the center, with cells tending to disjoint. Our findings indicate that wastewater with high COD concentration can cause a substantial damage to submersed plant, nevertheless, chitosan probably could alleviate the membrane lipid peroxidization and ultrastructure phytotoxicities, and protect plant cells from stress of high COD concentration polluted water.     

Removal of cadmium using MnO2 loaded D301 resin

MnO2 loaded weak basic anion exchange resin D301 （Anion exchange resin, macroreticular weak basic styrene） as adsorbent has been prepared and applied to the removal of cadmium. The adsorption characteristics have been investigated with respect to effect of pH, equilibrium isotherms, removal kinetic data, and interference of the coexisting ions. The results indicated that the Cd^2＋ could be efficiently removed using MnO2 loaded D301 resin in the pH range of 3-8 from aqueous solutions with the co-existence of high concentration of alkali and alkaline-earth metals ions. The saturate adsorption capacity of the Cd^2＋ was 77.88 mg/g. The adsorption process followed the pseudo first-order kinetics. The equilibrium data obtained in this study accorded excellently with the Langmuir adsorption isotherm.     

Effect of coagulation pretreatment on the fouling of ultrafiltration membrane

The purpose of this study is to understand the effect and mechanism of preventing membrane fouling, by coagulation pretreatment, in terms of fractional component and molecular weight of natural organic matter （NOM）. A relatively higher molecular weight （MW） of hydrophobic compounds was responsible for a rapid decline in the ultrafiltration flux. Coagulation could effectively remove the hydrophobic organics, resulting in the increase of flux. It was found that a lower MW of neutral hydrophilic compounds, which could remove inadequately by coagulation, was responsible for the slow declining flux. The fluxes in the filtration of coagulated water and supernatant water were compared and the results showed that a lower MW of neutral hydrophilic compounds remained in the supernatant water after coagulation could be rejected by a membrane, resulting in fouling. It was also found that the coagulated flocs could absorb neutral hydrophilic compounds effectively. Therefore, with the coagulated flocs formed on the membrane surface, the flux decline could be improved.     

Penetration analysis of elements and bioleaching treatment of spent refractory for recycling

Acidithiobacillus ferrooxidans ATCC23270 and Acidithiobacillus thiooxidans TM-32 were used for bioleaching of spent refractories of aluminium and copper melting furnaces for their recycling.Firstly,penetration of elements into aluminium melting furnace refractory was investigated and it was found that up to 7 cm from surface was contaminated.Comparison on leaching efficiency by the strains ATCC23270 and TM-32 found that the strain ATCC23270 could treat larger amount of the refractories than the strain TM-32 could do.In the experiment of bioleaching of spent refractory aluminium melting furnace by the strain ATCC23270,high leaching efficiency were obtained on Al,Si,and Ca,and extremely low leaching performance was,however,shown on the rest of elements i.e.,Na,Mn,and Zn.Under the strain TM-32 use,relatively high leaching performance was recognized on Al,Si,Ca,Na,Mn,and Zn.In the experiment of bioleaching for spent refractory copper melting furnace,almost the same leaching trends were shown on Cu,Zn,Al,and Si under the strains ACTT23270 and TM-32 uses.     

Simultaneous removal of ammonium and phosphate by zeolite synthesized from coal fly ash as influenced by acid treatment

Zeolite synthesized from fly ash （ZFA） without modification is not efficient for the purification of NH4＋ and phosphate at low concentrations that occur in real effluents, despite the high potential removal capacity. To develop an effective technique to enhance the removal efficiency of ammonium and phosphate at low concentrations, ZFA was modified with acid treatment and the simultaneous removal of ammonium and phosphate in a wide range of concentration was investigated. It was seen that when compared with untreated ZFA, only the treatment by 0.01 mol/L of H2SO4 significantly improved the removal efficiency of ammonium at low initial concentrations. The behavior was well explained by the pH effect. Treatment by more concentrated H2SO4 led to the deterioration of the ZFA structure and a decrease in the cation exchange capacity. Treatment by 0.01 mol/L H2SO4 improved the removal efficiency of phosphate by ZFA at all initial P concentrations, while the treatment by concentrated H2SO4 （≥0.9 mol/L） resulted in a limited maximum phosphate immobilization capacity （PIC）. It was concluded that through a previous mild acid treatment （e.g. 0.01 mol/L of H2SO4）, ZFA can be used in the simultaneous removal of NH4＋ and P at low concentrations simulating real effluent.