| Phthalic Acid Esters（PAEs）are highly harmful to humans and are abundant in the environment,especially in natural waters.Now a lot of water treatment plant routine treatment of endocrine disruptors is very low,PAEs once the drinking water into the human body,it will be rich,it is difficult to rule out,over time will interfere with the body’s nervous system and reproductive system.Therefore,how to remove the trace PAEs in water safely and efficiently has become an urgent problem to be solved.DEP,DBP and DOP,which are commonly used in industry,are selected as the research object.The pollution of these three kinds of PAEs in Zhangjiang River was investigated.A systematic study of the removal efficiency of PAEs using carbon nanotube modified self-made membrane（NF1）and commercial nanofiltration membrane（NF2）.The main results of the final study are as follows:（1）The content of PAEs in Zhangjiang River was 0.40194.3470μg/L,and the main pollutants were DOP.The dry season content is higher than other periods.Therefore,the concentration of PAEs in the wet season is much lower than that in the dry season.The downstream content is greater than the upstream.（2）After standing at room temperature and 0.1 MPa pressure,the pure water flux of homemade nanofiltration membrane was measured at 311.437 L/m2·h and the flux was 46.538L/m2·h,for 1 g/L BSA solution,the retention rate was 97.71%;After standing at room temperature and 0.6 MPa pressure,the pure water flux of self-made nanofiltration membrane was37.373 L/m2·h.The flux of monovalent ion（NaCl）solution was 32.854 L/m2·h,the rejection was34.13%.The flux of divalent ion（MgSO4）was 28.447 L/m2·h,and the rejection was 97.64%.（3）The experiment examined the influencing factors of nanofiltration membrane removal of PAEs.The results show,With the increase of operating pressure,both NF1 and NF2 fluxes are greatly increased and the rejection rate increased slowly.With the increase of the temperature of the feed solution,the flux of the NF1 and NF2 increases with the increase of the PAEs,and the reverse rejection decreases gradually.With the increase of the initial concentration of the raw material,the flux of the NF1 and NF2 decreased and the rejection increased.With the increase of pH,the flux of PAEs increased and the rejection decreased.With the increase of ionic strength,the flux of PAEs decreased and the rejection increased.By comparison,the flux of NF1 to PAEs was less than NF2,but the rejection was greater than NF2.（4）The adsorption performance of NF1 on PAEs was studied.The adsorption capacity of PAEs increased with the increase of the initial concentration of the raw materials.The rejection of PAEs by NF1 mainly depends on membrane adsorption and membrane pore sieving effect.The adsorption equation of DEP,DBP and DOP on the surface of the nanofiltration membrane was fitted by Langmuir and Freundlich adsorption equation respectively.It was found that the Freundlich adsorption equation could better reflect the adsorption of PAEs on the surface of the nanofiltration membrane.The correlation coefficient R2 More than 0.998.The adsorption capacity（K）of DEP,DBP and DOP was 0.0537,0.0914 and 0.1688.The adsorption capacity index（1/n）was 0.6203,0.6203 and 0.5876,which indicated that PAEs were easy to be Adsorption.（5）The effects of three common agents on the NF1 after contamination were studied.The results showed that when the mass concentrations of hydrochloric acid,sodium hydroxide and sodium hypochlorite solution were 0.4%,0.8%,1.0%,and the cleaning time was 20 min,30 min,and 20 min respectively,the cleaning effect was the best,and the membrane flux could be restored respectively.It was 83.4%,94.6%,and 97.8%before it was contaminated. |
