Research Article published by Research Journal in Engineering and Applied Sciences
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.