Potentials of agric wastes activated carbons for water softening

Abstract

Various studies have been conducted to address softening of hard water. Ion exchange, electro-based techniques, membrane filtration and adsorption are the most reported techniques in softening hard water. In the present work, performances of these techniques are reviewed and discussed. Likewise, adsorbents that have so far been used in water softening, their efficiencies and drawbacks have been reported. Best adsorbent has been proposed based on optimum pH and local availability. In addition to the review of existing work on hardness removal, we have performed some preliminary experiments to study the performance of adsorbents, namely coconut and cashewnut shell activated carbons. The results are presented in here and it was found that, both adsorbents perform better in water softening but cashewnut shell activated carbon performs the best. These adsorbents are cheaply and locally available, which makes their integration into the softening systems low cost and highly performing owing to their chemical contents and subsequent activations.