The Defluorination Of Alumina Sol Modified Fly Ash Zeolite And The Kinetic Study

Fluorine is a kind of active chemical elements, long-term excessive intake of fluoride can cause serious harm to human body,can cause dental fluorosis, skeletal fluorosis and hardening of the arteries and other symptoms.Therefore,The management of high fluoride water pollution get the attention of the parties.NaY-type zeolite with fly ash was compounded by alkali fusion assisted hydrothermal,Modified with alumina sol and alumina load of composite adsorbent prepared by wet method, applied in fluorine wastewater treatment respectively. fly ash modified zeolite was characterized By X- ray diffraction(XRD), infrared spectroscopy(IR), scanning electron microscopy(SEM), transmission electron microscopy(TEM) and N2 adsorption desorption technology. The results showed that:1. Ratio of soda ash to 1.2,750 ℃ Pretretment calcining temperature(calcining method is a two-calcined, calcined 10 min each), the concentration of the alkali 2.2 mol / L, at 100 ℃ crystallization crystallization conditions 24 hours, synthesized particle size of about 300 nm, specific surface area of 508.2 m2 / g, pore volume of 0.342 cm3 / g of NaY molecular sieve..2. With alumina sol modified zeolite composite adsorbent(FA- Al) of fluorine ion adsorption rate of 78.06%, higher than the wet load alumina composite zeolite samples(FA/Al) for fluorine ion adsorption rate(60%).3. In PH = 6, room temperature conditions shock absorption 2.5 h, alumina sol modified zeolite(FA-Al) in water 5.0 mg / L fluoride ion removal can to 86.63%, and the concentration of fluoride in drinking water absorption drops Fluoride concentrations in drinking water standard or less.4. Kinetic studies showed that the modified zeolite alumina sol(FA-Al) a fluorine ion adsorption rate of the first and second primary control pHase by adsorption; adsorption isotherms showed that the adsorption material(FA-Al) is non-uniform surface structure; the thermodynamic analysis results showed that the adsorption material(FA-Al) on the adsorption of fluoride ion is spontaneous exothermic reaction, the adsorption process via chemical adsorption.5.The desorption rate is 95%.With 0.005 mol / L solution of potassium aluminum sulfate as a desorbent to adsorption of fluoride ion adsorption material(FA-Al) desorption, capacity changed little after regeneration of adsorption four times, The modified material(FA-Al) used in industrial wastewater treatment fluorine, the same after four regenerations, and the adsorption rate remained at 86%.Our country has a large number of fly ash resources, raw materials readily available and inexpensive, and can be applied to not only synthetic zeolites fluorine wastewater treatment, it can also replace other zeolites used in industrial catalysis, ion exchange, adsorption, and other fields. n this study, We Used waste treat waste and synthesized zeolite synthesis, This environmental governance and economic aspects have value and significance of practical application.