Research On Adsorption Performance Of Coal Gangue Synthetic Zeolite To Ammonium Nitrogen In Wastewater

With the fast industrialization of our country, our sources are getting more andmore intense and water are polluted, so it is very important to reuse the deserted sourcesand to treat waste water. Ammonium nitrogen waste water, if not treated well, willcause eutrophication in water body, and harm human organs. Low recyclying rate ofcoal gangueand water granulated slag leads to occupation of large area of preciousland and pollution of the environment.The paper chooses waste coal gangue as raw materials to produce zeolite byalkali melting method to solve the problem of limited sources, hard to regenerate, highcost of nature zeolite. The other zeolite involves addition of water granulated slag tocoal gangue and synthesys by alkali-ultrasonic method. The produced zeolites are usedas adsorbent to treat ammonium nitrogen waste water. The subject studied theadsorption mechanism of the zeolite to ammonium nitrogen by adsorption isothermaltest and kinetics tests.The adsorption ability to ammonium nitrogen of zeolite produced by alkali meltingmethod was compared with that of produced by alkali melting-ultrasonic method, thefactor affacting adsorption performance of baking time, solid-liquid ratio, aging time,crystallization time; dose of water granulated slag, ultrasonic time, solid liquid ratio,crystallization temperature, crystallization time were studied: the latter has smallersolid-to-liquid ratio and matures faster. The scanning electric mirror and XRD spectrumshow that the zeolite added with slag has more fluffy form, the synthetical zeolite hasbetter crystallinity than that without adding slag. The best condition for the syntheticalcoal gangue to adsorb ammonium nitrogen is: dose0.024g/ml, vibration time60min, pH7; the remove ratio of ammonium nitrogen under this condition is63.63%; the bestcondition for the synthetical coal gangue slag to adsorb ammonium nitrogen is: dose 0.024g/ml, vibration time45min, pH7, the remove ratio of ammonium nitrogen underthis condition is57.29%.The isothermal adsorption test and adsorption kinetic test of the two kinds ofzeolite to rare earth ammonium nitrogen waste water shows:1) the l/n of the two zeoliteare both between0.1-0.5, showing the adsorption is easy; of the3isothermaladsorption line model of Langmuir, Freundlich and Temkin, the Freundlich equationbetter describe the adsorption activity of the2kinds of zeolite to ammonium nitrogen;2)the adsorption equilibrium time of coal gangue zeolite and coal gangue slag zeolite arerespectively45min and60min; in the process of adsorption, both zeolites fits to thequasi secondary kinetic fitting line, the coal gangue slag zeolite has better correlation tothe fitting line, which is0.9989; particle diffusion is the control step for adsorption ofammonium nitrogen by coal gangue zeolite, liquid membrane diffusion is the controlstep for adsorption of ammonium nitrogen by coal gangue slag zeolite; effectivediffusivity of coal gangue zeolite Dc=2.4686×10^-7cm²/s; effective diffusivity of coalgangue slag zeolite Dc=2.2043×10^-7cm²/s.The study result provides a new method to utilize waste coal gangue and slag,solving the problem of occupation of land and environment pollution, also used to treatammonium nitrogen waste water, the subject has high benefit of economy andenvironment.