The Research On Biodegradation Of Dicyclohexyl Phthalate

Dicyclohexyl phthalate (DCHP) is one kind of new plastic plasticizer, which used at the rise stage in the domestic,is already listed as one of environment hormones by world wild animal foundation (WWF).Microorganisms are responsible for the complete destruction of PAEs in the environment.However,degradation of DCHP by pure species of microorganisms has been largely neglected.On the basis of summarizing the related references home and abroad, a series of shake flask experiments had been conducted to study the biodegradation of DCHP. Results indicated the DCHP degrading strain isolated from the actived sludge at a land fill leachate treatment plant were able to grow on DCHP as sole carbon and energy sources. This DCHP highly effective degeneration fungus grows good on the nutrition agar-agar culture medium, assumes the light red, the colony is big, the edge is neat, the surface is smooth, the bulge, is not transparent, leather blue negative, bacillus. Carries on molecular classification——16S rRNA homology analysis, determines this bacterium the gene sequence, demonstrates this DCHP highly effective degeneration bacteria Yu Hongqiu (Rhodococcus). So far, domestic does not have the report about rhodococcus (Rhodococcus) to degrade DCHP. Refers to GenBank the general procedure, this bacterium naming is Rhodococcus sp.HY2. Take this strain as the degeneration microorganism, has studied the DCHP biodegradation under the single matrix condition.The effect of initial DCHP concentration on the degradation was investigated between 5.0mg/l to 100mg/l,and the results showed that the biodegradation process conformed to the first-order kinetic model. The biodegradation rates of DCHP decreased and inhibition effects of DCHP increased greatly. Compares with the domestic report, the biodegradation effect is good. The optimal pH,temperature and rocker rotational speed for DCHP biodegradation were 7.0,30℃,150r/min, respectively. the possibly degradation way of DCHP is,the Cyclohexyl break into the butyl, namely the production DBP,other short chain passes through a series of oxidizing reaction derivation into the ethanoic acid.