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911.
地下水污染源分类识别是有序开展地下水污染防控工作的前提。以典型地下水污染源为研究对象,建立综合考虑优控污染物、污染源特征的地下水重点污染源识别指标体系,以污染源危害性评价结果作为重点污染源的判别依据。将哈斯(Hasee)图解法与综合评分法相结合,用于地下水优控污染物识别,同时引入修正的内梅罗综合污染指数法,对多组分的地下水优控污染物开展综合评价,并选择3个典型地下水污染源进行分类识别方法实地验证。结果表明:污染源S1、S2和S3的危害性等级分别为Ⅲ、Ⅲ、Ⅱ。在区域地下水污染分类防控与分级管理中,应对危害性等级较高的污染源S1和S2加以重点关注。  相似文献   
912.
赣南稀土矿区由于受离子型稀土矿开采的影响,地下水污染严重。在查阅国内外相关文献的基础上,阐述了赣南稀土矿区矿山开采和原地浸矿导致的地下水稀土元素、三氮(离子态的氨氮、亚硝酸盐氮和硝酸盐氮)和硫酸盐污染现状,分析了该类型地下水污染的危害,总结目前已有的地下水修复方法并分析其应用局限性,提出适用于赣南稀土矿区的地下水污染治理思路。  相似文献   
913.
The use of Conductive-Diamond Electrochemical Oxidation (CDEO) and Sonoelectrochemical Oxidation (CDSEO) has been evaluated for the removal of caffeine of wastewater. Effects of initial concentration, current density and supporting electrolyte on the process efficiency are assessed. Results show that caffeine is very efficiently removed with CDEO and that depletion of caffeine has two stages depending on its concentration. At low concentrations, opposite to what it is expected in a mass-transfer controlled process, the efficiency increases with current density very significantly, suggesting a very important role of mediated oxidation processes on the removal of caffeine. In addition, the removal of caffeine is faster than TOC, indicating the formation of reaction intermediates. The number and relative abundance of them depend on the operating conditions and supporting electrolyte used. In chloride media, removal of caffeine is faster and more efficiently, although the occurrence of more intermediates takes place. CDSEO does not increase the efficiency of caffeine removal, but it affects to the formation of intermediates. A detailed characterization of intermediates by liquid chromatography time-of-flight mass spectrometry seems to indicate that the degradation of caffeine by CDEO follows an oxidation pathway similar to mechanism proposed by other advanced oxidation processes.  相似文献   
914.
Metal contamination is a recurring problem in Peru, caused mainly by mine tailings from a past active mining activity. The Ancash region has the largest number of environmental liabilities, which mobilizes high levels of metals and acid drainages into soils and freshwater sources, posing a standing risk on human and environmental health. Native plant species spontaneously growing on naturally acidified soils and acid mine tailings show a unique tolerance to high metal concentrations and are thus potential candidates for soil phytoremediation. However, little is known about their propagation capacity and metal accumulation under controlled conditions. In this study, we aimed at characterizing nine native plant species, previously identified as potential hyperaccumulators, from areas impacted by mine tailings in the Ancash region. Plants were grown on mine soils under greenhouse conditions during 5 months, after which the concentration of Cd, Cu, Ni, Pb, and Zn was analyzed in roots, shoots, and soils. The bioaccumulation (BAF) and translocation factor (TF) were calculated to determine the amount of each metal accumulated in the roots and shoots and to identify which species could be better suited for phytoremediation purposes. Soil samples contained high Cd (6.50–49.80 mg/kg), Cu (159.50–1187.00 mg/kg), Ni (3.50–8.70 mg/kg), Pb (1707.00–4243.00 mg/kg), and Zn (909.00–7100.00 mg/kg) concentrations exceeding national environmental quality standards. After exposure to mine tailings, concentrations of metals in shoots were highest in Werneria nubigena (Cd, 16.68 mg/kg; Cu, 41.36 mg/kg; Ni, 26.85 mg/kg; Zn, 1691.03 mg/kg), Pennisetum clandestinum (Pb, 236.86 mg/kg), and Medicago lupulina (Zn, 1078.10 mg/kg). Metal concentrations in the roots were highest in Juncus bufonius (Cd, 34.34 mg/kg; Cu, 251.07 mg/kg; Ni, 6.60 mg/kg; Pb, 718.44 mg/kg) and M. lupulina (Zn, 2415.73 mg/kg). The greatest BAF was calculated for W. nubigena (Cd, 1.92; Cu, 1.20; Ni, 6.50; Zn, 3.50) and J. bufonius (Ni, 3.02; Zn, 1.30); BCF for Calamagrostis recta (Cd, 1.09; Cu, 1.80; Ni, 1.09), J. bufonius (Cd, 3.91; Cu, 1.79; Ni, 18.36), and Achyrocline alata (Ni, 137; Zn, 1.85); and TF for W. nubigena (Cd, 2.36; Cu, 1.70; Ni, 2.42; Pb, 1.17; Zn, 1.43), A. alata (Cd, 1.14; Pb, 1.94), J. bufonius (Ni, 2.72; Zn, 1.63), and P. clandestinum (Zn, 1.14). Our results suggest that these plant species have a great potential for soil phytoremediation, given their capability to accumulate and transfer metals and their tolerance to highly metal-polluted environments in the Andean region.  相似文献   
915.
Artisanal fishery activities support the livelihoods of millions of people worldwide, particularly in developing countries. Within these fisheries, distal global drivers can promote switching between alternative target resources. These drivers can promote the rapid development of new, unregulated and previously unexploited fisheries that pose a threat to the sustainability of ecosystems. In this paper, we describe a new artisanal shore gathering activity that targets a previously unexploited resource: the sandhopper (Orchestoidea tuberculata). The activity is driven by aquarium trade demand for food. We used mixed methods to describe the activity, assessed basic socio-economic incentives, and estimated Catches per Unit Effort. Results show that the sandhopper plays an important role for the livelihoods of shore gatherers engaged in the activity. Gatherers have adapted and developed two main extraction methods with different degrees of investment and extraction rates. Furthermore, gatherers have developed local knowledge regarding the ecology and management of the resource. Results show that economic incentives can motivate a rapid expansion of this unregulated activity. Future research gaps and management options to address the development of this fishery are discussed in light of these findings.  相似文献   
916.
Biodiversity offsets are becoming increasingly common across a portfolio of settings: national policy, voluntary programs, international lending, and corporate business structures. Given the diversity of ecological, political, and socio-economic systems where offsets may be applied, place-based information is likely to be most useful in designing and implementing offset programs, along with guiding principles that assure best practice. We reviewed the research on biodiversity offsets to explore gaps and needs. While the peer-reviewed literature on offsets is growing rapidly, it is heavily dominated by ecological theory, wetland ecosystems, and U.S.-based research. Given that majority of offset policies and programs are occurring in middle- and low-income countries, the research gaps we identified present a number of risks. They also present an opportunity to create regionally based learning platforms focused on pilot projects and institutional capacity building. Scientific research should diversify, both topically and geographically, in order to support the successful design, implementation, and monitoring of biodiversity offset programs.  相似文献   
917.
Environmental Science and Pollution Research - In city playgrounds, there is a potential risk of harming children’s health by contamination coming from anthropogenic activities. With the aim...  相似文献   
918.
Environmental Science and Pollution Research - Seasonal and daily cycles of BTX were studied in a non-industrialized city (Alicante) and an urban area near an oil refinery plant (Castellón) in...  相似文献   
919.
为分析参数不确定性对填埋场渗漏风险评估结果的影响,构建了填埋场地下水污染风险评价的物理过程模型,在此基础上,分别采用模糊理论和概率理论刻画模糊不确定性参数和随机不确定性参数,同时采用基于随机理论的Monte Carlo方法模拟模糊不确定参数,最终构建了基于模糊随机耦合的填埋场地下水污染风险评价方法。采用该模型对东北某一般工业固废填埋场进行案例研究,结果表明,实测浓度在模型模拟的的浓度区间(10%~90%分位值浓度)之内。说明本模型构建的模糊-随机耦合的地下水污染风险评价模型能较准确地预测地下水中污染物实际浓度,可以用于填埋场地下水污染风险评价.风险评估结果表明,该填埋场地下水的潜在污染物为As和Mn,其中As为主要健康风险物质,其非致癌风险值超过风险可接受水平的概率为22%,致癌风险超过10-4的概率为33%,超过10-5的概率为86%,应该采取措施控制含As填埋废物中As的溶出,降低其环境风险;Mn的非致癌风险值小于风险可接受水平的概率为100%,无风险。  相似文献   
920.
文章介绍了印染废水典型脱色技术的现状和进展,并着重分析了各种脱色技术的脱色机制,突出了典型脱色技术中的理论因素,介绍并阐明了一些脱色理论新观点,如吸附剂改性增效原理、分子结构与絮凝效果的联系、小剂量氧化剂偶合絮凝、脱色菌的质粒对脱色率的影响等,并从工艺角度分析了各种脱色方法的应用.  相似文献   
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