Study On Effect And Mechanism Of Modified Zeolite Combined With Polymerization Aluminum Chloride In Treating Ammonia Nitrogen And Total Phosphorus In Domestic Sewage

In order to improve the removal rate of ammonia nitrogen,total phosphorus and flocculation rate in domestic wastewater,to achieve the utilization of zeolite and harmless treatment of sewage.In this paper,four kinds of modified methods were used to modify,adding a small amount of polymeric aluminum chloride,the adsorption properties and surface characteristics of nitrogen and phosphorus in water were studied.The pore size of natural zeolite is not conducive to the adsorption of nitrogen and phosphorus in wastewater.This paper focus on the process of modification by nitrogen and phosphorus removal rate,determined the choice of saline stain modified zeolite calcination.The condition was determined to be NaOH impregnation concentration was 0.5 mol/L,MgCl₂ concentration was 1.0 mol/L,the ignition temperature set 105 ?,this time to change the zeolite to ammonia nitrogen removal rate was 86.5%,the total phosphorus removal rate was37.2%,compared with natural zeolite on nitrogen and phosphorus removal rate were increased by 31.2% and 23.6%.After treatment,the concentration of ammonia nitrogen was4.06mg/L,total phosphorus concentration was 2.72mg/L.The removal rate of ammonia nitrogen,total phosphorus and flocculation rate were found by adding modified zeolite and polymeric aluminum chloride in sewage.When modified zeolite dosage was 30 mg,the removal rate of ammonia nitrogen was 85.5%,total phosphorus removal rate was 43.7%,the flocculation rate was 59.3%.When PAC dosage was 30 mg,the removal rate of ammonia nitrogen was 34.6%,total phosphorus removal rate was 83.8%,flocculation rate was 92.7%.The best result effected that the ratio of modified zeolite and polymerization aluminum chloride was 1:1,the adsorption time was 60 min,the pH value of sewage was 5,the adsorption temperature was 30?,the removal rate of ammonia nitrogen was 83.7%,the removal rate of total phosphorus was 92.4%,flocculation rate was 93.4%.The primary and secondary order of the adsorption effect was adding proportion,temperature,adsorption time,pH value.Using scanning electron microscopy,X-ray diffraction and infrared spectrum analysis,the surface characteristics of ammonia nitrogen and total phosphorus in the treatment of domestic wastewater by modified zeolite combined with polyaluminum chloride were analyzed.Through the SEM chart analysis,we found that the modified process made the surface of zeolite more orderly,and the particles were more dense and small;Isothermal adsorption experimental results found that the modified zeolite adsorption of ammonia nitrogen in line with the Langmuir model,the total phosphorus in sewage was consistent with the Freundlich model.According to XRD results,the main components of zeolite were clinoptilolite,accompanied by silicon dioxide,aluminum oxide and magnesium oxide.Themodification process changed the structure of the zeolite crystal.Infrared spectrum analysis showed that the structure of modified zeolite had changed,and polymeric aluminum chloride was loaded into zeolite crystals.