Reduced Graphene Oxide Filtration Membranes for Dye Removal—Production and Characterization

Abstract

Dye removal from manufacturing and textile industry wastewater is one of the biggest challenges in plants. The improper disposal of water with residual dyes can contaminate effluents and fresh water sources. In this work, filtration membranes based on reduced graphene oxide (rGO) were fabricated by the spray coating method, and its capability to remove dyes from water was evaluated. Graphene oxide was prepared by a modified Hummers method and posteriorly reduced with ascorbic acid; a simple and fast spray coating fabrication method was employed to produce stable membranes, which were analyzed in a home-made permeation cell. Raman spectroscopy and scanning electron microscopy (SEM) were able to prove that rGO dispersion was formed by graphene flakes with about 45.9 μm of lateral dimension; X-ray diffraction, SEM and Raman analyses indicate that the spray method was efficient in producing stable and uniform filtration membranes; and UV-vis absorption spectra of feed and permeation solution indicate that rGO membranes were capable in removing dye from water. By the main results, it is possible to affirm that rGO filtration membranes are an efficient, low-cost, scalable and fast way to remove dyes from wastewater.

Removal of Azo Dyes from Aqueous Effluent Using Bio-Based Activated Carbons: Toxicity Aspects and Environmental Impact

“…Generally, biodegradation for dye remediation can be carried out using fungi, bacteria, algae and plants, and yeasts. The efficiency of the microorganism is determined by its natural activity and availability [62]. The biodegradation of the azo dyes is mainly influenced by the used cell or enzymes.…”

“…The biodegradation of the azo dyes is mainly influenced by the used cell or enzymes. However, the degradation process can also involve the use of microbial biomass, which is more efficient in eliminating the toxic dyes [62]. The biodegradation process decomposes the dye particles completely.…”