An optimization model for removal of zinc from industrial wastewater

Industrial wastewater is one of the crucial environmental concerns. Biosorption is an effective method used to remove toxic heavy metals from wastewater. Biosorption utilizes the capability of biomass to remove metal ions from wastewater. The determination of operating conditions, namely, the type and the amount of biomass to be used in the process as well as the processing time, are the key issues in the process. This paper proposes an optimization model for removal of zinc from wastewater. A biomass marine alga, Gracilaria Corticata (GC), is used as biosorbent. Derivation of zinc absorption kinetics model is first provided. A non-linear optimization model is then developed to determine the optimal operating conditions subject to satisfying a desired removal percentage while minimizing the total cost. The experimental results show that GC can be used well for zinc removal and the proposed optimization model can effectively reduce the process cost. The proposed approach is illustrated through a simplified numerical example.