Removal of heavy metal (Cu2+) by immobilized microalgae biosorbent with effect of temperature and contact time

Abstract

The purpose of this research was to removed heavy metal of Copper (Cu2+) with biotechnology using mixed-microalgae of Chlorella sorokiniana, Monoraphidium sp. and Scenedesmus obliquus bound in Na-Alginate. The effect of contact time and temperature on biosorption rate to achieve the highest efficiency were studied. Mixed-microalgae were dried in the oven, hulled, and trapping onto alginate polymer to forming an immobilized biosorbent or beads. The decrease of Cu2+ concentration was analyzed using Atomic Absorption Spectroscopy (AAS). Optimization of parameters was conducted by photobioreactor in batch system using concentrations of 20 mg/L Cu which were containing wastewater, biosorbent concentration of 0.5 g/g, pH 4 with setting of contact time (60, 120, 180) minutes and temperature (25, 35.45) oC. The results show that the maximum biosorption occurred at pH 4, temperature 35oC, contact time 180 minutes and removal efficiency of 96.4% was achieved. The research proved that immobilized biosorbent was very effective in reducing Cu2+ in wastewater and able to be used as a competitive and environment-friendly alternative method to control heavy metal pollution in water.