Study On Modification And Phosphorus-Adsorption Capacity Of Zeolite

Phosphorus is a necessary element of human life activity, while phosphorus is also essential nutrients for biological growth, considered biological stability control factor. On the one hand, Eutrophication in large extent is because of the harm caused by phosphorus pollution, and therefore phosphorus removal from wastewater makes more sense in the control of eutrophication side, so long as to remove phosphorus from waste water, we can solve the problem of water eutrophication. On the other hand, the biological stability of drinking water, related to the depth of phosphorus removal technologies to ensure the stability of filtered water creatures.By comparing the current domestic and international use of various phosphorus removal methods, zeolite adsorption method is considered to have advantage of cost-effective, non-toxic harmless and is a very good water treatment method. Zeolite is a common adsorbent, but the adsorption capacity of natural zeolite is very low, must be modified for its activation. Active magnesium oxide has a good phosphorus removal effect, therefore, we use zeolite as carrier which is loaded on with active magnesium oxide for phosphorus testing. On this condition, a study on modification of natural zeolite and its phosphorus ability was carried out.In modification experiment the best modification method was established. Natural zeolite which was modified by being soaked in Sodium hydroxide of 1mol/L concentration for 1h and then being soaked in magnesium chloride of 20% concentration for 2 days and then being roasted at temperature 500℃for 2h could effectively remove phosphate from water.The structures of natural zeolite and modified zeolite were observed by SEM, XRD and FT-IR. Based on these, the reason and effect of modification were further analyzed.Static experiments was carried out in order to examine phosphorus ability of modified zeolite. The results showed that the adsorption capacity of zeolite was greatly enhanced after being modified, which obtained 0.76mg/g for phosphorus solution with 80mg/L concentration. There were many factors affecting the adsorption capacity of modified zeolite, including raw water pH, concentration, exposure time. The adsorption isotherm of modified zeolite conformed to Freundlich equation, and the rate of adsorption conformed to Banerm equation. The regeneration of used modified zeolite was also studied and the result showed that modified zeolite had preferable stability.