Cost-effective in-situ remediation technologies for complete mineralization of dyes contaminated soils

Dyes & dyes intermediates are one of the important and critically polluted industrial sectors, generating a large environmental liability. Therefore characterization of microbial community structure and diversity of contaminated soils helps to optimize the bioremediation strategies and performance. This study investigated the roles of environmental variables and contamination levels in shaping microbial community structure at an abandoned aged. In total, 20 bacterial and 4 fungal phyla were identified across soils with different physiochemical properties and concentration of the contaminants. Taxonomic analysis revealed the Proteobacteria, Firmicutes, Ascomycota and Basidiomycota represented the lineages and accounted for 49.5%-51.2%, 5.1%-15.3%, 2.5%-3.8% and 1.6%-2.1% of the total population, respectively. Microbial community (site 1) achieved decolorization rate of 972 ± 1.21 mg dyes kgsoil^-1d^-1 after 15d and 692 ± 1.4 mg kg-soil^-1d^-1 COD removal rate after 30 day of the experiment. Microbial community mineralized intermediates, 4-amino benzenesulfonate, 6-amino naphthalene sulfonate and benzene/naphthalene sulfonate in TCA cycle and stimulate the growth of selected soil bacteria, primary nutrient as well as plant growth of contaminated soil.