The Study On Biodegradation Of Phthalic Acid Esters DCHP And BBP

On the basis of summarizing the related references home and abroad,a great deal of experiments had been done to study removal characteristics of BAF on the Endocrine Disruptors Dicyclohexyl phthalate ester and butyl benzyl phthalate . Results show that the Biological filter column can effectively remove the water column trace DCHP and BBP, wiht a water temperature of 25℃and a empty bed contact time of 8h , the removal rate of DCHP could reach 96.3% ,and the BBP is 95.7% by the Biological filter column; with a temperature of 7℃and a empty bed contact time of 8h, then the removal rate of DCHP could reach up to 79.3%, and the BBP is 83.5%; When the DCHP and BBP's concentration in manual configuration of water is about 2mg/L, after the Biological filter column,the outlet concentration of DCHP can decline to 0.05mg/L at the lowest,the BBP is 0.09mg/L;The removal rates of the Biological filter column to DCHP and BBP subject to water temperature, pH and empty bed contact time and other factors; The higher the temperature,the greater of the removal rate;because the process of microbial metabolize DCHP and BBP can produce phthalic acid and other acidic substances, The outlet water pH became lower, the greater of the removal rate,the bigger of the difference between the water inlet and outlet; as the extension of the empty bed contact time (EBCT), the concentrations of DCHP and BBP decreased gradually. the increase of EBCT extended the contact time of biofilm with organic matter. so that microbes have more time to use the organic pollutants in water; The growth and breeding of microbes in the biological filter column were affected by the energy and carbon source provided by the organic compounds in water. In upflow reactor, with the height of filtering layer increasing, the energy material cut down gradually,so the number of microbes also cut down with it,and the increase of removal of DCHP and BBP in the biological filter column decreased too. The biofilm of potsherd filling in the biological filter column exists in the form bacteria micelle, and mainly spherical bacteria and Brevibacterium are in that;By GC/MS analysis,it shows that,the degradation products of DCHP( Dicyclohexyl phthalate)containing Di-hexyl phthalate,Dibutyl phthalate, Monobutyl phthalate,Dimethyl phthalate, and Pathalic acid, etc.the degradation products of BBP(Butyl benzyl phthalate) containing Dibutyl phthalate,Dimethyl phthalate and Pathalic acid, etc. it can be inferred that the pathway of DCHP biological degradation was:after DCHP degradate to Dibutyl phthalate two ways maybe exist,one is that Dibutyl phthalate degradate to Monobutyl phthalate then Pathalic acid;the other way is that Dibutyl phthalate degradate to Dimethyl phthalate then Monomethyl phthalate, then Pathalic acid, and finally to Carbon dioxide and water; the pathways of BBP biological degradation could be that Benzene of the BBP branched-chain crack to Dibutyl phthalate, and then generate Dimethyl phthalate, then Pathalic acid, and finally to Carbon dioxide and water。...