Synergistic effect of ozonation and filtration with graphene-based membranes in the removal of flame retardants in multi-compound systems: Experimental and DFT study

Author(s)

Neves, Tauany de Figueiredo ; Cristale, Joyce ; Camparotto, Natalia Gabriele ; Mastelaro, Valmor Roberto ; Dantas, Renato Falcao ; Prediger, Patricia

• Document type: Journal article
• Source: JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING; v. 13, n. 1, p. 16-pg., 2024-12-07.

Abstract

Ozonation, although widely applied to treat water and effluents contaminated by organophosphate flame retardants (OPFRs), it can result in the generation of by-products that may be more toxic than the starting molecules. An alternative method for surmounting this challenge is the coupling of ozonation with filtration membranes. In this study, new polyacrylonitrile (PAN) membranes modified with graphene oxide (GO) functionalized with Safranin dye (SF) were synthesized, characterized and applied to remove organophosphate flame retardants (OPFRs) in multi-compound systems remaining after ozonation treatment. The PAN@fGO membrane, endowed with phenyl groups, phenazinium cations, electron-rich organic functions, with a rougher morphological profile and lower hydrophilicity, outperformed the PAN membrane in removing OPFRs. With a removal potential of 31.2, 42.7, 50.8, 59.5 and 62.6 % for tris(2-chloroisopropyl) phosphate (TCIPP), tris(2-chloroethyl) phosphate (TCEP), tri-n-butyl phosphate (TNBP), tris(2-butoxyethyl) phosphate (TBOEP), and triphenyl phosphate (TPHP), respectively. A synergistic effect was observed when the modified membrane was coupling with ozonation in multi-compound systems, reaching removal efficiencies of 43.7, 54.9, 59.6, 65.8 and 97.95 % for TCIPP, TCEP, TNBP, TBOEP and TPHP, respectively. Moreover, the combination of ozonation followed by PAN@fGO membrane filtration demonstrated efficacy in reducing the toxicity of the treated effluent to the vegetable Eruca sativa. The results, corroborated by calculations of molecular chemical descriptors based on DFT and characterizations of the membrane after the removal process, that the reaction with O3 in multi-compound systems was more effective in molecules with higher reactivity and the PAN@fGO interacts with the contaminants through hydrophobic, H-bonding, and it-it interactions. (AU)

• FAPESP's process: 23/02041-8 - Preparation of MOF-based polymeric membranes containing niobium by rotary jet-spun and its application in the removal of contaminants in water
• Grantee: Natália Gabriele Camparotto
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 22/14834-0 - Synthesis of new nanoadsorbents, their characterizations and applications in pollutant adsorption in water
• Grantee: PATRICIA PREDIGER
• Support Opportunities: Regular Research Grants
• FAPESP's process: 19/25228-0 - Development of new membranes based on graphene oxide for the removal of contaminants in water
• Grantee: Tauany de Figueiredo Neves
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• 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: 13/07296-2 - CDMF - Center for the Development of Functional Materials
• Grantee: Elson Longo da Silva
• Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC