ECONOMIC APPRAISAL OF A GROUND WATER DEVELOPMENT PROJECT1

A ground water development project in the northern part of Thailand was appraised by means of benefit-cost analysis. This is the first project in Thailand to develop ground water for irrigation purposes and it is also the first project which made use of an underground PVC pipe water distribution system. Results indicate that the project is economically feasible. In comparing different water distribution systems, it is also found that distribution by means of underground PVC pipes is more economical compared to an open ditch system if the life of the latter is relatively short and the rates of inflation are high.     

AUTOMATED WEB GIS BASED HYDROGRAPH ANALYSIS TOOL,WHAT1

The separation of the base flow component from a varying streamflow hydrograph is called “hydrograph analysis.” In this study, two digital filter based separation modules, the BFLOW and Eckhardt filters, were incorporated into the Web based Hydrograph Analysis Tool (WHAT) system. A statistical component was also developed to provide fundamental information for flow frequency analysis and time series analysis. The Web Geographic Information System (GIS) version of the WHAT system accesses and uses U.S. Geological Survey (USGS) daily streamflow data from the USGS web server. The results from the Eckhardt filter method were compared with the results from the BFLOW filter method that was previously validated, since measured base flow data were not available for this study. Following validation, the two digital filter methods in the WHAT system were run for 50 Indiana gaging stations. The Nash‐Sutcliffe coefficient values comparing the results of the two digital filter methods were over 0.91 for all 50 gaging stations, suggesting the filtered base flow using the Eckhardt filter method will typically match measured base flow. Manual separation of base flow from streamflow can lead to inconsistency in the results, while the WHAT system provides consistent results in less than a minute. Although base flow separation algorithms in the WHAT system cannot consider reservoir release and snowmelt that can affect stream hydrographs, the Web based WHAT system provides an efficient tool for hydrologic model calibration and validation. The base flow information from the WHAT system can also play an important role for sustainable ground water and surface water exploitation, including irrigation and industrial uses, and estimation of pollutant loading from both base flow and direct runoff. Thus, best management practices can be appropriately applied to reduce and intercept pollutant leaching if base flow contributes significant amounts of pollutants to the stream. This Web GIS based system also demonstrates how remote, distributed resources can be shared through the Internet using Web programming.     

三维电极法深度处理成品油库含油污水

为解决成品油库含油污水处理后COD不达标的问题,以铁碳复合材料为填充粒子、以石墨电极为阴阳极构建了三维电极,考察了三维电极法深度处理成品油库含油污水的处理效果及其影响因素。实验结果表明:在电压15 V、反应时间60 min、废水pH 7、曝气量60 L/h、液固比0.6 m L/g的优化工艺条件下,COD去除率可达72.4%;处理后出水COD降至67 mg/L,满足GB 8978—1996《污水综合排放标准》中的一级标准。     

活性炭纤维脱除二氧化碳的实验研究

采用活性炭纤维(ACF)作为吸附材料,研究了ACF对CO_2和N_2的吸、脱分离特性。结果表明,粘胶基活性炭纤维(V-ACF)和聚丙烯腈基活性炭纤维(PAN-ACF)对CO_2和N_2都表现出较好的吸附效果,其中V-ACF对CO_2和N_2的吸附系数高达9,说明ACF是很好的吸附分离材料。ACF对不同烟气浓度和温度下对CO_2吸附的结果说明,ACF对于高浓度CO_2更易于脱除;讨论了ACF在不同解析温度或时间对吸附的影响和ACF的热稳定性,结果表明,在较高解析温度或者较长解析时间下更加容易脱除CO_2,且再生时间短,最佳的解析时间为15 min。经过相同的多次实验,ACF的性能稳定,再生效率稳定在86%。     

新疆油田盆5气田放空气回收技术应用

新疆油田盆5气田采用分子筛对天然气处理站的放空气进行回收,介绍了分子筛的吸附原理、回收技术原理及工艺流程、净化脱水压力稳定安全措施等。通过优化破乳剂类型及注入量,净化脱水后的放空气满足回收利用要求。此项回收技术的利用,每年可减排废气5209.2×104m3,回收天然气约360×104m3,增加经济效益360万元。     

Ground-level ozone in the Pearl River Delta and the roles of VOC and NO(x) in its production

In many regions of China, very rapid economic growth has been accompanied by air pollution caused by vehicle emissions. In one of these regions, the Pearl River Delta, the variations of ground-level ozone and its precursors were investigated. Overall, the ambient concentrations of NO(2) increased quickly between 1995 and 1996, but then slightly decreased due to stringent nitrogen oxide (NO(x)) emission controls. Nonetheless, ambient NO(2) levels in the Pearl River Delta remained high. The regional average concentrations of volatile organic compounds (VOCs) were 290 ppbC in summer and 190 ppbC in autumn. Local emissions and long-distance transportation of pollutants play important roles in the regional distribution of VOCs. Ambient O(3) production is significant in urban areas and also downwind of cities. The relative incremental reactivities (RIRs), determined by an observation-based model, showed that ground-level ozone formation in the Guangzhou urban area is generally limited by the concentrations of VOCs, but there are also measurable impacts of NO(x).     

GIS在震后应急反应中的应用

震后应急反应是减轻震害的关键措施之一。震后应急的基础在于信息的收集和处理。ＧＩＳ（地理信息系统）具有很强的信息管理能力和空间数据处理、分析能力。借助于这个系统,可以解决以往应急反应中存在的资料分散、资料更新慢、管理费用大以及大量信息难以提取、查询和使用等问题。ＧＩＳ与震后应急反应的结合可以大大提高应急反应的速度和准确性。     

Fe（Ⅲ）水解过程中无机阴离子的影响作用

本文通过ＰＯ＾３－ ４，Ｆ＾－，ＳＯ＾２－ ４，Ｃｌ＾－，ＮＯ＾－ ３和ＣｌＯ＾－ ４存在时，０．１ｍｏｌ／１ ＦｅＣｌ３溶液的碱中和曲线的分析对比，说明了用曲线斜率区分滴定曲线为三个区域：（Ａ）自发水解反应；（Ｂ）聚合反应；（Ｃ）沉淀反应，以及阴离子对中和曲线的影响及其规律，指出阴子子对Ｆｅ（Ⅲ）浓度中和反应影响为不同程度的竞争配位，参与聚合及电中和脱稳，使沉淀反应提前等。并与ＯＨ＾－共同形成Ｆ     

有机污染物半导体多相光催化氧化机理及动力学研究进展

本文系统总结了有机污染物半导体多相光催化氧化机理及动力学研究进展现状，阐述了几种特定有机污染物的光催化氧化机理，并对有关机理方面进一步研究的必要性和方向进行了探讨。