Experimental Study Of Nodified Clinoptilolite Adsorption On N,P,K Removal In Bovine Urine Wastewater

With the rapid development of China's large-scale livestock and poultry breeding reduction set,the problem of environmental pollution of excrement of livestock and poultry production is becoming more and more serious.Causing serious air pollution,groundwater,surface water,soil and environment,has a direct impact on people's health and normal life.This study aimed at Dali Erhai P N,eutrophication,choose environmentally friendly natural clinoptilolite as an adsorbent material,and makes,sodium modification and rare earth modified heat load,made of composite modified clinoptilolite.Taking Dengchuan County at a dairy farm cattle urine wastewater as treatment object,composite adsorption behaviour of Modified Clinoptilolite to ammonia nitrogen,phosphorus,potassium in wastewater was studied,the effects of pH value of water,contact time,temperature,amount of adsorbent for ammonia nitrogen,phosphorus,potassium adsorption,the best adsorption condition determine.And the composite modified ammonia nitrogen,phosphorus,potassium clinoptilolite adsorption in wastewater by the adsorption isotherm,adsorption kinetics model of dynamic experiment,etc.Finally,the mechanism of material science and the characterization of adsorption ammonia nitrogen,phosphorus,potassium of natural zeolite and Modified Clinoptilolite is discussed preliminarily.The results show that:The experimental study on optimum adsorption conditions are:modified clinoptilolite dosage(g)and water volume(mL)according to the ratio of 9:50 dosing,pH 8,30?,adsorption of 2.0h.Under this condition,using clinoptilolite and modified clinoptilolite to adsorp cow urine wastewater(concentration of ammonia nitrogen,phosphorus,potassium,respectively is:2491.33mg/L,56.92mg/L,5396mg/L),the results showed that the adsorptive performance of modified clinoptilolite to adorb ammonia nitrogen,phosphorus,potassium in wastewater was better than natural clinoptilolite.The removal rate of ammonia,phosphorus,potassium was 44.4%,85.2%and 25.1%respectively,concentration of ammonia nitrogen,phosphorus,potassium were decreased to 13 84.18mg/L,8.42mg/L,3988mg/L.And compared with the removal rate of clinoptilolite,the removel rate of ammonia nitrogen phosphorus,potassium adsorbed by modified clinoptilolite was increased 16%,40%,9%respectively.Using the Modified Clinoptilolite treatment of cow urine wastewater,the zeolite of K increased by 50.9%,the content of P increased by 144.1%,It promotes the application potential of modified clinoptilolite to become agricultural fertilizer after treatment of cow urine wastewater.Isothermal adsorption curves of modified clinoptilolite adsorption of ammonia nitrogen,potassium accords with Langmuir isothermal adsorption equation.And the adsorption isotherm of phosphorus feels with Freundlich isothermal adsorption equation.The dynamic experimental results show that when the water flowing into the zeolite column is large,the penetration time is shorter,and the smaller the penetration capacity of zeolite.Study on dynamic characteristics of modified clinoptilolite to absorb ammonia nitrogen,phosphorus,potassium,the results showed that the adsorption process is a typical fast adsorption and slow balance process,kinetic curves of modified clinoptilolite adsorption of ammonia nitrogen,phosphorus,and potassium conforms to the second quasi-dynamic model.Natural clinoptilolite and modified clinoptilolite was confirmed by BET,XRD,XRF,SEM,energy spectrum and infrared spectrum detection,the results show that,the modified clinoptilolite increased the specific surface area,pore diameter,the formation of the soft sponge.Zeolite crystallinity was increased,no obvious change in crystal structure.The mechanism of modified clinoptilolite adsorbing ammonia nitrogen,phosphorus shows that the adsorption process may includes two steps:(1)In the solution,ammonia nitrogen,phosphorus and potassium are in the form of ions to be transferred to the exchange of zeolite lattice site;(2)With chemical complexation or ion exchange on the adsorption sites,ammonia nitrogen,phosphorus and potassium are adsorped on the surface of the zeolite or into the pore of zeolite.Using the modified clinoptilolite to adsorb cow urine wastewater ammonia nitrogen,phosphorus and potassium in plant nutrition elements,on the one hand,nutrients can be recycled,on the other hand it can reduce subsequent load of wastewater treatment.It can provide technical reference for the recycling of nutrients in the livestock and poultry breeding wastewater and the research on wastewater treatment.