Combination of a Highly Efficient Biological System and Visible-Light Photocatalysis Pretreatment System for the Removal of Phthalate Esters from Wastewater

To save energy and increase treatment efficiency, a visible-light photocatalysis system was coupled with biological for the continuous removal of phthalate esters (PAEs) from synthetic wastewater. Di-(2-ethylhexyl) (DEHP), dibutyl (DBP), dimethyl (DMP) were treated using an iodine-doped TiO2 photocatalyst, reactions followed first-order kinetics (similar to ultraviolet photocatalysis) produce phthalic acid as intermediate product. The effects various operating factors, such PAE concentrations, pH, light intensity, retention time (RT), coexistence PAEs, on individual investigated. DEHP-degrading bacteria isolated DEHP-contaminated soil, purified through serial dilution, then identified DNA sequencing. results indicated that optimal conditions photoreactor pH 5, temperature 30 °C, intensity 300 W, RT 5.5 min. DEHP, which contains long branched chains, more difficult degrade than DMP, short alkyl side chains. Pseudomonas sp. most dominant in soil inoculated packed bed reactor (PBR) complete degradation. effluent containing PAEs pretreated under RT. This resulted becoming biodegradable, could be completely removed by PBR. photobiological achieved efficiencies 99.6%, 99.9%, 100% DBP, respectively, during treatment. this study indicate developed is effective, energy-saving, cost-efficient tool treating wastewater PAEs.