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61.
通过对贵州织金蒙家大坡地下水水化学指标进行分析。结果表明,研究区地下水Ca2+受环境影响最小、空间变异性最小,Na+受环境影响最大、空间变异性最大;各阴阳离子含量与TDS含量呈显著正相关关系,其相关性依次为:Ca2+SO2-4Mg2+Cl-HCO-3K+Na+;TDS含量的增加主要受SO2-4离子的影响,总硬度的变化主要受Ca2+的影响;地下水成分主要来自于碳酸盐矿物的溶解,其次是硫酸盐、含硫矿物、硅酸盐矿物以及盐岩的溶解,地下水类型主要向SO4·HCO3-Ca型和HCO3·SO4-Ca型转化。 相似文献
62.
为了解工作环境条件因素对系统故障概率的影响的特征,同时丰富连续型空间故障树(CSFT)的理论框架,提出因素重要度分布的概念。因素重要度分布从经典故障树的概率重要度发展而来,目的是研究系统所处环境因素变化导致系统可靠性变化的程度。给出元件和系统的因素重要度分布概念、公式及所需基础数据,并分析因素重要度分布的正负分布特点。使用该概念研究元件X1和系统T的因素t重要度分布和因素c重要度分布。结果表明:在不同环境中,对于因素t或c变化影响元件或系统的故障概率变化程度是不同的。因素重要度分布有效地表达了t和c对元件或系统的故障概率影响特征。 相似文献
63.
通过向黏土中添加重金属试剂,模拟煅烧试验制作烧结砖.采用酸消解试验研究烧结砖中重金属的总量,采用欧盟NEN7371方法测试烧结砖中重金属的有效释放量,采用NEN7375方法进行块状烧结砖浸出试验,研究烧结砖样品中Cr、Ni、As、Cd和Pb的释放特性.结果表明:烧结砖中重金属的有效释放量低于总量,释放率从大到小为Cd、As、Pb、Ni、Cr;在块状浸出过程中,Cr、Ni、As累积释放量达到平衡的时间为16 d,Pb为4d,而Cd的累积释放量一直有上升的趋势;Cr、Ni、As的释放机理主要为扩散控制,Cd为溶解作用,Pb为表面冲刷作用;5种重金属释放速率从大到小为Ni、Cr、Pb、As、Cd. 相似文献
64.
65.
Susana Batel Patrick Devine-Wright 《Journal of Environmental Planning and Management》2015,58(6):1076-1095
A national-local ‘gap’ is often used as the starting point for analyses of public responses to large scale energy infrastructures. We critique three assumptions found in that literature: the public's positive attitudes, without further examining other type of perceptions at a national level; that local perceptions are best examined through a siting rather than place-based approach; that a gap exists between national and local responses, despite a non-correspondence in how these are examined. Survey research conducted at national and local levels about electricity transmission lines in the UK confirm these criticisms. Results do not support a gap between national and local levels; instead, both differences and similarities were found. Results show the value of adopting a place-based approach and the role of surveys to inform policy making are discussed. 相似文献
66.
This paper reviews key challenges and opportunities addressed by the New York City Environmental Justice Alliance's (NYC-EJA) Waterfront Justice Project, a citywide campaign to promote climate resilience and sustainability in urban industrial waterfront communities of New York City. NYC-EJA is a non-profit membership-driven network linking grassroots organisations from low-income neighbourhoods and communities of colour in their struggle for environmental justice. The Waterfront Justice Project is documenting community vulnerability in the context of climate change impacts, sources of industrial pollution, and demographic and socio-economic trends. This campaign is enabling community-based organisations, environmental justice communities, city planners, local and state government agencies, local business-owners, and other stakeholders to work in partnership to achieve community resilience while advocating for local jobs and promoting best practices in pollution prevention. New York City's waterfront policies ease the siting and clustering of public infrastructure, water pollution control plants, waste transfer stations, energy facilities, and heavy manufacturing uses in six areas designated as Significant Maritime and Industrial Areas (SMIAs). The SMIAs are located in environmental justice communities, largely low-income communities and communities of colour, in the South Bronx, Brooklyn, Queens, and Staten Island. New York City's local waterfront land use and zoning policies create cumulative risk exposure not only to residents and workers in the host waterfront communities, but also, in the event of storm surge or sea-level rise, to neighbouring, upland communities. 相似文献
67.
Heather Lovell 《Local Environment》2015,20(11):1363-1382
In recent writing on sociotechnical transitions theory communities are mostly conceived of as being local and place-based (“grassroots”). In this paper the implications for sociotechnical transitions theory of having multiple communities operating at different geographical scales, and with different objectives, are examined through a case study of low-carbon innovation in forests. The focus of analysis is the communities promoting sociotechnical innovations in the measurement of forest carbon. Innovation is being driven by the international United Nations climate policy initiative “Reducing Emissions from Deforestation and forest Degradation” (REDD+). The rise of REDD+ policy has prompted a flurry of activity in related scientific research, especially in the field of remote sensing. But other types of community are also actively positioning themselves as experts in forest carbon measurement: there are multiple communities at work, each with varying claims to innovation and expertise, from local (place-based) forest communities to international communities of foresters and forest ecologists. Recognition of the multiple communities operating within sociotechnical systems usefully draws our attention to the politics of innovation. 相似文献
68.
Endocrine disrupting chemical(EDC) pollution in river-based artificial groundwater recharge using reclaimed municipal wastewater poses a potential threat to groundwater-based drinking water supplies in Beijing, China. Lab-scale leaching column experiments simulating recharge were conducted to study the adsorption, biodegradation, and transport characteristics of three selected EDCs: 17β-estradiol(E2), 17α-ethinylestradiol(EE2) and bisphenol A(BPA). The three recharge columns were operated under the conditions of continual sterilization recharge(CSR), continual recharge(CR), and wetting and drying alternative recharge(WDAR). The results showed that the attenuation effect of the EDCs was in the order of WDAR CR CSR system and E2 EE2 BPA, which followed first-order kinetics. The EDC attenuation rate constants were 0.0783, 0.0505, and 0.0479 m-1 for E2, EE2 and BPA in the CR system, respectively. The removal rates of E2, EE2, and BPA in the CR system were 98%, 96% and 92%, which mainly depended on biodegradation and were affected by water temperature.In the CR system, the concentrations of BPA, EE2, and E2 in soil were 4, 6 and 10 times higher than in the WDAR system, respectively. According to the DGGE fingerprints, the bacterial community in the bottom layer was more diverse than in the upper layer, which was related to the EDC concentrations in the water-soil system. The dominant group was found to be proteobacteria, including Betaproteobacteria and Alphaproteobacteria, suggesting that these microbes might play an important role in EDC degradation. 相似文献
69.
Immobilization of lead in anthropogenic contaminated soils using phosphates with/without oxalic acid 总被引:1,自引:0,他引:1
Understanding the effects of oxalic acid(OA) on the immobilization of Pb(Ⅱ) in contaminated soils by phosphate materials, has considerable benefits for risk assessment and remediation strategies for the soil. A series of phosphate amendments with/without oxalic acid were applied to two anthropogenic contaminated soils. We investigated the immobilization of Pb(Ⅱ) by KH2PO4, phosphate rock(PR), activated phosphate rock(APR) and synthetic hydroxyapatite(HAP) at different phosphate:Pb(P:Pb) molar ratios(0, 0.6, 2.0 and 4.0) in the presence/absence of 50 mmol oxalic acid/kg soil, respectively. The effects of treatments were evaluated using single extraction with deionized water or Ca Cl2, Community Bureau of Reference(BCR) sequential extraction and toxicity characteristic leaching procedure(TCLP)methods. Our results showed that the concentration of water extractable, exchangeable and TCLP-Pb all decreased with incubation time. The concentration of water-extractable Pb after120 days was reduced by 100% when soils were amended with APR, HAP and HAP + OA, and the TCLP-Pb was 5 mg/L for the red soil at P:Pb molar ratio 4.0. Water-soluble Pb could not be detected and the TCLP-Pb was 5 mg/L at all treatments applied to the yellow-brown soil. BCR results indicated that APR was most effective, although a slight enhancement of water-soluble phosphate was detected at the P:Pb molar ratio 4.0 at the beginning of incubation. Oxalic acid activated phosphates, and so mixing insoluble phosphates with oxalic acid may be a useful strategy to improve their effectiveness in reducing Pb bioavailability. 相似文献
70.
Omar Farah Nadia Loo Yu Xiang Lee Yei Lie Dzulkornain Chairil Anuar Mohammed P.Mohd Afandi Samsu Azhari Baharuddin 《环境科学学报(英文版)》2015,28(2):81-94
Co-composting of poultry manure and rubber wood sawdust was performed with the ratio of 2:1(V/V) for a period of 60 days. An investigation was carried out to study the extracellular enzymatic activities and structural degradation utilizing Fourier transform infrared spectroscopy(FT-IR), thermogravimetry and differential thermal analysis(TG/DTA)and scanning electron microscopy(SEM). The microbial succession was also determined by using denaturing gel gradient electrophoresis(DGGE). The compost was able to reach its highest temperature of 71°C at day 3 and stabilized between 30 and 40°C for 8 weeks.CMCase, FPase and β-glucosidase acted synergistically in order to degrade the cellulosic substrate. The xylanase activities increased gradually during the composting and reached the peak value of 11.637 U/g on day 35, followed by a sharp decline. Both Li P and Mn P activities reached their peak values on day 35 with 0.431 and 0.132 U/g respectively. The FT-IR spectra revealed an increase in aromaticity and a decrease in aliphatic compounds such as carbohydrates as decomposition proceeded. TGA/DTG data exhibited significant changes in weight loss in compost samples, indicating degradation of organic matter. SEM micrographs showed higher amounts of parenchyma exposed on the surface of rubber wood sawdust at day 60, showing significant degradation. DGGE and 16 S r DNA analyses showed that Burkholderia sp., Pandoraea sp., and Pseudomonas sp. were present throughout the composting process. Ornithinibacillus sp. and Castellaniella ginsengisoli were only found in the initial stage of the composting, while different strains of Burkholderia sp. also occurred in the later stage of composting. 相似文献