Research On Electro-dewatering Characteristics Of Inoculated Biological Conditioning Sludge

With policy paying more attention to environmental protection,energy conservation and emission reduction,the laws and regulations on the treatment and disposal of urban sewage sludge have been further improved,and more requirements have been put forward for the economics,energy consumption and efficiency of sludge disposal methods.Electro-dewatering(EDW)can efficiently reduce the water content of sludge from about 85%to less than 60%,which has attracted extensive attention in engineering applications.Sludge biological conditioning(BC)is a method to change the structure and composition of sludge which can further improve the sludge dewaterability limit.Therefore,it is very meaningful to combine biological conditioning with EDW to research new sludge dewatering method.In this paper,a biological conditioning method to change the properties of sludge by using sludge decomposition is proposed to explore the ability of improving the efficiency and dewaterability limit of EDW.Firstly,this paper analyzes the change characteristics of biological conditioning sludge,and explores the feasibility of improving the EDW effect by BC method from the perspective of dewaterability limit,energy consumption and the changes in the properties of sludge and filtrate,and confirms the BC’s appropriate temperature for the best EDW effect.The experimental results show that 60g 24 hours of 35℃ BC sludge with a water content of 86.33%dewater to the lowest water content of 54.31%after 35.5 voltage and 0.1MPa pressure EDW for 15 minutes.Compared with noneBC sludge with water content of 62.44%under the same EDW conditions,the BC’s water content is 8.13%lower.At the same time,when the above-BC sludge reaches 37.56%solid content,the dewatering rate is nearly 2 times but the energy consumption increases little.Then,according to the improvement effect of the water content of the sludge after EDW,selected the best dewatering sludge as the inoculated sludge then mixing with the original sludge.Analyzing the influence of inoculation on the properties of the sludge.The BC time and EDW effect of the inoculated sludge are studied with the factors of EDW characteristics and the change of the properties of the sludge and filtrate.Although the inoculation BC does not improve the dewatering limit of sludge,the BC time is compressed by 50%,which improves the efficiency of the inoculation process.Finally,through layered BC-EDW sludge and collecting filtrate at different times during the EDW process.Analyze the layer-time characteristics of inoculated BC sludge and filtrate,and explore the process of BC sludge’s influence to EDW,which founded the hydrolysis of microorganism is the key factor to improve the effect of BC-EDW.