Potential use of alkaline treated algae waste biomass as sustainable biosorbent for clean recovery of cadmium(II) from aqueous media: batch and column studies

Abstract

In order to make it more suitable for biosorption process, algae waste obtained after oil extraction, have been activated by alkaline treatment and used for cadmium(II) removal in batch and column systems. For batch systems, the effect of initial cadmium(II) concentration and contact time was studied in optimal experimental conditions (pH of 5.0, 8 g biomass·L−1). Langmuir isotherm model and pseudo-second order kinetics model describe the experimental data well. For column studies, the alkaline treated algae waste biomass was mixed with an industrial ion exchanger resin (Purolite A-100) in order to prevent the clogging of column. Bohart-Adams, Thomas and Yoon-Nelson models were used to fit breakthrough curves obtained under varying conditions. Five biosorption/desorption cycles have yielded between 98.83 and 92.39% biosorbent regeneration. The biosorbent could efficient remove cadmium(II) from industrial wastewater, and obtained effluent has better quality characteristics. The results presented in this study indicate that the alkaline treated algae waste biomass can be successfully used for large scale treatment of wastewater.