Data analysis
The degradation data for toxic chemicals collected for this study fit first-order kinetic equations well: S = S0exp (–k1t), t1/2 = ln 2/k1, where t is the time, S0 the initial substrate concentration, S the substrate concentration at time t, and k1 the degradation rate constant. Toxic chemical remaining percentage [%] = (residual chemical concentration/initial chemical concentration) × 100. Toxic chemical removal rate [%] = [1– (residual chemical concentration/initial chemical concentration)] × 100. Statistical significance was accepted at p < 0.05. The data were analyzed by t test with SPSS version 10.0 (SPSS Inc., Chicago, IL, USA).