Nano LTA Zeolite in Water Softening Process: Synthesis, Characterization, Kinetic studies and process optimization by Response Surface Methodology (RSM)

In the present study, nano zeolite A (LTA) was synthesized by the alkaline fusion method without adding an organic template. Effect of temperature and aging time were studied on the crystallinity and morphology of the final product. The synthesized LTA was characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC) and N2 adsorption/desorption technique. The prepared nano LTA zeolite was applied to the water softening process. The main effects and interaction of factors such as pH, the amount of LTA, initial total hardness, temperature and contact time were investigated by response surface methodology (RSM). The obtained optimum values of factors were applied to hard water to remove Ca2+ and Mg2+ ions. Pseudo-first and second-order models were applied to kinetic and rate data. It was found that the adsorption rate follows the pseudo-second-order kinetic model.