HEMiao-lin,ZHANGYan-ping,LIYi-bing.Enhancement and Mechnism of Electrolysis Coupled Fe2+-activated Persulfate Oxidation for Excess Sludge Dewatering[J].China Water & Wastewater,2023,39(15):15-22.
Enhancement and Mechnism of Electrolysis Coupled Fe2+-activated Persulfate Oxidation for Excess Sludge Dewatering
China Water & Wastewater[ISSN:1000-4062/CN:12-1073/TU]
volume:
第39卷
Number:
第15期
Page:
15-22
Column:
Date of publication:
2023-08-01
- Keywords:
- sludge dewatering; electrolysis; peroxydisulfate; ferrous iron; extracellular polymeric substances (EPS)
- Abstract:
- Electrolysis (EC) coupled Fe2+/peroxydisulfate (PDS) was employed to pretreat excess sludge. The effects of electrolysis time, voltage, PDS dosage and Fe2+ to PDS molar ratio on sludge dewatering performance were investigated, and the mechanism was analyzed by means such as measuring extracellular polymeric substances (EPS), three-dimensional fluorescence spectrum (EEM) and scanning electron microscopy (SEM). EC/Fe2+/PDS effectively improved the sludge dewatering performance. When the voltage was 25 V, the dosage of PDS was 2 g/L, the Fe2+ to PDS molar ratio was 0.4 and the electrolysis time was 30 min, the capillary suction time (CST) was reduced by 58.3%, the moisture content of sludge cake was decreased to 74.2%, and the SCOD of supernatant reached 367.8 mg/L. The EC/Fe2+/PDS system effectively promoted the conversion of Fe3+ to Fe2+, improved the utilization rate of Fe2+ and PDS, and reduced the dosage of reagent. In addition, it effectively cracked the structure of sludge floc and EPS, and degraded and transferred proteins, polysaccharides and humic acids in tightly bound EPS (TB?EPS). The correlation analysis showed that CST had a strong correlation with total EPS, and the theoretical value of EPS was 320 mg/L when the dewatering performance was the best.
Last Update:
2023-08-01