Biosorption of pollutants from chemically derived wastewater using Microcoleus sp.

Abstract Microcoleus sp. is a versatile microorganism widely available in the environment and easily culturable. Hence, there is a progressing demand for wastewater treatment using this novel biosorption medium. The design of such a treatment method may be defined as an optimisation problem of algal dose and hydraulic retention time for attaining an adequate removal efficiency of heavy metals (Cr6+, Ni2+, and Zn2+) and nutrients (PO43- and NO3-). Batch experiments on synthetic wastewater were conducted for algal doses varying from 0.5 to 25 g/L and hydraulic retention times from 1 to 7 days. Significant removal efficiencies of greater than 90% were observed for the heavy metals, 75% of PO43- removal, and no removal of NO3- was found under continuous daylight. The single-factor ANOVA test confirms the statistical significance of the varying parameters on the pollutant removal efficiency. Langmuir and Freundlich's adsorption isotherms indicate satisfactory adsorption of the contaminants about the separation factor and the adsorption intensity constant. The R2 > 0.67 and RMSE < 0.21 suggest a good fit of the modelled data. Following this, the study suggests that the use of Microcoleus sp. is a prospective bioremediation technique for industrial and municipal wastewater.