长江三角洲典型地区农田土壤中多氯联苯残留状况

选择地处长江三角洲的苏南某市为试区,对该市农田土壤中18种PCBs同系物的残留量进行了调研,以揭示非污染区农田土壤中PCBs的残留现状,以及各种同系物在农田土壤中的分布特征.结果表明:PCBs残留总量介于数十至数千ng·kg^-1水平,除PCB₇₇未检出外,其它17种PCBs同系物有不同程度地检出,残留量及检出率最高的分别是PCB₁₃₈和PCB₁₈₀.土壤的不同利用方式对PCBs残留量有一定影响,水稻土中PCBs残留量最高,传统菜地中PCBs残留量最低.不同利用方式土壤中同系物残留的分布状况具有不同的特征,而同系物的分布特征从一定程度上能反映污染物的来源:稻土中PCBs主要来源于灌溉水,而传统蔬菜地PCBs主要来源为大气降尘,大棚土壤中PCBs则主要来自于农用化学品.     

夜鹭卵中几种多氯联苯(PCBs)的残留特征

分析了江苏无锡鼋头渚和江西共青城夜鹭卵中多氯联苯同系物的残留状况.无锡地区样品中检出6种PCB同系物-28,52,101, 138,153,180-,其中高氯取代的PCB 153,138,180占所测PCBs总量的85%以上;共青城样品中只检出3种PCB同系物-52,153,180-,其中高氯取代的PCB 153和180占所测PCBs总量的95%以上.可见生物样品中高氯取代的PCBs更容易富集.无锡地区样品中PCBs的残留水平比共青城样品高,其中PCB180的残留量差异显著-P=0.003<0.01-.无锡工业发展水平高于共青城可能是导致两地间样品差异的原因,因此可以通过对夜鹭卵中PCBs的残留量来监测区域环境中PCBs的污染状况.     

活性污泥性质对短期膜污染影响的解析研究

采用统计分析方法研究了16种不同性质活性污泥混合液对膜生物反应器膜污染的影响机理.结果表明,胞外聚合物(extracellular polymeric substances,EPS)、溶解性有机物(soluble microbial products,SMP)、上清液胶体颗粒(suspended solids insupernatant,SS_s)、污泥混合液粘度(μ)、相对疏水性(relative hydrophobicity,RH)、Zeta电位(Zeta potential)均对膜生物反应器膜渗透性能有显著的影响作用,其与膜污染阻力的皮尔逊相关系数r_p分别为:0.898、0.712、0.810、0.691、0.837、-0.881;同时发现,胞外聚合物是影响活性污泥中溶解性有机物含量(r_p=0.682)、污泥粘度大小(r_p=0.633)、上清液胶体颗粒含量(r_p=0.783)、Zeta电位(r_p=-0.953)及相对疏水性大小(r_p=0.877)的主要因素;在活性污泥性质中胞外聚合物是影响膜污染的根本原因,是膜生物反应器膜污染的重要影响因素.     

福建海域中华白海豚皮脂的多氯联苯研究

用气相色谱-质谱联用仪测定了福建海域中华白海豚(Sousa chinesis)皮脂中25种多氯联苯(PCBs)同系物的含量,并分析了其组成特征以及国际毒性当量。结果表明,白海豚皮脂的PCBs含量为1.731×10-6,同族物组成以含6和5个Cl的化合物为主,分别占总量的55.94%和19.06%,含Cl 5个以上的PCBs占总量的87.99%。PCBs同系物中以PCB153和PCB138含量最高,分别占总量的21.19%和21.17%,其次分别是PCB149、PCB101、PCB170、PCB52、PCB118、PCB180,在3.41%和9.04%之间。皮脂的PCBs国际毒性当量为2.165×10-9,没有对白海豚的健康造成威胁。     

贵州红枫湖地区水稻土多氯联苯和有机氯农药的残留

调查了红枫湖周边水稻土的7种多氯联苯（PCBs）和13种有机氯农药（OCPs）的含量分布.结果显示,DDTs及其代谢产物、HCHs的异构体、异狄氏剂、七氯等有机氯农药及PCB 28和PCB 52在所有样品中均被检出.与国内外污染区相比,PCBs含量较低.研究区土壤中污染物的组成结果类似,PCBs以3～5氯取代的同属物为主,农药以DDTs为主.剖面土壤中∑PCBs含量范围为8.9～55.9 ng/g,主要以3～5氯取代的PCBs为主,平均占PCBs总量的89%.∑DDTs含量为 4.7～42.6ng/g,以p,p′-DDE,p,p′-DDT为主.DDT/（DDD+DDE）的比率表明红枫湖地区水稻田中DDTs的降解速率不同,暗示其环境条件的差异.α-HCH/γ-HCH为0.28～0.90,表明红枫湖地区水稻田中HCHs在环境中残留时间很长,经历了光解和生物作用等变化.PCBs对TEQ的贡献较低,为0.06～0.51 pg/g.     

螃蟹活动对闽江河口互花米草沼泽湿地土壤温室气体排放通量的影响

于2015年1月（冬季）、4月（春季）、6月（夏季）和9月（秋季）,以闽江河口互花米草沼泽湿地为研究区,采用静态箱与气相色谱结合的方法,研究螃蟹对湿地土壤CO₂、CH₄和N₂O排放通量及综合增温潜势的影响。研究表明：温室气体排放季节变化较为显著,CO₂、CH₄排放通量最大值均出现在夏季,N₂O排放通量最大值出现在秋季,CO₂、CH₄和N₂O排放通量最小值均出现在春季。与无螃蟹组相比,高潮滩和中潮滩螃蟹组CO₂、CH₄和N₂O排放通量均值都增大,其中高潮滩螃蟹组CO₂、CH₄和N₂O排放通量依次增大了46.36%、66.67%和69.66%,中潮滩螃蟹组CO₂、CH₄和N₂O排放通量依次增大了53.57%、142.97%、73.08%。相关性分析结果表明：土壤CO₂排放通量与土壤温度显著正相关（n=96,p＜0.05）,CH₄和N₂O排放通量与土壤温度显著正相关（n=96,p＜0.01）;N₂O排放通量与土壤pH显著正相关（n=96,p＜0.01）,与土壤含水量显著正相关（n=96,p＜0.05）。综上所述,螃蟹活动对闽江河口互花米草沼泽湿地土壤的干扰促进了温室气体的排放,为有效调节湿地碳、氮固持作用和湿地生态系统科学管理提供了参考。     

透水/不透水格局特征对汇水单元径流污染的影响

深入揭示透水/不透水下垫面格局特征（组成、位置和比例等）对城市地块汇水单元地表径流及污染产生能力的影响,对减轻城市内涝及控制面源污染具有重要意义.利用景观格局指数分析透水/不透水下垫面格局特征与地表径流总量（Q）、溶解态污染物累积负荷（L_d）和颗粒态污染物累积负荷（L_p）之间的关系.结果表明：①表征破碎度的斑块密度（PD）与最大斑块指数（LPI）分别与Q和L_d呈正、负相关,PD与L_d呈显著正相关（r=0.59,P<0.05,以COD计）,LPI与L_d呈显著负相关（r=-0.60,P<0.05,以COD计）;②表征复杂度的景观形状指数（LSI）和平均斑块形状（MSI）分别与Q和L_p呈正、负相关性,LSI与L_p呈显著正相关（r=0.61,P<0.05,以TP计）,MSI与L_p呈极显著负相关（r=-0.62,P<0.01,以TP计）;③表征聚散度的内聚力指数（COHESION）和分散指数（SPLIT）分别与Q和L_d呈负、正相关性,COHESION与L_d呈显著负相关（r=-0.59,P<0.05,以COD计）,SPLIT与L_d呈显著正相关（r=0.6,P<0.05,以COD计）;④在城市小尺度透水面格局规划上,适量减少细小规则斑块的散乱分布,增加较大的不规则斑块或斑块群,对有效调控地表径流及污染有积极影响.通过透水/不透水面的破碎度、复杂度和聚散度与汇水区单元径流产生和污染输出的相关性分析,以期从格局特征（面积、距离和形状等）考虑合理配置LID设施调控径流污染提供新思路.     

2017年1月天津市区PM2.5化学组分特征及高时间分辨率来源解析研究

为了快速分析天津市区冬季以及重污染过程中PM_2.5的化学组成特征及来源,本研究于2017年1月利用在线监测仪器快速采集了天津市区环境受体中PM_2.5及其化学组分的小时数据,并通过PMF（positive matrix factorization,正定矩阵因子分解法）模型解析了天津市区2017年1月及重污染过程中PM_2.5的主要贡献源类,分析了重污染过程中排放源的变化趋势.结果表明：2017年1月天津市区PM_2.5浓度为6.0~449.0 μg·m^-3,平均值为153.3 μg·m^-3.NO₃^-、SO₄^2-、NH₄⁺是PM_2.5中水溶性离子的主要组分,三者之和占水溶性离子总量的88.3%.NH₄⁺与Cl^-、NO₃^-、SO₄^2-均表现出显著的正相关性（r=0.82,0.95,0.97;p<0.01）.NO₃^-和SO₄^2-（r=0.90;p<0.01）,Ca²⁺与Mg²⁺（r=0.65;p<0.01）均表现出显著的相关性,说明它们分别具有较高的同源性.OC和EC也是PM_2.5的重要组成部分,两者之和占PM_2.5质量浓度的20.4%.重污染过程中,PM_2.5及其主要离子的浓度显著的增加（p<0.01）,并存在较高的二次离子生成.PMF解析结果表明,二次源类是天津市区2017年1月PM_2.5的首要源类,分担率为38.1%,其次为机动车源（分担率为25.6%）、燃煤源（分担率17.1%）、扬尘（分担率10.1%）和生物质燃烧（分担率9.1%）.重污染过程中,二次源是PM_2.5的主要贡献源类,分担率达到39.3%;说明重污染期间存在显著的二次转化及二次粒子的积累过程.重污染发生演变过程中,二次源、机动车源和燃煤源对PM_2.5贡献表现出显著增加的趋势,而扬尘和生物质燃烧的贡献则没有显著增加.     

Effect of C/N ratio, aeration rate and moisture content on ammonia and greenhouse gas emission during the composting

Gaseous emission (N₂O, CH₄ and NH₃) from composting can be an important source of anthropogenic greenhouse gas and air pollution. A laboratory scale orthogonal experiment was conducted to estimate the effects of C/N ratio, aeration rate and initial moisture content on gaseous emission during the composting of pig faeces from Chinese Ganqinfen system. The results showed that about 23.9% to 45.6% of total organic carbon (TOC) was lost in the form of CO₂ and 0.8% to 7.5% of TOC emitted as CH₄. Most of the nitrogen was lost in the form of NH₃, which account for 9.6% to 32.4% of initial nitrogen. N₂O was also an important way of nitrogen losses and 1.5% to 7.3% of initial total nitrogen was lost as it. Statistic analysis showed that the aeration rate is the most important factor which could affect the NH₃ (p = 0.0189), CH₄ (p = 0.0113) and N₂O (p = 0.0493) emissions significantly. Higher aeration rates reduce the CH₄ emission but increase the NH₃ and N₂O losses. C/N ratio could affect the NH₃ (p = 0.0442) and CH₄ (p = 0.0246) emissions significantly, but not the N₂O. Lower C/N ratio caused higher NH₃ and CH₄ emissions. The initial moisture content can not influence the gaseous emission significantly. Most treatments were matured after 37 days, except a trial with high moisture content and a low C/N ratio.     

不同年龄夜鹭卵中有机氯农药污染的生物指示

通过对太湖鼋头渚 2 0 0 0年采集的二龄、三龄和四龄夜鹭卵以及相应年龄组夜鹭的捕食物中有机氯残留的检测 ,发现捕食物中HCH和DDT的平均残留量随年龄增加而增加 .除γ HCH外 ,其它 15种有机氯农药在卵样中均有检出 ,残留水平最高的为p ,p′ DDE ,占有机氯农药残留总量的 85 %以上 .β HCH是六六六类中持留性最强的组分 ,其残留量仅次于p ,p′ DDE .研究发现 ,p ,p DDT和 β HCH检出率为 10 0 % ,而其它类型农药只有很低的检出率 ,这与我国有机氯农药使用的历史情况相吻合 .随着亲鸟年龄增加 ,卵中 β HCH残留量有所提高 ,p ,p′ DDE残留量似有先升后稍降的趋势 .统计结果表明 :各年龄组有机氯残留量差异不明显 ,因此在用夜鹭卵作有机氯污染的生物指示时可以不考虑年龄差异所带来的影响 .     

洞庭湖不同营养级鱼组织中PCBs的分布特征

采用稳定同位素分析技术和气相色谱-高分辨质谱联用技术,测定了洞庭湖6种鱼组织的稳定氮同位素丰度值（δ¹⁵N值）和多氯联苯（PCBs）的含量,研究了鱼组织中PCBs分布特征及其与营养级的相关性.结果表明,∑PCBs₁₁₅的浓度范围为0.04~9.77ng/g湿重,在鲤鱼性腺组织中最高.毒性当量为：0.0003~2.39pg/g湿重,在鳡鱼脂肪组织中最高.洞庭湖鱼中PCBs的含量处于较低水平.PCB28,52,95,99,101,105,110,118,138,153,155和209在所有组织中检出.Co-PCBs,Ind-PCBs和PCB209具有组织分布特异性.不同计量方式下,鱼组织中PCBs与δ¹⁵N值具有相关性的同类物不同.     

渤海湾脉红螺中多氯联苯和多溴联苯醚的测定分析

应用GC/HRMS对渤海湾脉红螺中的PCBs(多氯联苯)和PBDEs(多溴联苯醚)2类持久性有机污染物进行了测定分析.结果表明:雄性脉红螺中PCB(3～10氯代)的质量分数(10.1 ng/g,以干质量计)和PBDEs(BDE28、BDE47、BDE99、BDE100、BDE153、BDE154、BDE209)的质量分数(1.74 ng//g)均高于雌性脉红螺(分别为8.09和1.38 ng/g);雄性脉红螺中PCBs的WHO-TEQ(毒性当量,8.41 pg/g,以脂肪质量计)高于雌性脉红螺(4.34 pg/g),其中PCB118和PCB126的贡献率分别为13%和77%.脉红螺的不同组织中,性腺和消化腺中w(PCBs)和w(PBDEs)最高,肌肉组织中最低;主要同类物为PCB118、PCB101、PCB28、PCB138、PCB180、PCB52、PCB153和5-PCB以及BDE209.渤海湾脉红螺的消化腺可以作为PCBs和PBDEs的生物指示物.     

Occurrence and congeners specific of polychlorinated biphenyls in agricultural soils from Southern Jiangsu, China

A total of 198 agricultural soil samples were collected from Zhangjiagang and Changshu in Southern Jiangsu for analysis of 13 polychlorinated biphenyls （PCBs） in order to assess the levels of pollution, sources, area distribution, and potential risk for the environment. All methods were rigorously tested and an adequate quality control was ensured. Only one site had no PCBs residues, and the highest total PCBs concentration in the surface soils was 32.83 ng/g. The average concentration in all the soil samples was 4.13 ng/g, signaling low-level pollution. Tetra-, penta-, and hexa-chlorinated biphenyls were dominant species in soil samples, accounting for more than 75% of ∑PCBs in the soil samples. PCB118 was the most abundant congener in all the samples. The PCB118 was about 20% of ∑PCBs. The soil organic matter content showed only a weak correlation with the levels of all PCB congeners, in which a better correlation was noted for the more volatile lighter PCB congeners than for the heavier homologues. To a certain extent, the sources and land use seemed to influence the levels of PCBs.     

Levels and distributions of polychlorinated biphenyls in sewage sludge of urban wastewater treatment plants

Concentrations of polychlorinated biphenyls (PCBs) have been measured in sewage sludge samples from 8 urban wastewater treatment plants in Beijing, China. The PCB congeners were analyzed by isotope dilution high resolution gas chromatography/high resolution mass spectrometry method. The concentration of PCBs ranged from 65.6 to 157 ng/g dry weight (dw), with a mean value of 101 ng/g dw. The dioxin-like PCB WHO-TEQs (World Health Organization-Toxic Equivalents) of the sludge were lower than 1 pg /g dw. Conse...     

GC-NCI-MS法测定底泥中类二(噁)英多氯联苯

建立了气相色谱/负化学负离源/质谱(G-NCI-MS)法测定底泥样品中世界卫生组织(WHO)推荐的12种类二(噁)英多氯联苯.底泥样品采用索氏提取,酸碱复合硅胶柱净化,选择离子扫描监测,同位素稀释内标法定量.比较PCBs各单体在负化学负离源(NCI)和电子轰击电离源(EI)条件下的灵敏度,发现PCBs各单体在NCI条件...     

Bioconcentration kinetics of PCBs in various parts of the lifecycle of the tadpoles Xenopus laevis

Polychlorinated biphenyls （PCBs） in Xenopus laevis have been reported only for a few congeners. Additionally, there is very little information on the ability of Xenopus laevis to bioconcentrate PCBs. To address these issues, the tadpole Xenopus laevis was exposed to Aroclor 1254 mixtures in water at room temperature for 110 d followed by an additional 110 d of nonspiked PCBs in the water for the control group. During the whole process, bioconcentration factors （BCFs） of PCBs ranged from 1180 to 15670. For most PCB congeners, the highest and lowest bioconcentrations of the kinetic curves were found to be remarkably simultaneous, respectively. All 141 PCB congeners under the same experimental conditions had no linear correlation on the lgBCF versus lgKow relationship. The relationship between lgBCFs and lgKow followed a parabolic pattern indicative of selective bioconcentration, suggesting that the kinetic curves of the PCB congeners observed in the lifecycle of the tadpoles may be concentrated due to the amphibian special species and internal metabolism. In contrast, lgBCFs for PCBs were inversely related to lgKow, suggesting that a metabolism of the higher Kow PCB congeners occurred. These results support the author＇s conclusion that the tadpole Xenopus laevis plays major roles in the bioconcentration of PCB congeners, and demonstrated that the exposure kinetic curves of PCB congeners are complex. Besides the amphibian metamorphous development, the lifecycle of the tadpole Xenopus laevis also may be of importance in determining the bioconcentration of PCB congeners.     

Topsoil dichlorodiphenyltrichloroethane and polychlorinated biphenyl concentrations and sources along an urban-rural gradient in the Yellow River Delta

The Yellow River Delta (YRD) is a typical agricultural and petrochemical industrial area of China. To assess the current status of soil dichlorodiphenyltrichloroethane (DDT) and polychlorinated biphenyls (PCB) residues, topsoil samples (0-15 cm) (n = 82) were collected in Bincheng District, at the geographic center of the YRD. The total concentrations of six DDT homologues were within 3.3-3819 μg/kg, with a mean concentration of 191 μg/kg, showing significant increase along urban-rural gradient. Soil concentrations of seven indicator PCBs in the area ranged from non-detectable to 87.0 μg/kg, dominated by heavily chlorinated PCBs (PCB-101 and -118). Soil PCBs concentrations were significantly greater in urban than suburban and rural areas. Principal component and multiple linear regression analysis suggest that 86.4% of soil DDTs originate from past DDT usage, and 13.6% originate from dicofol application. Soil PCBs most likely originate from the petrochemical industry (77.1%), municipal solid waste disposal (16.5%), local commercial PCB homologues usage (5.2%), and long-range atmospheric deposition (1.2%). In general, soil DDTs pollution was classified as low level, and mean PCBs concentrations were below the severe contamination classification range. Because PCB-118 is a dioxin-like congener, monitoring and remediation is advised to assess and reduce negative environmental and human health effects from soil DDTs and dioxin-like congeners in the study area.     

哈尔滨市土壤中PCBs的污染现状研究

采用GC／MS法对哈尔滨市18个表层土壤及1个深层土壤中PCBs的浓度进行了测定,并讨论了PCBs在土壤中的分布特征及同族体的组成情况。结果表明,该市表层土壤中∑PCBs浓度分布在0．025-1．795ng／g之间,平均值为0．545ng／g,深层土壤中未能检测到目标物,土样中共有18种同系物有不同程度的检出,主要以五氡联苯为主,其中工业区的土壤样品中∑PCBs含量最高。     

广州市类二噁英-多氯联苯大气沉降通量和组成

研究了广州市4个采样点2005年11月到2006年3月期间的类二噁英-多氯联苯(DL-PCBs)的沉降通量和组成.研究表明,广州市DL-PCBs的平均沉降通量为223pg·m-·2d-1,对应的毒性当量为1.5pg·m-·2d-1.城区DL-PCBs的沉降通量是郊区的1.6倍.各采样点DL-PCBs同系物分布相同,主要的同系物为PCB118、PCB105、PCB77,其平均含量分别为30%、18%和17%.湿季的DL-PCBs的沉降通量高于干季,表明降水对沉降通量影响明显.通过初步的源分析,发现某些含PCBs产品和固体废物焚烧可能是大气中DL-PCBs主要的来源.