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填闲作物防治菜田土壤硝酸盐污染的研究进展 总被引:7,自引:0,他引:7
探讨了通过调整蔬菜生产的轮作结构,运用生物修复的原理,引入适宜的深根系填闲作物对深层土壤硝酸盐吸收利用,以避免硝酸盐进一步淋失,提高氮素的利用率的可行性。填闲作物应选择生长迅速、生物量大、氮素累积能力强的作物,在考虑填闲作物防治硝酸盐淋溶的同时,要兼顾其经济利用价值,并指出结合深根系的填闲作物进行合理轮作是蔬菜安全生产及可持续发展的途径之一。 相似文献
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土壤是动植物赖以生存的载体,重金属污染不仅严重侵害人体健康,而且破坏土壤耕作功能。土壤重金属污染具有涉及面广、受害人多、技术性强等特点,加之因果关系认定与证据收集难度大,促使受害人的权利救济遭遇现实困境。建议在严格责任、修复费用次优受偿、惩罚性赔偿等原则指引下,完善能实现受害者联合、节约司法资源、促进企业产业升级的集团诉讼制度;建构以重金属污染基金制度与重金属污染责任保险制度为主要路径的中国土壤重金属污染损害的社会化救济机制。 相似文献
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土壤植物系统与人类生产生活密切相关,本文对土壤———植物系统重金属背景值、环境容量、迁移转化及污染的生态效应等方面的研究现状进行了论述,并结合国情提出了今后这一领域研究工作重点 相似文献
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重金属与土壤微生物的相互作用及污染土壤修复 总被引:19,自引:1,他引:19
阐述了微生物与重金属间的相互作用,指出土壤重金属污染影响微生物活性、生物量,且重金属对微生物具有一定的生态毒性。可通过微生物的氧化-还原作用、生物吸附富集和溶解作用,达到修复重金属污染土壤的目的。 相似文献
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为了解江苏省某镇表层土壤重金属污染特征,采集并测定了190个土壤样品的As、Cd、Hg和Pb 4种重金属含量,分析土壤重金属的分布特征,综合运用内梅罗综合污染指数法和污染负荷指数法两种评价方法对土壤重金属污染状况进行评价。结果表明:该镇表层土壤中As、Cd和Pb含量平均值高于土壤背景值,Hg与之相反。4种重金属都是主要受到点源污染的影响,其中As的高含量区主要分布在镇的正西边,Cd和Pb的高含量区主要分布在镇的中心区域,Hg的高含量区主要分布在东部以及东北区域。经内梅罗综合污染指数法评价,安全、警戒线、轻污染、中污染和重污染样点的比例分别为5.79%、32.11%、52.11%、4.74%和5.26%。经污染负荷指数法评价,无污染、轻度污染、中度污染和重度污染样点的比例分别为73.69%、25.26%、1.05%和0%。在内梅罗综合污染指数法和污染负荷指数法评价的结果中,有55.26%的样点评价结果相同,而44.74%的样点不同,但都显示出污染程度从镇中心向四周逐渐降低的变化态势。 相似文献
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为研究燃煤电厂重金属排放对周边土壤重金属污染的影响,测定了某燃煤电厂烟囱入口烟气中Cd、Cr、Hg、Ni、Pb、As含量,同时根据当地气象及地形条件,在燃煤电厂周边采集19个土壤样品,分析了土壤中重金属含量及分布情况,并对其污染程度进行评价.结果表明,燃煤电厂烟气中6种重金属元素的质量浓度为0.02~2.00μg/m3... 相似文献
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苏北地区农业环境问题及管理方案的探讨 总被引:4,自引:0,他引:4
配合江苏省“碧海计划”和盐城市海洋经济绿色农业的发展,探讨了现阶段农业环境污染控制的直接政策管理、经济手段和人工生态工程处理三种方案,其中政策管理,如减少化肥农药的施用规定能减少污染,直接经济投入少,但是执行管理成本高,且政策见效慢;经济手段能减少污染,但环境目标达标不确定,且需要完善的市场环境,目前来说,本地区市场机制不完善,会出现“市场失灵”现象;人工湿地生态工程,前期投入大,但管理成本低,环境目标确定,但不能快速削减污染负荷。三种方案各有所长,在实际操作中,应针对不同区域的农业产业状况、方案时间迟度组合使用。 相似文献
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为了解大辽河水环境中重金属污染来源及其污染程度,对大辽河上游来水以及主要排污口的表层水体和表层沉积物主要重金属(Cr、Co、Cd、Mn、Zn、Ni、Cu、Pb、As)浓度进行了研究,并分别采用综合污染指数评价法和地累积指数评价法对表层水体和表层沉积物污染程度进行了评价。结果表明,大辽河上游来水中Cr、Cd、Zn、Cu、As、Pb元素浓度均低于《地表水环境质量标准》(GB 3838—2002)Ⅰ类标准规定的限值;太子河中Cr、Co、Ni、Cu、Zn、Cd、Pb元素浓度较高,海城河Mn、As元素浓度较高;主要排污口水体中Cr、Cu、As、Cd、Pb元素浓度均低于GB 3838—2002的Ⅰ类标准规定的限值,其中纱厂潮沟、港监潮沟排污口水体重金属浓度较高。大辽河沉积物重金属浓度表现出自上游向下游递减的特征,西潮沟、港监潮沟排污口沉积物重金属浓度高于其他排污口。综合污染指数评价法表明,大辽河水质情况较好,太子河存在较高的潜在污染风险;而地累积指数评价法表明,大辽河主要汇入河流和主要污染源沉积物重金属污染程度大多为清洁,只有西潮沟排污口沉积物中As处于轻度污染,需要引起注意。 相似文献
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Jose J Giridhar R Anas A Loka Bharathi PA Nair S 《Environmental pollution (Barking, Essex : 1987)》2011,159(10):2775-2780
Over the past three decades heavy metal pollution has increased substantially in Cochin estuary, south west coast of India. Here we studied the distribution, diversity and enzyme expression profile of culturable microbial population along a pollution gradient. The distribution of resistance against 5 mM concentration of Zn, Co, Ni and Cu was observed among 90-100% of bacterial isolates retrieved from highly polluted Eloor, whereas it was less than 40% in Vypin and Munambam. Similarly, there was a difference in the distribution and diversity of bacterial phyla with predominance of Proteobacteria in Eloor and Firmicutes in Munambam and Vypin. We observed that 75-100% of the organisms retrieved from Eloor had low levels of expression for hydrolytic enzyme. In conclusion, the heavy metal pollution in Cochin estuary brought in reduction/adaptation in the distribution, diversity and enzyme expression profile of bacteria, which may impart adverse impacts on ecosystem functioning. 相似文献
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Mobility of metals and metalloids in a multi-element contaminated soil 20 years after cessation of the pollution source activity 总被引:5,自引:0,他引:5
Clemente R Dickinson NM Lepp NW 《Environmental pollution (Barking, Essex : 1987)》2008,155(2):254-261
Knowledge of trace element concentrations and mobility is important in the ecotoxicological assessment of contaminated soils. We analysed soil pore water under field conditions to provide new insights into the mobility of residual contaminants in the surface 50cm of a highly contaminated woodland soil. Cadmium and Zn were highly mobile in the acidic soil, concentrations increasing with depth in soil pore water, showing considerable downward mobility. High levels of surface organic matter restricted the solubility of Cu, Pb and Sb, with highest concentrations being found close to the surface. Dissolved organic carbon in pore water had a strong influence on mobility of Cu, Zn, Pb and Sb. Elevated As had moved from the organic surface horizons but was largely immobilised in deeper layers and associated with Fe and Al oxides. The measured differential mobility of pollutants in the present study is highly relevant to protection of groundwater and other receptors. 相似文献
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杭州市机动车尾气污染和控制对策 总被引:3,自引:0,他引:3
随关经济的快速发展,城市道路交通和机动车尾气污染成为人们关注的热点,通过对杭州市机动车行驶现状及路检情况调查,分析了机动车排污分担率及尾气排放的潜在影响,提出控制机动车尾气大大气污染的对策。 相似文献
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Health risks of heavy metals in contaminated soils and food crops irrigated with wastewater in Beijing, China 总被引:24,自引:0,他引:24
Khan S Cao Q Zheng YM Huang YZ Zhu YG 《Environmental pollution (Barking, Essex : 1987)》2008,152(3):686-692
Consumption of food crops contaminated with heavy metals is a major food chain route for human exposure. We studied the health risks of heavy metals in contaminated food crops irrigated with wastewater. Results indicate that there is a substantial buildup of heavy metals in wastewater-irrigated soils, collected from Beijing, China. Heavy metal concentrations in plants grown in wastewater-irrigated soils were significantly higher (P相似文献
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上海市霾污染判别指标体系初步研究 总被引:2,自引:0,他引:2
随着全球变暖及工业污染排放的蔓延式发展,由空气污染带来的区域能见度恶化越来越成为中国东部经济发达地区所面临的严重区域性问题,常出现大范围的雾霾天气,造成区域空气质量的恶化及能见度水平的下降.基于对能见度及相对湿度、颗粒物浓度和组分的观测分析及影响能见度的相对湿度和空气污染因子的理论分析,提出了环保范畴内的霾污染概念,并制定了包括能见度、颗粒物浓度及其组分的上海市霾污染判别指标体系,基于颗粒物组分观测数据,对相对湿度因子进行了参数化.根据所提出的指标体系,通过上海市某点位一年观测数据的跟踪分析发现,根据霾污染判别指标体系计算得到的霾污染天数与气象学意义上的霾天数具有很好的对应关系,且新的判别指标体系能很好地区分霾污染和浮尘过程. 相似文献
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Yu-Pin Lin Bai-You Cheng Tsun-Kuo Chang 《Environmental pollution (Barking, Essex : 1987)》2010,158(1):235-244
This study identifies the natural background, anthropogenic background and distribution of contamination caused by heavy metal pollutants in soil in Chunghua County of central Taiwan by using a finite mixture distribution model (FMDM). The probabilities of contaminated area distribution are mapped using single-variable indicator kriging and multiple-variable indicator kriging (MVIK) with the FMDM cut-off values and regulation thresholds for heavy metals. FMDM results indicate that Cr, Cu, Ni and Zn can be individually fitted by a mixture model representing the background and contamination distributions of the four metals in soil. The FMDM cut-off values for contamination caused by the metals are close to the regulation thresholds, except for the cut-off value of Zn. The receiver operating characteristic (ROC) curve validates that indicator kriging and MVIK with FMDM cut-off values can reliably delineate heavy metals contamination, particularly for areas lacking background information and high heavy metal concentrations in soil. 相似文献