Study On The Preparation Of Modified ATP Adsorbent And Its Removal Of Emerging Pollutants In Wastewater

China is scarce on water resources,and water pollution has further exacerbated the shortage of water resources.Pharmaceuticals and personal care products（PPCPs）are a class of emerging pollutants,mainly including antibiotics,anti-inflammatory drugs,fragrances,etc.These substances are difficult to be biodegraded and transformed after entering the environment,resulting in their difficulty to be removed in sewage treatment entirely and then discharage.Therefore,the efficient removal technology of PPCPs in water bodies has become the focus of attention for experts in the environmental field.Attapulgite（ATP）in clay minerals is rich in resources,low in cost,large in specific surface area,and has excellent adsorption performance.Since the surface is charged negatively,it has a good adsorption effect on cationic PPCPs,but it is limited to anionic type.To solve this problem,this thesis first acidified ATP to study its adsorption performance for PPCPs,and then used surfactants and chitosan respectively to modify ATP to prepare composite materials,and explore its adsorption performance of anionic PPCPs.The main contents are as follows:1.The adsorption material HAMA was prepared by simple acid modification based on ATP,and the adsorption of two typical antibiotics was studied.The specific surface area and pore size of HAMA were increased significantly by FT-IR,BET,and other methods.By exploring the effects of adsorption time,dosage,p H and other factors on the adsorption performance of tetracycline（TC）and ciprofloxacin（CIP）,it was concluded that the HAMA material reached adsorption equilibrium within a short time,and the removal rates of TC and CIP reached 91.2%and 97.6%respectively.In response to sudden water pollution incidents,HAMA was ball-milled and magnetically modified to be separated easily from wastewater;HAMA was desorbed and regenerated for 5 cycles,showing that HAMA has strong stability and recyclability;Taking actual water as background,the simulation experiment of sudden water pollution was carried out,the removal rate of TC and CIP by the magnetic modified material is still excellent,and it is feasible to deal with it.2.Cetyltrimethylammonium chloride（CTAC）,a cationic surfactant,was selected to modify the ATP to prepare the composite material CCMA with different modification ratios.XRD,FT-IR,Zeta potential with other characterizations showed that the surface charge of the adsorption material changed from negative to positive,and the internal crystal structure was not affected after modification.Using diclofenac sodium（DS）as the anionic target pollutant,the best-modified proportion of adsorbent CCMA3 was selected to carry out the influencing factor experiment.The results showed that the reaction reached equilibrium quickly,the pH of the initial solution had little effect on the adsorption,and the effect of coexisting anions was as follows SO₄^2->CO₃^2->Br^->Cl^-.The adsorption of DS on CCMA3 was in good agreement with the quasi-second-order kinetic model and Freundlich isotherm.The XRD and FT-IR images before and after DS adsorption were compared to discuss the adsorption mechanism.Besides,the regeneration cycle of the adsorbent material was also investigated.3.Combining ball milling method and co-precipitation method,we prepared a new,non-toxic and easily degradable magnetic chitosan modified ATP adsorption material（MCMA）.Zeta potential results showed that the p H_PZCof MCMA increased and the adsorption range widened.Through a series of static adsorption experiments and the adsorption kinetics and isotherm fitting,the results show that MCMA can successfully adsorb and remove DS,and the theoretical maximum adsorption capacity is 704.2 mg·g^-1,and the data fitting shows that the pseudo-second-order kinetic equation and Freundlich isothermal model are more consistent.