Thermodynamic and Kinetic Investigations for Biosorption of Chromium(VI) With Green Algae (Pithophora oedogonia)

Abstract

Heavy metals are the conservative pollutants which cannot be degraded by bacterial attack and are permanent addition to marine environment. Their conservation usually exceeds the allowable levels usually found in water ways and soil. They locate their way up the food chain and due to their accumulation, can disrupt biological process. Recently, biosorption has come up as effective tool in which biomass of various organisms have been tested. In the present study, the biosorptive potential of algae biomass of green algae (Pithophora oedogonia) has been investigated for removal of toxic heavy metal, such as chromium (VI) ions. Various physico-chemical factors have been optimized for biosorptive capacities of sorbates by sorbents. Optimum pH was found to be 4 and optimum temperature was 30°C for Cr (VI). Various adsorption models were elucidated to data, such as Langmuir, Freundlich and Temkin isotherms whereas Freundlich model was found to be fittest showing multilayer sorption. Pseudo-second order kinetic model was also found to fit for this study with regression coefficient value of 0.97. Additionally, Fourier Transform Infra-red Spectroscopic studies (FTIR) indicated various electronegative functional groups on the surface of green algae (Pithophora oedogonia) which could possibly offer the binding sites for cations under investigation.