RENZheng-ran,GAOJin-hua,WANGJia-wei,et al.Impacts of Thermal Hydrolysis Temperature on Sludge Biodegradability and Effluent COD in Wastewater Treatment Plant[J].China Water & Wastewater,2025,41(15):1-7.
Impacts of Thermal Hydrolysis Temperature on Sludge Biodegradability and Effluent COD in Wastewater Treatment Plant
China Water & Wastewater[ISSN:1000-4062/CN:12-1073/TU]
volume:
第41卷
Number:
第15期
Page:
1-7
Column:
Date of publication:
2025-08-01
- Abstract:
- The effects of thermal hydrolysis temperature on the physicochemical properties, biogas yield, and refractory organic matter of sludge were investigated through experiments involving sludge thermal hydrolysis at temperatures ranging from 110 ℃ to 170 ℃ and subsequent anaerobic digestion at 40 ℃. The results showed that as the temperature increased, solid organic matter gradually dissolved, leading to a significant increase in the concentration of soluble organic matter. At 170 ℃, the concentrations of soluble protein and polysaccharides in the sludge reached 14.7 g/L and 2.5 g/L, respectively (both calculated as COD), while the concentration of volatile fatty acids (VFAs) also rose with increasing temperature. These changes enhanced biogas production in sludge, with the VS biogas yield increasing from 345 L/g to 513 L/g. Thermal hydrolysis at 170 ℃ increased the concentration of refractory COD in the anaerobic digestion filtrate to 2 888 mg/L, compared to 1 600 mg/L for untreated sludge. Under full?load operation, without using thermal hydrolysis technology, the reflux of digested sludge filtrate would increase the effluent COD to 16.4 mg/L; when the temperature was 170 ℃, the COD increased to 19.2 mg/L. Proper control of the temperature can effectively reduce the generation of refractory COD, minimizing its impact on the effluent quality of the wastewater treatment plant.
Last Update:
2025-08-01