Biosorbability of Coconut Husk Char in Polyatomic Ions Sequestration from Contaminated Surface Water

Agricultural waste has increased colossally with development in agricultural production causing environmental nuisance and degradation. Utilization of coconut husks, one of such type of waste, as a biosorbent for polluted surface water treatment, was considered in this study. Polluted surface water was gently passed through two similar columns loaded with 100 and 200 g of coconut husk char respectively. The treated water samples collected after 30, 60, 90, 120 and 150 mins were examined for SO₄^2-, NO₃^- and PO₄^3- ions concentration. Removal efficiency for SO₄^2-, NO₃^- and PO₄^3- ions on 100 g coconut husk char after 150 mins detention time were 70, 78 and 91% respectively. Freundlich isotherm model gave a better description of the data (R² > 0.96). Sorption data was well described by second order pseudo kinetics (R² > 0.85).  An amount of 100 g of the biosorbent has a strong affinity for these types of ion removal in contaminated water. Coconut husk char as a biosorbent is a panacea to significant concentrations of polyatomic ions in polluted surface water.

Agricultural waste; Coconut husk char; Isotherm model; Polyatomic ions; Pseudo kinetic model