用生物科技处理饮用水

美国已开发出用生物科技处理饮用水技术，这种技术经济可靠。据叛国媒体报道，这种技术可消除地下水中的硝酸盐。由于农民广泛泛使用氮肥和动物粪便作肥料，地下水遭受硝酸盐污染的情况在农村日益严重。当饮用水中含硝酸盐过量时，可导致多种疾病，而农村又是以地下水为主要饮用水源。美国加利福尼亚州电力研究所结合美国政府和民间机构共同研究开发的除硝酸盐新技术，具有低成本、简单及可靠的优点。这种处理技术是计地下水流过安装无害细菌网的水塔，细菌能将硝酸盐转化为氮，然后加以过滤，以达到去除硝酸盐的目的。用生物科技处理饮用水     

电极生物膜法去除地下水中的硝酸盐

地下水硝酸盐污染日益严重,为了克服传统生物处理工艺的脱氮效果不甚理想、容易造成二次污染等缺点,对操作简单、脱氮效率高、不需后续处理的新型的电极生物膜法工艺进行研究。采用电极生物膜法处理含硝酸盐污染的地下水。自行设计了一套电极生物膜反应器,对停留时间、电流、温度、碳氮比、等主要影响因素进行了研究,得出了最佳工艺条件:停留时间3小时,电流40mA,温度30°C,碳氮比为1。     

青岛市售冬季大棚蔬菜中亚硝酸盐、硝酸盐含量的测定及安全性评价

蔬菜中亚硝酸盐、硝酸盐含量是其卫生品质的重要指标之一,研究运用格里斯试剂比色法及紫外分光光度法检测了青岛市场上冬季大棚蔬菜217个样品中亚硝酸盐、硝酸盐含量。结果表明,青岛市七区蔬菜市场上叶菜类硝酸盐污染较为严重,大部分蔬菜的亚硝酸盐处于轻、中度污染状态。研究为当地蔬菜的安全供应提供了理论依据和数据支持。     

地下水中重金属污染原位修复技术的研究进展

地下水重金属污染是当前人们面临的重要环境问题之一,成为当前人类生存和发展亟待解决的重要问题之一。文章综述了原位修复技术在治理地下水重金属污染的应用,并且主要介绍了原位修复技术中可渗透反应墙修复技术(PRB)、原位生物修复技术和原位电动修复技术的研究进展,以及原位修复技术的发展前景。     

受农业活动影响的地下水中异常高的硝酸盐污染

补给区有农田的含水层中硝酸盐浓度异常高,含水层的有限水外流和非完整井导致地下水的再循环。提出一个综合方法,从时间和空间上描述源项——硝酸盐淋滤——的特征,并将源项与含水层的流体动力学特征相联系。该方法被应用于重污染含水层的研究。结果表明,须将不利流体动力学条件与灌溉和施肥管理不善结合起来考虑,方可解释地下水中高达160mg/LNO_3-N。     

食品中亚硝酸盐过量的危害与防治

硝酸盐是自然界中广泛存在的一种无机盐.人类的食品与饮水中均含有微量的硝酸盐.但在某些情况下,食品中硝酸盐含量会激增.存在于食品中过量的硝酸盐,在一系列细菌的硝基还原酶的作用下,可将硝酸盐还原成亚硝酸盐.食品中过量的亚硝酸盐,是引发人体中毒、致癌和死亡的原因之一.因此,硝酸盐在食品中过量存在问题,已引起世界各国科学界极大关注.     

浅析广西合山矿区地下水中SO2-4污染情况及防治措施

广西合山矿区SO2-4对地下水的污染主要是由煤矿开采诱发的一种地质灾害.该煤矿中富含硫的特点更易在有氧条件下形成SO2-4.通过描述地下水SO2-4污染的情况及给村民带来的危害,认真探讨了SO2-4的形成条件和来源,并对SO2-4污染地下水的趋势进行了分析和预测.针对SO2-4的污染情况提出了较切实际的防治措施,最大限度地控制和减少SO2-4对地下水的危害,解决当地村民的饮水问题和灌溉问题,促进矿区的可持续发展.     

太原市蔬菜硝酸盐污染状况与防治对策

分析了太原蔬菜主产区6大类14种蔬菜中硝酸盐和亚硝酸盐含量,并对蔬菜硝酸盐污染现状进行了评价,提出防治蔬菜硝酸盐、亚硝酸盐污染危害的对策。     

蔬菜中硝酸盐和亚硝酸盐的污染

综述了硝酸盐和亚硝酸盐的危害、污染来源、蔬菜中的污染现状、蔬菜中硝酸盐积累机理及控制措施。     

固体废物中的重金属对土壤及地下水污染的研究

固体废物给社会和生态环境带来的危害无疑是巨大的,在部分领域甚至远超废水、废气的危害,其产生源头分散,数量庞大,组成成分复杂,形态和性质变化多样,可能含有各种有害污染物,并对环境造成了污染,危害了人类健康,阻碍了我国社会的发展。其中,固体废物中的重金属对土壤及地下水的不良影响十分显著,带来的危害难以估量,因而日益受到人们的关注。目前,预防、治理土壤和地下水重金属污染是生态环境保护的关键内容之一。本文介绍了我国固体废弃物处置现状、处理技术以及土壤和地下水重金属污染研究现状,立足实践,提出了几项土壤重金属污染修复和地下水重金属污染治理技术,以期找到解决土壤和地下水重金属污染问题的有效方法与措施。     

Using delta15N- and delta18O-values to identify nitrate sources in karst ground water, Guiyang, southwest China

Nitrate pollution of the karstic groundwater is an increasingly serious problem with the development of Guiyang, the capital city of Guizhou Province, southwest China. The higher content of NO3- in groundwater compared to surface water during both summer and winter seasons indicates that the karstic groundwater system cannot easily recover once contaminated with nitrate. In order to assess the sources and conversion of nitrate in the groundwater of Guiyang, we analyzed the major ions, delta(15)N-NH4+, delta(15)N-NO3-, and delta(18)O-NO3- in surface and groundwater samples collected during both summer and winter seasons. The results show that nitrate is the major dominant species of nitrogen in most water samples and there is a big variation of nitrate sources in groundwater between winter and summer season, due to fast response of groundwater to rain or surface water in the karst area. Combined with information on NO3- /Cl-, the variations of the isotope values of nitrate in the groundwater show a mixing process of multiple sources of nitrate, especially in the summer season. Chemical fertilizer and nitrification of nitrogen-containing organic materials contribute nitrate to suburban groundwater, while the sewage effluents and denitrification mainly control the nitrate distribution in urban groundwater.     

地下水水质分析及地下水污染治理措施

近年来,我国社会经济迅速发展,城市化建设进程逐步加快,但随之环境污染问题也变得愈发严重,尤其是地下水污染问题.虽然我国的水资源比较丰富,但由于人口众多,所以,在供水上依然存在较大压力.目前,地下水是我国主要的供水来源,如果地下水受到污染,水质受到破坏,就会对人们的身体健康带来严重威胁和隐患,因此,需要采取科学合理的治理...     

Hydrodynamic and microbial processes controlling nitrate in a fissured-porous karst aquifer of the Franconian Alb, southern Germany

Concentrations and stable isotope compositions of nitrate from 11 karst springs in the Franconian Alb (southern Germany) were determined during low flow and high flow conditions to assess sources and processes affecting groundwater nitrate. During low flow, nitrate concentrations in groundwater were around 0.10 mM in springs draining forested catchments, whereas in agricultural areas nitrate concentrations were typically higher reaching up to 0.93 mM. The isotopic composition of groundwater nitrate during low flow (delta15N values of -3.1 to 6.7% per hundred, delta180 values of +2.1 to 4.0% per hundred) in concert with concentration data suggests that nitrate is formed by nitrification in forest and agricultural soils. In addition, synthetic fertilizer N that has undergone immobilization and subsequent remineralization likely constitutes an additional nitrate source in agriculturally used catchments. During recharge conditions, concentrations and delta15N values of groundwater nitrate changed little, but delta18O values were significantly elevated (up to 24.5%o per hundred suggesting that around 25% of the nitrate was directly derived from atmospheric deposition. Groundwater dating revealed that low nitrate concentrations in groundwater (_> or =0 years) are consistent with a mixture of old low nitrate-containing and young water, the latter being affected by anthropogenic N inputs predominantly in the agriculturally used catchment areas during the last few decades. Thermodynamic and hydrogeological evidence also suggests that denitrification may have occurred in the porous rock matrix of the karst aquifer. This study demonstrates that a combination of hydrodynamic, chemical, and isotopic approaches provides unique insights into the sources and the biogeochemical history of nitrate in karst aquifers, and therefore constitutes a valuable tool for assessing the vulnerability of karst aquifers to nitrate pollution in dependence on land use and assessing their self-purification capacity.     

土壤与地下水环境管理问题思考与对策

土壤与地下水是生态环境的重要组成部分,土壤、地下水污染防治和保护,关系着"米袋子"、"菜篮子"、"水缸子"的安全,关系美丽中国建设,与人们日常生活密切相关.由于工业、农业等生产活动以及产业结构的调整,我国的土壤与地下水环境管理还存在一些不足,土壤污染持续加剧,对社会发展造成不利影响,对人民健康安全构成威胁.由于土壤和地...     

基于制革工业浅析地下水环境影响评价

制革和毛皮加工是继造纸、酿造后轻工业领域第三大污染行业,造成了严重的环境问题,特别是水污染问题。环境影响评价是拟对人为活动可能造成的环境影响进行分析论证,并提出采取污染防治措施和对策,为生态环境主管部门及审批部门提供审批、决策依据。本文主要在结合实际工作经验和以往研究成果的基础上,总结阐述了制革工业对地下水环境影响评价的重点及难点,尤其对地下水解析法模型进行详细阐述,旨在为今后相关工作提供借鉴。     

地下水环境污染治理及风险防范分析

在水资源的构成中,地下水是重要水源之一.随着全球范围内水资源短缺的日益加剧,对地下水的开发和利用显得越来越重要.但人们在以往的生产活动中,为了追求经济效益,忽视了对水资源的保护,从而使地下水环境污染问题较为突出.所以,为了保护地下水,实现对地下水资源的有效利用,在实际工作中,应结合地下水环境污染的类型和原因,采取有效的...     

Tracking sources of unsaturated zone and groundwater nitrate contamination using nitrogen and oxygen stable isotopes at the Hanford site, Washington

The nitrogen and oxygen isotopic compositions of nitrate in pore water extracts from unsaturated zone (UZ) core samples and groundwater samples indicate at least four potential sources of nitrate in groundwaters at the U.S. DOE Hanford Site in south-central Washington. Natural sources of nitrate identified include microbially produced nitrate from the soil column (delta15N of 4 - 8 per thousand, delta18O of -9 to 2 per thousand) and nitrate in buried caliche layers (delta15N of 0-8 per thousand, delta 18O of -6to 42 per thousand). Isotopically distinctindustrial sources of nitrate include nitric acid in low-level disposal waters (delta15N approximately per thousand, delta 18O approximately 23%o) per thousandnd co-contaminant nitrate in high-level radioactive waste from plutonium processing (6'5delta1of 8-33 % o, per thousand18delta oO -9 to 7%0). per thousandThe isotopic compositions of nitrate from 97 groundwater wells with concentrations up to 1290 mg/L NO3- have been analyzed. Stable isotope analyses from this study site, which has natural and industrial nitrate sources, provide a tool to distinguish nitrate sources in an unconfined aquiferwhere concentrations alone do not. These data indicate that the most common sources of high nitrate concentrations in groundwater at Hanford are nitric acid and natural nitrate flushed out of the UZ during disposal of low-level wastewater. Nitrate associated with high-level radioactive UZ contamination does not appear to be a major source of groundwater nitrate at this time.     

工业场地地下水污染修复技术的应用研究

在社会发展过程中,随着城市化建设和工业化进程的加快,产生了大量的工业污染场地,这些场地不仅会阻碍城市的可持续发展,还会对人们的生存环境造成不可逆的破坏.本文通过对工业场地地下水污染特征进行分析,探讨了地下水污染控制技术的适用范围,并重点对地下水污染修复技术进行了研究,以期为工业场地地下水污染修复技术的应用提供理论借鉴.     

Decadal geochemical and isotopic trends for nitrate in a transboundary aquifer and implications for agricultural beneficial management practices

Nitrate contamination of aquifers is a global agricultural problem. Agricultural beneficial management practices (BMPs) are often promoted as a means to reduce nitrate contamination in aquifers through producer optimized management of inorganic fertilizer and animal manure inputs. In this study, decadal trends (1991-2004) in nitrate concentrations in conjunction with 3H/3He groundwater ages and nitrate stable isotopes (delta15N, delta18O) were examined to determine whether BMPs aimed at reducing aquifer-scale nitrate contamination in the transboundary Abbotsford-Sumas aquifer were effective. A general trend of increasing nitrate concentrations in young groundwater (< approximately 5 yr) suggested that voluntary BMPs were not having a positive impact in achieving groundwater quality targets. While the stable isotope data showed that animal manure was and still is the prevalent source of nitrate in the aquifer, a recent decrease in delta15N in nitrate suggests a BMP driven shift away from animal wastes toward inorganic fertilizers. The coupling of long-term monitoring of nitrate concentrations, nitrate isotopes, and 3H/3He age dating proved to be invaluable, and they should be considered in future assessments of the impact of BMPs on nutrients in groundwaters. The findings reveal that BMPs should be better linked to groundwater nutrient monitoring programs in order to more quickly identify BMP deficiencies, and to dynamically adjust nutrient loadings to help achieve water quality objectives.     

Saturated zone denitrification: potential for natural attenuation of nitrate contamination in shallow groundwater under dairy operations

We present results from field studies at two central California dairies that demonstrate the prevalence of saturated-zone denitrification in shallow groundwater with 3H/ 3He apparent ages of < 35 years. Concentrated animal feeding operations are suspected to be major contributors of nitrate to groundwater, but saturated zone denitrification could mitigate their impact to groundwater quality. Denitrification is identified and quantified using N and O stable isotope compositions of nitrate coupled with measurements of excess N2 and residual NO3(-) concentrations. Nitrate in dairy groundwater from this study has delta15N values (4.3-61 per thousand), and delta18O values (-4.5-24.5 per thousand) that plot with delta18O/delta15N slopes of 0.47-0.66, consistent with denitrification. Noble gas mass spectrometry is used to quantify recharge temperature and excess air content. Dissolved N2 is found at concentrations well above those expected for equilibrium with air or incorporation of excess air, consistent with reduction of nitrate to N2. Fractionation factors for nitrogen and oxygen isotopes in nitrate appear to be highly variable at a dairy site where denitrification is found in a laterally extensive anoxic zone 5 m below the water table, and at a second dairy site where denitrification occurs near the water table and is strongly influenced by localized lagoon seepage.