Bioremediation and Biomass Production with the Green Microalga Chlorococcum humicola and Textile Mill Effluent (TE)

The study aimed at possible bioremediation of textile mill effluent (TE) and simultaneous production of useful biomass. The green, unicellular microalga, Chlorococcum humicola was grown in TE. Even in undiluted effluent, this alga reduced several important effluent parameters from 9 to 94% in 6 days and produced increased biomass with improved cell contents as compared to control. Strikingly, NO 3 and NO 2 –nitrogen went below detectable limits within 3 days. In a comparative growth experiment, the growth rate of the alga was maximum in 10% dilution of effluent with supplementation of 0.15% NaNO 3 . This alga produced extracellular H 2 O 2 , even in dark which was limited by nitrogen. TE-grown cells accumulated 32% more lipids and 25% more starch as compared to control. Further, two allelopathic extracellular free fatty acids, namely palmitic and linoleic acids, were detected.