Ceramic-supported graphene oxide membrane bioreactor for the anaerobic decolorization of azo dyes. (February 2022)

• Record Type: Journal Article
• Authors: Amin, Mohammad Shaiful Alam; Stüber, Frank; Giralt, Jaume; Fortuny, Agustí; Fabregat, Azael; Font, Josep
• Is Part Of: Journal of water process engineering. Volume 45(2022)
• Publication Date: 2022-02
• Subjects: Graphene oxide -- Membrane -- Azo dye -- Anaerobic decolorization; Water-supply engineering -- Periodicals; Saline water conversion -- Periodicals; Seawater -- Distillation -- Periodicals; Sanitary engineering -- Periodicals; Sewage -- Purification -- Periodicals; 627
• DOI: 10.1016/j.jwpe.2021.102499
• Languages: English
• ISSNs: 2214-7144

Abstract

Abstract: A continuous compact membrane bioreactor consisted of ceramic-supported graphene oxide membrane (CSGoM) was implemented for the first time for anaerobic biodecolorization of monoazo Acid Orange 7 (AO7), diazo Reactive Black 5 (RB5), and triazo Direct Blue 71 (DB71) solutions, showing excellent decolorization potential. The membrane was prepared by vacuum filtration of various graphene oxide solutions using a UF ceramic flat element. The decolorization efficiency of the CSGoM bioreactor, made from 1 mg·mL −1 of GO solution (B-CSGoM-1), was investigated for several structurally distinct azo dyes, initial feed concentrations, and permeate fluxes. Maximum color removal was achieved under low feed concentration (50 mg·L −1 ) and permeate flux (0.05 L·m −2 ·h −1 ), reaching 99% for AO7, 96% RB5, and 92% for DB71. At this low permeate flux, the biodecolorization was stable for all azo dye solutions irrespective of the feed concentration. In a subsequent experiment under higher feed concentration and permeate flux (100 mg·L −1 and 0.10 L·m −2 ·h −1 ), the decolorization slightly fell to 93%, 85%, and 81% for monoazo, diazo, and triazo solutions, respectively. The existence of anaerobic bacteria ( Geobacter and Pseudomonas guangdongensis ) in the B-CSGoM-1 biofilm confirms that they could perform efficient biodegradation of azo dye molecules in association with the graphene oxide membrane. Graphical abstract: Unlabelled Image Highlights: A compact Ceramic-Supported Graphene Oxide Membrane Bioreactor was made to remove dyes by anaerobic biodegradation. Enhanced dye decolorization performance gives high quality treated water without further additional treatment. Nanoporous CSGoM acts as biofilm support, rapid electron transporter, and pollutant immobilizer. Geobacter and Pseudomonas Guangdongensis are the dominant bacteria for dye decolorization.