Degradation of benzo(a)pyrene in Yangtze River source water with functional strains.

Degradation of benzo(a)pyrene (BaP) existing in the Yangtze River, used as source water for Nanjing City, China, was investigated with functional strains. The removal rates of BaP were 37.5, 20.8 and 70.8% for the three strains of the native bacterium NJ, and the two functional strains of Xhhh and Fhhh, respectively. The Fhhh specific degradation rate of BaP was 3.02 x 10(-6) day(-1), which was 1.9-fold of the rate with NJ and 3.7-fold of the rate with Xhhh. The concentrations of BaP in the source water, tap water and Fhhh reactor effluent were 8.3-, 7.6-, and 2.4-fold of that of the oral carcinogenicity unit risk. The results suggest that the functional strain Fhhh could be used for the reduction of BaP concentrations in source water and hence reduction of carcinogenic risk.