NITRATE CONTAMINATION IN OREGON WELL WATER: GEOLOGIC VARIABILITY AND THE PUBLIC'S PERCEPTION1

ABSTRACT: Approximately 4.5 million people in the United States who rely on well water are exposed to nitrate‐N concentrations exceeding the 10 mg/l standard. In this study in the Southern Willamette Valley in Oregon we reassessed nitrate‐N in rural wells sampled in 2000–2001, compared nitrate‐N concentrations among geological units, and surveyed residents about their perceptions of well water quality. Nitrate‐N concentrations were again sampled in 2002 and found to have increased significantly from the previous period. With rapid population growth in the area, the potential health risk in drinking well water that exceeds 10 mg/l nitrate‐N warrants continued public education. Nitrate‐N concentrations were found to be higher in the Holocene alluvium of the Willamette River and the Pleistocene sand and gravel post‐Missoula Flood deposits. Researchers conducting future studies may choose to stratify and monitor wells by geologic unit and by other parameters that estimate input of nutrients to the environment. Opinions differed between agricultural landowners and nonagricultural landowners with regard to the impact that agricultural fertilizers may have on water quality. Participants were supportive of a range of regulatory actions that might be used by homeowners or landowners to address ground water contamination. Given that the area is now designated a Groundwater Management Area, understanding local stakeholders’perceptions is critical and strategic and has the potential to help public agencies manage potential conflicts of opinion among stakeholders, build consensus, and help guide the approach to restoring ground water quality.     

REVIEW ON GLOBAL NATURAL DISASTERS IN 2000

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用纳滤膜分离技术处理发电厂循环冷却水

简要介绍了纳滤膜的定义和原理，并且对用纳滤膜处理厂循环冷却水进行工艺和经济技术分析。     

Chemical Changes in Sediment Pore-Waters of an Acidic Mining Lake After Addition of Organic Substrate and Lime for Stimulating Lake Remediation

In the past five years, enclosures have beeninstalled in an acidic mining lake in Lusatia to investigate insitu remediation processes. They were treated with straw, withstraw and Carbokalk, or with Carbokalk alone, where Carbokalkis a by-product of the sugar industry (solid precipitate ofnon-sugars after lime clarification of extracted sugar beetjuice). Sediment samples were taken as cores to get informationabout the behaviour of organic and inorganic components insediment pore-water with depth. Vertical distributions of pH,soluble reactive phosphate, nitrate, ammonium, silica,aluminium, iron, manganese, calcium, magnesium, sodium,potassium, sulphate, and DOC were measured. The resultingprofiles, each consisting of 15 data points at differentdepths, were compared by cluster analysis. The similarities ofsediment cores from different treated enclosures relating toprofiles of chemical components were discussed. Increasedconcentrations of potassium and sulphate were found in pore-water after substrate treatment. The data imply dissolution ofpotassium iron sulphate hydroxide minerals (jarosite) after anincrease of pH caused by dissolution of lime and by sulphatereducing processes which were stimulated by organic substrateaddition.     

Estimation of Cumulative Frequency Distribution for Carbon Monoxide Concentration from Wind-Speed Data, in Buenos Aires (Argentina)

In this article we apply and test a methodology to estimate cumulative frequency distribution for air pollutant concentration from wind-speed data. We use the inverse relationship after Simpson et al. (Atmospheric Environment, 19, 75–82, 1985) between the opposing percentile values in the statistical distributions for air pollutant concentrations and wind-speed data. This relationship is valid, irrespective of the statistical distributions of both variables, if an inverse relationship between them is also applicable. The available data are five years of 8-h average carbon monoxide concentration and 8-h mean wind-speed, observed in Buenos Aires (Argentina). The performance of the obtained empirical expressions in estimating cumulative frequency distributions for 8-h CO is statistically evaluated. The results show that it is possible to obtain an acceptable cumulative frequency distribution for 8-h CO concentration at the site if the cumulative frequency distribution for wind-speed is known. Q–Q plots show a good agreement between estimated and observed values. From our data, the mean relative error of the estimations was found to be as much as 8.0%.     

Integrated Assessment of Air Pollution Abatement Strategies in Urban Areas: Application to the Greater Athens Area

This paper presents an integrated system for the assessmentof technical and non-technical measures that are putforward in order to reduce air pollution levels in urbanareas. In contrast to the majority of the currentlyemployed assessment tools, this system allows for theevaluation of any proposed air pollution control measure interms of its combined impact on air quality and socialwelfare, by correlating the environmental and economicaspects of alternative air pollution abatement solutions.Based on the multi-pollutant, multi-effect concept, thesystem presented aims in providing policy-makers with areliable tool for the objective assessment of the mostcost-effective packages of measures, the latter beingallocated according to the particular features and needs ofthe areas examined.     

彭州市环境空气质量变化趋势及规律分析

“九五”期间 ,彭州市环境空气监测主要因子有二氧化硫、二氧化氮、总悬浮颗粒物、降尘和降水。市区空气中主要污染物排序依次为降尘、总悬浮颗粒物、二氧化硫、二氧化氮。其季节变化规律一般为第一季度 >第二季度 >第四季度 >第三季度。主要污染物年变化依次为降尘、总悬浮颗粒物、二氧化硫、二氧化氮 ,在“九五”期间除降尘量出现缓慢下降趋势外 ,其余 3项均不明显。     

炼厂隔油后污水的有机构成及混凝处理

采用GC/MS技术分析了炼厂隔油后污水的有机组成,并研究了不同混凝剂处理污水的效果,以及对有机构成的影响。结果表明,隔油后污水中的有机物质主要是C6–C8,其中酚类物质的含量最高;PAM和PAC混凝处理隔油后污水,可使污水中的有机物质总浓度及各物质的相对比例均发生变化,PAM降低烃类物质的效果好于PAC,而后者降低酚类物质的效果好于前者;在PAC处理污水时,同时投加少量活性炭可有效改变PAC脱除COD的性能。     

临夏回族自治州旅游客源市场分析与定位

本文在临夏州客源市场调查与分析的基础上,确定其客源市场应定位在周边地区,包括兰州、定西、甘南、青海省西宁、同仁等地市;在完善和发展观光休闲旅游的基础上,发展文化修学游、民族节庆体验游、生态休闲度假游、黄河三峡风情游、穆斯林民俗游、古生物考古游,并提出了相应的市场开发策略。     

隧洞施工通风系统事故树分析

在采矿、铁路、公路及水利水电工程中，常常采用长距离隧洞或隧道来穿越高山。而隧洞的施工以其施工技术复杂、难度大、风险高，经常成为控制工程工期的主要环节，隧洞施工中的通风换气系统，关系到施工能否顺利进行和施工作业人员的人身安全，根据隧洞施工通风系统的运行特点，采用安全系统分析中的事故树（FTA）方法，对隧洞施工中通风系统的安全性进行定性分析，找出影响通风安全的主要因素，并提出了通风安全管理对策，可以保证施工作业的顺利进行和人身安全，提高整个施工作业的安全度。