Ozonation combined to BAC filtration for secondary effluent treatment containing moderate concentration of heavy metals

Author(s)

Malvestiti, Jacqueline Aparecida ; Meira, Manoel Messias Coutinho ; Silva, Maina Ruth Conceicao ; de Sousa, Iure Bernardino ; Cavalcante, Rodrigo Pereira ; Tornisielo, Valdemar Luiz ; Dantas, Renato Falcao

• Document type: Journal article
• Source: CHEMICAL ENGINEERING JOURNAL; v. 500, p. 12-pg., 2024-11-02.

Abstract

The treatment of industrial and urban effluents is a recognized strategy for environmental preservation, which brings benefits not only to fauna and flora but also to human health. In this paper, the combination effect of ozonation (O-3) and biological activated carbon (BAC) filtration treatments on the inorganic contaminants removal, disinfection, and mitigation of toxicity in secondary effluent from wastewater treatment plants (WWTP) were evaluated. Disinfection efficiency was evaluated using total coliforms and Escherichia coli inactivation, and toxicity was investigated by Eruca sativa germination, Artemia salina larvae and Daphnia similis. The O-3-BAC system was efficient to remove metals, disinfect the samples and reduce toxicity. The combined treatment reduced 99.9 % of the assessed metal concentration and >= 96 % on samples enriched with 2x the concentration allowed by Brazilian legislation. O-3-BAC also demonstrated superior bactericidal performance compared to BAC and O-3 alone, exhibiting a 5-log reduction within 24 h against total coliforms and 4-log reduction in E. coli, whereas BAC and O3 achieved <= 3-log inactivation. Regarding toxicity, the bioassays demonstrated that the combined treatment effect improved the relative germination of E. sativa (similar to 97 %), and the relative root elongation showed no differences compared to the control group (similar to 100 %). Similar behavior was also observed in the analysis with wheat and radish seeds, with no differences noted between the treated samples and the positive control. In relation to A. salina, no toxic results were observed even at high metals concentration. Additionally, BAC treatment reduced D. similis immobilization from 97 +/- 6 % to a level with no observed effect. The observed synergy suggests that the O-3-BAC combination may address a variety of pollutants and improve treatment efficacy. (AU)

• FAPESP's process: 22/04015-1 - Effects of oxidative treatments on microplastic pollution and its associated chemical and biological risks
• Grantee: Jacqueline Aparecida Malvestiti
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 22/16554-4 - Application of radiometric techniques to characterize the retention, mobility, toxicity, and degradation of herbicide nanocarrier systems in the environment
• Grantee: Valdemar Luiz Tornisielo
• Support Opportunities: Regular Research Grants
• FAPESP's process: 22/00454-0 - Assessment of a multibarrier tertiary treatment for micropollutants removal from WWTP of São Paulo
• Grantee: Renato Falcão Dantas
• Support Opportunities: Regular Research Grants
• FAPESP's process: 19/26210-8 - Investigation of the contribution of advanced oxidation processes in the multi-barrier treatment of biotreated effluents
• Grantee: Rodrigo Pereira Cavalcante
• Support Opportunities: Scholarships in Brazil - Post-Doctoral