Fan Q.,Sun Yat Sen University |
Shen C.,Sun Yat Sen University |
Wang X.,Sun Yat Sen University |
Li Y.,Guangzhou Research Institute of Environmental Protection |
And 4 more authors.
Asia-Pacific Journal of Atmospheric Sciences
A strong dust-storm (23-25 April, 2009) occurred in the provinces of Inner Mongolia, Gansu, and Shanxi, North China. Cities along the storm path (from north to south: Xi'ning, Lanzhou, Chengdu, Changsha, and Guangzhou) all experienced a sharp increase in particle matter (PM10) concentration. This is the first case that an Asian dust storm hit Guangzhou in Southern China. The impacts of dust storm on the characteristics of PM were investigated using samples collected in Guangzhou during 27-29 April, 2009. In addition, the mass concentration and chemical composition during a normal non-dust period (12-14 May, 2009) were compared with those in dust period. The results show that the concentration of PM10 during the dust episode (0.231 mg m -3) was twice higher than that in the non-dust episode (0.103 mg m-3). Chemical analysis showed that concentrations of metal elements, enrichment factors of metal elements, and soluble ions during the dust episode were very different from those of non-dust. The total concentration of metal elements content in PM10 was 53.5 μg m-3 in the dust episode, which is about two times higher than that in non-dust episode (28.5 μg m-3). Increases in concentrations of Na, Ti, Zn, Cu, and Cr ranged from zero to 100% during the dust episode. However, the enrichment factors in non-dust episode were higher than that in dust-storm period, indicating that the above five chemicals originated mainly from local sources in Guangzhou. The concentrations of K, Mg, Al, Fe, Mn, V, and Co increased by over 100% in the dust episode, indicating their origins of remote sources. In the dust period, some water-soluble ions increased in PM10, but the main components in PM10 were SO4 -, NO3 - and NH4 +. At last, we assessed the sources of dusts by analyzing synoptic situation and back trajectories of air mass in Guangzhou, and demonstrated that the main source of the dust storm was from Mongolia. © 2013 The Korean Meteorological Society and Springer. Source
Zhang J.-E.,South China Agricultural University |
Liu J.-L.,Guangzhou Research Institute of Environmental Protection |
Ouyang Y.,St. Johns River Water Management District |
Liao B.-W.,Chinese Academy of Forestry |
Zhao B.-L.,South China Agricultural University
Mangrove wetlands are important in the removal of nutrients, heavy metals, and organic pollutants from wastewater within estuarine systems due to the presence of oxidized and reduced conditions, periodic flooding by incoming and outgoing tides, and high clay and organic matter content. This study investigated the removal efficiency of nutrients and heavy metals from wastewater by the mangrove Sonneratia apetala Buch-Ham in a simulated wetland. Eight different treatments, namely, three concentration levels of wastewaters, with and without planting of the mangrove species, and one control (with salted water) each for both with and without planting of the mangrove species, were employed in this study. Results showed that the amounts of total mangrove biomass from different treatments were in the following order: PL-TW (planted with ten times higher-than-normal wastewater concentration) > PL-FW (planted with five times higher-than-normal wastewater concentration) > PL-SW (planted with normal wastewater concentration) > PL-NW (planted with no wastewater), whereas the magnitude of the heavy metal contents in the biomass was in the following order: Cu > Pb > Cd > Zn. Very good linear correlations existed between the biomass and the nutrients or heavy metals. The Sonneratia apetala Buch-Ham species had its own selectivity for uptake of heavy metals regardless of the initial heavy metal contents and was more effective in the removal of nutrients than heavy metals. Our study suggested that mangrove wetlands with Sonneratia apetala Buch-Ham species had great potential for the removal of nutrients and heavy metals in coastal areas. © 2010 Elsevier B.V. All rights reserved. Source
Qu J.,Chinese Academy of Sciences |
Qu J.,Lanzhou University |
Zeng J.,Chinese Academy of Sciences |
Li Y.,Lanzhou University |
And 7 more authors.
This study assessed household CO2 emissions (related to the consumption of necessary and luxury goods and services) of peasants and herdsmen households in arid-alpine regions in Gansu, Qinghai and Ningxia provinces, China. We also explored whether agriculture types, family income and family size have played any role in household CO2 emissions. In order to address these issues, we: (i) developed assessment indicators for household emissions; (ii) conducted semi-structured questionnaire household surveys; and (iii) employed input-output analysis (IOA). The results showed that, the average household CO2 emission per capita is 1.43 tons (t) CO2; the proportion of subsistence emissions (related to the consumption of necessary goods and services) accounts for 93.24%, whereas luxury emissions (generated due to consumption of specific goods and services that are consumed only when household income improves) only account for 6.76%t. Moreover, household CO2 emissions increase with family income and family size, but per capita emissions are inversely related to family size. The highest average household emissions were found in the alpine agricultural and pastoral region (6.18t CO2), followed by the irrigated agricultural region (6.07t CO2) and the rain-fed agricultural region (5.34t CO2). In consideration of insignificant amount of household emissions from these poor and vulnerable groups of the society, this study suggests to follow the principle of fairness while making energy conservation, emission reduction and adaptation policies. © 2013 Elsevier Ltd. Source
Wang M.,Peking University |
Zeng L.,Peking University |
Lu S.,Peking University |
Shao M.,Peking University |
And 7 more authors.
An automatic gas chromatograph system equipped with a mass spectrometer and a flame ionization detector (GC-MS/FID) was developed for online measurements of volatile organic compounds (VOCs) in the atmosphere. This system consisted of a custom-built cryogen-free cooling device that can create an ultra-low temperature of -165°C, a two-channel sampling and pre-concentration system, and a commercial GC-MS/FID. One channel in the sampling and pre-concentration system was designated to trap C2-C5 hydrocarbons, whereas the other was designed to trap other VOC species. The newly developed GC-MS/FID system was then employed to measure VOCs in ambient air, and its observation data were compared with those from three well-established techniques, including an offline GC-MS/FID coupled with canister sampling, a proton transfer reaction-mass spectrometer (PTR-MS), and an online gas chromatograph system equipped with an FID and a photo ionization detector (GC-FID/PID). The online and offline GC-MS/FID measurements for alkanes, acetylene, C2-C3 alkenes, C6-C8 aromatics, and halocarbons showed good agreement. In addition, the online GC-MS/FID measurements for C6-C9 aromatics, acetone, and methacrolein + methylvinylketone (MACR + MVK) agreed well with the PTR-MS observations. Mixing ratios of C2-C7 alkanes, C3-C5 alkenes, and C6-C8 aromatics also showed good agreement between the online GC-MS/FID and GC-FID/PID techniques. These inter-comparison results demonstrated the accuracy of online GC-MS/FID measurements for C2-C12 NMHCs, C3-C4 carbonyls, and halocarbons. © 2014 The Royal Society of Chemistry. Source
Liu M.,Peking University |
Liu M.,Guangdong Institute of Eco environmental and Soil Sciences |
Shao J.,Peking University |
Zhou B.,Guangzhou Research Institute of Environmental Protection |
And 2 more authors.
Chinese Journal of Applied and Environmental Biology
Microbial electricigenic respiration is a new microbial metabolism mode. Microbial fuel cells (MFC) based on microbial electricigenic respiration represent lots of advantages, such as high coulombic efficiency, no requirement for addition of exogenous electron-carrying mediators and long-term sustainability. In the paper presents a review on the working principle of MFC, main species of electricigens, influential factors of electricigenic respiration, similarities and differences between electricigenic respiration and Fe(III) respiration, describes two aspects of the mechanisms of microbial electricigenic respiration which includes intracellular and exocellular electron transfer, and finally proposes a wild application prospect of microbial fuel cells based on electricigenic respiration. Source