Decolorisation of textile wastewater using biosynthesised iron oxide nanomaterials and Optimisation by Response Surface Methodology

Abstract

In this study, the bacteria (Pseudomonas sp.) was isolated and cultured for biogenic fabrication of Fe3O4 (synthesised using bacterial cell mass) and Fe3O4@ME (synthesised using bacterial extracts) nanoparticles. The biomolecules of the bacterial extract function as a reducing and capping agent, giving the nanoparticle surface negative charges, according to the FTIR and Z potential analysis. The parameters were optimised and screened for indigo blue (IB) dye adsorption onto Fe3O4 and Fe3O4@ME nanoparticles. This work used the Design of the Experimental (DoE) method rather than the conventional one‐variable‐at‐a‐time method. The central composite design (CCD) experiment consisted of 13 experimental runs, and an analysis of variance (ANOVA) was performed to analyse the results. The models for IB dye removal using Fe3O4 and Fe3O4@ME nanomaterials showed adjusted R2 values of 0.99 and 0.99 and predicted R2 values of 0.97 and 0.99, respectively, indicating good model fit. The optimum conditions required for 70 and 64 % colour removal for Fe3O4 and Fe3O4@ME nanomaterials, respectively, are observed at 0.050 gm sorbent doses at the constant room temperature and contact time of 100 min.