Desorption of Cu2+ from a biosorbent derived from the marine alga Durvillaea potatorum

The desorption and recovery of Cu2+ from a biosorbent material derived from marine alga Durvillaea potatorum were studied. The biosorbent was a pretreated biomass of Durvillaea potatorum with calcium chloride solution and thermal treatment. The Cu2+ was adsorbed onto the biosorbent and then desorbed by various elution solutions. Batch desorption tests established a solution of 0.35 M hydrochloric acid as the most appropriate eluting agent. Fixed-bed desorption recovery curves for Cu2+ were also obtained. In addition, batch desorption recovery curves for Cu2+ were obtained for multiple consecutive adsorption-desorption cycles and the biosorption properties of the biomass for Cu2+ were compared after the fifth cycle to evaluate the stability of the biomass. The use of a mixture of 0.35 M hydrochloric acid and 0.5 M calcium chloride as the eluting agent improved the stability of the biosorbent in the multiple adsorption-desorption cycles. The desorption kinetics were similar to those observed in the adsorption process. The desorption process was not significantly affected by temperature.