The factors including inflow SS, pythogenous sewage, loading rate Ns, dissolved oxygen which affect sedimentation performance of A-step activated sludge were studied in the paper. The experimental results indicated: t...The factors including inflow SS, pythogenous sewage, loading rate Ns, dissolved oxygen which affect sedimentation performance of A-step activated sludge were studied in the paper. The experimental results indicated: the inflow SS distinctly improve sedimentation performance of activated sludge; the pythogenous sewage easily worsen sedimentation performance of activated sludge, and canceling primary sedimentation tank and cesspool would avail to stable running of sewage treatment plant. The effect of loading rate Ns on EPS is highly remarkable, and EPS and polysaccharide are correlated evidently with sedimentation performance of activated sludge. When high loading rate Ns is 3.0 kgBOD5/kgMLSS·d, EPS is 17.15mgEPS/gVSS and polysaccharide is 8.15mg/g VSS, which is less 40% than activated sludge of 0.3 kgBOD5/kgMLSS·d loading rate Ns; meanwhile the effect of dissolved oxygen on EPS is less, and dissolved oxygen does not affect sedimentation performance of activated sludge in high loading rate; the polysaccharide content of activated sludge in high loading rate does not benefit the growth of filament, and furthermore the hydrophobicity of activated sludge is good, which cause good sedimentation performance of sludge in high loading rate.展开更多
Through analyzing the present conditions of water supply networks technical administration files in Chongqing, this paper points out the significance and urgency for exploiting advanced water supply networks informati...Through analyzing the present conditions of water supply networks technical administration files in Chongqing, this paper points out the significance and urgency for exploiting advanced water supply networks information system. It also gives the concept of GIS and some suggestions for the exploitation.展开更多
Most cities of our country now adopt the method of concentative pipe nets in water supply. In order to meet the users'' request of hydraulic pressure, some small residential areas or building groups have estab...Most cities of our country now adopt the method of concentative pipe nets in water supply. In order to meet the users'' request of hydraulic pressure, some small residential areas or building groups have established water supply systems of secondary compression. Now most water supply enterprises do much work in purification processes of waterworks so as to improve the water quality; however, the secondary pollution because of water supply pipe nets is ignored. An investigation was done by special team of “security technology of water quality in residential areas” and they investigated water quality of waterworks and health and quarantine stations in big and middle cities of the whole country. The result indicates that secondary pollution of pipeline networks indeed exists. So, in order to resolve the question of secondary pollution and to provide people with clean and secure drinking water, the reason that secondary pollution came into being must be understood, moreover, concrete methods and measures aimed at each reason should be found out.展开更多
文摘The factors including inflow SS, pythogenous sewage, loading rate Ns, dissolved oxygen which affect sedimentation performance of A-step activated sludge were studied in the paper. The experimental results indicated: the inflow SS distinctly improve sedimentation performance of activated sludge; the pythogenous sewage easily worsen sedimentation performance of activated sludge, and canceling primary sedimentation tank and cesspool would avail to stable running of sewage treatment plant. The effect of loading rate Ns on EPS is highly remarkable, and EPS and polysaccharide are correlated evidently with sedimentation performance of activated sludge. When high loading rate Ns is 3.0 kgBOD5/kgMLSS·d, EPS is 17.15mgEPS/gVSS and polysaccharide is 8.15mg/g VSS, which is less 40% than activated sludge of 0.3 kgBOD5/kgMLSS·d loading rate Ns; meanwhile the effect of dissolved oxygen on EPS is less, and dissolved oxygen does not affect sedimentation performance of activated sludge in high loading rate; the polysaccharide content of activated sludge in high loading rate does not benefit the growth of filament, and furthermore the hydrophobicity of activated sludge is good, which cause good sedimentation performance of sludge in high loading rate.
文摘Through analyzing the present conditions of water supply networks technical administration files in Chongqing, this paper points out the significance and urgency for exploiting advanced water supply networks information system. It also gives the concept of GIS and some suggestions for the exploitation.
文摘Most cities of our country now adopt the method of concentative pipe nets in water supply. In order to meet the users'' request of hydraulic pressure, some small residential areas or building groups have established water supply systems of secondary compression. Now most water supply enterprises do much work in purification processes of waterworks so as to improve the water quality; however, the secondary pollution because of water supply pipe nets is ignored. An investigation was done by special team of “security technology of water quality in residential areas” and they investigated water quality of waterworks and health and quarantine stations in big and middle cities of the whole country. The result indicates that secondary pollution of pipeline networks indeed exists. So, in order to resolve the question of secondary pollution and to provide people with clean and secure drinking water, the reason that secondary pollution came into being must be understood, moreover, concrete methods and measures aimed at each reason should be found out.
