An Eco-friendly and Economical Approach for Removal of Remazol Blue, Malachite Green and Rhodamine B Dyes from Wastewater using Bio-char Derived from Chlorella Vulgaris Biomass

Background:: Rapid urbanization and industrialization has led to depletion of water resource and generation of enormous amount of wastewater. One among them is textile industry which discharge huge amount of dye wastewater into aquatic environment. Methods:: This study deals with adsorption of Remazol blue, Malachite green and Rhodamine B dyes into bio-char derived from Chlorella vulgaris biomass cultivated from municipal wastewater. Column studies were performed to depict the industrial usage of bio-char for treatment of large quantity of wastewater. Effect of temperature, time, pH, dye concentration and adsorbent dosage on dye removal was studied in batch process. Results:: The best batch adsorption conditions are temperature (25⁰C), time (60min), pH (7), dye concentration (100ppm) and adsorbent dosage (1g) with ± 5% for all three dyes. Dye removal percentage of bio-char increased with increased in adsorbent dosage to 94.5%, 88.2% and 90.1% for Remazol blue, Malachite green and Rhodamine B dyes at 1g/L adsorbent dosage. Freundlich isotherm exhibited correlation coefficient (R2) values of 0.99, 0.98 and 0.99 for Remazol blue, Malachite green and Rhodamine B dyes respectively. Kinetic studies revealed that all three dyes followed pseudo first order model. Increase in column bed height resulted in increased dye removal percentage since increase in bed height resulted in increase in bio-char quantity with more number of surface area. Conclusion:: From the study, it can be concluded that Bio-char was the economical and eco-friendly alternative adsorbent for wastewater treatment process. Bio-char reusability study revealed that it could be used for 3-4 consecutive cycles.