Removal of total hardness using low cost adsorbents

Abstract

Water hardness is an undesirable quality of water in many regions around the world. Hardness can be removed by different methods like ion exchange method, reverse osmosis, distillation, lime soda process etc. But owing to the increase in cost, energy and hectic processes in these methods, it is essential to find an alternative method for softening of water. Nowadays, adsorption methods are gaining attention due its simplicity and efficiency. Efficiency of different adsorbents like Amorphophallus campanulatus (Elephant foot yam), wheat straw ash and rice husk ash and coconut shell activated carbon which are naturally available are investigated in this study. Yam is freely abundant and found to be more efficient compared to others. The efficiency of softening is above 80% for yam. Value of equilibrium constant (RL) and adsorption intensity factor (n) gives the feasibility and intensity of adsorption. Acidic modification has given a negative impact in softening of water for the used materials. High carbon containing substance in ash form has brilliant adsorption ability. Investigations to find out efficiencies are done by optimizing parameters such as adsorbent dosage, pH and contact time. The performances are assessed by isotherm studies. These studies and experiments are done to suggest a simple setup which rectifies the problems of conventional methods for the removal of hardness.