Key factors governing alkaline pretreatment of waste activated sludge  

作　　者：Xianli Shi Li Deng Fangfang Sun Jieyu Liang Xu Deng 

机构地区：[1]College of Life Sciences, Shenzhen Key Laboratory of Marine Bioresources and Ecology, Shenzhen University

出　　处：《Chinese Journal of Chemical Engineering》2015年第5期842-846,共5页中国化学工程学报（英文版）

基　　金：the National Natural Science Foundation of China(51078234);Shenzhen R&D fund(JCYJ20140418193546101);Shenzhen University R&D fund(T201203)

摘　　要：Alkaline pretreatment is an effective technology to disintegrate sewage sludge, where alkali dosage and sludge concentration are two important factors. p H value or alkali concentration is usually adjusted in order to determine a proper dosage of alkali. Our work has found that this is not a good strategy. A new parameter, the ratio of alkali to sludge(Ra/s), is more sensitive in controlling the alkali dosage. The sludge concentration Csand retention time t are two other important factors to consider. The validity of these arguments is confirmed with modeling and experiments. The individual effect of Ra/s, Csand t was studied separately. Then the combined effect of these three factors was evaluated. The sludge disintegration degree of 44.7% was achieved with the optimized factors. Furthermore, an alkaline-microwave combined pretreatment process was carried out under these optimized conditions. A high disintegration degree of 62.3% was achieved while the energy consumption of microwave was much lower than previously reported.Alkaline pretreatment is an effective technology to disintegrate sewage sludge, where alkali dosage and sludge concentration are two important factors, pH value or alkali concentration is usually adjusted in order to deter- mine a proper dosage of alkali. Our work has found that this is not a good strategy. A new parameter, the ratio of alkali to sludge （Ra/s）, is more sensitive in controlling the alkali dosage. The sludge concentration Cs and reten- tion time t are two other important factors to consider. The validity of these arguments is confirmed with model- ing and experiments. The individual effect of Ra/s, Cs and t was studied separately. Then the combined effect of these three factors was evaluated. The sludge disintegration degree of 44.7% was achieved with the optimized factors. Furthermore, an alkaline-microwave combined pretreatment process was carried out under these optimized conditions. A high disintegration degree of 62.3% was achieved while the energy consumption of microwave was much lower than previously reported.

关 键 词：Waste activated sludge Alkaline pretreatment Waste treatment Optimization Biodegradation Bioprocess design 

分 类 号：X703[环境科学与工程—环境工程] TS749.2[轻工技术与工程—制浆造纸工程]