The mechanical dewatering of activated sludge is troublesome due to its high compressibility of solids. The dewatering can be enhanced dramatically by the use of electroosmosis,in which an electric field is applied to...The mechanical dewatering of activated sludge is troublesome due to its high compressibility of solids. The dewatering can be enhanced dramatically by the use of electroosmosis,in which an electric field is applied to the sludge cake.In this study,the influence of filter cloth on the cathode on the dewatering of activated sludge was investigated.It was found that thicker filter cloth led to lower water removal from the sludge cake,so a stainless steel cathode net with small pore size instead of filter cloth was applied,which improves the dewatering efficiency and reduces the electric power consumption.Moreover,water absorbent materials were helpful to remove the water from the sludge cake.For the electroosmotic dewatering at 7 kPa and 24 V·cm-1,the water content in the sludge cake decreased to 60%(by mass) with the average 0.075 kW·h·kg-1of water removed by using the cathode net.展开更多
The dewaterability of activated sludge conditioned by chitosan flocculant was studied. The effects of chitosan characteristics such as molecular weight, degree of deacetylation, and dose on the dewaterability were inv...The dewaterability of activated sludge conditioned by chitosan flocculant was studied. The effects of chitosan characteristics such as molecular weight, degree of deacetylation, and dose on the dewaterability were investigated. The sludge dewaterability is evaluated in terms of specific resistance to filtration, residual turbidity of supernatant, moisture content of cake, and settling rate. Sludge dehydrating behaviors conditioned with CTS, PAM and PAC flocculants were compared. The conditioning was also carried out with dual flocculants in two stages. It is found that the sludge conditioned with CTS has better dewaterability than that with PAC. The optimum conditions with chitosan are: dose 0.8 - 1.2 g per 100 g dry cake, molecular weight 300,000, and degree of deacetylation 70%. The conditioning in two stages with dual flocculants is found to be more effective than that with single flocculant.展开更多
基金Supported by Tianjin Application Basis and Advanced Technology Studied Plans(09JCYBJC08200)
文摘The mechanical dewatering of activated sludge is troublesome due to its high compressibility of solids. The dewatering can be enhanced dramatically by the use of electroosmosis,in which an electric field is applied to the sludge cake.In this study,the influence of filter cloth on the cathode on the dewatering of activated sludge was investigated.It was found that thicker filter cloth led to lower water removal from the sludge cake,so a stainless steel cathode net with small pore size instead of filter cloth was applied,which improves the dewatering efficiency and reduces the electric power consumption.Moreover,water absorbent materials were helpful to remove the water from the sludge cake.For the electroosmotic dewatering at 7 kPa and 24 V·cm-1,the water content in the sludge cake decreased to 60%(by mass) with the average 0.075 kW·h·kg-1of water removed by using the cathode net.
文摘The dewaterability of activated sludge conditioned by chitosan flocculant was studied. The effects of chitosan characteristics such as molecular weight, degree of deacetylation, and dose on the dewaterability were investigated. The sludge dewaterability is evaluated in terms of specific resistance to filtration, residual turbidity of supernatant, moisture content of cake, and settling rate. Sludge dehydrating behaviors conditioned with CTS, PAM and PAC flocculants were compared. The conditioning was also carried out with dual flocculants in two stages. It is found that the sludge conditioned with CTS has better dewaterability than that with PAC. The optimum conditions with chitosan are: dose 0.8 - 1.2 g per 100 g dry cake, molecular weight 300,000, and degree of deacetylation 70%. The conditioning in two stages with dual flocculants is found to be more effective than that with single flocculant.
