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Matured compost, derived from a mechanical and biological treatment (MBT) plant, was used as a precursor to produce catalysts through hydrothermal and thermal carbonization, HC and PC, respectively. HC and PC displayed suitable properties to act as catalysts in the catalytic wet peroxide oxidation (CWPO) treatment of the highly polluted leachate waters generated in the same MBT plant (TOC0 = 27 g L-1; COD0 = 60 g L-1; BOD5,0 = 23 g L-1). The influence of catalyst loading and pH were studied, considering multiple additions of H2O2. The best experimental conditions found were T = 80º C, pH0 = 3.0, 7.2 g L-1 of HC catalyst, 85.7 g L-1 of H2O2, added in five batches in one-hour intervals between each addition. Under these experimental conditions, removals of 43%, 52%, 93%, 82%, 35%, 95% and 93% for the COD, TOC, BOD5, aromaticity, chlorides, turbidity and color number (CN) were, respectively, observed. Ion exchange resins and coagulation–flocculation were studied as pretreatment options to reduce the complexity of the leachate waters and enhance the CWPO results. Both strategies resulted in higher mineralization and enhanced the consumption efficiency of H2O2 (H2O2 ). The sequential treatment using coagulation–flocculation and CWPO with PC catalyst showed the best results, achieving abatement of 94%, 70%, 98%, 93%, 31%, 96% and 95% for COD, TOC, BOD5, aromaticity, chlorides, turbidity and CN, respectively. This work was financially supported by project “VALORCOMP-Valorización de compost y otros desechos procedentes de la fracción orgánica de los residuos municipales”, with reference 0119_VALORCOMP_2_P, through FEDER under Program INTERREG; Base Funding- UIDB/50020/2020 of the Associate Laboratory LSRE-LCM-funded by national funds through FCT/MCTES (PIDDAC); CIMO (UIDB/00690/2020) through FEDER under Program PT2020 and national funding by FCT, Foundation for Science and Technology and European Social Fund, FSE, through the individual research grant SFRH/BD/143224/2019 of Fernanda Fontana Roman. info:eu-repo/semantics/publishedVersion |
