| Nitrogen and phosphorus elements go into the water,the most direct consequence is the cause of water eutrophication phenomenon.At present,adsorption method is widely used in the field of phosphorus removal,which is fast,efficient and easy to carry out phosphorus recovery.this study is based on the preliminary study of the research group,for the removal of eutrophic phosphorus,the developed Al/Ca/Fe composite metal oxide adsorbent can be used to adjust the strength density to reduce the operating cost of adsorption and phosphorus removal,and to solve the problems before adsorption agent encountering water and making adsorbent deliquescence,while the prepared adsorbent can be applied to aeration tank,fluidized bed and other structures,To better meet the requirements of practical engineering applications.The results of this study are as follows:(1)The strength of the adsorbent particles was adjusted by changing the amount of bentonite,adding water glass and cement on the basis of the mass ratio of Al/Ca/Fe oxide of 2:1:1.The results show that the effect of bentonite is poor,the adsorption capacity of water glass is decreased and can not be long-term,and the deliquescence phenomenon is easy.The addition of cement has a decrease in adsorption capacity,but compared with the adsorbent prepared in the previous stage,The quality loss rate of the adsorbent is controlled within 6%,the strength is obviously improved.325,425 two kinds of cement and Al/Ca/Fe oxides were prepared at different proportions.Theadsorption capacity of 425 cement was higher than that of adding 325 cement.The adsorption capacity of the cement was higher than that of the adsorption The adsorption capacities of the two kinds of cement and Al/Ca/Fe oxides at the ratio of 1:0.25 were8.243mg/g and 9.641mg/g,respectively.After 500? sintering,425 cement standing adsorption up to 14.54mg/g.(2)Al/Ca/Fe oxide and alumina were sintered at 1150?,respectively,with 425 cement to 1:1.5 ratio of mixing,hydration,curing,smashing,the particle strength of the adsorbent prepared by this method satisfies the requirements and can be placed in water for a long time without deliquescence.By two kinds of adsorbents for the preparation of the test,the results show that the Al composite adsorbent and Al/Ca/Fe composite adsorbent adsorption capacity was 23.86mg/g and 22.42mg/g respectively,the Al adsorption effect is better than that of Al/Ca/Fe type adsorbent.By acid activation,the adsorption amount of the two adsorbents decreased,and the adsorption capacity of the two adsorbents increased with the activation at 500?,but decreased slightly at 100 and300?.(3)The SEM images of Al/Ca/Fe and Al adsorbents by adding 425 cement were analyzed before and after adsorption.The results indicate that two kinds of adsorbent had more porosity on the outer surface,which can guarantee a certain amount of adsorption.And after adsorption,the adsorbent adsorbed more phosphate on the outer surface,partially filled in the pores,and partially deposited on the outer surface.(4)The density of the Al/Ca/Fe type adsorbent is adjusted by preparing the phenolic resin pellets,the small grains as the masterpieces to prepare the adsorbents,and the 3D microspheres as the masterpieces to prepare the adsorbents.The experiments show that the adsorbents prepared by the three methods can not ensure long-term suspension in water.The phenolic resin pellets are sintered and the powder is sintered;the adsorbents prepared by the microbeads are sintered and sintered after sintering;the adsorbent part prepared by the 3D printer pellets is suspended in the water,and the density can be reduced to a certain extent,Shaking under the ball damage phenomenon. |
PDF Full Text Request