Removal Of Heavy Metal Ions By Electro Intensified Combined Bioadsorption And Mathematic Simulations

Electro biotechnology became one of emerging technology over the past two decades. With the combine of elect-biotechnology and adsorption, this study emphasized the theory and experiment for the removal of heavy metal ions from the wastewater.Five sorbents were chosen to research the adsorption ability. The Bacillus subtilis live vaccine and unliving ones are two kinds of biosorbent, and 20⁴0 mesh silica sands are inorganic sorbents. The mixed Bacillus subtilis and silica sands are combined sorbent. Another combined sorbent is the mixed unliving B. subtilis and silica sands.The process of organism adsorbing heavy metal ions was analyzed. A competitive adsorption kinetic differential equation and adsorption isotherm equation have been set up in the case the single heavy metal ion and multi-ions coexist. The quasi first-order and quasi two order kinetic equations were solved by mathematic method.A series of adsorption kinetic and adsorption isotherm experiments were achieved with Cu²⁺, Zn²⁺ and Cd²⁺ on different sorbents. Here, the single ion and multi-component coexisting competitive adsorption were considered, which was proved consistent with the experimental data. The results show that the adsorption ability is decreasing when multi-ions coexist, and the competitive ions existing restrain the adsorption ability. The higher adsorption ability was, the more it would be affected. It was found that a rule obtained from the adsorption isotherm experimental data of unliving subtilis, silica sands and the combined sorbent adsorbing the Cu²⁺, Zn²⁺ and Cd²⁺ can be used to guide the factual operation. When two kinds of sorbents are combined, the adsorption performance will rely much more on the sorbent with higher adsorption ability.The parameters of adsorption kinetic and adsorption isotherm for single ion and multi-ions competitive adsorption model were measured and fitted by least-square method. Compared simulation results with experimental data, the adsorption...