The Effects of Temperature and pH On Decolourization of Dye Contaminated Soil by Pseudomonas aeruginosa DM1.

Abstract

This study investigated the effects of pH and temperature on the decolourization of textile effluent contaminated soilby Pseudomonas aeruginosa DM1. The physicochemical parameters of the textile effluents were temperature (33.5 oC), pH (6.10), Total Dissolved Solids (465.5 mg/L), Total Soluble Solids (310 mg/L), Dissolved Oxygen (0.162 mg/L), Biological Oxygen Demand (0.13 mg/L), Chemical Oxygen Demand (123.5 mg/L). The Pseudomonas aeruginosa DM1 was isolated from textile effluent contaminated soil samples in Challawa, Kano State, Nigeria. The 3 mL culture of the isolate was inoculated into medium comprising 2 g of yeast extract, 2 g of glucose, 2.8 g of lactose broth in 50 ml of different concentrations of the effluent (0%, 5%, 10%, 30%, 50%, 70%, 90% and 100 %) and incubated for 30 days at 37 oC. The effects of temperature (30 °C, 35 oC, 40 oC, 45 oC) and pH (4, 6, 8, and 10) on the decolourisation potential of the isolates were determined. The rate of biodecolourisation was determined using spectrophotometry at 600 nm. The optimum biodecolorization temperature was 35 oC (60.7%) after 30 days while the optimum pH was 6 with biodecolorization rate of 85.1%. The results obtained in this study revealed that 35 oC and pH 6 were optimum for decolourization by Pseudomonas aeruginosa DM1 of textile effluent contaminated soil.