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Evaluating the effectiveness of advanced oxidation processes for leachate treatment: A systematic review
Authors: Mohammad Ali Zazouli, Zabihollah Yousefi, Esmaeil Babanezhad, Reza Ali Mohammadpour, Alireza Ala
Number of views: 10
Background: Leachate, containing challenging-to-degrade organic substances and persistent toxins,
poses significant environmental concerns. Advanced oxidation processes (AOPs) have emerged as a
promising solution for effective leachate treatment. This research provides a comprehensive review of
the impact of various AOPs in leachate treatment.
Methods: This systematic review was conducted, encompassing commonly used AOPs such as ozone,
peroxone, O3/catalyst, Fenton, photo-Fenton, UV/TiO2, photolytic persulfate, O3/UV, and O3/H2O2/
UV. Extensive searches were performed using reputable databases, including EBSCO, PubMed, Web
of Science, and Google Scholar. Specific keywords and inclusion/exclusion criteria were applied. Data
regarding leachate treatment parameters were meticulously summarized and analyzed using descriptive
statistical methods.
Results: The efficiency of AOPs in removing leachate organic matter varied, with chemical oxygen
demand (COD) removal ranging from 41% to 83% in treatment systems. The order of effectiveness was
found to be: O3/UV/H2O2 > photo-Fenton > UV/TiO2 > Fenton > persulfate (PS) > O3/UV > O3/H2O2 > O3/
catalyst > ozonation (O3). The highest COD removal efficiency of 83.75% was achieved using the O3/UV/
H2O2 AOP approach. The removal efficiency of color also varied, ranging from 32% to 100%, depending
on the leachate’s characteristics, concentration, and specific treatment process utilized.
Conclusion: AOPs, particularly the hybrid approach using O3/UV/H2O2, significantly enhance waste
leachate treatment by effectively degrading persistent organic compounds through the generation of
hydroxyl radicals. Further research is required to optimize AOPs and improve their efficiency in waste
leachate treatment.