污泥电渗透脱水后热干燥过程中粘壁特性研究

采用电渗透脱水技术作为污泥热干燥的前处理技术,考察了电渗透脱水后污泥含水率以及干燥方式对热干燥过程中污泥粘壁特性的影响.结果表明,电渗透脱水技术有效降低了污泥的粘壁强度.当采用间接干燥时,电渗透脱水后阴阳两极的污泥粘壁强度分别降低了64.5％和92.0％;而采用直接干燥时,电渗透脱水后阴阳两极的污泥粘壁强度则分别降低了69.2％和92.0％.电渗透脱水后,污泥含水率是影响污泥粘壁强度的重要因素之一.污泥电渗透脱水之后,阴极的污泥粘壁强度先随含水率的降低逐渐增大,当污泥含水率降至60％时,污泥的粘壁强度达到最大,之后反而开始减小;而阳极的污泥粘壁强度却接近0.相比间接干燥方式,电渗透脱水后直接干燥方式可降低污泥的粘壁强度.直接干燥方式下,阴极的污泥粘壁强度约为间接干燥下的0.87倍;而阳极的污泥粘壁强度接近0.

Study on the Sludge Adhering Behavior in Thermal Drying Process after Electroosmotic Dewatering

By using electroosmotic dewatering technology as the pretreatment technology of sludge heat-drying,the effect of sludge moisture content and drying methods after electroosmotic dewatering on the sludge adhesion characteristics during heat-drying process was investigated.Some laws were found in the followings：the electroosmotic dewatering technology effectively reduces the sludge adhesion strength.When using indirect drying after electroosmotic dewatering,the sludge adhering strength of cathode and anode are reduced by 64.5％ and 92.0％ ; while using direct drying,the sludge adhering strength of cathode and anode are reduced by 69.2％ and 92.0％.The moisture content after electroosmotic dewatering is one of important factors influencing the sludge adhesion strength.The sludge adhesion in the cathode firstly increases gradually with the moisture content reducing and reaches the maximum when the moisture content is about 60％,but then begins to reduce;while the sludge adhesion strength in the anode is nearly close to 0.Compared to the indirect drying method,the direct drying method after electroosmotic dewatering reduces the sludge adhesion strength.In the cathode,the sludge adhesion strength by direct drying method is about 0.87 times of the indirect drying ; while the sludge adhesion strength in the anode is nearly close to 0.