COMPARISON OF ADDITIVES IN THE REMOVAL OF PHENOLIC-COMPOUNDS BY PEROXIDASE-CATALYZED POLYMERIZATION

Several additives, polyethylene glycol, gelatin and some polyelectroly tes, were studied to compare their behaviour in the removal of phenoli c compounds from aqueous solution by horseradish-peroxidase-catalyzed polymerization. The effects of additives on optimum pH range, horserad ish-peroxidase saving, reaction stoichiometry and minimum additive req uirements were investigated. The fate of additive after reaction was a lso studied. The experimental results showed that all tested additives significantly reduced the horseradish-peroxidase requirement. Compari son among them revealed that polyethylene glycol was the best choice f rom all perspectives. It saved more peroxidase and had no negative ove rdose effect shown by gelatin and polyelectrolytes. At minimum polyeth ylene glycol dose, there was little polyethylene glycol remaining in s olution after completion of reaction. However, a considerable amount o f gelatin remained in solution even at the minimum gelatin dose. Also, gelatin produced more precipitate than polyethylene glycol. (C) 1997 Elsevier Science Ltd.