Adsorption of Ni2+ from aqueous solutions by pretreated biomass of marine macroalga Durvillaea potatorum

Biosorption of heavy metals can be an effective process for the removal and recovery of heavy metal ions from aqueous solutions. The biomass of marine macroalgae has been reported to have high uptake capacities for a number o f heavy metal ions. In this paper the adsorption properties of a pretreated biomass of macroalga Durvillaea potatorum for Ni2+ were investigated. Adso rption isotherms and kinetics were obtained from batch adsorption experimen ts. The adsorption capacities were pH dependent and a maximum adsorption ca pacity was obtained to be 1.13 mmol/g at a pH of about 6. A modified Langmu ir model was proposed for the correlation of pH-dependent isotherms. The ad sorption process was fast; 90% of adsorption occurred within 25 minutes and equilibrium was reached at around 1 hour. Light metal ions at a concentrat ion of 10 mM did not affect Ni2+ adsorption significantly. Fixed-bed breakt hrough curves for Ni2+ removal were also obtained. This study demonstrated that the pretreated biomass of D. potatorum can be used as an effective bio sorbent for the treatment of Ni2+-containing wastewater streams.