基于三维荧光光谱特征峰的水体有机污染物综合指标检测

对来源不同一的32个水样进行三维荧光光谱的测定,并用5种典型有机物的荧光特征峰A(腐殖酸类)、C(腐殖酸类)、B(络氨酸类)、T1(色氨酸类)、T2(色氨酸类)进行了单一和组合式建模,发现对于来源不同一的水体的总有机含碳量(TOC)、化学耗氧量(COD)的检测采用这种提取特征峰建模的效果并不理想.该研究说明,依据典型特...     

Water conservation due to greywater treatment and reuse in urban setting with specific context to developing countries

In India, the per capita water availability is reducing day by day due to rapid growth in population and increasing water demand. Greywater treatment and reuse is one of the feasible options in developing countries like India to overcome this problem. A greywater collection, treatment and reuse system was designed and implemented in an urban household having a water requirement of 165 liter per capita per day (lpcd) and a greywater generation rate of 80 lpcd. An upflow-downflow greywater treatment plant having a screening, sedimentation, filtration and disinfection as major treatment processes was constructed and treated greywater is used for toilet flushing and to irrigate the vegetables in the backyard of the household. Greywater characterisation indicates that COD and BOD are sufficiently reduced during the treatment and there is also substantially reduction in Escherichia coli count. The payback period of this greywater treatment and reuse system is estimated to be 1.6 year.     

Influence of parameters on the heterogeneous photocatalytic degradation of pesticides and phenolic contaminants in wastewater: a short review

In recent years, the application of heterogeneous photocatalytic water purification processes has gained wide attention due to its effectiveness in degrading and mineralizing the recalcitrant organic compounds as well as the possibility of utilizing the solar UV and visible-light spectrum. This paper aims to review and summarize the recent works on the titanium dioxide (TiO(2)) photocatalytic oxidation of pesticides and phenolic compounds, predominant in storm and wastewater effluents. The effects of various operating parameters on the photocatalytic degradation of pesticides and phenols are discussed. Results reported here suggest that the photocatalytic degradation of organic compounds depends on the type and composition of the photocatalyst and, light intensity, initial substrate concentration, amount of catalyst, pH of the reaction medium, ionic components in water, solvent types, oxidizing agents/electron acceptors, catalyst application mode, and calcination temperature in the water environment. A substantial amount of research has focused on the enhancement of TiO(2) photocatalysis by modification with metal, non-metal and ion doping. Recent developments in TiO(2) photocatalysis for the degradation of various pesticides and phenols are also highlighted in this review. It is evident from the literature survey that photocatalysis has good potential to remove a variety of organic pollutants. However, there is still a need to determine the practical utility of this technique on a commercial scale.     

Quantifying water savings from willow removal in Australian streams

Willows (Salix Spp.), while not endemic to Australia, form dense stands in many stream locations. Australia has been experiencing a long-term drought and potential water extraction by willows is considered a significant problem, although little global scientific evidence exists to support such concerns. The extent of willow occupation in Australian streams has been deemed large enough to warrant investigation of their evapotranspiration rates and quantification of potential water savings from willow removal. Willows situated in-stream (permanent water) and on stream banks (semi-permanent water) were monitored over three summers from August 2005 to May 2008 employing heat pulse velocity sap flux sensors and field measurement of water balance components. A comparative study of native riparian River Red Gum trees was also undertaken. Differences in transpiration flux rates between willows with permanent and semi-permanent access to water were substantial, with peak transpiration of 15.2 mm day(-1) and 2.3 mm day(-1) respectively. Water balance calculations over the three year period indicate that an average potential net water saving of 5.5 ML year(-1)ha(-1) of crown projected area is achievable by removal of in-stream willows with permanent access to water. On stream banks, replacement of willows with native riparian vegetation will have no net impact on site water balances. Results also indicate that under the influence of natural environmental events such as drought, heat stress and willow sawfly infestation, evapotranspiration rates from in-stream willows remain greater than that from open water. These results will have important implications in environmental management of willows and in future water resource allocation and planning in Australia.     

生物质秸秆成型燃料的制备、应用与市场

介绍了国内外生物质能源技术的应用及生物质燃料的研发制备情况,分析了目前生物质燃料制备技术、资源化利用的现状以及存在的问题,针对符合中国国情的生物质(秸秆)成型燃料生产技术及市场需求进行了分析探讨。     

Allocation of supplementary aeration stations in the Chicago waterway system for dissolved oxygen improvement

The Chicago Waterway System (CWS), used mainly for commercial and recreational navigation and for urban drainage, is a 122.8 km branching network of navigable waterways controlled by hydraulic structures. The CWS receives pollutant loads from 3 of the largest wastewater treatment plants in the world, nearly 240 gravity Combined Sewer Overflows (CSO), 3 CSO pumping stations, direct diversions from Lake Michigan, and eleven tributary streams or drainage areas. Even though treatment plant effluent concentrations meet the applicable standards and most reaches of the CWS meet the applicable water quality standards, Dissolved Oxygen (DO) standards are not met in the CWS during some periods. A Use Attainability Analysis was initiated to evaluate what water quality standards can be achieved in the CWS. The UAA team identified several DO improvement alternatives including new supplementary aeration stations. Because of the dynamic nature of the CWS, the DUFLOW model that is capable of simulating hydraulics and water quality processes under unsteady-flow conditions was used to evaluate the effectiveness of new supplementary aeration stations. This paper details the use of the DUFLOW model to size and locate supplementary aeration stations. In order to determine the size and location of supplemental aeration stations, 90% compliance with a 5 mg/l DO standard was used as a planning target. The simulations showed that a total of four new supplementary aeration stations with oxygen supply capacities ranging from 30 to 80 g/s would be sufficient to meet the proposed target DO concentration for the North Branch and South Branch of the Chicago River. There are several aeration technologies, two of which are already being used in the CWS, available and the UAA team determined that the total capital costs of the alternatives range from $35.5 to $89.9 million with annual operations and maintenance costs ranging from $554,000 to $2.14 million. Supplemental aeration stations have been shown to be a potentially effective means to improve DO concentrations in the CWS and will be included in developing an integrated strategy for improving water quality in the CWS.     

Risk factors for elevated Enterococcus concentrations in a rural tropical island watershed

Associations were examined between riparian canopy cover, presence of cattle near streams, and month of year with the concentration of Enterococcus (Most Probable Number (MPN)/100 ml) in surface water at Waipā watershed on the North Side of the Hawaiian island Kaua'i. Each one percent decrease in riparian canopy cover was associated with a 3.6 MPN/100 ml increase of waterborne Enterococcus. Presence of cattle near monitoring sites was associated with an increase of 99.3 MPN/100 ml of Enterococcus in individual grab samples. Lastly, summer samples (July) were substantially higher in concentration of Enterococcus than winter collected samples (February) in Enterococcus in sampled streams. These results suggest that reducing canopy cover and introduction of cattle into riparian zones may contribute to increases of Enterococcus concentrations in stream water.     

The Sensitivity of Northern Groundwater Recharge to Climate Change: A Case Study in Northwest Alaska1

Clilverd, Hannah M., Daniel M. White, Amy C. Tidwell, and Michael A. Rawlins, 2011. The Sensitivity of Northern Groundwater Recharge to Climate Change: A Case Study in Northwest Alaska. Journal of the American Water Resources Association (JAWRA) 47(6):1228–1240. DOI: 10.1111/j.1752‐1688.2011.00569.x Abstract: The potential impacts of climate change on northern groundwater supplies were examined at a fractured‐marble mountain aquifer near Nome, Alaska. Well water surface elevations (WSE) were monitored from 2004‐2009 and analyzed with local meteorological data. Future aquifer response was simulated with the Pan‐Arctic Water Balance Model (PWBM) using forcings (air temperature and precipitation) derived from fifth‐generation European Centre Hamburg Model (ECHAM5) global circulation model climate scenarios for extreme and modest increases in greenhouse gases. We observed changes in WSE due to the onset of spring snowmelt, low intensity and high intensity rainfall events, and aquifer head recession during the winter freeze period. Observed WSE and snow depth compared well with PWBM‐simulated groundwater recharge and snow storage. Using ECHAM5‐simulated increases in mean annual temperature of 4‐8°C by 2099, the PWBM predicted that by 2099 later freeze‐up and earlier snowmelt will decrease seasonal snow cover by one to two months. Annual evapotranspiration and precipitation are predicted to increase 27‐40% (55‐81 mm) and 33‐42% (81‐102 mm), respectively, with the proportion of snowfall in annual precipitation decreasing on average 9‐25% (p < 0.05). The amount of snowmelt is not predicted to change significantly by 2099; however, a decreasing trend is evident from 2060 in the extreme ECHAM5 greenhouse gas scenario. Increases in effective precipitation were predicted to be great enough to sustain sufficient groundwater recharge.     

我国环保行业职业教育发展状况及展望

"十一五"时期我国的环境保护工作取得了突破性进展,环保产业发展势头强劲,形成了门类比较齐全的产业体系。各行业企业、环保产业单位、环保服务领域、环保系统等对环保人才有着巨大的需求。通过分析我国环保行业职业教育开展情况,论述了环保行业职业教育的发展趋势,提出了环保行业职业教育面临的三大任务和四项重点工作领域。     

建立水质自动监测系统的思考

结合章郭水质自动监测系统的可行性研究,在建立水质自动监测系统过程中对监测站位的选取、监测项目的选择、水质自动监测系统的组成、数据的采集与处理、系统的维护及管理、存在的问题等方面进行探讨,水质自动监测系统的建设可以弥补水质监测的不足,同时为实施总量控制及环境管理提供了可靠的依据。