Organic Degradation Potential of Real Greywater Using TiO2-Based Advanced Oxidation Processes

Water

Dheaya Alrousan¹  Khalid Bani-Melhem¹  Patrick Dunlop²  Arsalan Afkhami² 

[1] Department of Water Management and Environment, Faculty of Natural Resources and Environment, The Hashemite University, 13115 Zarqa, Jordan;Nanotechnology and Integrated Bioengineering Centre, School of Engineering, Ulster University, Jordanstown BT37 0QB, Northern Ireland, UK;

关键词: photocatalysis;    TiO2;    greywater;    ozonation;    peroxonation;    advanced oxidation processes;   

DOI  :  10.3390/w12102811

来源: DOAJ

【 摘 要 】

In keeping with the circular economy approach, reclaiming greywater (GW) is considered a sustainable approach to local reuse of wastewater and a viable option to reduce household demand for freshwater. This study investigated the mineralization of total organic carbon (TOC) in GW using TiO₂-based advanced oxidation processes (AOPs) in a custom-built stirred tank reactor. The combinations of H₂O₂, O₃, and immobilized TiO₂ under either dark or UVA irradiation conditions were systematically evaluated—namely TiO₂/dark, O₃/dark (ozonation), H₂O₂/dark (peroxidation), TiO₂/UVA (photocatalysis), O₃/UVA (Ozone photolysis), H₂O₂/UVA (photo-peroxidation), O₃/TiO₂/dark (catalytic ozonation), O₃/TiO₂/UVA (photocatalytic ozonation), H₂O₂/TiO₂/dark, H₂O₂/TiO₂/UVA, H₂O₂/O₃/dark (peroxonation), H₂O₂/O₃/UVA (photo-peroxonation), H₂O₂/O₃/TiO₂/dark (catalytic peroxonation), and H₂O₂/O₃/TiO₂/UVA (photocatalytic peroxonation). It was found that combining different treatment methods with UVA irradiation dramatically enhanced the organic mineralization efficiency. The optimum TiO₂ loading in this study was observed to be 0.96 mg/cm² with the highest TOC removal (54%) achieved using photocatalytic peroxonation under optimal conditions (0.96 mg TiO₂/cm², 25 mg O₃/min, and 0.7 H₂O₂/O₃ molar ratio). In peroxonation and photo-peroxonation, the optimal H₂O₂/O₃ molar ratio was identified to be a critical efficiency parameter maximizing the production of reactive radical species. Increasing ozone flow rate or H₂O₂ dosage was observed to cause an efficiency inhibition effect. This lab-based study demonstrates the potential for combined TiO₂-AOP treatments to significantly reduce the organic fraction of real GW, offering potential for the development of low-cost systems permitting safe GW reuse.

【 授权许可】

Unknown