深圳市表层土中氟化物组成及分布

为探究深圳市表层土中氟化物的组成及其与土壤性质参数(有机碳和pH值)的相关关系,应用氟离子选择电极法测定了深圳市表层土中总氟(TF)、可萃取有机氟(EOF)的含量,用固相萃取分离富集与高效液相色谱串联质谱的方法分析了深圳市表层土中全氟化合物(PFCs)的残留水平.结果表明,深圳市表层土中氟化物主要以无机态存在,呈TF>>EOF>> IF(可鉴别F,即以氟计量的总PFCs)的分布规律; EOF仅占TF的0.04%,IF占EOF的0.32%,显示近99.7%的EOF仍属未知.深圳市表层土中PFOA、PFOS分别占∑PFCs的43%(18%~100%)和20%(n.d.~44%),是表层土中主要的PFCs污染物,就空间分布而言,∑PFCs呈西高东低的趋势.表层土中EOF和∑PFCs含量受土壤性质参数的影响,pH值与EOF(P<0.05)、∑PFCs(P<0.01)含量呈负相关,有机碳则与EOF、∑PFCs呈正相关(P<0.01).     

淮河流域土壤中全氟化合物的空间分布及组成特征

为了阐明淮河流域土壤中全氟化合物(PFCs)的暴露特征和潜在来源,2008年10月在淮河安徽段共采集了18个表层土壤样品,通过离子燃烧色谱(CIC)测定总氟(TF)和可提取有机氟(EOF),以及采用高效液相色谱/质谱联用(HPLC/MS-MS)分析了16种PFCs,其中11种PFCs有不同程度的检出.PFCs含量为n.d.～1.22 ng·g-1,其中全氟辛酸(PFOA)、全氟壬酸(PFNA)和全氟辛烷磺酸(PFOS)是主要的PFCs.在这些土壤样品中,PFCs含量相差不大,但组成不一,主要来源于周边小型化工厂的排放以及大气的干湿沉降.利用氟原子质量平衡原理,分析得出PFCs占EOF比例为0.3%,EOF占TF比例为0.02%,一方面说明除PFCs外仍有很大一部分可提取有机氟难以定性和定量,且离子态氟及未提取出的有机氟是TF的主要成分,另一方面受现有标准物质和检测技术限制,尚不能完全甄别和分析出PFCs的含量及未知的有机氟.     

安徽省部分城市土壤中全氟化合物空间分布及来源解析

为探究安徽省城市土壤中全氟化合物(perfluorinated compounds,PFCs)的污染特征、空间分布及潜在的来源.2013年采集安徽省7个城市共11个土壤样品,利用超高效液相色谱-串联质谱联用分析了15种PFCs的含量,并运用主成分分析-线性回归法解析其可能来源.结果表明,被调查的11个城市土壤样品中的ΣPFCs的含量(以干重计,下同)范围为1.15~5.89 ng·g-1,平均含量2.69 ng·g-1.含量最高的单体PFCs是全氟辛烷磺酸(perfluorooctane sulfonate,PFOS),含量范围为n.d.~3.56 ng·g-1,均值含量为0.96 ng·g-1,其次是全氟辛烷羧酸(perfluorooctane acid,PFOA),含量范围为n.d.~2.89ng·g-1,均值含量为0.64 ng·g-1;ΣPFCs含量最高地区是滁州地区(5.89 ng·g-1),以PFOS和PFOA为主,其次为宣城市泾县(4.04 ng·g-1),而其中PFOS含量高达3.56 ng·g-1,占ΣPFCs的88.1%,这可能与该地发达的造纸行业有关;与我国其他地区土壤中PFCs含量相比,安徽省被调查地区的城市土壤中PFCs的含量居于中等水平;安徽省部分城市土壤中60%的PFCs可以有4个因子进行解释,代表性PFCs有PFOA、全氟丁烷磺酸(perfluorobutane sulfonate,PFBS)、全氟十二烷羧酸(perfluorododecanoic acid,PFDo A)、全氟丁烷羧酸(perfluorobutane acid,PFBA)和PFOS.     

金华市萤石矿区土壤氟污染评价

对金华市萤石矿区村庄表层土进行了全氟(TF)、水溶态氟(WF)含量的测定.利用单因子指数法、地质累积指数法和健康风险评估法进行了四个矿区和一个非矿区的土壤质量评价.结果表明,供试土壤TF含量范围28.36~56 052.39mg·kg-1,算术平均值8 325.90 mg·kg-1,几何均数为1 555.94 mg·kg-1,中位数为812.98 mg·kg-1,变异系数为172.07%.供试土壤WF含量变化范围在0.83~74.63 mg·kg-1,算术均值为16.94 mg·kg-1,几何均数为10.59 mg·kg-1,中位值为10.17mg·kg-1,变异系数为100.10%.TF和WF含量远远高于全国地氟病发生区平均水平.供试土壤氟污染受人为因素影响显著.杨家、冷水坑、花街矿区土壤氟污染最为严重,大仁矿区次之,非矿区基本没有受到氟污染.经口摄入土壤是最主要的暴露途径,参数敏感性分析表明儿童体重对危害商的影响最大,3种评价方法呈极显著正相关.     

自来水处理工艺对溶解相中全氟化合物残留的影响

为探究自来水原水到出厂水各处理环节对自来水中全氟化合物(perfluorinated compounds,PFCs)残留的影响,了解原水中PFCs的季节性变化规律,应用WAX固相萃取分离富集与高效液相色谱-质谱联用相结合的方法,分析了深圳市某自来水厂一年间原水、出厂水及絮凝池、沉降池、砂滤池、臭氧+活性炭池出水溶解相中13种PFCs的残留水平.结果表明,原水和出厂水中ΣPFCs残留呈春夏高而秋冬低的趋势,检出的PFCs呈中短链(C≤10)长链(C≥11)的分布,而全氟辛烷磺酸是PFCs最典型残留种态.在原水经过的5个处理环节中,臭氧+活性炭、沉降和砂滤具有PFCs去除效应,然而絮凝和液氯消毒却分别使短链(C≤6)和中链(10≥C≥7)PFCs显著上升,导致出厂水中ΣPFCs浓度较原水增加了10%～44%.但出厂水中PFCs残留远低于其限值,尚不足以影响人体健康.     

深圳市沿岸表层海水中全氟化合物的残留特征及其分布规律

为探究深圳市沿海岸表层海水中全氟化合物（perfluorinated chemicals,PFCs）的残留特征及其分布规律,应用固相萃取分离、富集与高效液相色谱-质谱联用相结合的方法,研究了深圳市沿海岸18处表层海水中15种PFCs的残留特征、分布规律及其成因.结果表明,深圳沿海岸表层海水中PFCs总的残留水平（ΣPFCs）受人类活动影响显著,位于珠江和东宝河入海口下方的西部沿岸表层海水中PFCs残留显著高于开发程度轻、人口稀疏的东部沿岸（P〈0.05）;而自然条件下,表层海水中ΣPFCs残留呈湾内高于湾外的规律.沿海岸表层海水中PFCs的主要残留种态为中、短链的全氟辛烷磺酸（perfluorooctanesulfonate,PFOS）、全氟辛酸、全氟己酸和全氟戊酸,其相似的环境行为（P〈0.05,P〈0.01）可能与PFCs相关产品的生产过程有关;聚类分析结果进一步显示,PFOS（R2=0.409 2）残留可作为评价深圳沿海岸表层海水中PFCs污染状况的典型参数.     

深圳市大气中全氟化合物的残留特征

为探究深圳市大气中全氟化合物(perfluorinated compounds,PFCs)的残留特征,基于负载XAD-4的PUF膜被动采样器采集了2014年11月1日至2015年1月31日深圳市12个位点的大气样品,分析了大气中7种挥发性PFCs和15种离子型PFCs的含量及分布特征.结果表明,深圳市大气中ΣPFCs平均浓度为79.0 pg·m-3(23.7~157 pg·m-3),以挥发性PFCs为主.8∶2氟调聚醇(fluorotelomer alcohol,FTOH)、6∶2 FTOH和全氟戊酸(perfluoropentanoic acid,PFPe A)、全氟辛酸(perfluorooctane acid,PFOA)分别是挥发性和离子型PFCs的主要组分.深圳市大气中挥发性和离子型PFCs的空间分布相同,均呈西北高东南低的态势.此外,6∶2 FTOHs、8∶2 FTOHs、PFPe A、PFHx A和PFOA与PM_(2.5)、PM_(10)呈正相关(P0.05,P0.01),而与PM_(10)的相关性更显著.     

深圳近岸海域全氟化合物的污染特征

为探究深圳近岸海域全氟化合物(perfluorinated compounds,PFCs)的污染特征,2013年9月采集了深圳近岸(离岸﹥2km)10份表层海水和7份表层沉积物.采用固相萃取分离、富集,结合高效液相色谱-质谱联用的方法测定了其中16种PFCs的含量.结果表明,表层海水中有10种PFCs不同程度地检出,包括C4、C6和C8全氟磺酸盐(perfluorinated sulfonates,PFSAs)和C5~C11全氟羧酸(perfluorinated carboxylic acids,PFCAs).ΣPFCs质量浓度范围在1.74~14.7 ng·L-1之间,其中PFBS、PFOS和PFOA是主要的PFCs.ΣPFCs质量浓度分布呈西高东低的态势,伶仃洋和深圳湾ΣPFCs质量浓度显著高于大亚湾和大鹏湾(P0.05),距岸越远ΣPFCs质量浓度越低.表层海水中PFCs可能主要来自于近岸污水的排放以及河流入海的输入.表层沉积物中有8种PFCs不同程度地检出,包括C6和C8PFSAs和C5,C6,C8~C11PFCAs.ΣPFCs含量范围在2.22~2.62μg·kg-1之间,其中PFOS是主要的PFCs.ΣPFCs含量变化很小,可能主要来自对上覆海水中PFCs的吸附.沉积物吸附PFCs的能力随碳链长度增加而增强,且相同碳链长度的情况下,PFSAs较PFCAs更易于被吸附.此外,不同近岸海域PFCs质量浓度比较结果表明,深圳近岸海域表层海水PFBS污染较为严重,而沉积物PFOS含量与其他海域相差不大.     

钱塘江(杭州段)表层水中全氟化合物的残留水平及分布特征

为探究钱塘江(杭州段)表层水中全氟化合物(PFCs)的污染特征,应用固相萃取净化、富集与超高效液相色谱-串联质谱联用相结合的方法,对14个监测断面采集于2014年7月和2015年1月的表层水样品中16种PFCs进行了分析,研究其残留水平和分布规律.监测结果显示钱塘江(杭州段)表层水有8种PFCs不同程度的检出,包括C4和C8全氟烷基磺酸以及C4~C9全氟烷基羧酸,均为中短链PFCs.ΣPFCs质量浓度范围为0.98~609 ng·L~(-1),其中全氟辛酸(PFOA)质量浓度范围0.59~538 ng·L~(-1),为主要污染因子,全氟辛烷磺酸(PFOS)检出浓度较低,为0~2.48 ng·L~(~(-1)).污染物空间分布略有差异,位于上游兰江的兰江口和将军岩断面检出浓度较高,总体上呈现上游高于下游的趋势.特征组分含量比率显示流域内工业污废水排放是水体中PFCs残留的主要来源.钱塘江(杭州段)水体中PFCs污染与钱塘江流域上游产业布局密切相关,主要污染输入来自上游兰江,沿途吸纳的含PFCs的污废水对水体污染有一定影响.研究结果表明钱塘江水体中存在着广泛的PFCs特别是PFOA污染,需要有关部门引起足够的重视.     

不同功能区表层土中全氟化合物污染指纹及其来源解析

为探究区域功能对其表层土中全氟化合物(perfluorinated compounds,PFCs)污染指纹与含量水平的影响,采用固相萃取分离富集、高效液相色谱-质谱联用与源解析相结合的方法,分析了深圳市公园、居民小区、十字路口、工厂周边4个功能区和城市背景共76份表层土中14种PFCs的含量.结果表明,深圳市表层土总PFCs(ΣPFCs)含量受区域功能影响显著,呈工厂周边(P<0.001)>>十字路口(P<0.01)>>居民小区(P<0.05)>>公园>城市背景的分布.其中工厂周边、居民小区、公园表层土中PFCs呈中链(P<0.05)>>长链>短链的分布,而十字路口则呈中链≈短链(P<0.05)>>长链的分布.同时,以全氟辛烷磺酸、全氟辛酸、全氟十三酸为主要标志物的3个主成分可以解释深圳表层土超过81%的ΣPFCs,十字路口以及电镀、油漆厂周边表层土呈现出较清晰的PFCs污染指纹.     

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.