Modified nano-calcium carbonate with dodecyl trimethyl ammonium bromide and its adsorption properties of Congo red
Nano-calcium carbonate(CaCO3)was prepared from solid waste desulphurized gypsum in the condition of ammonia water and CO2 gas.The nano-calcium carbonate was modified by the surfactant dodecyl trimethyl ammonium bromide(DTAB).DTAB-CaCO3 was characterized and its adsorption performance for Congo red solution was studied.The effects of DTAB-CaCO3 dosage,temperature,ρ(Congo red)and time on the adsorption results were investigated.The adsorption kinetics and isothermal adsorption process were fitted and the thermodynamic parameters were calculated.The results show that when ρ(Congo red)=50 mg/L,m(DTAB)∶V(CaCO3)=0.20 g/L,pH=2 adsorption time is 120 min,the adsorption rate can reach 95％.The adsorption process is exothermic and spontaneous,and conforms to Langmuir isothermal single molecular layer adsorption model and second-order adsorption kinetic model.
Desulfurized gypsumNanometer calcium carbonateModifiedAdsorptionCongo red
万方数据
