昆明市大气总悬浮颗粒物和PM2.5上多溴联苯醚的分布特征和潜在风险

为探究PBDEs（多溴联苯醚）在昆明大气中的环境行为,于2014年3月对昆明8个采样点大气TSP（总悬浮颗粒物）和PM_2.5样本进行了收集并利用GC-MS技术对其上附着的PBDEs的13种同系物进行了测定,进而对TSP和PM_2.5上PBDEs的分布特征和潜在风险进行了分析.结果表明:附着在TSP上的∑PBDE浓度（多溴联苯醚的总质量浓度）的范围为21.10~175.00 pg/m3.而附着在PM_2.5上的∑PBDE浓度范围为17.50~149.00 pg/m3,约占TSP中∑PBDE浓度的35.31%~85.14%,并且高溴化的同系物（BDE-138~BDE-209）比低溴化的同系物（BDE-17~BDE-99）更容易附着在PM_2.5上,约占∑PBDE浓度的8.50%~61.60%.对大气颗粒物中PBDEs的潜在影响和空气吸入暴露剂量评估结果表明,成人和儿童对PBDEs的DED_air（呼吸日暴露量）分别在5.28~43.75和6.90~57.23 pg/（kg·d）之间,TDI（每日总摄入量）分别在114.78~951.09和150.00~1 244.13 pg/（kg·d）之间,远低于最低无害水平[1 mg/（kg·d）].BDE-99的TDI分别为11.09~72.39和14.35~94.57 pg/（kg·d）,均低于最低摄入水平[260 pg/（kg·d）].研究显示,昆明市大气TSP和PM_2.5上的PBDEs对人体不存在健康风险.      

广州市夏季大气中多氯联苯和多溴联苯醚的含量及组成对比

用GC-ITD-MS和GC-NCI-MS分别测定了广州市区4个代表性的地点大气中多氯联苯(PCBs)和多溴联苯醚(PBDEs)的含量.∑64PCBs的含量范围为307.2～2720.8 pg·m-3,含量处于世界中等水平;除工业区两侧的黄浦和天河2个采样点外,市区∑10PBDEs和BDE-209的含量范围分别为41.5～256.8 pg·m-3和116.3～888.7 pg·m-3,∑10PBDEs的含量和世界其它地方相当,而BDE-209的含量高于其它地区.PCBs中主要以三、四和五氯代PCBs为主,它们的含量占∑64PCBs的80%以上,同系物分布与国外不同,原因可能是我国曾生产和使用不同的工业产品.PBDEs中以四、五和十溴BDEs为主,其含量占∑11 PBDEs的80%以上,BDE-209、BDE-47和BDE-99是主要成分,表明污染主要来自于五溴和十溴联苯醚工业品4个采样点∑10PBDEs和∑64PCBs含量的分布表明这两类污染物有不同的排放源,PCBs主要来自于老城区,而PBDEs主要来自于新工业区.     

广州市室内尘土中多溴联苯醚的分布特点及来源

随机采集了广州市46个家庭和12个办公室内尘土样品,同时采集了17个室外尘土样品、2个电视机和2个电脑尘土样品并分析了室内尘土中多溴联苯醚(PBDEs)的含量、单体分布及来源.结果表明,家庭尘土中∑10PBDEs(BDE28,47,66,85,99,100,153,154,183,209之和)的含量为 564.3~9654ng/g,中值和均值分别为 2686,3407ng/g;办公室尘土中∑10PBDEs 的含量为 1737~4408ng/g,中值和均值分别为3133,3179ng/g.室内尘土中PBDEs的最主要单体为BDE209,分别占家庭尘土和办公室尘土∑10PBDEs的97.4%和99.0%.BDE47、99和183在室内尘土中含量也较高.大多数室内尘土中∑10PBDEs的含量高于室外,说明室内可能有重要的PBDEs释放源.室内尘土中PBDEs的主要工业品来源为十溴联苯醚,五溴联苯醚次之,八溴联苯醚较少.     

家庭尘土中多溴联苯醚的含量及人体暴露水平初步研究

在广州和海口随机采集了52个家庭尘土样品,用GC/MS定量分析了样品中∑10PBDEs(BDE28,47,66,85,99,100,153,154,183,209之和)的含量、单体组成模式和可能的影响因素,并估算了成年人和婴幼儿通过尘土摄入对PBDEs的暴露水平.结果表明,所有样品中都检出PBDEs,∑10PBDEs的含量范围为544.2～9 654 ng/g,中位值和平均值分别为2 547 ng/g和3 096 ng/g,广州样品中∑10PBDEs含量明显高于海口样品.尘土中PBDEs含量与家用电器和含聚氨酯泡沫家具数量、电器使用时间没有显著相关性.家庭尘土中PBDEs的主要成分是BDE209,其平均含量高达3 021 ng/g,占∑10PBDEs含量的73.70%～99.74%,平均值为96.85%.BDE47、99和183是∑9PBDEs(BDE209除外)中含量最丰富的单体,其含量均值分别为24.48%、23.99%和21.66%,广州和海口样品的单体组成没有显著区别.成年人和婴幼儿通过尘土摄入对PBDEs的暴露水平分别为10.59～254.7 ng/d和140.1～509.3 ng/d,由于婴幼儿的尘土摄入量远大于成年人,其对PBDEs的暴露水平也明显偏高.尘土摄入是人体暴露于PBDEs的重要途径,对婴幼儿更是如此.     

南海北部大气气相多溴联苯醚的含量及来源

通过"实验三号"开放航次在南海北部采集了32个大气样品,用气相色谱/质谱联用仪分析了样品中的多溴联苯醚(PBDEs)同系物,并对其含量、组成特征、空间分布及主要来源进行了研究.结果表明,南海北部大气中7种PBDEs总浓度为0.07～35.9 pg.m-3,四溴(BDE-47)和五溴(BDE-99和-100)化合物为主要组成,分别约占PBDEs总量的51.5%和36.9%,显示工业五溴联苯醚的使用是其主要来源;中国东南沿海和菲律宾附近PBDEs浓度较高,南海靠近越南中部海域大气PBDEs含量较低.后推气流轨迹分析指出:我国东南沿海,特别是珠江三角洲,以及我国台湾和菲律宾等地区陆源污染物的外溢是引起南海北部地区PBDEs浓度较高的主要原因.     

典型电器工业区河涌沉积物中的多溴联苯醚空间和垂直分布

对珠江三角洲佛山市顺德区容桂镇电器工业区河涌沉积物多溴联苯醚(PBDEs)的含量进行了空间和垂直分布研究.选择该镇中心城区内河涌作为研究河道,根据河涌水流情况选取8个采样点采集沉积物样品.所有样品中均检出PBDEs.各监测点的PBDEs总含量变化范围为62～349 ng.g-1(平均为178 ng.g-1),各采样点的浓度差异较大.其中,十溴联苯醚含量为56～337 ng.g-1(平均为171 ng.g-1),占PBDEs总含量的90%～99%(平均95%).所检测到的部分同系物(如BDE-196、197和203)可能是BDE-209的降解产物.PBDEs的垂直分布模式显示,0～10 cm层面样品的PBDEs浓度为147 ng.g-1,30～40 cm层面样品的PBDEs浓度为260 ng.g-1,PBDEs在沉积物中的丰度随垂直深度的增加而增加.12种同系物在采自各个深度层样品中的比例基本相同,由十溴工业品来源的BDE-209、208、207和206占总PBDEs的94%,而五溴和八溴所占比例较低.由此可见,该地区普遍存在PBDEs污染,其中十溴联苯醚是最主要污染物,这可能与十溴工业品是电器工业主要使用的阻燃材料相关.     

我国典型电子废弃物拆解地农田土壤中的多溴联苯醚

选择我国主要电子垃圾拆解地清远龙塘-石角地区作为研究区,以14种多溴联苯醚(Polybrominated Diphenyl Ethers,PBDEs)化合物为研究对象,探讨了PBDEs化合物在龙塘-石角地区农田土壤中的含量、同系物组成及空间分布状况,分析了土壤TOC、土地利用方式(水旱轮作)等对农田土壤PBDEs含量特征的影响.结果表明,清远龙塘-石角地区农田土壤中14种PBDEs化合物的总量平均为(19.0±20.1)ng·g-1(以干重计),明显低于来自路边、拆解中心、居民区等表土中的PBDEs含量.研究区农田土壤中PBDEs的空间分布与土壤TOC呈现出一致性特征,当去除TOC的影响后,作为点源的电子垃圾拆解地成为土壤PBDEs分布的关键控制因素.水旱轮作的土地利用方式下,在一个轮作周期内,当轮作为水稻且土壤处于淹水状态时土壤中的PBDEs含量最低.总体来看,农田土壤中的PBDEs动态受土壤水含量、作物种植情况、土壤水旱状态等多因素的综合影响,表现出不确定的变化特征.本文的研究成果对土壤-作物系统PBDEs的行为研究进行了补充,并可为完善现有的土地质量评估体系提供基础资料.     

东海沉积物中多溴联苯醚的分布特征研究

采集分析了中国东海28个表层沉积物和7个柱状沉积物.结果表明,东海表层沉积物中除BDE-209外∑PBDEs的浓度范围为0.20~2.09ng/g dw,BDE-209的浓度范围为0.57~2.87ng/g dw,在总PBDEs中所占浓度百分比为57.9%~76.7%;接下来分别是BDE-99和BDE-47,所占比例分别为11.7%~21.5%和7.1%~17.4%.表层沉积物中PBDEs分布呈现出(离海岸线)由近及远浓度越来越低的趋势,由北到南浓度上升的趋势.东海柱状沉积物中PBDEs浓度随着深度加深呈现出先上升后下降的趋势,很好的反映出了PBDEs在中国大陆的使用历史和现状.表层沉积物TOC含量在0.54%~0.88%之间,柱状沉积物TOC的含量在0.62%~0.88%之间,而且不管是表层沉积物(R2=0.723,P0.01)还是柱状沉积物(R2=0.595,P0.01),PBDEs浓度和TOC含量之间有较强的线性关系,表明沉积物中TOC含量是影响PBDEs分布的一个重要因素.     

多溴联苯醚在电子废弃物拆卸地沉积物中的垂直分布

采用气相色谱质谱联用仪对采自清远电子废弃物拆卸地水库钻孔沉积物中的多溴联苯(polybrominated diphenyl ethers,PBDEs)进行了分析,调查其在沉积物中的垂直分布.结果表明,PBDEs在所有的样品中均检出,含量为0.43～141 ng/g,平均为9.26 ng/g.PBDEs在下层(16 cm以下)沉积物中含量较低、变化很小(0.43～2.30 ng/g),但在上层沉积物中含量明显增加(2.90～141 ng/g),反映了当地电子废弃物拆卸活动的影响;3种工业源的PBDEs,即五溴、八溴和十溴PBDEs,表现出相似的垂向分布趋势,说明其来源的一致性.其中,十溴PBDEs是最主要的PBDEs,平均占所有PBDEs的79.6%,其次是五溴PBDEs(14.7%),而八溴PBDEs所占比例最低(5.69%).3种PBDEs的组成模式显示,它们与相应的工业品PBDEs组成都有一定差异,可能因其降解行为不同所致.一些PBDE的同族体组成在沉积钻孔的垂直变化也进一步说明高溴代PBDE在沉积物的埋藏期间可能发生了降解,虽然还需要进一步研究证实.     

河北邯郸钢铁冶炼区周边麦田土和小麦籽粒的多环芳烃含量及其组分谱特征

在大型邯郸钢铁公司周边不同样区的麦田成对采集表层土壤和成熟的小麦籽粒样品,检测US EPA优控的16种母体多环芳烃(polycyclic aromatic hydrocarbons,PAHs)的浓度和组分谱,确定当地麦田表土PAHs的空间分布特征、与总有机碳TOC分数的相关性.由此,初步开展PAHs源解析,并简单探讨小麦籽粒PAHs与表土PAHs的关联性.结果表明,麦田表土总PAHs平均中位数含量为398.9 ng·g-1(范围123.4~1 626.4 ng·g-1),根据丹麦的土壤质量标准,所有表土样品中PAHs总含量超过限值占18%,而苯并[a]芘含量超过限值的样品占总数的10%.表土PAHs组分谱以中、高环组分为主体.利用同分异构体特征比值进行初步源解析,显示煤与生物质燃烧和交通燃油(尾气)是当地PAHs主要混合排放源.各样区麦田表土TOC分数与PAHs总含量、与不同环数组分含量都呈现类似的显著正相关.邯郸钢铁公司周边麦田小麦籽粒的总PAHs平均中位数含量为27.0 ng·g-1(范围19.0~34.0 ng·g-1),PAHs含量较低且未超过欧盟与国内的相关食品卫生标准.小麦籽粒中优势低环组分占总体的84%,其组分谱分布与麦田表土有所不同,显示小麦籽粒的PAHs除去根部吸收、传输外,还存在大气干湿沉降通过叶表(气孔)进入小麦体内等其它输入途径.     

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.