Conventional Fenton reaction needs to add inorganic acid to adjust pH to achieve high oxidation efficiency. In this study, sludge bioacidification resulted from Thiobacilhts thiooxidans reduced the sludge pH to meet the requirement of Fenton reaction, and Fenton oxidation of the acidified sludge for sludge disintegration was optimized. The sludge disintegration is characterized by the concentration change of SCOD, poly-saccharides and proteins in sludge supernatant. With an addition of 3 g/L sulfur powder into the sludge as energy substance, bioacidification process needed about 2 d to reduce the sludge pH to about 2.5. After sludge bioacidification, the concentrations of SCOD, polysaccharides and proteins increased from 106.12, 33.53 and 13.98 mg/L to 760.68, 103.37 and 79.08 mg/L, respectively, and bioacidification process resulted in a relative low sludge disintegration efficiency. The Fenton oxidation results indicated that the optimal conditions of the Fenton oxidation of the acidified sludge were: H2O2 dosage of 10 g/L, Fe2+ dosage of 1200 mg/L and reaction time of 90 min. Under the optimal conditions, the concentrations of SCOD, polysaccharides and proteins in sludge supernatant rose up to 4206.78, 486.47 and 414.53 mg/L, respectively. Bioacidification-Fenton oxidation process showed high sludge disintegration efficiency.
Juyuan XING Changgeng LIU Duo ZHANG Jianbin GUO Panyue ZHANG
College of Resource and Environment, Wuhan University of Technology, Wuhan, China Key Laboratory of Environmental Biology and Pollution Control (Ministry of Education), Hunan Univers Beijing Key Lab for Source Control Technology of Water Pollution, Beijing Forestry University, Beiji School of Soil and Water Consenation, Beijing Forestry University, Beijing China Key Laboratory of Environmental Biology and Pollution Control (Ministry of Education), Hunan Univers