Intensification of supercritical water oxidation (ScWO) by ion exchange with zeolite for the reuse of landfill leachates.

Autor: Scandelai APJ; Department of Chemical Engineering, State University of Maringá, 5790 Colombo Avenue, Jd. University, 87020900 Maringá, Parana, Brazil. Electronic address: paulascandelai@hotmail.com., Zotesso JP; Department of Chemical Engineering, State University of Maringá, 5790 Colombo Avenue, Jd. University, 87020900 Maringá, Parana, Brazil., Vicentini JCM; Department of Chemical Engineering, State University of Maringá, 5790 Colombo Avenue, Jd. University, 87020900 Maringá, Parana, Brazil., Cardozo Filho L; Department of Chemical Engineering, State University of Maringá, 5790 Colombo Avenue, Jd. University, 87020900 Maringá, Parana, Brazil., Tavares CRG; Department of Chemical Engineering, State University of Maringá, 5790 Colombo Avenue, Jd. University, 87020900 Maringá, Parana, Brazil.
Jazyk: angličtina
Zdroj: The Science of the total environment [Sci Total Environ] 2021 Nov 10; Vol. 794, pp. 148584. Date of Electronic Publication: 2021 Jun 26.
DOI: 10.1016/j.scitotenv.2021.148584
Abstrakt: The disposal of solid residues in sanitary landfills results in the formation of a complex, variable, and recalcitrant wastewater, known as leachates. Supercritical water oxidation (ScWO) can be applied to treat leachates although most studies are based on removing the most relevant contaminants, such as organic matter and ammonia. Therefore, comprehensive analysis of this process is essential for large-scale applications. In this study, we investigated a system composed of ScWO and ion exchange using zeolite (ScWO/zeolite) for the reuse possibilities of treated leachates based on different regulations for municipal wastewater reuse. This system was applied to both raw leachate (RL) and leachate treated via conventional processes at the studied landfill (PL). The continuous ScWO reactor operated under a pressure of 23 MPa at 600 °C without the addition of oxidants. A commercial zeolite (clinoptilolite) in a fixed-bed glass column was used for ion exchange. The intensified system significantly improved the characteristics of RL by removing 89% of COD and 99% of NH 3 -N. Moreover, the contaminant concentrations of PL were within the limits for discharge and reuse, except arsenic and molybdenum contents. The unexpected high concentrations of arsenic in RL and PL necessitated the requirement of further investigation of the complex and toxic characteristics of leachates. Nevertheless, the intensified process was conducted without the addition of oxidants or auxiliary substances and resulted in a less expensive and more environmentally -friendly process that can be applied for the treatment of leachates with similar characteristics.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2021 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
Externí odkaz: