Monitoring gas- and particulate-phase short-chain polychlorinated paraffins in the urban air of Dalian by a self-developed passive sampler

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.     

The effect of interaction between Bacillus subtilis DBM and soil minerals on Cu(Ⅱ) and Pb(Ⅱ) adsorption

The effects of interaction between Bacillus subtilis DBM and soil minerals on Cu(Ⅱ)and Pb(Ⅱ)adsorption were investigated.After combination with DBM,the Cu(Ⅱ)and Pb(Ⅱ)adsorption capacities of kaolinite and goethite improved compared with the application of the minerals independently.The modeling results of potentiometric titration data proved that the site concentrations of kaolinite and goethite increased by 80%and 30%,respectively after combination with DBM.However,the involvement of functional groups in the DBM/mineral combinations resulted in lower concentrations of observed sites than the theoretical values and led to the enhancement of desorption rates by NH_4NO_3 and EDTA-Na_2.The DBM-mineral complexes might also help to prevent heavy metals from entering DBM cells to improve the survivability of DBM in heavy metal-contaminated environments.During the combination process,the extracellular proteins of DBM provided more binding sites for the minerals to absorb Cu(Ⅱ)and Pb(Ⅱ).In particular,an especially stable complexation site was formed between goethite and phosphodiester bonds from EPS to enhance the Pb(Ⅱ)adsorption capacity.So,we can conclude that the DBM–mineral complexes could improve the Cu(Ⅱ)and Pb(Ⅱ)adsorption capacities of minerals and protect DBM in heavy metal-contaminated environments.     

热解析技术处理汞污染土壤研究进展

土壤既是大气汞与水体汞的汇,又是汞再次释放的源。土壤汞最终通过迁移等方式进入周边环境,危害人体和动植物的健康。综述了传统的汞污染场地修复技术,总结了热解析技术的影响因素、添加剂的协同处理以及热解前后土壤形态变化等,并对热解析技术处理汞污染土壤所存在的问题以及后续发展进行了展望。     

河流治理与修复工程技术模式研究进展

我国"十三五"期间将开展大量河流修复的工程应用,但目前河流修复工程方案主要从治理技术的应用出发,对修复模式的考虑较少。文章综述了国内外关于河流水质改善的研究和工程报道,总结了在治理河流有机污染与营养盐污染中常用的在线和离线治理工程构建模式,为河流修复工程的设计和实施提供参考。     

便携式气相色谱/质谱联用快速测定固定污染源废气中的挥发性卤代烃研究

建立了便携式GC-MS快速测定固定污染源废气中挥发性卤代烃方法,26种卤代烃内标定量工作曲线的相关系数r≥0.985,线性关系良好;精密度好,相对标准偏差2.33%～18.1%;准确度高,加标回收率为101%～134%;方法检出限为0.002 ppm～0.016 ppm.在实际现场监测固定污染源中挥发性卤代烃时,使用便携式GC-MS的速查(Survey)功能初步判断样品浓度,确定稀释倍数,并验证了气袋和玻璃注射器采样对挥发性卤代烃测定结果无显著性差异.     

环境现状监测与评价中存在的问题研究

环境影响评价中,环境质量现状监测是了解评价区环境质量状况的基础,也是预测评价中参照的本底值.为了进一步规范环境影响评价中的环境现状监测与评价,对环境影响评价中现状监测及评价中存在的问题进行了调查.目前环境现状监测与评价中存在监测布点不合理、采样不规范、评价不科学等问题.针对存在的问题提出了改进对策,促进环境现状监测与评价更趋于科学化.     

Mobility of acid-treated carbon nanotubes in water-saturated porous media

The production, use, and disposal of nanomaterials may inevitably lead to their appearance in water. With the development of new industries around nanomaterials, it seems necessary to be concerned about the transport of nanomaterials in the environment. In this paper, the transport of acid-treated carbon nanotubes (CNTs) in porous media was investigated. Before the mobility investigation, the stability of acid-treated CNT dispersions was studied using ultraviolet-visible spectra and it was indicated that, under the chemical conditions employed in this work, there was no apparent aggregation. The mobility investigation showed that transport of acid-treated CNTs increased with treatment time due to increase in particle zeta potential. Carbon nanotubes treated with nitric acid for 2, 6, and 12 h possessed measured zeta potentials of -30.0, -43.0, and -48.5 mV, respectively. Utilizing clean-bed filtration theory, we showed that acid-treated CNTs have the potential to migrate 3.28, 5.67, and 7.69 m in saturated glass beads, respectively. We showed that solution ionic strength and pH have important effects on the mobility of acid-treated CNTs. Increasing the pH from 6.0 to 7.9 resulted in an increase in migration potential from 2.96 to 10.86 m. Increasing the ionic strength from 0.005 to 0.020 M resulted in a decrease in CNT migration potential from 5.67 to 1.42 m.     

Environmental impacts of the shelter forests in Horqin Sandy land, northeast China

Assessing environmental effects of shelter forests is primarily necessary for realizing their greatest protective benefits. The Three-North Shelter Forest Program (TNSFP), the largest ecological afforestation program in the world, has been operated for three decades in China but so far lacks comprehensive assessment of its environmental impacts. Horqin Sandy Land (HSL) in Northeast China is one of the key areas in the TNSFP implementation. To identify the principal contributors to environmental changes in HSL, we evaluated impacts of variations in landscape features, shelter forest areas, climatic factors, and social factors on changes in sandy land areas from 1978 to 2007, by using Gray Relational Analysis. Our analysis showed that during the period 1978 to 2007, the sandy land area decreased by 3.9% in low aeolian dunes, 14.5% in low mountains and hills, and 98.9% in high elevation alluvial flats of HSL. Factors with Gray Correlation Degrees >0.9 were identified as the patch shape index (PSI) and the landscape isolation index (LII) of grasses in low aeolian dunes, PSI of grasses in mountains and hills, and area of broadleaved forests and LII of shrubs in alluvial flats. It is concluded that establishment of the shelter forests has played a significant role in controlling the expansion of sandy land in HSL. To sustain the long-term environmental benefits of the shelter forests in the remaining period for TNSFP construction, suitable tree species should be selected and planted at appropriate densities based on the local precipitation, groundwater and landform conditions, and the system stability of the total landscape.     

GC-MS法分析花椒油树脂主要成分

在时花椒风味物质的研究中,采用传统的有机溶剂萃取,并通过GC-MS对提取物进行了定性,实验结果表明,花椒中的香味物质主要有棕榈酸、芳樟醇、胡椒酮.