Jin, H.; Lin, S.; Yang, Y.; Liang, Z.; Chen, Y.; Hua, L.; Zhang, Y.; Jia, H.; Zhang, G.; Wang, T. Excess Sludge Disintegration by Discharge Plasma Coupled with Thiosulfate. Water2023, 15, 3313.
Jin, H.; Lin, S.; Yang, Y.; Liang, Z.; Chen, Y.; Hua, L.; Zhang, Y.; Jia, H.; Zhang, G.; Wang, T. Excess Sludge Disintegration by Discharge Plasma Coupled with Thiosulfate. Water 2023, 15, 3313.
Jin, H.; Lin, S.; Yang, Y.; Liang, Z.; Chen, Y.; Hua, L.; Zhang, Y.; Jia, H.; Zhang, G.; Wang, T. Excess Sludge Disintegration by Discharge Plasma Coupled with Thiosulfate. Water2023, 15, 3313.
Jin, H.; Lin, S.; Yang, Y.; Liang, Z.; Chen, Y.; Hua, L.; Zhang, Y.; Jia, H.; Zhang, G.; Wang, T. Excess Sludge Disintegration by Discharge Plasma Coupled with Thiosulfate. Water 2023, 15, 3313.
Abstract
Disposal and treatment of excess sludge is a huge problem in waste water treatment plants. Discharge plasma oxidation is an effective approach for sludge dewatering and digestion. In this study, the excess sludge disintegration by non-thermal discharge plasma coupled with thiosulfate (TSA) was investigated. The soluble chemical oxygen demand (SCOD) increased to 404.93 mg L-1 after 20 min of single discharge plasma treatment, and it further increased to 549.08 mg L-1 after adding 15 mmol L-1 of TSA; the water content of filter cake also further decreased in the presence of TSA. There existed an appropriate TSA dosage. In the discharge plasma coupled with TSA system, reactive oxygen species (·OH and ·O2-) were produced and played important roles in sludge disintegration. The addition of TSA promoted the production of ·OH. These reactive oxygen species destroyed the floc structures and promoted the transformation of organic substances, leading to reduction in average size of sludge flocs. The ratio of soluble extracellular polymer substances (S-EPS) was enhanced, while the ratio of tightly bound fraction was reduced after treatment. Thus, discharge plasma coupled with TSA promoted the lysis of microbial cells and released intracellular organic matter and bound water, finally improving sludge dewaterability.
Environmental and Earth Sciences, Waste Management and Disposal
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