In order to explore the technological characteristics of the simultaneous removal of phthalate esters (PAEs) as well as nitrogen and phosphorus by the novel technology of three-dimensional biofilm-electrode coupled with iron/sulfur reactor (3DBER-S-Fe), the changes of the total nitrogen (TN),total phosphorus (TP),DBP,DEHP,NO3--N, SO42- and pH value were analyzed under the hydraulic retention time (HRT) of 8 h, 6 h and 4 h respectively. The results showed that 3DBER-S-Fe could remove nitrogen, phosphorus and PAEs effectively. Under the HRT of 8 h, 6 h and 4 h, the removal rates of TN were 80.99%, 78.85% and 64.76%; TP were 65.18%, 67.17% and 43.44%; DBP were 96.72%, 97.32% and 96.53%; DEHP were 91.89%, 81.57% and 74.30%, respectively. There were heterotrophic denitrification, hydrogen autotrophic denitrification and sulfur autotrophic denitrification processes in the 3DBER-S-Fe, the elemental sulfur could compensate for the relative shortage of denitrification electron donor caused by the increase of NO3--N load in the influent as a result of maintaining a high efficiency of the denitrification system when the HRT was shortened from 8h to 4h; the iron ions produced by the corrosion of the sponge iron filler in the system had a sustainable and efficient function of removing phosphorus by precipitation; the 3DBER-S-Fe process combined the interactions of physical adsorption, biological degradation and electrochemical processes which supported its high removal rates of DBP and DEHP under the different HRT conditions.
Keywords: hydraulic retention time; nitrogen and phosphorus removal; phthalate esters (PAEs); reclaimed water; three-dimensional biofilm-electrode.