Abstract:
Purpose – The purpose of this paper is to investigate the efficacy of bacterial exopolysaccharides (Eps) in
reactive black 5 (RB5) textile dye wastewater bioremediation.
Design/methodology/approach – The Eps were produced by bacteria isolated from cotton gin
trash soils collected from different cotton-growing regions in Kenya for comparison purposes. A broth
medium reconstituted using molasses was assessed for its capacity to produce the Eps. RB5 textile dye
wastewater was optimized for dye removal under different temperatures, times and molasses
concentrations. Dye removal was studied by Lovibond-Day Light Comparator, UV–Vis
spectrophotometer and FTIR.
Findings – It was found that cotton gin trash soils contained Eps-producing bacteria. Three of the Eps
studied were found to have the capacity to remove at least 80% of the dye from the wastewater.
Research limitations/implications – This research did not assess the efficacy of the RB5 dye removal
from the wastewater by mixtures of the Eps.Practical implications – Bioremediation of textile dye wastewater with Eps produced by bacteria
cultured from cotton gin trash soil is significant because it will offer an effective and cleaner alternative to the
chemical coagulants.
Social implications – Alternative treatment of textile wastewater with the Eps would result in safer water
being released into the water bodies as opposed to the chemically treated wastewater that contains remnant
chemicals.
Originality/value – Research on the use of Eps produced by bacteria isolated from cotton gin trash soils
for removal of RB5 dye from textile wastewater has not been done before.
