Intercationic effect on biosorbent efficacy

The efficacy of the biosorbent coconut hust (Cocos nucifera) was tested for the removal of lead, copper, zinc, and nickel metal ions using batch experiments in multimetal solution system under controlled experimental conditions. It is found that metal sorption increases when the equilibrium metal concentration rises. At highest experimental solution concentration (150mg/L), the removal of metal ions was 92.52% for lead, 79.55% for copper, 63.23% for zinc, and 68.10% for nickel, while at lowest experimental solution concentration (25mg/L), the removal of metal ions was 94.80% for lead, 86.81% for copper, 84.63% for zinc, and 82.36% for nickel. Biosorption equilibrium isotherms were plotted for metal uptake capacity (q) against residual metal concentrations (C-f) in solution. The q vs. C-f sorption isotherm relationship was mathematically expressed by Langmuir and Freundlich models. The values of separation factor were between zero and one indicating favorable sorption for four tested metals on the biosorbent. The surface coverage values were approaching unity with increasing solution concentration, indicating effectiveness of the biosorbent.