Bisphenol A Degradation Using Fe³⁺-activated CaO₂ And O₂ Supply Through CaO₂ Slow Relasing In Microbial Systems

The performance of calcium peroxide?CaO₂?oxidation catalyzed by Fe³⁺ for the removal of bisphenol A?BPA?from aqueous solution was investigated first.The ability of chelating agents?CAs?,such as citric acid?CA?,oxalic acid?OA?,ethylenediaminetetraacetic?EDTA?and tartaric acid?TA?,to accelerate the BPA degradation and to reduce the Fe³⁺ dosage was assessed.Furthermore,Ferric sludge was reused as a source of catalyst to reduce solid waste accumulation.Results showed that the dosage of CaO₂ and Fe³⁺ progressively influenced the BPA degradation and the optimal dosage was 2.0 mM CaO₂ and 3.0 mM Fe³⁺.The addition of CAs efFectively enhanced the BPA removal in CaO₂/Fe³⁺ system and remarkably reduced Fe³⁺utilization from 3.0 mM to 0.25 mM.BPA degradation increased from 21.3%?without CAs?to 98.3%,98.9%,95.5%,95.0%with 1.0 mM CA,OA,EDTA and TA respectively.When 2.4 g/L Ferric sludge was used as catalyst source,a 95.1%removal of BPA was achieved in the presence of OA.This study presents a high-impact contribution to Fenton-based wastewater treatment that can increase treatment efficiency and decrease waste sludge yield.Furthermore,an oxygen slow-releasing material?OSRM?consisted of calcium peroxide?CaO₂?,stearic acid?SA?and quartz sand was used to improve oxygen supplying during bioremediation.The oxygen-releasing rates of CaO₂ powder and OSRM with difFerent SA content were investigated.The efficacy of OSRM as an oxygen supplier was assessed by the water remediation experiments using activated sludge.Results showed that CaO₂ powder was efFectively embedded by S A under anhydrous conditions.The oxygen-releasing rate decreased with increasing SA contents.Moreover,the OSRM exhibited higher oxygen-releasing capacity,and more efFective pH control ability than CaO₂ powder.The water remediation experiments showed better removal of COD and NH4+-N with OSRM as the oxygen supplier.These results provided detailed information when CaO₂ being applied as the oxygen supplier in water remediation,which can serve as reFerences for field application of bioremediation.