土石围堰在江头地湖水环境治理工程中的应用

当前,我国水利事业不断发展,水利工程数量不断增多。为了发挥水利工程的经济、社会和生态效益,保障水利工程的防渗性能,一些工程项目中逐渐应用了土石围堰施工技术,有效提升了水利工程的施工质量。本文就围堰的分类、设计、施工要点等进行介绍,同时结合实际应用案例进行说明,为相关研究和施工人员提供参考。

Enhanced Biological Phosphorus Removal in SBR Using Glucose as a Single Organic Substrate

Enhanced biological phosphorus removal(EBPR) was investigated in an anaerobic/aerobic sequencing batch reactor(SBR) supplied with glucose as a single organic substrate.The results illustrated that EBPR process could also occur successfully with glucose other than short chain fatty acids(SCFAs).High phosphorus release and poly-hydroxyalkanoate(PHA) accumulation in the anaerobic phase was found vital for the removal of phosphorus during the aerobic phase.The measurement of intracellular reserves revealed that glycogen had a higher chance to replace the energy role of poly-P under anaerobic conditions.Moreover,glycogen was also utilized as the carbon source for PHA synthesis,as well as a reducing power as reported earlier.The accumulated PHA in this system was mainly in the form of poly-hydroxyvalerate(PHV) instead of poly-hydroxybutyrate(PHB),and was inferred to be caused by the excess reducing power contained in glucose.Lactate as a fermentation product was also found released into the bulk solution.Applying fundamental biochemistry knowledge to the experimental results,a conceptual biochemical model was developed to explain the metabolism of the glucose-induced EBPR.

Mercury pollution in the Chongqing part of the Three Gorges Reservoir area and its remediation and prevention

Mercury pollution in the Three Gorges Reservoir area of P.R.China merits special attention.We investigated into the current situation in the Chongqing part of the Reservoir area,identified the pollution sources and proposed some suggestions for the remediation and prevention of mercury pollution in this area.Atmospheric mercury in Chongqing was mainly from coal burning and releases of mercury-containing products such as various types of lights and fever thermometers.Urban drainage in Chongqing and Changshou,and runoffs from the high mercury background area in the lower reaches of the Wujiang River contributed most of the mercury in the water of the Yangtze River.A majority of the blame should be laid on mercury and gold mining in the Wujiang valley.We suggested foresting sloping lands to relieve soil erosion and prevent mercury-bearing soil from running into rivers,educational activities to discourage use of mercury-containing products and improved infrastructure to collect mercury-containing wastes for reducing mercury releases,more facilities for treating wastewater and solid waste to accommodate increased requirements of discharge,and growing selected perennial plants in mercury-contaminated land to absorb the mercury in soil.We also suggested concerted operation of a dedicated water-quality monitoring system,reinforced legislation and an effective administrative mechanism to ensure lasting efforts are invested in curbing mercury releases and restoring mercury contaminated land and water in the Reservoir area.

Research on ground water pollution by ieacheate of waste dump of open pit coal mine

On the basis of investigation and research on the pollution source and pollution pathway of Yujiagou area,by the ground water quality analysis and the leaching and soaking experiments of the gangue,reliable data were obtained.The experiment results prove that these inorganic salt elements are easily dissolved by the water.The main pollu- tion factors in the ground water are consisted with the main pollution factor in the leading water of the gangue.By synthetically analyzing,a conclusion is shown that the salts in the leacheate of the waste dump of open pit coal mine are the primary pollution source for groundwater of Yujiagou area.An assessment is made about the degree of pollution of the ground water in the study area.

Inactivation of Giardia by Ozone and Its Disinfect Mechanisms

This study was to investigate the effect of ozone （ O3 ） inactivation on Giardia in water by the fluorescence staining method. In order to elucidate the dominant mechanisms of inactivation, cell surface or inner cell components damage were comparatively examined by scanning dectron microscopy （SEM）. Results suggested that O3 had a stronger effect on inactivating capability. Firstly, when the concentration of O3 was above 2.0 mg/L and the contact time was up to 5 min, it showed a significant inactivating effect. Secondly, the effect of turbidity on inactivation was also found to be significant in synthetic water; when turbidity increased, the inactivating effect decreased. Thirdly, the inactivating rates were improved with a temperature increase from 5 to 25℃, but decreased when the temperature were out of this range. The inactivating capability of O3 was stronger under acidic conditions than alkalic conditions. Lastly, when the concentration of organic matter in the reactive system was increased, probably due to the competition between G/ard/a and organics on O3, the inactivating rate was decreased; in addition, the cellular morphology of Giardia varied with different contact times. At contact time of 30 s, cells were rotundity and sphericity; at 60 s they became folded, underwent emboly, and burst; and at 240 s, the cell membrane of Giardia shrinked and collapsed completely.

Public Participation in Rural Environmental Governance around the Water Source of Xiqin Water Works in Fujian

Public participation is an important way to improve the overall effect and social recognition of rural environmental governance in water source areas. Public participation makes environmental governance measures more targeted and effective, contributes to protecting the basic environmental rights of the public, and makes it easier to meet the livelihood needs of rural people. Public participation in rural environmental governance in water source areas is characterized by complex behavior and is dependent on public willingness to participate. Amongst other factors, it is subject to the combined influences of both internal（psychological cognition） and external（environmental regulation） conditions. This paper builds a theoretical framework for understanding public participation behavior in rural environmental governance, and uses it to analyze a case in the rural area surrounding the Xiqin Water Works in Fujian Province. In the case study, the public shows high willingness to participate, but low actual rates of participation. At the same time, the willingness of villagers to pay for the control of pollution from livestock and poultry breeding varies greatly from village to village, and there are also noticeable individual differences in public participation in the use of public collection points for rural household waste. We found that gender, understandings of environmental protection and perception of environmental regulation, play a key role in influencing the willingness of farmers to pay for the control of pollution from livestock and poultry breeding. Individual awareness of environmental protection, environmental protection facility conditions, and environmental service quality had a significant influence on public participation in the use of public collection points for rural household waste.