Performance evaluation of novel Mica@reduced graphene oxide fixed rotating disk reactor in treatment of anaerobically reduced textile dyeing wastewater containing aromatic amines

BACKGROUND Anaerobically reduced textile dyeing wastewater containing aromatic amines can cause serious environmental problems as a consequence of their toxicity. RESULTS The performance of a novel design, laboratory-scale mica@reduced graphene oxide (rGO) reactor fixed on three rotating disks was evaluated for the removal of anaerobically reduced textile dyeing wastewater containing aromatic amines. Fourier-transform infrared and UV-visible spectroscopy analyses of wastewater after anaerobic treatment revealed that it contained high aromatic compound concentrations. Scanning electron microscope images confirmed that the rGO nanosheets were deposited on the mica surface by the spin-coating method aromatic amines adsorbent. The effects of wastewater initial chemical oxygen demand (COD) concentration (100, 500 and 1500 mg L-1), pH (5, 7 and 9) and processing temperature (293, 303 and 313 K) on the aromatic compounds and COD removal using the designed reactor were investigated. The results indicated that aromatic molecule adsorption occurred faster with higher wastewater COD concentration. Also, increase in pH improved the mica@rGO adsorption. Likewise, the increase in temperature caused swelling in the stacked graphene layers, resulting in new surfaces for adsorption, leading to an increase in reactor efficiency. The experimental results indicated that the adsorption process fitted well with the Langmuir isotherm model and pseudo-second-order reaction kinetics. The thermodynamic study revealed that the adsorption was spontaneous. CONCLUSION The improvement in the removal of aromatic molecules by Mica@rGO indicates that the novel designed reactor has a great potential for the treatment of textile wastewater. (c) 2021 Society of Chemical Industry (SCI).