The Degradation Effect And Mechanism Of1,2,4-Trichlorobenzene By Selenatrum Carpricornutum

1,2,4-Trichlorobenzene (1,2,4-TCB) widely used in industry, is moderately volatile organic compounds.Because its hazards are potential and persistent,it has been listed as one ofthe priority pollutants by many counties in the world.Many reports have confirmed that demonstrated a strong ability to remove bacteria chlorophenyl. As primary producers in aquatic ecosystems, Algae has certain ability to degrade chlorobenzene with the characteristic of tiny, rapid propagation,wide dist ribution, fast adsorption and high purification efficiency. Most studies focusedon the toxi-city of organic pollutants to algae, but the basic research on the degradation abilityof Algae is few. Ther efore, this study took the Selenastrum capricornutum as a study object to examine its ability of degrade for chlorobenzene under different concentration and environment conditions andachieve the preliminary analysis of degradation pathways and provided a theoretical basis foruse of algae to degrade chlorobenzene compounds in water environment and ecological restoration.The main research contents are are as follows:1Different concentrations of1,2,4-Trichlorobenzene degradation about Selenastrum capricomutum(1) Different initial concentrations of1,2,4-Trichlorobenzene have certain biological degradability, degradation reactions correspond to the first-order kinetics.1,2,4-Trichlorobenzene initial concentration of1mg/L, the7d the degradation rate up to52.8%, the degradation halftime is the most little is6.62d, the concentration of1,2,4-Trichlorobenzene optimum degradation.(2)When the1,2,4-Trichlorobenzene initial concentration increased to5mg/L or more, it will inhibit the growth of Selenastrum capricornutum.1Selenastrum capricornutum1,2,4-Trichlorobenzene degradation efficiency under different environmental conditions.(1)When the1,2,4-Trichlorobenzene initial concentration is the l.Omg/L. the initial concentration of the algae species is12±0.32mg/L,and culture temperature was30℃and light intensity39901x,1,2,4-Trichlorobenzene7d optimal amount of degradation and degradation rate of0.536mg/L and53.6%.(2)Algae species the initial concentration, incubation temperature and light intensity will affect Selenastrum capricornutum degradation for1,2,4-Trichlorobenzene, in which the light intensity is the main influencing factors, followed by the initial concentration of algae species and culture temperature. Excessive light will inhibit the degradation of algae chlorobenzene.3Selenastrum capricornutum degradation intermediate metabolite for1,2,4-TrichlorobenzeneDetermination of the Selenastrum capricornutum the degradation products.Experimental results show that7d degradation of the final product of phenol,also found that1,2,4-trichlorobenzene degradation process,the chlorine substituent on the phenyl ring is replaced by other more reactive groups, did not make the degradation reaction benzene ring fracture. With most bacterial degradation of1,2,4-Trichlorobenzene dechlorination-open-loop or open loop after dechlorination pathways mechanism.