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The effect of Eulaliopsis binata on the physi-chemical properties, microbial biomass, and enzymatic activities in Cd-Pb polluted soil 全文
2016
Yu, Hui | Xiang, Yanci | Zou, Dongsheng
Pot culture experiment using mining wasteland soil was carried out to study the effect of Eulaliopsis binata on the heavy-metal polluted soil with the growth of 90, 180, 270, and 360 days. Soil nutritional components, heavy metal, microbial biomass, and enzymatic activities were analyzed in this study, and the control group had no plants. The results showed that heavy metal contents decreased with E. binata growth, extractable Cd and Pb decreased 28 and 15 % after 1 year, but the difference was not significant compared with the control. While soil nutritional components, microbial biomass and enzymatic activities increased significantly as compared with the control. Comparing with pre-experiment, soil organic matter, N, P, K, microbial biomass C, N, P, invertase, urease, acid phosphatase, and catalase increased 0.9, 1.1, 3.0, 1.1, 0.4, 0.3, and 0.5 times, respectively. The indexes of soil nutritional components, microbial biomass, and enzymatic activities are positively correlated to each other, while they are negatively correlated to heavy metal content respectively. E. binata has positive influence on Cd-Pb pollution soil and broad application prospects in remediating heavy-metal polluted soil.
显示更多 [+] 显示较少 [-]A stable isotope approach and its application for identifying nitrate source and transformation process in water 全文
2016
Xu, Shiguo | Kang, Pingping | Sun, Ya
Nitrate contamination of water is a worldwide environmental problem. Recent studies have demonstrated that the nitrogen (N) and oxygen (O) isotopes of nitrate (NO₃ ⁻) can be used to trace nitrogen dynamics including identifying nitrate sources and nitrogen transformation processes. This paper analyzes the current state of identifying nitrate sources and nitrogen transformation processes using N and O isotopes of nitrate. With regard to nitrate sources, δ¹⁵N-NO₃ ⁻ and δ¹⁸O-NO₃ ⁻ values typically vary between sources, allowing the sources to be isotopically fingerprinted. δ¹⁵N-NO₃ ⁻ is often effective at tracing NO⁻ ₃ sources from areas with different land use. δ¹⁸O-NO₃ ⁻ is more useful to identify NO₃ ⁻ from atmospheric sources. Isotopic data can be combined with statistical mixing models to quantify the relative contributions of NO₃ ⁻ from multiple delineated sources. With regard to N transformation processes, N and O isotopes of nitrate can be used to decipher the degree of nitrogen transformation by such processes as nitrification, assimilation, and denitrification. In some cases, however, isotopic fractionation may alter the isotopic fingerprint associated with the delineated NO₃ ⁻ source(s). This problem may be addressed by combining the N and O isotopic data with other types of, including the concentration of selected conservative elements, e.g., chloride (Cl⁻), boron isotope (δ¹¹B), and sulfur isotope (δ³⁵S) data. Future studies should focus on improving stable isotope mixing models and furthering our understanding of isotopic fractionation by conducting laboratory and field experiments in different environments.
显示更多 [+] 显示较少 [-]Monitoring of heavy metal levels in the major rivers and in residents’ blood in Zhenjiang City, China, and assessment of heavy metal elimination via urine and sweat in humans 全文
2016
Sheng, Jianguo | Qiu, Wenhui | Xu, Bentuo | Xu, Hui | Tang, Chong
The coastal areas of China face great challenges, owing to heavy metal contamination caused by rapid industrialization and urbanization. To our knowledge, this study is the first report of the levels of heavy metals in the major rivers of Zhenjiang, one of the most important cities of the Yangtze River Delta in China. In addition, we measured heavy metal levels in the blood of 76 residents of Zhenjiang. The results suggest that the presence of heavy metals in the blood may threaten human health and the distribution appeared to correspond to most highly populated areas and/or areas with high traffic. We also found that the concentration of heavy metals in human blood showed an accumulation effect with increase in age. Moreover, the levels of most heavy metals were lower in participants who regularly exercised than in those who did not. We studied heavy metal levels in the urine and sweat of another 17 volunteers to monitor the elimination of bioaccumulated heavy metal. Heavy metals were found in the urine and sweat of all the 17 participants and were more concentrated in sweat. Induced micturition and sweating appear to be potential methods for the elimination of heavy metals from the human body.
显示更多 [+] 显示较少 [-]Air quality improvement during 2010 Asian games on blood coagulability in COPD patients 全文
2016
Zhang, Zili | Wang, Jian | Guo, Meihua | Xiong, Mingmei | Zhou, Qipeng | Li, Defu | Shu, Jiaze | Lu, Wenju | Sun, Dejun
Exposure to elevated levels of ambient air pollutants can lead to adverse cardiovascular effects. Perturbation of the coagulation balance is one of the potential mechanisms. However, evidence regarding the impact of improvement in air pollution on blood coagulability in COPD patients has never been reported. Coagulation processes are known to be of relevance for cardiovascular pathology; therefore, this study aimed to investigate the association of short-term air pollution exposure with blood marker (D-dimer) of coagulation. A 3-year (through the Asian game) cohort study based on the GIRD COPD Biobank Project was conducted in 36 COPD patients to estimate whether changes in measurements of D-dimer were associated with changes in pollutant concentration, comparing for 51 intervention days (November 1–December 21) in 2010 with the same calendar date of baseline years (2009 and 2011). Daily mean concentrations of air pollutants and meteorological variables were measured during the time. Daily PM₁₀ decreased from 65.86 μg/m³ during the baseline period to 62.63 μg/m³ during the Asian Games period; daily NO₂ decreased from 51.33 to 42.63 μg/m³. SO₂ and other weather variables did not differ substantially. We did not observe statistically significant improvements in D-dimer levels by 9.86 % from a pre-Asian game mean of 917 ng/ml to a during-Asian game mean of 1007 ng/ml, platelet number by 11.66 %, PH by −0.15 %, PCO₂ by −6.54 %, and PO₂ by −1.16 %. In the post-Asian game period, when pollutant concentrations increased, most outcomes approximated pre-Asian game levels, and similar effects were also demonstrated in D-dimer, platelet number, and arterial blood gas. For D-dimer and platelet number, we observed statistically significant increases associated with increases in NO₂ at lag 1–3 and SO₂ at lag 2–4. For PH, PCO₂, and PO₂, any significant effect was not demonstrated. This study gives no support to the hypothesis that reduction in air pollution levels during the 2010 Asian game is associated with activation of blood coagulation with COPD patients. However, one step forward has been made on the gap between improved air pollution and blood coagulability. Meanwhile, our study also provides evidence for the presence of a hypercoagulative state in systemic circulation in COPD patients. Additional studies employing other susceptible populations and endpoints are pending.
显示更多 [+] 显示较少 [-]Dynamism of household carbon emissions (HCEs) from rural and urban regions of northern and southern China 全文
2016
Maraseni, Tek Narayan | Qu, Jiansheng | Yue, Bian | Zeng, Jingjing | Maroulis, Jerry
China contributes 23 % of global carbon emissions, of which 26 % originate from the household sector. Due to vast variations in both climatic conditions and the affordability and accessibility of fuels, household carbon emissions (HCEs) differ significantly across China. This study compares HCEs (per person) from urban and rural regions in northern China with their counterparts in southern China. Annual macroeconomic data for the study period 2005 to 2012 were obtained from Chinese government sources, whereas the direct HCEs for different types of fossil fuels were obtained using the IPCC reference approach, and indirect HCEs were calculated by input-output analysis. Results suggest that HCEs from urban areas are higher than those from rural areas. Regardless of the regions, there is a similarity in per person HCEs in urban areas, but the rural areas of northern China had significantly higher HCEs than those from southern China. The reasons for the similarity between urban areas and differences between rural areas and the percentage share of direct and indirect HCEs from different sources are discussed. Similarly, the reasons and solutions to why decarbonising policies are working in urban areas but not in rural areas are discussed.
显示更多 [+] 显示较少 [-]Effect of ageing on the availability of heavy metals in soils amended with compost and biochar: evaluation of changes in soil and amendment properties 全文
2016
Venegas, A. | Rigol, A. | Vidal, M.
Remediation strategies using soil amendments should consider the time dependence of metal availability to identify amendments that can sustainably reduce available pollutant concentrations over time. Drying-wetting cycles were applied on amendments, soils and soil + amendment mixtures, to mimic ageing at field level and investigate its effect on extractable Cd, Cu, Ni, Pb and Zn concentrations from three contaminated soils. The amendments investigated were municipal waste organic compost and biochars. The amendments, soils and mixtures were characterised by their physicochemical properties at different ageing times. The amendments were also characterised in terms of sorption capacity for Cd and Cu. The sorption capacity and the physicochemical properties of the amendments remained constant over the period examined. When mixed with the soils, amendments, especially the compost, immediately reduced the extractable metals in the soils with low pH and acid neutralisation capacity, due to the increase in pH and buffering capacity of the mixtures. The amendments had a relatively minor impact on the metal availability concentrations for the soil with substantially high acid neutralisation capacity. The most important changes in extractable metal concentrations were observed at the beginning of the experiments, ageing having a minor effect on metal concentrations when compared with the initial effect of amendments.
显示更多 [+] 显示较少 [-]Simultaneous removal of ammonia and hydrogen sulfide gases using biofilter media from the biodehydration stage and curing stage of composting 全文
2016
Hou, Jiaqi | Li, Mingxiao | Xia, Tianming | Hao, Yan | Ding, Jie | Liu, Dongming | Xi, Beidou | Liu, Hongliang
Biofiltration of NH₃ and H₂S with different packing media, biodehydration stage compost (BSC), and curing stage compost (CSC) was studied. Meanwhile, fluorescence excitation–emission matrix (EEM) spectroscopy was used to characterize the conversion mechanisms of organic matter during these biofiltration processes. Both biofilters were effective for the simultaneous removal of NH₃ and H₂S when inlet concentrations of NH₃ and H₂S were 0–50 and 50–250 mg/m³, respectively. An abrupt increase in the inlet gas concentrations of NH₃ and H₂S to 100–150 and 200–250 mg/m³, respectively, caused the decrease in the removal efficiencies (REs) of NH₃ and H₂S in the BSC biofilter, followed by a slow upturn. By contrast, relatively steady REs of both NH₃ and H₂S were observed in the CSC biofilter. After 60 days of operation, the average REs of NH₃ and H₂S were more than 95 % in the CSC biofilter. During the operation of CSC, nitrate and nitrite peaked around the 30th day, whereas sulfate showed a steady increase. The excitation–emission matrix fluorescence and parallel factor analysis (EEM-PARAFAC) indicated that the simultaneous inlet of NH₃ and H₂S facilitated the degradation of protein-like substances, whereas humic-like substances played an important role in the packing filters for the treatment of the two odorous pollutants.
显示更多 [+] 显示较少 [-]Genotoxicity of quinolone antibiotics in chlorination disinfection treatment: formation and QSAR simulation 全文
2016
Li, Min | Wei, Dongbin | Du, Yuguo
Lots of unexpected disinfection by-products were formed during the chlorination disinfection of contaminated water bodies, leading to a potential threat to human health and ecological safety. In this study, SOS/umu assay was used to trace the genotoxicity variation of 20 quinolone compounds during the chlorination disinfection. Furthermore, two- and three-dimensional quantitative structure-activity relationship models were developed based on the electronic and hydrophobic properties of the quinolones, which were used to quantify the impact of the different structural features of the compounds on their genotoxicity variation. The results revealed that quinolones bearing hydrophilic substituents with less H-bond donors and negative charge at the 1-position of the quinolone ring exhibited a positive correlation with genotoxicity elevation. More notably, the chlorination of quinolones in both ultrapure water and secondary effluent matrices provided comparable levels of genotoxicity, indicating that our research could potentially be used to evaluate the environmental risk of quinolone antibiotics in chlorination disinfection treatment.
显示更多 [+] 显示较少 [-]Socioeconomic constraints on the technological choices in rural sewage treatment 全文
2016
Gu, Baojing | Fan, Liangcong | Ying, Zechun | Xu, Qingshan | Luo, Weidong | Ge, Ying | Scott, Steffanie | Chang, Jie
Technological innovation is one of the potential engines to mitigate environmental pollution. However, the implementation of new technologies sometimes fails owing to socioeconomic constraints from different stakeholders. Thus, it is essential to analyze constraints of environmental technologies in order to build a pathway for their implementation. In this study, taking three technologies on rural sewage treatment in Hangzhou, China as a case study, i.e., wastewater treatment plant (WTP), constructed wetland (CW), and biogas system, we analyzed how socioeconomic constraints affect the technological choices. Results showed that socioeconomic constraints play a key role through changing the relative opportunity cost of inputs from government as compared to that of residents to deliver the public good—sewage treatment—under different economic levels. Economic level determines the technological choice, and the preferred sewage treatment technologies change from biogas system to CW and further to WTP along with the increase of economic level. Mismatch of technological choice and economic level results in failures of rural sewage treatment, e.g., the CW only work well in moderately developed regions in Hangzhou. This finding expands the environmental Kuznets law by introducing the coproduction theory into analysis (i.e., inputs from both government and residents are essential for the delivery of public goods and services such as good environmental quality). A match between technology and socioeconomic conditions is essential to the environmental governance.
显示更多 [+] 显示较少 [-]Mobility of as, Cu, Cr, and Zn from tailings covered with sealing materials using alkaline industrial residues: a comparison between two leaching methods 全文
2016
Jia, Yu | Maurice, Christian | Öhlander, Björn
Different alkaline residue materials (fly ash, green liquor dregs, and lime mud) generated from the pulp and paper industry as sealing materials were evaluated to cover aged mine waste tailings (<1 % sulfur content, primarily pyrite). The mobility of four selected trace elements (Cr, Cu, Zn, and As) was compared based on batch and column leaching studies to assess the effectiveness of these alkaline materials as sealing agents. Based on the leaching results, Cr, Cu, and Zn were immobilized by the alkaline amendments. In the amended tailings in the batch system only As dramatically exceeded the limit values at L/S 10 L/kg. The leaching results showed similar patterns to the batch results, though leached Cr, Cu, and Zn showed higher levels in the column tests than in the batch tests. However, when the columns were compared with the batches, the trend for Cu was opposite for the unamended tailings. By contrast, both batch and column results showed that the amendment caused mobilization of As compared with the unamended tailings in the ash-amended tailings. The amount of As released was greatest in the ash column and decreased from the dregs to the lime columns. The leaching of As at high levels can be a potential problem whenever alkaline materials (especially for fly ash) are used as sealing materials over tailings. The column test was considered by the authors to be a more informative method in remediation of the aged tailings with low sulfur content, since it mimics better actual situation in a field.
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