Study On Adsorption Properties Of Bentonite Modified And Granulation Of Nutrients In The Water

Bentonite has been widely used in wastewater treatment for its large specific surface area,good adsorption capacity and cation exchange capacity,and has been widely used in practical application.This study explores several bentonite modified method,using the modified through inorganic drug magnesium sulfate and calcium chloride,and researching granular bentonite adsorption column dynamic adsorption simulated wastewater containing ammonia nitrogen and phosphate.Research mainly through three aspects,the effect of bentonite powder modification and granulation on the adsorption properties of ammonia nitrogen and phosphate in water,the test of granular bentonite adsorption column dynamic adsorption simulated wastewater containing ammonia nitrogen and phosphate,to explore the change of bentonite adsorption of nitrogen and phosphorus from wastewater.The main research contents and results are as follows:?1?Effect of Modified bentonite powder to ammonia nitrogen with phosphate adsorption propertiesBentonite optimum modification conditions:modified concentration is 0.1 mol/L,modified drugs is CaCl₂,adsorption time is 40 min.After the bentonite is modified by CaCl₂ or MgSO4,montmorillonite interlayer spacing and the specific surface area increase,it promotes the ions adsorption reaction,the removal rate of modified clay is higher than bentonite not modified.CaCl₂ modified soil adsorption capacity is greater than that of MgSO4 modified soil.The ions initial concentration of NH4+ and PO43-increase,removal of contaminants in water are increased,however,the growth rate of the initial concentration is greater than that of the removal of contaminants in water and ultimately reduce water nutrient removal.Therefore,ammonia nitrogen and phosphate removal rates of CaCl₂ Modified clay increase with the initial concentration,as MgSO4 modified soil is.When modified bentonite meanwhile adsorb ammonia nitrogen and phosphate,its adsorption properties affect each other.The exchange adsorption between two kinds of cation of mixed soil?two kinds of modified soil mixing?inhibits that of single cation with NH4+ in water,so the ammonia removal rate of mixed soil is lower than that of nonmixed soil.?2?Effect of bentonite particles granulation to ammonia nitrogen with phosphate adsorption propertiesUsing bentonite as raw material,and 2%?mass fraction?of AICl3 solution as adhesive agent made of particles,diameter 3?4 mm,in the oven in 105 ? under the baking 3 h and again in muffle furnace in 500 ? under the burning 4 h,bentonite particles obtained by this method has the best adsorption properties to nutrients in the water.After the bentonite is made of particles,its adsorption performance was significantly decreased.But whether it is powder or granular,the adsorption properties of CaCl₂ modified bentonite were the best.CaCl₂ modified particles maximum adsorption concentration of ammonia nitrogen in water is 40 mg/L,and the nonmodified particles is 37 mg/L.The maximum adsorption concentration of CaCl₂ modified particles to phosphate is 2.9 mg/L,and the nonmodified particles is 5.6 mg/L.?3?Test of granular bentonite adsorption column dynamic adsorption simulated wastewaterWhen the hydraulic retention time is 60 min,the removal rate of ammonia nitrogen and phosphate is the highest,and the running time is also the most,so the optimum hydraulic retention time of the device is 60 min.The smaller the hydraulic retention time,the greater the amount of water flowing through the adsorption column in the same time.Then bentonite particles poorly contact with waste wate,the removal rate of ammonia nitrogen and phosphate was smaller.Therefore,the smaller the hydraulic retention time,the lower the removal rates of ammonia nitrogen and phosphate,the less the maximum running days.Adsorption column adsorption of Sand Lake water,the removal rates of ammonia nitrogen and phosphoric all are lower than the theoretical value for other pollutants in the actual waste water,the maximum running days is the same.The best use of bentonite in this study is to use 0.1 mol/L CaCl₂ modified bentonite,static adsorption of 40 min?bentonite particles is oscillation adsorption 60 min under 100 r/min?,and can simultaneously adsorbe N and P in wastewater.That bentonite is applied to the actual wastewater treatment needs to solve the problem of soil water separation because of its difficult settlement.