Studies Of Biosorption Of Heavy Metals In Solution

In this paper we studied the heavy metal biosorption of three biosorbent: aerobic biosorbent, anaerobic biosorbent, SBR biosorbent. The objective was to study the effects of environmental transformation on metal-biosorbent interactions and the mechanisms of metals adsorption. The conditions of adsorption were tested by batch tests. Results were as follows:Aerobic biosorbent are mainly Gram negative bacteria, anaerobic biosorbent SBR biosorbent are Gram positive bacteria. The value of pH would have significant effect on the metal ions. With the pH values rise, the removal efficiency rise either. The optimal pH to Cu²⁺, Zn²⁺, Mn²⁺ were around 5, and to Fe³⁺ was around 2.5. Anaerobic biosorbent and SBR biosorbent have better removal efficiency to heavy metals than aerobic biosorbent The higher the temperature, the higher the adsorption capacity. But, it has little efficiency to the removal of heavy metals. When the quantity of the biosorbent was increased, the removal efficiency added. The equilibrium was well described by Langmuir and Freundlich isotherm models in the studied concentration range.The equilibrium time of the adsorption of heavy metals onto the biosorbent are 60min. The kinetic processes of the adsorption included fast phase and slow phase, and the kinetic processes followed the Lagergren second-order rate expression, but it cann't described by the first-order rate expression.