Ambient PM2.5 samples were collected at four sites in Xiamen, including Gulangyu (GLY), Hongwen (HW), Huli (HL) and Jimei (JM) during January, April, July and October 2013. Local source samples were obtained from coal burning power plants, industries, motor vehicles, biomass burning, fugitive dust, and sea salt for the source apportionment studies. The highest value of PM2.5 mass concentration and species related to human activities (SO42–, NO3–, Pb, Ni, V, Cu, Cd, organic carbon (OC) and elemental carbon (EC)) were found in the ambient samples from HL, and the highest and lowest loadings of PM2.5 and its components occurred in winter and summer, respectively. The reconstructed mass balance indicated that ambient PM2.5 consisted of 24% OM (organic matter), 23% sulfate, 14% nitrate, 9% ammonium, 9% geological material, 6% sea salt, 5% EC and 10% others. For the source profiles, the dominant components were OC for coal burning, motor vehicle, biomass burning and sea salt; SO42– for industry; and crustal elements for fugitive dust. Source contributions were calculated using a chemical mass balance (CMB) model based on ambient PM2.5 concentrations and the source profiles. GLY was characterized by high contributions from secondary sulfate and cooking, while HL and JM were most strongly affected by motor vehicle emissions, and biomass burning and fugitive dust, respectively. The CMB results indicated that PM2.5 from Xiamen is composed of 27.4% secondary inorganic components, 20.8% motor vehicle emissions, 11.7% fugitive dust, 9.9% sea salt, 9.3% coal burning, 5.0% biomass burning, 3.1% industry and 6.8% others.
Study on effective disposal and utilization of sewage sludge has recently been the target of growing interest in China. However, potential risks are associated with the use of sludge due to its contamination with toxic organics, heavy metals and pathogenic microorganisms. In this study, a screening assessment was conducted on sewage sludge samples collected from 17 different sewage treatment plants in Beijing, based on a batch of in vitro bioassays, including a set of recombinant gene yeast assays for endocrine disruption, and an ethoxy resorufin-O- deethylase (EROD) assay using H4IIE cells for aryl hydrocarbon receptor (Ah-R) agonistic activities. Our results suggested that moderate levels of estrogen receptor agonistic activities (0.9 ng E2. g-1 to 6.8 ng E2. gl, dw), but relative higher androgen receptor antagonistic activ- ities (nd to 45%), progestin receptor antagonistic activities (nd to 80%) and Ah-R agonistic activities (1390 to 6740 pg 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)·g-1, dw) were found in sewage sludge samples. However, there were no significant correlations between the toxic effects of sewage sludge and the sewage treatment processes. In addition, the 17β-estradiol (E2) equivalent quantity (EEQ) level of the sewage sludge was increased after the composting treatment, whereas the 2,3,7,8-tetrachlorodi- benzo-p-dioxin toxic equivalent quantity (TEQ) level of sewagesludge composted was much lower than that of sewage sludge. 相似文献
The solubilization of eight selected substituted indole compounds (SICs) by carboxymethyl‐β‐cyclodextrin (CMCD) in water is reported. The results show that their solubility was well improved in CMCD aqueous solution, and the stoichiometry of inclusion complex of the studied SICs with CMCD was 1: 1. The acute toxicity to Photobacterium phosphoreum of the investigated SICs in CMCD aqueous solutions was also investigated and was compared with that in water. The results show that the toxicity of five studied SICs decreased while the toxicity of the rest three SICs increased in CMCD aqueous solutions, but neither the increase nor the decrease was significant. 相似文献
Yunnan Province has many and unique natural resources and rich biodiversity. Natural reserves (NRs) play a significant role in maintaining and protecting the biodiversity and stability of ecosystems in this area. Yunnan is a typically eco-environmentally fragile area; thus positive effects of NRs are important in the construction of an ecological safety barrier for southwest China. Evaluation of the effectiveness of management of NRs has been implemented to improve management outcomes. This study provides indices to evaluate problems and management effectiveness for 60 NRs, covering national and provincial NRs of Yunnan Province. These indicate that management of NRs suffers from inadequate funding, poor infrastructure and equipment, low community participation, and a lack of government support. The indices had relatively low scores for infrastructure and equipment, ecotourism, monitoring, and evaluation, but high scores for planning and design and ownership. There were significant positive correlations between protection rank, size, age of NRs, and management effectiveness. International exchanges and collaboration would help to improve management of the NRs. NRs that straddle administrative boundaries had relatively higher scores than those within an administrative unit. Management success was not correlated with staff input, which might imply low efficiency of staff in this area. Some recommendations are offered to improve management of NRs based on analysis of management problems and identification of influencing factors. 相似文献