ZHENGSong-chao,ZHANGYan-ping,LITian-tian,et al.Ultraviolet Coupled with Zero-valent Iron to Activate Persulfate for Improving Sludge Dewaterability[J].China Water & Wastewater,2023,39(11):15-22.
Ultraviolet Coupled with Zero-valent Iron to Activate Persulfate for Improving Sludge Dewaterability
China Water & Wastewater[ISSN:1000-4062/CN:12-1073/TU]
volume:
第39卷
Number:
第11期
Page:
15-22
Column:
Date of publication:
2023-06-01
- Keywords:
- sludge dewatering; persulfate; zero-valent iron; ultraviolet; extracellular polymeric substance (EPS)
- Abstract:
- To improve the dewatering performance of sludge, ultraviolet coupled with zero?valent iron to activate persulfate (UV/Fe0/PDS) was used to condition the sludge, and the results were compared with that of the PDS, UV/PDS and Fe0/PDS systems. Using capillary suction time (CST), specific resistance of filtration (SRF) and sludge cake moisture content as evaluation indexes, the effects of reaction time, molar ratio of Fe0 to PDS (Fe0∶PDS), PDS dosage and initial pH on sludge dewatering performance were investigated, and the mechanism was analyzed. UV could cooperate with Fe0 to activate PDS to a certain extent, so as to improve the sludge dewatering performance. Under the conditions of room temperature, initial pH of 4, Fe0∶PDS=0.6, PDS dosage of 200 mg/g and UV irradiation reaction for 20 min, CST was decreased from 61.5 s to 19.2 s, SRF was decreased from 10.9×1012 m/kg to 2.2×1012 m/kg, and the moisture content of sludge cake was decreased to 73.9%. The analysis of EPS showed that SO4-· could transform the highly hydrophilic loose binding extracellular polymer (LB-EPS) and tightly binding EPS (TB-EPS) into soluble EPS (S-EPS), and reduce the protein substances in EPS that were not beneficial to sludge dewatering. After UV/Fe0/PDS conditioning, the sludge floc was broken and the absolute value of Zeta potential was reduced, which was conducive to sludge dewatering.
Last Update:
2023-06-01