An ecofriendly approach for bioremediation of contaminated water environment: Potential contribution of a coastal seaweed community to environmental improvement

摘要

High levels of heavy metals like copper ions in many industrial based effluents lead to serious environmental and health problems. Biosorption is a potential environmental biotechnology approach for biotreatment of aquatic sites polluted with heavy metal ions. Seaweeds have received great attention for their high bioremediation potential in recent years. However, the co-application of marine macroalgae for removal of heavy metals from wastewater is very limited. Thus, for the first time in literature, a coastal seaweed community composed of Chaetomorpha sp., Polysiphonia sp., Ulva sp. and Cystoseira sp. species was applied to remove copper ions from synthetic aqueous medium in this study. The biosorption experiments in batch mode were conducted to examine the effects of operating variables including pH, biosorbent amount, metal ion concentration and contact time on the biosorption process. The biosorption behavior of biosorbent was described by various equilibrium, kinetic and thermodynamic models. The biosorption of copper ions was strongly influenced by the operating parameters. The results indicated that the equilibrium data of biosorption were best modeled by Sips isotherm model. The values of mean free energy of biosorption computed from Dubinin-Radushkevich isotherm model and the standard Gibbs free energy change indicated a feasible, spontaneous and physical biotreatment system. The pseudo-second-order rate equation successfully defined the kinetic behavior of copper biosorption. The pore diffusion also played role in the control of biosorption process. The maximum copper uptake capacity of biosorbent was found to be greater than those of many other biosorbents. The obtained results revealed that this novel biosorbent could be a promising material for copper ion bioremediation implementations.