FENGShu-xing,SUN Ming-liang,LUOCong-wei,et al.UV222/H2O2 Pre-oxidation Enhanced PAC Coagulation for Algae Removal: Performance and Mechanism[J].China Water & Wastewater,2025,41(3):35-42.
UV222/H2O2 Pre-oxidation Enhanced PAC Coagulation for Algae Removal: Performance and Mechanism
China Water & Wastewater[ISSN:1000-4062/CN:12-1073/TU]
volume:
第41卷
Number:
第3期
Page:
35-42
Column:
Date of publication:
2025-02-01
- Keywords:
- UV222; H2O2; polyaluminum chloride (PAC); coagulation; algae
- Abstract:
- The performance of UV222/H2O2 and UV254/H2O2 pre-oxidation systems on enhanced coagulation for algae removal were compared. Under the conditions of H2O2 dosage of 0.3 mmol/L, polyaluminum chloride (PAC) dosage of 0.8 mg/L, UV irradiation dose of 1 300 mJ/cm2, and UV222/UV254 irradiation time of 30 min/15 min, the removal efficiencies of algal cells by the UV222/H2O2 and UV254/H2O2 pre-oxidation enhanced coagulation systems were 80% and 87.5%, respectively. These values represented improvements of 55% and 62.5% over the removal efficiency achieved with PAC alone. Following the completion of the sedimentation process, there was a significant reduction in aromatic proteins and soluble microbial products within the extracellular organic matter. The mechanism study revealed that the pre-oxidation processes using UV222/H2O2 and UV254/H2O2 generated a significant amount of hydroxyl radicals. These radicals oxidized organic matters on the surface of algal cells, leading to an increase in Zeta potential, thereby enhancing the efficiency of coagulation for algae removal. Furthermore, the results from inverted fluorescence and scanning electron microscopy analysis demonstrated that UV254/H2O2 pre-oxidation exhibited greater destruction towards algal cells compared to UV222/H2O2 pre-oxidation. The latter method was found to be a gentler approach for enhanced coagulation for algae removal, effectively preventing secondary pollution.
Last Update:
2025-02-01