Fiber Reactor Capsule Of Extracellular Polysaccharides Of Modified Heavy Metal Ion Adsorption

An exopolysaccharide (EPS) was produced by Myxobacterium Sorangium cellulosum NUST06. The chemical modified condition of EPS and its characterization on treating water containing lead and copper was investigated.The EPS was fermented by Myxobacterium Sorangium cellulosum NUST06. In different temperature as well as under different reactants ratio condition, EPS was reacted to acetic anhydride, tertiary butyl alcohol and cyclohexanol respectively. The reaction mechanism was determined by the infrared spectrum. With the spectrophotometer absorbency was measured when the EPS derivative was dissolved in the deionized water, then we could realize its solubility situation. The results showed that the solubility of EPS derivative is lower than the original EPS. The reaction by EPS with acetic anhydride happened more easily than the others.The modified EPS was investigated as adsorbents for Pb²⁺ and Cu²⁺ solution. With the sodium acetate as a catalyst, the EPS derivative was obtained from the EPS and the acetic anhydride at 60℃ for 3h, and was used to adsorb different concerntration of Pb²⁺ and Cu²⁺ solution with a continuous flowing system. The atom spectrophotometer was used to determine the concentration of ions. The results showed that EPS derivative adsorbed more ions than original EPS in the initial concentration of 40mg/L and 80mg/L Pb solutions. The optimal pH value for the EPS derivative adsorbing Pb²⁺ and Cu²⁺ is 4.60 and 4.50 respectively. With the increasing the initial concentaation of Pb²⁺ and Cu²⁺, the ions removing rate of the EPS derivative decreased. The 1mol/L HCl solution can desorbed the Pb²⁺ and Cu²⁺ from the EPS derivative, and the desorption rate is 75.8% for Pb²⁺ and 95.6% for Cu²⁺. The EPS derivative in adsorbing Pb²⁺ and Cu²⁺ was possibly resulted from its hydrophobic and ionic exchanging properties.