| HCB is one of 12 typical Persistent Organic Pollutants(POPs), which is serious hazards to human health and the environment.Objectives: The anaerobic flora degrading HCB screened out from the polluted environment is isolated by method of isolation of anaerobic bacteria. The growth characteristics of flora and the degradation characteristics between single strain and hybrid strains are studied.Method: 1) Activation and isolation of anaerobic bacteria dechlorinating HCB. The flora are activated and isolated by special method of isolation of anaerobic bacteria. 2) Optimization of culture conditions of the flora. Use three factors - level orthogonal design method to study the best growth conditions for the flora. 3) Comparation between single strain and mixtured-strains on the ability of dechlorinating HCB. The different bacteria are mixed with the same volume ratio for the study on the degradability of HCB.Results: Through isolating and purifying repeatedly, we obtain four strains that can live on HCB as the sole source of carbon and energy. And the optimal condition is: temperature 30°C, pH 7.0, concentration of the HCB with 3mg·L-1, and inoculation with 0.2%. The flora can not meet with 1,2,4,5-tetrachlorobenzenes and sodium pentachlorophenate as the sole carbon source. After seven days, the degradation rate of HCB by single strain is: Y1:65.9%, Y2:49.6%, Y3:75.3 %, Y4: 73.8%. The degradation rates of ten groups of test in eleven are more than 60%.Conclusions: Each strain obtained from this study has a better degradability of HCB. The average degradation rate of HCB is 66.2%, and is up to 75.3% at most. The average degradation rates of HCB of flora are: two strains mixed(63.9%) |
