Biosorption of Cu from ferruginous wastewater by algal biomass

Abstract

The biosorbent prepared from Sargassum algal biomass binds approximately 2.3 meq/g of metal cations from water by ion exchange. The values of ion exchange equilibrium constants showed that the affinities of metals towards the biosorbent decrease in the following order Cu>Ca>Fe. A flow-through sorption column was used to continuously and selectively remove Cu 2+ from the feed containing Cu and Fe ions. A chromatographic effect in the column performance caused by different sorption affinities of the metal ions studied was successfully predicted by the equilibrium column model. The biosorbent saturated with Cu was regenerated with 0.1 M HCl. When Fe(III) was present in the mixed feed solution as suspended solids (SS) the column removed Cu 2+ by biosorption and Fe(III) solids by in-depth filtration while producing effluent free of heavy metals from the feed containing 25 mg/l of Cu 2+ and Fe(III) as SS in the concentration range of 15–40 mg/l. Effective copper removal/recovery from ferruginous wastewater using Sargassum biosorbent was demonstrated.