The Study Of Composite Molecular Sieve To Remove The Micropollutant In The Water

In case of serious drinking source water pollution and high stand of the water, water quality can not reached by traditional treatment. This research uses the composite molecular sieve to removal fluoride and NH₃-N from water through static adsorption. The effects of various factors, such as temperature, pH value, contact time consistency, on the removal efficiency during the adsorption of molecular sieve were analyzed. The adsorption research is studied hrough the dynamic adsorption test of composite molecular sieve tester, O3/ composite molecular sieve tester and the active carbon/ composite molecular sieve.The research on F^- shows us that, by using the composite molecular sieve with the amount of 8g and the size of less than 0.9mm to treat 100ml fluoride water with the concentration of 5mg/L, the fluoride removal efficiency of molecular is up to more than 90.77%. The variation of the removal of F^- with the temperature increased first followed by decreasing, and reacheed the peak with the removal efficiency of 92.7% at 50℃. The removal of F^- was higher in weak acidic condition than alkali, and shown the best removal efficiency of 91.8% when pH=4. The contact time was propotional to the defluoridation efficiency at the initial stage and reached the equilibrium state in 45min. The absorption rate followed the second-order kinetic equation and the curve of absorption isotherm agreed with Langmuir equation well. Saturated absorption amount is 2.869mg/g(F^- ).The research on NH₃-N shows us that, by using the composite molecular sieve with the amount of 5g to treat 100L fluoride water with the concentration of 5mg/L, the fluoride removal efficiency of molecular is up to more than 85.42%. The variation of the removal of F^- with the temperature increased first followed by decreasing, and reacheed the peak with the removal efficiency of 92.7% at 50℃. The removal of F^- was higher in weak acidic condition than alkali, and shown the best removal efficiency at the condition of faintly acid and alkalescence. The contact time was propotional to the defluoridation efficiency at the initial stage and reached the equilibrium state in 45min. The absorption rate followed the second-order kinetic equation and the curve of absorption isotherm agreed with Langmuir equation well. Saturated absorption amount is 1.624mg/g(NH₃-N ).Dynamic test results showed that the higher the hydraulic loading, zeolite reactor to remove the effect of fluoride and ammonia nitrogen worse. The removal effect of water can reach the stander at the hydraulic loading of 0.3m³/m²·h. Fluoride and ammonia nitrogen removal rate with the height of the fill increases, and as the increase in running time, saturated layer gradually move up. Molecular sieve reactor, ozone / molecular sieve and zeolite / activated carbon reactor fluoride and ammonia are the initial removal rates were running about 80%, the latter with the running time increases, the water fluoride and ammonia concentration increased gradually. Molecular sieve reactor, ozone / zeolite regeneration cycle of the reactor for 12 days, zeolite / activated carbon regeneration cycle of the reactor was 8 days. Ozone / Zeolite reactor has good organic matter and UV₂₅₄ removal is better than the other two reactors. Ozone / Zeolite reactor 23 kinds of organic matter removal effect better, the best results. Saturated molecular sieve regeneration after time to 10h or more, 50mlAl₂ (SO₄)₃ +50 mlNaCl ratio of liquid on the regeneration of molecular sieve regeneration of the best results. The molecular sieve regenerated molecular sieve with unused, compared to the pollutant removal efficiency was slightly lower.