ZHANGXin-xi,HEYu-xiang,ZHANGShi-hua,et al.Characteristics of Sludge Autothermal Thermophilic Digestion in the Viscosity Transition Zone Aerated by Pure Oxygen[J].China Water & Wastewater,2024,40(5):93-98.
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Characteristics of Sludge Autothermal Thermophilic Digestion in the Viscosity Transition Zone Aerated by Pure Oxygen

China Water & Wastewater[ISSN:1000-4062/CN:12-1073/TU] volume: 第40卷 Number: 第5期 Page: 93-98 Column: Date of publication: 2024-03-01
Author(s):
ZHANG　Xin-xi1; 2; 3;  HE　Yu-xiang1;  ZHANG　Shi-hua1; 2;  LI　Jia-wei1;  FENG　Cheng-min1;  WANG　Kai1
（1. College of Architectural Engineering， Anhui University of Technology， Ma’anshan 243002， China； 2. School of Civil and Architectural Engineering， Nanjing Tech University Pujiang Institute， Nanjing 211200， China； 3. Engineering Research Center of Biofilm Water Purification and Utilization Technology of Ministry of Education， Ma’anshan 243032， China）
Keywords:
sludge viscosity;  pure oxygen aeration;  autothermal thermophilic aerobic digestion;  solid content
Abstract:
The autothermal aerobic digestion of concentrated sludge has low organic matter content per unit volume, making it is difficult to achieve the goal of autothermal and temperature rise. In addition, aerobic composting of dehydrated sludge has the problems such as poor oxygen supply and mass transfer, strong fermentation odor and serious secondary pollution. This paper measured the viscosity curve of sludge with different solid contents, selected three kinds of sludge with different solid contents in the viscosity transition zone, compared the autothermal digestion aerated by pure oxygen and air, and investigated the performance of sequential batch digestion of sludge. The viscosity of sludge increased exponentially with the change of solid content, and the viscosity of sludge with solid content of 6%-9% was in the transition zone between gradual change and abrupt change. When the solid content of sludge was in the range of 7.01%-8.79%, the maximum temperature of digestion with pure oxygen aeration was 4.2-5.8 ℃ higher than that of air aeration, and the VS removal rate was 8.64%-14.12% higher. When the solid content of sludge was 7.99%, the digestion temperature and VS removal rate were the highest. Compared with the traditional sludge autothermal aerobic digestion, the autothermal digestion of sludge with pure oxygen aeration in the viscosity transition zone significantly increased the uniformity of oxygen supply, solid content of sludge and heat generation performance, and significantly reduced the odor production and digester volume.
Last Update: 2024-03-01