Microbial hydrolysis of textile dyes.

Textile processing factories use dyes on the fabrics to achieve a number of objectives which includes; increasing product value, addition of colour and intricacy to textiles. Textile dyes are known to be toxic and some are carcinogenic. One of the challenges facing textile industries today is how to safely dispose of textile effluent dyes. The objective of this research was to hydrolyse textile dyes using microbes. Pseudomonas species namely: Pseudomonas putida, Pseudomonas fluorescens, and Pseudomonas sp. In a 1:1: ratio were used. The Pseudomonas species are unique in such that the can hydrolyse noxious chemicals, for example, phenols and its family. In this study the ability and rate of the selected Pseudomonas species to degrade the textile effluent was studied. The dye concentration/COD and/or photometric absorbency of the sample were observed as a means of monitoring the bio-reaction progress. Experiments were conducted at pH of 6.5 - 8 and temperature 30°C - 40°C which is optimum for these types of microbes. Result showed that the percentage COD (mg/1) removal after one day for the effluent water ranged from 38% to 70% (average 51 %). The percent decrease in colour for the wastewater on the second day ranged from 53% to 84% (average 72%). Results further showed that the percent dye removal was more than 97 percent in 8 days for pure dye and more than 73 percent in seven days for effluent water. It was concluded that the bio-reaction could be used to treat textile mill effluents with retention time of 2 to 3 days.