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261.
262.
上海青浦地区大气降水的化学特征 总被引:2,自引:1,他引:1
利用上海青浦地区2003—2014年观测的大气降水监测资料,分析该区域12 a以来大气降水的酸化程度、化学组成特征,探讨降水中化学成分的不同来源及相对贡献。结果表明:降水pH年均值为4.43~6.33,酸雨频率为2.6%~86.8%,降水酸化程度大致经历了明显恶化和波动变化2个阶段。降水电导率年均值为1.77~4.01 m S/m,呈下降趋势。降水中各离子雨量加权平均当量浓度顺序为SO_4~(2-)NH_4~+Ca~(2+)NO_3~-Cl~-Na~+Mg~(2+)F-K~+,SO_4~(2-)、NH+4、Ca~(2+)和NO_3~-是降水中的主要离子,占离子总量的83.0%;降水类型由硫酸型向硫酸和硝酸混合型转变。降水离子中的二次组分SO_4~(2-)、NO_3~-和NH_4~+绝大部分来源于人为源,Ca~(2+)、Mg~(2+)和K+主要来自于土壤源和人为源的贡献,Cl~-主要来自海洋源,同时人为源的影响也不可忽视。 相似文献
263.
基于主成分分析-多元线性回归的松花江水体中多环芳烃源解析 总被引:2,自引:1,他引:1
对松花江全流域14个监测断面的16种美国环保局优先控制的多环芳烃(PAHs)的主要来源及其贡献率应用主成分因子分析-多元线性回归模型(PCA-MLR)进行了来源解析。结果表明:松花江全流域为化石和石油燃料的复合PAHs污染,水体环境中PAHs首要污染源为化石燃料燃烧和交通污染,合计贡献率为63.1%,第二大污染源为工业和民用燃煤污染,合计贡献率为36.9%,沿江的石化、石油基地、大型焦化厂、电厂都是PAHs的主要来源。 相似文献
264.
Distribution,sources, and ecological risk assessment of SVOCs in surface sediments from Guan River Estuary,China 总被引:1,自引:0,他引:1
Xinran He Xiaojuan Song Yong Pang Yiping Li Binlin Chen Zhihua Feng 《Environmental monitoring and assessment》2014,186(7):4001-4012
The contamination of semi-volatile organic compounds (SVOCs) in the surface sediments of the Guan River Estuary, China was fully investigated. Total concentrations of 56 species of SVOCs ranged from 132 to 274 ng/g with an average of 186 ng/g (dry weight). Polycyclic aromatic hydrocarbon (PAH) concentrations were positively correlated with clay content and negatively correlated with sediment grain size. Source identification indicated that PAHs originated mainly from pyrolytic sources. However, intense ship traffic in the estuary may provide sources of petrogenic PAHs. Organochlorine pesticides (OCPs) mainly originated from direct input of dichlorodiphenyltrichloroethanes (DDTs) during some industrial processes. The SVOC concentrations were also compared with International Sediments Quality Guidelines and Sediments Quality Criteria, and the results indicated that negative biological impacts may originate from high concentrations of FLO, p,p′-DDE, and total DDTs. 相似文献
265.
便携式GC/MS热脱附法直接测定环境空气中挥发性有机物 总被引:3,自引:1,他引:2
采用便携式气相色谱/质谱联用热脱附法直接测定环境空气中的挥发性有机物,优化了试验条件。方法在5×10-9~100×10-9范围内线性良好,39种化合物的检出限为1.1μg/m3~19μg/m3,标准气体平行测定的RSD≤11.0%,回收率在80%~120%之间。 相似文献
266.
Lan Q Cui K Zeng F Zhu F Liu H Chen H Ma Y Wen J Luan T Sun G Zeng Z 《Environmental monitoring and assessment》2012,184(8):4921-4929
Phthalate esters (PAEs) were examined in indoor and outdoor dust samples from the subtropical city of Guangzhou, China. The ∑(16)PAEs concentrations ranged from 121 to 3,223 μg g(-1) dust, with the median concentration of 840 μg g(-1) dust. Significantly higher concentrations of PAEs in dust samples were found in offices where electrical and electronic devices, carpet pads, and office furniture were widely used. Of the 16 PAEs, diisobutyl phthalate (DiBP), di-n-butyl phthalate (DnBP), and di(2-ethylhexyl) phthalate (DEHP) dominated the PAEs in indoor and outdoor dust samples, and accounted for >96.8% and >93.1% of the ∑(16)PAEs concentrations, respectively. The median daily inhalation exposure of ∑(16)PAEs were 3.53 and 0.247 μg kg(-1) body weight day(-1), and at the 95(th) percentile were 7.62 and 0.530 μg kg(-1) body weight day(-1), up on the measured concentrations and estimated dust ingestion rates, respectively, for toddles and adults. The ubiquitous distribution of PAEs as noted in this study suggests the need for detailed assessment of PAEs concentrations using more sites and to further investigate the factors influencing PAEs exposure in China. 相似文献
267.
Li YX Han W Yang M Feng CH Lu XF Zhang FS 《Environmental monitoring and assessment》2012,184(8):5035-5041
Concentrated animal feeding operations have been recognized as one of the most important contributors of natural estrogens which show significant endocrine-disrupting properties in aquatic environments. In this study, the concentrations of 17α-estradiol (17α-E2), 17β-estradiol (17β-E2), estrone (E1), and estriol (E3) in several matrices, including soils (surface and deep), sediments (surface and deep), and groundwaters, around a typical dairy farm were surveyed using gas chromatography/mass spectrometry. Of the two farmlands, surface and subsurface sediments in waste lagoon and along effluent drainage drench, the concentrations of 17α-E2, 17β-E2, and E1 ranged from below detection limit to the highest level of 6.60 μg/kg, except that E3 was not detectable. Three estrogens of 17α-E2, 17β-E2, and E1 with the concentrations of 3.18-31.61 ng/L were observed in two groundwater samples. The results clearly demonstrated the vertical migration and horizontal transport of estrogens in the investigated area. Within 750-m distance, it was observed the attenuation of 17α-E2, 17β-E2, and E1 along the effluent route and the horizontal migration of estrogens was less than 1,350 m in this survey. 相似文献
268.
The accelerated industrialization and urbanization in the last three decades around the Pearl River Delta within Guangdong Province in China have led to serious concerns about the impacts on the aquatic environment. In the present study, the genotoxicity of the sediments collected from the Pearl River was evaluated by micronucleus (MN) assay with Vicia faba root tip cells, and the 16 EPA priority polycyclic aromatic hydrocarbons (PAHs) and heavy metals (HMs, including Cr, Cu, As, Se, Cd, Hg, and Pb) in the sediments were determined respectively by GC-MS, inductively coupled plasma mass spectrometry, and inductively coupled plasma atomic emission spectrometry. The results showed that there were significant increases of MN frequencies observed in the sediment-exposed groups, compared with the negative group (P?0.05, P?0.01), indicating that the sediments clearly had genotoxicity to the V. faba root cells. The total concentrations of the priority PAHs (250-13,656 ng g(-1), dry weight) and HMs (As, 22,770-36,639 μg kg(-1); Cr, 39,333-133,343 μg kg(-1); Cu, 36,145-159,270 μg kg(-1); Pb, 51,210-166,642 μg kg(-1); Cd, 475.4-1,818.9 μg kg(-1); Hg, 59.9-460.8 μg kg(-1); and Se, 331.7-1,250.4 μg kg(-1), dry weight) were close to those obtained from other urbanized and industrialized areas, which have been considered moderately polluted. There was a clear positive correlation between MN potency and the molar concentrations of Hg and Pb in the sediments (Hg, r?=?0.94; Pb, r?=?0.91), suggesting that Hg and Pb were the most important factors that posed the sediments higher genotoxicity to V. faba root cells. Our results suggested that both biological and chemical approaches are necessary to be included in a battery of tests to assess the eco-environmental risks of sediments. 相似文献
269.
270.
北京地区冬季典型PM2.5重污染案例分析 总被引:9,自引:6,他引:3
对2013年1月10—14日发生的持续性PM2.5重污染过程从污染过程演变、气象条件影响、与气态污染物关系、区域污染背景、PM2.5浓度空间分布演变及其与地面风场的关系、PM2.5组分特征等多个方面进行全面的分析,较为完整地还原了该次重污染案例的形成原因以及主要影响因素。主要结论包括:该次重污染过程是稳定气象条件下导致的局地污染物积累,再叠加华北区域性污染的影响共同造成,其中10、12日北京地区PM2.5浓度的快速增长反映了周边污染传输的显著影响;逆温不但造成污染物难以扩散,且不同的逆温类型对PM2.5浓度水平有显著影响,同时还发现逆温的破坏导致近地面高浓度污染物向上扩散,造成百花山出现峰值高污染浓度现象;NO2与PM2.5浓度水平的高相关性反映交通污染二次转化对PM2.5浓度水平的影响,在较高湿度条件下,SO2浓度水平对湿度敏感且表现为负相关性;该次污染过程中OM、SO2-4、NO-3、NH+4等组分在PM2.5质量浓度中的占比超过70%,说明燃煤、机动车等仍是北京地区最主要的污染来源,同时SO2-4占比最高也说明区域污染传输对该次重污染的显著贡献。 相似文献