Effect of Di(2-Ethylhexyl) Phthalate on Denitrification Process

To study the effect of di( 2-ethylhexyl) phthalate( DEHP) on the denitrification process and its removal,two denitrification sequencing batch reactors( SBR) were operated for 180 d.One of them was fed with 1. 0 mg /L DEHP and the other was not. Batch denitrification tests were implemented at irregular intervals during 180 d. All results showed that denitrification activities were inhibited by DEHP addition. If the reaction time was enough,denitrification could be completed thoroughly. Denitrification activities recovered after 35 d of DEHP addition,which indicated that the inhibition effect of DEHP on denitrification was not constant. Nitrite reduction was more susceptible to DEHP than nitrate reduction,thus resulted in a high nitrite accumulation during the denitrification with DEHP addition. DEHP removal efficiency was more than 90% in each SBR whether or not with DEHP addition.