Research On Transfer Of Phthalate Acid Esters Hormone In WWTP And Its GAC Adsorption And Biodegradability

Environmental hormone is a class of chemical compounds in environment. It may affect human and animal on their normal endocrines, leading to reproductive, developmental and behavioral disorder. Phthalate acid esters (PAEs) are an important group of environment hormones. Their main application is as plasticizers in the manufacture of plastics. In recent years, large amount of plastics have caused a wide distributions in the world. The thesis focuses on this challenge, aiming to investigate the transportation, transference and degradation rules of toxic and harmful organic matter in two wastewater treatment plants (WWTP) at Harbin by using liquid-liquid extraction (LLE)and solid phase extraction (SPE). Choosing environment hormone--phthalate acid esters (PAEs) as research object, the presence, transportation and degradation of PAEs were investigated in secondary and advanced treatment process. Then the activated carbon adsorption and aerobic biodegradation of PAEs were made in this thesis.This research indicated that most organic pollutants could be removed by secondary treatment plant, the removal ratios of trace organic pollutant are 79% ~ 94% for Taiping WWTP, 88%~90% of removal ratio for Wenchang WWTP. The organic species numbers detected in the two WWTP are 73 and 70 by means of LLE, 87 and 101 by means of SPE, respectively. The total numbers of organic pollutants detected in this study are 102, about 12 species are belong to Stress control pollutants in water environment by USEPA and 6 species are belong to China priority controlled pollutant in black lists. Most pollutants in effluent are PAEs.Though the water quality of effluent meets the national discharge standard after secondary and advanced treatment, the PAEs are also existed in the outflow. The removal ratio of DMP, DEP and DBP by the A/O aeration tank can reach highly at 99%, 95.10% and 70.06%, respectively, but it is no removal efficiency for DnOP, which is terribly low residue concentration and hard to be degraded. It is a little bit ascending trends after the advanced treatment process. So it can be concluded that low molecular weight of DMP, DEP and DBP can be removed effectively by the secondary and advanced treatment process, and it doesn't fit for removal of high molecular weight of DnOP, we must go in for effective processes to dispose the PAEs.High water-solubility of DMP and DEP can be removed in secondary treatment, but most high fat-solubility of DBP and DnOP are adsorbed in primary and secondary sludge. The concentrations of DBP in Anaerobic and oxidation tanks are 1.90μg/L and 13.25μg/L, DnOP concentrations reach highly at 24.96μg/L and 39.70μg/L. The high concentration in effluent and residual sludge can provide significant progress for the PAEs-accumulated in bio-organism and risk evaluation of remnant activated sludge discharging from WWTP.It can be found that the pH should be controlled in acidic condition and the optimum pH value is 6.0 when the activated carbon adsorbs PAEs. The removal efficiency decreases with the increasing of molecular weight and initial concentration of different PAEs and increases with the augment of GAC dosage.The GAC can be regenerated by the mode of sparse HCl (1:10) + methanol +ultrasonic for twenty minutes to some extent, its adsorption capacity will gradually wear off with the used times of GAC, but its use time and life-span enhances greatly. The adsorption of DMP follows the Freundlich equation. The adsorption constant Kf=142.879mg/g and 1/n=0.1712 indicated that the adsorption capability of DMP is huge and concentration effect is small during the adsorption. Therefore it can be served as an effective method for wastewater and advanced treatment of PAEs.In the process of acclimation, with gradually increasing the concentration of PAEs and decreasing the present concentration of acetic sodium, the domestication will succeed easily. The domestic sludge has good degradation performance on PAEs, and it reduces the inhibited activity and poisonous function on microorganism. The biodegradation of domestic sludge on DMP and DEP follows the first order kinetic characteristics, the degradation constant decreases and the half life increases with the increasing initial concentration. The biodegradation of non-domestic sludge on DMP and DEP follows zero order kinetics; the relationship of linearity is fit well.