Enhancing removal and recovery of magnesium from aqueous solutions by using modified zeolite and bentonite and process optimization

摘要

Natural and modified zeolite and bentonite are investigated and characterized for extraction of magnesium from aqueous solutions. Magnesium removals as high as 85.21% and 81.73% were achieved by calcined bentonite and microwave radiated zeolite, respectively. The effects of various operational parameters were studied and optimized using selected isotherms. Maximum Mg (II) adsorption capacities of 26.24 and 35.67mg center dot g(-1) were obtained on pristine and calcined bentonites, respectively. Thermodynamic studies suggest that magnesium adsorption on natural bentonite is spontaneous and endothermic (9.13 kj center dot mol(-1)). Also, desorption study of natural bentonite demonstrates that HNO3 is more effective by offering 89.11% desorption than other desorptive counterparts.