Decolourisation of Textile Wastewater by Dye Degrading Microorganisms Isolated from Textile Effluent

摘要

Dyes mostly used in the textile industry end up in their wastewater. The treatment of textile effluent has become necessary because of its associated environmental and health problems. In this study, five bacterial isolates were obtained from textile effluent. The isolated bacteria were used to decolourise effluent samples in a time-dependent manner and the change in colour was observed using an Ultraviolet-visible spectrophotometer. After 24 hours, decolourisation efficiencies of the five isolates were calculated and the highest decolourisation efficiency (78.5%) was observed with one of the isolates (E12). Isolate E23 recorded 64.7% followed by isolate E9 (62.0%) and E21 (53.7%). Isolate E19 had the lowest decolourisation efficiency (2.6%). The isolated bacteria were identified with E9 as Aeromonas hydrophilia , E12 as Aeromonas hydrophilia , E19 as Pseudomonas aeruginosa , E21 as Aeromonas hydrophilia and E23 as Pseudomonas fluorescens . To achieve a decolourisation efficiency of 78.5%, 25 ml of textile wastewater should be inoculated with 1 ml of the isolate (E12) culture. Thus, Isolate E12 (Aeromonas hydrophilia ) is considered a promising candidate for biological textile wastewater treatment followed by isolate E23 (Pseudomonas fluorescens ).