| Currently bentonite is reported in the literature as a purifying agent have a lot ofresearch, but most studies just focus on bentonite modified and ignore the process ofdynamic adsorption and regeneration in water purification. In these studies, the practicalapplication of modified bentonite is not ideal. In this paper, poly(acrylic acid-acrylicsodium) bentonite composite was filled into a fixed bed and it was studied dynamicadsorption and regeneration of cadmium and lead ions in water purification.Based on the existing experiments on the synthesis of small synthetic experiment wasmagnified100times. The other conditions: the neutralization degree of acrylic acid was20%, the polymerization temperature was80℃, the reaction time was3h. In this paper, itstudied its adsorption of cadmium ions by different concentrations. The adsorption processis applied to the Langmuir isotherm model, Freundlich isotherm model and the Lagergrenisotherm model. The dynamic adsorption research shows that the BDST model can predictbreakthrough curves under different operating conditions. This paper establishedpoly(acrylic acid-acrylic sodium) bentonite composite dynamic adsorption model and gotnumerical solutions by matlab through finite difference method. The results showed that theapplication of a fixed-bed adsorption kinetics model and finite difference method can betterpredict the breakthrough curve in low initial concentrations and flow rates. Two models ofthe dynamics of cadmium ions can get reliable data. It has some significance to poly(acrylicacid-acrylic sodium) bentonite composite adsorption engineering design.In this paper, the saturation of the adsorption and desorption of composite bentonite isstatic, continuous desorption regeneration and regeneration. After using, as resolving agentssuch as acids and bases, as regenerant salt of the product was regenerated XRD, IR, SEMcharacterization and evaluation of regenerative adsorption capacity again.The results showthat bentonite composite by alkali regeneration become loose and bentonite some dissolvedout, the regenerative effect is very poor; bentonite composite with acid tof desorption andsalt of regeneration have good results, the bentonite composite have a stable structure by aconcentration of1mol/L of HCl as the desorbent and1mol/L NaCl regenerant. Thedesorption and regeneration time. It has a certain significance for poly(acrylic acid-acrylicsodium)bentonite composite recycling. Based on studies of bentonite composite cadmium ion adsorption, the adsorption oflead ions was studied. The adsorption process is equally applicable to the Langmuir model,Freundlich adsorption model and Lagergren kinetic model, the composite bentoniteadsorption capacity of lead ions is102.3mg/g. BDST model and Matlab predict thebreakthrough curves under different operating conditions. The effect is good. It indicate thatthese two models to predict the composite sorb other heavy metal ions. |
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