The concentration of short-chain polychlorinated paraffins(SCCPs) in the urban air of Dalian,China was monitored from September 2016 to August 2017 with a self-developed passive sampler(PAS1) and an active high-volume...The concentration of short-chain polychlorinated paraffins(SCCPs) in the urban air of Dalian,China was monitored from September 2016 to August 2017 with a self-developed passive sampler(PAS1) and an active high-volume sampler, simultaneously. PAS1 successfully collected the entire target SCCPs in the ambient air. Air SCCPs sampled by PAS1 were found be in the linear uptake stage during 181 days of sampling. Passive and active samples showed comparable congener profiles, and the dominant contributors of SCCPs in the two kinds of samples were similar. A significant linear correlation was observed between the total concentration of SCCPs sampled by PAS1 and active sampler in the four seasons. The passive sampling rates of the PAS1 for the gas and particulate phases of SCCPs were measured. The quantitative structure–property relationship of the sampling rate of PAS1(Rair) for gas-phase SCCPs was studied. From the molecular point of view, Rairwas mainly affected by the molecular weight and sub-cooled liquid vapor pressure of SCCPs. In general, SCCPs in the urban air of Dalian mainly existed in gas phase,lower molecular weight SCCPs primarily occurred in the gas phase, whereas higher molecular weight SCCPs were predominately adsorbed or absorbed on airborne particles. The air concentration of SCCPs in the four seasons were different, the correlation of the concentration of SCCPs in the air with the meteorology parameters was conducted. The exposure risk by intake air SCCPs of the residents around the sampling sites was evaluated according to the European risk assessment standards.展开更多
So far little is known about air–soil exchange under any sealed circumstances（e.g., in plastic and glass sheds）, which however has huge implications for the soil–air–plant pathways of persistent organic pollutant...So far little is known about air–soil exchange under any sealed circumstances（e.g., in plastic and glass sheds）, which however has huge implications for the soil–air–plant pathways of persistent organic pollutants including organochlorine pesticides（OCPs）. A newly designed passive air sampler was tested in a sealed chamber for measuring the vertical concentration profiles of gaseous phase OCPs（hexachlorocyclohexanes（HCHs） and dichlorodiphenyltrichloroethanes（DDTs））. Air was sampled at 5, 15, and 30 cm above ground level every 10 th day during a 60-day period by deploying polyurethane foam cylinders housed in acrylonitrile butadiene styrene-covered cartridges. Concentrations and compositions of OCPs along the vertical sections indicated a clear relationship with proximity to the mixture of HCHs and DDTs which escapes from the soils. In addition, significant positive correlations were found between air temperatures and concentrations of HCHs and DDTs. These results indicated revolatilization and re-deposition being at or close to dynamic pseudo-equilibrium with the overlying air. The sampler used for addressing air–soil exchange of persistent organic pollutants in any sealed conditions is discussed.展开更多
基金supported by the National Natural Science Foundation of China (No. 21577009)
文摘The concentration of short-chain polychlorinated paraffins(SCCPs) in the urban air of Dalian,China was monitored from September 2016 to August 2017 with a self-developed passive sampler(PAS1) and an active high-volume sampler, simultaneously. PAS1 successfully collected the entire target SCCPs in the ambient air. Air SCCPs sampled by PAS1 were found be in the linear uptake stage during 181 days of sampling. Passive and active samples showed comparable congener profiles, and the dominant contributors of SCCPs in the two kinds of samples were similar. A significant linear correlation was observed between the total concentration of SCCPs sampled by PAS1 and active sampler in the four seasons. The passive sampling rates of the PAS1 for the gas and particulate phases of SCCPs were measured. The quantitative structure–property relationship of the sampling rate of PAS1(Rair) for gas-phase SCCPs was studied. From the molecular point of view, Rairwas mainly affected by the molecular weight and sub-cooled liquid vapor pressure of SCCPs. In general, SCCPs in the urban air of Dalian mainly existed in gas phase,lower molecular weight SCCPs primarily occurred in the gas phase, whereas higher molecular weight SCCPs were predominately adsorbed or absorbed on airborne particles. The air concentration of SCCPs in the four seasons were different, the correlation of the concentration of SCCPs in the air with the meteorology parameters was conducted. The exposure risk by intake air SCCPs of the residents around the sampling sites was evaluated according to the European risk assessment standards.
基金supported by the Key Program of the Special Scientific Research Fund of Environmental Public Welfare Profession of China (No. 201109017)the National High Technology Research and Development Program (863) of China (No. 2012AA06A304)
文摘So far little is known about air–soil exchange under any sealed circumstances（e.g., in plastic and glass sheds）, which however has huge implications for the soil–air–plant pathways of persistent organic pollutants including organochlorine pesticides（OCPs）. A newly designed passive air sampler was tested in a sealed chamber for measuring the vertical concentration profiles of gaseous phase OCPs（hexachlorocyclohexanes（HCHs） and dichlorodiphenyltrichloroethanes（DDTs））. Air was sampled at 5, 15, and 30 cm above ground level every 10 th day during a 60-day period by deploying polyurethane foam cylinders housed in acrylonitrile butadiene styrene-covered cartridges. Concentrations and compositions of OCPs along the vertical sections indicated a clear relationship with proximity to the mixture of HCHs and DDTs which escapes from the soils. In addition, significant positive correlations were found between air temperatures and concentrations of HCHs and DDTs. These results indicated revolatilization and re-deposition being at or close to dynamic pseudo-equilibrium with the overlying air. The sampler used for addressing air–soil exchange of persistent organic pollutants in any sealed conditions is discussed.
文摘目的研究空气消毒剂中和剂鉴定试验方法。方法按照评价空气消毒效果的试验体系,用含中和剂的琼脂培养基平板置于六级安德森空气撞击式采样器内,采样后进行培养观察中和效果。结果含100 mg/L硫代硫酸钠的普通营养琼脂培养基对白色葡萄球菌的生长无影响。气雾室内按10 m l/m3用量气溶胶喷雾30 g/L浓度的过氧化氢溶液,喷雾后作用30 m in,用含100 mg/L硫代硫酸钠的普通营养琼脂平板置于采样器内采集空气200 L,培养后平板上白色葡萄球菌生长正常,说明残留消毒剂被有效中和。喷雾消毒剂后,空气采集量对中和效果有影响,本方法中采集量为≤200 L。结论按照评价空气消毒效果的试验体系,用六级筛孔空气撞击式采样器采样的中和剂鉴定方法能准确判断中和剂和中和产物对试验菌生长的影响,并能选择出有效的中和剂。
