垃圾渗滤液溶质运移的机理及数学模型

卫生填埋法是我国目前城市生活垃圾处理的主要手段.填埋法处理城市生活垃圾会产生大量污染物浓度高的渗滤液,若不加处理则会对周围环境水体产生二次污染,危害极大.为了控制和治理垃圾渗滤液,就需要对垃圾渗滤液的运移规律进行研究.以垃圾降解的生化反应机理为基础,综合考虑对流、弥散、扩散、吸附和有机物生物降解等作用,建立了垃圾渗滤液溶质运移的对流-弥散模型,并对其一维数学模型进行解析求解.     

二氧化氯深度处理垃圾渗滤液研究

利用二氧化氯对生物处理后的垃圾渗滤液进行深度处理,根据废水中有效氯浓度、COD、氨氮及细菌数等参数的分析,初步探讨了不同浓度的二氧化氯在不同处理时间内对垃圾渗滤液的处理效果。结果表明,对于COD初始浓度为450 mg/L左右的水样,二氧化氯的投加浓度达100 mg/L（有效氯）,反应时间在50 min时,处理水样可达到同类废水的国家二级排放标准;对于同样条件下的水样,当加入约25 mg/L的二氧化氯时可以杀灭水样中的大肠杆菌,加入浓度达到90 mg/L的二氧化氯时,可以杀灭水样中几乎所有的细菌。     

Dynamic characteristics of cool thermal energy storage systems—a review

Cool thermal energy storage (CTES) plays a significant role in conserving available energy, improving its utilization, and correcting the mismatch that occurs between the supply and demand of energy. It has been employed in many applications, for example, cool storage systems for air-conditioning and natural cooling of energy-efficient building. CTES is widely used in various industrial applications such as food and pharmacy processing, where large short duration loads are often required. This paper presents a review on CTES systems and characteristics. The dynamic characteristics of chilled water storage system, coil pipe cool storage system, packed bed cool storage system, gas hydrate cool storage system, and ice slurry cool storage system are analyzed and discussed. The applications of CTES system are summarized.     

古代经验对城市防涝的启示

研究现代城市暴雨后内涝灾害的原因,对照古城水系的经验,认为古代以河渠为城市排水干渠,密度大,行洪断面大,调蓄系统容量巨大,管理良好,是防止暴雨后城市内涝的重要经验,可供借鉴.     

基于遥感技术的艾比湖储水量和需水量研究

艾比湖湖水很浅,湖底平坦,沉积着巨厚的细沙和淤泥。依据自身特征及其他因素,针对艾比湖水量的收支情况,建立艾比湖的储水量和需水量的数学模型。其中艾比湖湖面面积数据是重要参数之一,利用遥感技术,采用资源卫星影像,结合Modis数据,解译提取获得。通过艾比湖储水量和需水量数据可以进一步预测艾比湖湖面面积的变化趋势,对本地区的生态及农业生产具有指征意义,为决策层制定防治对策提供科学依据。     

Decentralized Groundwater Recharge Systems Using Roofwater and Stormwater Runoff1

Stephens, Daniel B., Mark Miller, Stephanie J. Moore, Todd Umstot, and Deborah J. Salvato, 2011. Decentralized Groundwater Recharge Systems Using Roofwater and Stormwater Runoff. Journal of the American Water Resources Association (JAWRA) 48(1): 134‐144. DOI: 10.1111/j.1752‐1688.2011.00600.x Abstract: Stormwater capture for groundwater recharge in urban areas is usually conducted at the regional level by water agencies. Field and modeling studies in New Mexico indicate that stormwater diverted to retention basins may recharge about 50% of precipitation that falls on the developed area, even in dry climates. Comparable volumes of recharge may be expected at homes, subdivisions, or commercial properties with low‐impact development (LID) technologies for stormwater control that promote recharge over evapotranspiration. Groundwater quality has not been significantly impacted at sites that have been recharging stormwater to aquifers for decades. Distributed recharge systems may be a good alternative to centralized regional facilities where there is limited land for constructing spreading basins or little funding for new infrastructure. LID technologies borrowed from stormwater managers are important tools for groundwater managers to consider to enhance recharge.     

油品储运行业挥发性有机物排放控制技术评估

分析了我国油品储运行业的VOCs排放环节和特点。选取燃烧法、吸收法、吸附法、冷凝法、膜分离法等VOCs排放末端控制技术作为研究对象,介绍了各方法的原理和适用条件。建立了包括环境性能、技术性能、经济性能3方面共10项指标的综合评价指标体系。采用模糊评价方法分析了油品储运行业VOCs排放末端控制备选技术的综合性能。结果表明,冷凝法和膜分离法具有良好的综合性能,是油品储运行业VOCs排放的最佳末端控制技术。     

石化企业固定顶储罐挥发性有机物排放量影响因素的分析

采用美国国家环保局推荐的储罐挥发性有机物(VOCs)排放量定量计算方法,以北京某石化企业轻柴油固定顶储罐为案例对象,计算了固定顶储罐的总损失。通过对不同参数进行调节,比较分析了各变量对损失量的影响程度,得出了影响固定顶储罐静置储藏损失和工作损失的关键参数和次要参数。并在此基础上,提出了降低固定顶储罐VOCs排放量的对应措施。实验结果表明:影响固定顶储罐静置储藏损失的关键参数为油品蒸气相对分子质量、日平均液体表面温度和液体存储高度,次要参数为日环境温差和罐漆太阳能吸收率;影响工作损失的关键参数为油品蒸气相对分子质量、日平均液体表面温度和年净周转量。     

Delineation of soil and groundwater contamination using geophysical methods at a waste disposal site in Çanakkale, Turkey

Direct current (DC) resistivity, self potential (SP) and very low frequency electromagnetic (VLF-EM) measurements are carried out to detect the spread of groundwater contamination and to locate possible pathways of leachate plumes, that resulted from an open waste disposal site of Canakkale municipality. There is no proper management of the waste disposal site in which industrial and domestic wastes were improperly dumped. Furthermore, because of the dumpsite is being located at the catchment area borders of a small creek and is being topographically at a high elevation relative to the urban area, the groundwater is expected to be hazardously contaminated. Interpretations of DC resistivity geoelectrical data showed a low resistivity zone (<5 ohm-m), which appears to be a zone, that is fully saturated with leachate from an open dumpsite. The VLF-EM and SP method, support the results of geoelectrical method relating a contaminated zone in the survey area. There is a good correlation between the geophysical investigations and the results of previously collected geochemical and hydrochemical measurements.     

DNAPL distribution in the source zone: effect of soil structure and uncertainty reduction with increased sampling density

This paper focuses on parameters describing the distribution of dense nonaqueous phase liquid (DNAPL) contaminants and investigates the variability of these parameters that results from soil heterogeneity. In addition, it quantifies the uncertainty reduction that can be achieved with increased density of soil sampling. Numerical simulations of DNAPL releases were performed using stochastic realizations of hydraulic conductivity fields generated with the same geostatistical parameters and conditioning data at two sampling densities, thus generating two simulation ensembles of low and high density (three-fold increase) of soil sampling. The results showed that DNAPL plumes in aquifers identical in a statistical sense exhibit qualitatively different patterns, ranging from compact to finger-like. The corresponding quantitative differences were expressed by defining several alternative measures that describe the DNAPL plume and computing these measures for each simulation of the two ensembles. The uncertainty in the plume features under study was affected to different degrees by the variability of the soil, with coefficients of variation ranging from about 20% to 90%, for the low-density sampling. Meanwhile, the increased soil sampling frequency resulted in reductions of uncertainty varying from 7% to 69%, for low- and high-uncertainty variables, respectively. In view of the varying uncertainty in the characteristics of a DNAPL plume, remedial designs that require estimates of the less uncertain features of the plume may be preferred over others that need a more detailed characterization of the source zone architecture.