Simple assembly of graphene oxide functionalized with tannic acid on membranes to enhance dye removal

Abstract

Dyes disposal in water has become a global concern due to its toxicity to humans and the aquatic ecosystem. Membrane separation processes can be an option to deal with this environmental issue. In this study, graphene oxide was functionalized with tannic acid (TA-GO) to coat the surface of a microfiltration membrane (MF_TA-GO). The ATR-FTIR, SEM, and WCA techniques confirmed that the membrane surface was successfully modified. MF_TA-GO obtained excellent removal rates for the twilight yellow and safranine orange dyes, maintaining the water flux recovery at high levels (> 66%). These results were superior to those obtained by the pure membrane and the membrane modified solely with GO. They can be attributed to the higher compatibility of TA-GO with the membrane surface. In addition, MF_TA-GO may be reused in consecutive cycles, demonstrating an operational advantage. The proposed process can be an alternative to improve the characteristics of microfiltration membranes used for dye removal from contaminated water.

Keywords:

• Discoloration
• low fouling
• membrane modification
• microfiltration
• versatility
• wastewater treatment

Competing interests

The authors declare that they have no competing interests.

Consent for publication

The authors firmly state that they have substantively participated in this study and are prepared to take public responsibility for this purpose.

Availability of data and materials

The data supporting the findings of this study are available from the corresponding author, Angélica Marquetotti Salcedo Vieira, upon reasonable request.

Additional information

Funding

This study was supported by the National Council for Scientific and Technological Development (CNPq) and Higher Education Personnel Improvement Coordination (CAPES) Financing Code 001. The authors also thank the Complex of Research Support Center (COMCAP) of the State University of Maringá (UEM) for the characterization analysis.