Removal of aqueous phenol and 2-chlorophenol with purified soybean peroxidase and raw soybean hulls

In this study, the removal of phenol and 2-chlorophenol using soybean seed- hulls in the presence of hydrogen peroxide is demonstrated. The performance of a stirred membrane reactor containing soluble purified SEP was compared with a batch stirred reactor containing raw soybean seed-hulls. The purifi ed enzyme reactor proved to be ineffective while excellent results were obt ained with the crude seed-hulls for the removal of phenol and 2-chloropheno l. Four sequential batch reactors containing raw seed-hulls achieved greate r than 96% removal of phenol with a retention time of 20 min in each reacto r. A single batch reactor containing raw seed-hulls was effective in removi ng greater than 98.5% of 2-chlorophenol (initially at 1000 ppm) in less tha n 15 min. The performance of these reactors is comparable to existing HRP-b ased technology. The stability of the soybean peroxidase (SBP) enzyme was a lso examined in the presence of detergents (SDS, Tween 20 and Triton X-100) . Low concentrations of the detergents significantly increased the enzyme a ctivity and higher concentrations of detergents (up to 20% w/v) did not ina ctivate the SEP enzyme. These results demonstrate that SEP has good potenti al for the treatment of phenol contaminated solutions. (C) 1999 Society of Chemical Industry.