In order to describe the relationship between dynamic process and sludge removing load in active sludge system, a new method for designing the volume of aeration tanks was put forward based on the Michaelis and Menten...In order to describe the relationship between dynamic process and sludge removing load in active sludge system, a new method for designing the volume of aeration tanks was put forward based on the Michaelis and Menten equation. the influence of sludge returning was considered in the design. The result shows that the parameter of sludge reflux ratio plays a very important role in the design of active sludge system. In some given conditions,there exists an optimum reflux ratio which can make the volume of aeration tank be the minimum.展开更多
Effects of hydraulic retention time (HRT ) and gas volume on efficiency of wastewater treatment are dis- cussed based on a simulation experiment in which the domestic swage was treated by the two-stage-bio-contact oxi...Effects of hydraulic retention time (HRT ) and gas volume on efficiency of wastewater treatment are dis- cussed based on a simulation experiment in which the domestic swage was treated by the two-stage-bio-contact oxida- tion process. The result shows that the average CODCr, BOD5 , suspended solid (SS), and ammonia-nitrogen removal rate are 94.5 %, 93.2 %, 91.7 % and 46.9 %, respectively, under the conditions of a total air/water ratio of 5∶1 , an air/water ratio of 3:1 for oxidation tank 1 and 2:1for oxidation tank 2and a hydraulic retention time of 1 h for each stage. This method is suitable for domestic sewage treatment of residential community and small towns as well.展开更多
Tongshan area,a part of the floodplain of the abandoned Huanghe River, is one of the popular endemic fluorosis areas in East China. One of the reasons is high concentration of fluorine in shallow groundwater. Test res...Tongshan area,a part of the floodplain of the abandoned Huanghe River, is one of the popular endemic fluorosis areas in East China. One of the reasons is high concentration of fluorine in shallow groundwater. Test results of 36 groundwater samples show that fluorine concentration in shallow groundwater is 0.18–6.7 mg/L and 50 % of the samples exceed the Chinese drinking water quality standard. There exists a significant negative correlation in content between Ca2+ and F - . The correlations between fluorine concentration and other cations (for example Na+, K+, Mg2+) are not significant. The content of dissolved fluorine from the flooding sediments of the Huanghe River that varying from 5.6 mg/kg to 15.2 mg/kg plays an important role in forming the high fluorine groundwater. Usually, the dissolved fluorine content in silt is much higher than that in silty clay and clay. According to the geological investigation fluorine content in deep groundwater (over 60 m) is less than 1.0 mg/L and suitable for drinking, so it is an effective measure to prevent endemic fluorosis by extracting deep groundwater in disease areas.展开更多
文摘In order to describe the relationship between dynamic process and sludge removing load in active sludge system, a new method for designing the volume of aeration tanks was put forward based on the Michaelis and Menten equation. the influence of sludge returning was considered in the design. The result shows that the parameter of sludge reflux ratio plays a very important role in the design of active sludge system. In some given conditions,there exists an optimum reflux ratio which can make the volume of aeration tank be the minimum.
文摘Effects of hydraulic retention time (HRT ) and gas volume on efficiency of wastewater treatment are dis- cussed based on a simulation experiment in which the domestic swage was treated by the two-stage-bio-contact oxida- tion process. The result shows that the average CODCr, BOD5 , suspended solid (SS), and ammonia-nitrogen removal rate are 94.5 %, 93.2 %, 91.7 % and 46.9 %, respectively, under the conditions of a total air/water ratio of 5∶1 , an air/water ratio of 3:1 for oxidation tank 1 and 2:1for oxidation tank 2and a hydraulic retention time of 1 h for each stage. This method is suitable for domestic sewage treatment of residential community and small towns as well.
基金Project 2001KJ11 supported by National investigation of land and resources
文摘Tongshan area,a part of the floodplain of the abandoned Huanghe River, is one of the popular endemic fluorosis areas in East China. One of the reasons is high concentration of fluorine in shallow groundwater. Test results of 36 groundwater samples show that fluorine concentration in shallow groundwater is 0.18–6.7 mg/L and 50 % of the samples exceed the Chinese drinking water quality standard. There exists a significant negative correlation in content between Ca2+ and F - . The correlations between fluorine concentration and other cations (for example Na+, K+, Mg2+) are not significant. The content of dissolved fluorine from the flooding sediments of the Huanghe River that varying from 5.6 mg/kg to 15.2 mg/kg plays an important role in forming the high fluorine groundwater. Usually, the dissolved fluorine content in silt is much higher than that in silty clay and clay. According to the geological investigation fluorine content in deep groundwater (over 60 m) is less than 1.0 mg/L and suitable for drinking, so it is an effective measure to prevent endemic fluorosis by extracting deep groundwater in disease areas.
