Decolourization of Textile Dye Effluent by Resident Bacterial Species

Textile dye effluents are released into the environment without any pretreatment and pollute water, to prevent contamination of our valuable resources; removal of these pollutants is of great vitality. For this purpose, waste water samples were collected from dye contaminated sites of Kofar Mata dye pits based in Kano State. Certain parameters which include temperature and pH were determined in the Laboratory. The residual bacterial load was found to be in the range of 1.4 x106 - 4.0x106 cfu.ml-1. The frequency of occurrence ranged from 5 – 32 and the percentage frequency ranged from 4% - 25%. Eight bacterial isolates were identified which include two species of both Streptococcus sp (10.5%) and Enterococcus sp (14%), and one species of Bacillus sp (25%), Pseudomonas sp (16%), Staphylococcus sp (4%) and Escherichia sp (6%). Decolourization activity was tested for the removal of reactive black dye in liquid medium. The bacterium Bacillus thuringiensis showed the highest decolourization activity of 75% and Streptococcus schleiferi had the lowest decolourization of 32%. This study reveals that some bacteria inhibit in textile effluent, thereby utilizing the dyes as their sources of energy and nutrient, and imply their importance in treatment of industrial effluents.