The concentration of polychlorinated biphenyls （PCBs） in the urban air of Dalian, China was monitored from November 2009 to October 2010 with active high-volume sampler and semipermeable membrane device （SPMD） pas...The concentration of polychlorinated biphenyls （PCBs） in the urban air of Dalian, China was monitored from November 2009 to October 2010 with active high-volume sampler and semipermeable membrane device （SPMD） passive sampler. The concentration of PCBs （particle ＋ gas） （∑PCBs） ranged from 18.6 to 91.0 pg/m3, with an average of 50.9 pg/m3, and the most abundant dioxin-like PCB （DL-PCBs） was PCB118. The WHO-TEQ values of DL-PCBs were 3.6--22.1 fg/m3, with an average of 8.5 fg/m3, and PCB126 was the maximum contributor to ZTEQ. There was a much larger amount of PCBs in the gas phase than in the particulate phase. The dominant PCB components were lower and middle molecular weight PCBs. With increasing chlorination level, the concentration of the PCB congeners in the air decreased. The gas-particulate partitioning of PCBs was different for the four seasons. The gas- particulate partitioning coefficients （logKp） vs. subcooled liquid vapor pressures （logPL~） of PCBs had reasonable correlations for different sampling sites and seasons. The absorption mechanism contributed more to the gas-particulate partitioning process than adsorption. Correlation analysis of meteorological parameters with the concentration of PCBs was conducted using SPSS packages. The ambient temperature and atmospheric pressure were important factors influencing the concentration of PCBs in the air. The distribution pattern of the congeners of PCBs and the dominant contributors to DL-PCBs and TEQ in active samples and SPMDs passive samples were similar. SPMD mainly sequestrated gas phase PCBs.展开更多
With fossil fuel being the major source of energy,CO_(2) emission levels need to be reduced to a minimal amount namely from anthropogenic sources.Energy consumption is expected to rise by 48%in the next 30 years,and g...With fossil fuel being the major source of energy,CO_(2) emission levels need to be reduced to a minimal amount namely from anthropogenic sources.Energy consumption is expected to rise by 48%in the next 30 years,and global warming is becoming an alarming issue which needs to be addressed on a thorough technical basis.Nonetheless,exploring CO_(2) capture using membrane contactor technology has shown great potential to be applied and utilised by industry to deal with post-and pre-combustion of CO_(2).A systematic review of the literature has been conducted to analyse and assess CO_(2) removal using membrane contactors for capturing techniques in industrial processes.The review began with a total of 2650 papers,which were obtained from three major databases,and then were excluded down to a final number of 525 papers following a defined set of criteria.The results showed that the use of hollow fibre membranes have demonstrated popularity,as well as the use of amine solvents for CO_(2) removal.This current systematic review in CO_(2) removal and capture is an important milestone in the synthesis of up to date research with the potential to serve as a benchmark databank for further research in similar areas of work.This study provides the first systematic enquiry in the evidence to research further sustainable methods to capture and separate CO_(2).展开更多
基金supported by the National Natural Science Foundation of China (No.20877011)the DAAD (German Academic Exchange Service) Scientific Research Visiting Scholarship+3 种基金the Chinese National Programs for High Technology Research and Development (No.2011AA060604)the State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences (No.KF2009-17)the Key Laboratory of Industrial Ecology and Environmental Engineering,Ministry of Education of China (No.0802)the Scientific Research Foundation for Returned Overseas Chinese Scholars,Ministry of Education of China
文摘The concentration of polychlorinated biphenyls （PCBs） in the urban air of Dalian, China was monitored from November 2009 to October 2010 with active high-volume sampler and semipermeable membrane device （SPMD） passive sampler. The concentration of PCBs （particle ＋ gas） （∑PCBs） ranged from 18.6 to 91.0 pg/m3, with an average of 50.9 pg/m3, and the most abundant dioxin-like PCB （DL-PCBs） was PCB118. The WHO-TEQ values of DL-PCBs were 3.6--22.1 fg/m3, with an average of 8.5 fg/m3, and PCB126 was the maximum contributor to ZTEQ. There was a much larger amount of PCBs in the gas phase than in the particulate phase. The dominant PCB components were lower and middle molecular weight PCBs. With increasing chlorination level, the concentration of the PCB congeners in the air decreased. The gas-particulate partitioning of PCBs was different for the four seasons. The gas- particulate partitioning coefficients （logKp） vs. subcooled liquid vapor pressures （logPL~） of PCBs had reasonable correlations for different sampling sites and seasons. The absorption mechanism contributed more to the gas-particulate partitioning process than adsorption. Correlation analysis of meteorological parameters with the concentration of PCBs was conducted using SPSS packages. The ambient temperature and atmospheric pressure were important factors influencing the concentration of PCBs in the air. The distribution pattern of the congeners of PCBs and the dominant contributors to DL-PCBs and TEQ in active samples and SPMDs passive samples were similar. SPMD mainly sequestrated gas phase PCBs.
文摘With fossil fuel being the major source of energy,CO_(2) emission levels need to be reduced to a minimal amount namely from anthropogenic sources.Energy consumption is expected to rise by 48%in the next 30 years,and global warming is becoming an alarming issue which needs to be addressed on a thorough technical basis.Nonetheless,exploring CO_(2) capture using membrane contactor technology has shown great potential to be applied and utilised by industry to deal with post-and pre-combustion of CO_(2).A systematic review of the literature has been conducted to analyse and assess CO_(2) removal using membrane contactors for capturing techniques in industrial processes.The review began with a total of 2650 papers,which were obtained from three major databases,and then were excluded down to a final number of 525 papers following a defined set of criteria.The results showed that the use of hollow fibre membranes have demonstrated popularity,as well as the use of amine solvents for CO_(2) removal.This current systematic review in CO_(2) removal and capture is an important milestone in the synthesis of up to date research with the potential to serve as a benchmark databank for further research in similar areas of work.This study provides the first systematic enquiry in the evidence to research further sustainable methods to capture and separate CO_(2).
