Hardness removal of groundwater through sand, zeolite and rice husk activated carbon

Abstract

Recently the treatment for hard water was by using a technique that will give an impact on the environment and consumer. Sand, zeolite and rice husk-activated carbon can be used as a media for water hardness treatment by adsorption process. Performance of sand, zeolite and rice husk activated carbon (RHAC) for removal of Ca2+ and Mg2+ in hard water was investigated by employing a batch experimental set-up. The study considered X-ray fluorescence (XRF) spectroscopy analysis for the evaluation of the chemical composition of the media and Fourier transform infrared (FTIR) spectroscopy for the surface functional group. Experimental adsorption data were modelled by Langmuir, Freundlich and BET. The adsorption process followed the Langmuir isotherm model with high coefficients of correlation R2 (0.9888) for Ca2+ and R2 (0.9662) for Mg2+. The RL value in this study was less than one for both Ca2+ and Mg2+, indicating that the absorption of the metal ion onto all the media is favourable. The pseudo-second-order fitted well in correlation to the experiment results. The results indicate that sand, zeolite, and RHAC have chemisorption mechanisms and can be alternative media for hard water treatment using the adsorption process. Furthermore, there will be an advantage in terms of economic and environment-friendly media.