Evaluation of microalgal potential for biosorption of synthetic dyes

Abstract

Water pollution is one of the leading causes of death and disease worldwide. Different types of industries, including textile, use synthetic dyes for colouring process and produce a huge volume of coloured waste water. Release of such effluent without treatment in water bodies becomes a major threat for the ecological balance of water bodies. Various physico-chemical methods like coagulation, flocculation, ion exchange, membrane separation, oxidation, etc are available for the treatment of the dyes. Major drawbacks of these methods include high sludge production, disposal and handling, high cost and technical aspects, etc. Algal biomass has been found to be a potential and suitable biosorbent because of their fast growth and wide availability. We isolated algal strains from dye polluted and fresh water habitats. Adsorptional studies reveals that algal strains from both the habitats show variable decolorization performance for azo dyes i.e methyl orange and orange-g. The selected algal species (Chlorella vulgaris and Scenedesmus abundans) are from fresh water habitat. Different environmental parameters (pH, temperature, reaction time, dye concentration, biomass dosage etc) have been optimized, in order to get maximal colour removal. Both the test algae show different level of dye adsorption capacity and maximum up to 78 % decolourization of coloured water. FTIR analysis reveals the different functional groups responsible for colour removal under optimized conditions. SEM micrographs shows the morphological changes during the adsorptional studies. newline newline