An Investigation on Effectiveness of Grafted Potato Starch as an Adsorbent for Hard Water Treatment

Water is essential for the life of all living organisms. But water with very high hardness (Ca2+ and Mg2+) is harmful to health. In addition, hard water clogs the pipes in the industries. This study was conducted to investigate the effectiveness of grafted potato starch as an adsorbent for hard water treatment. Four samples of well water from Nzuguni, Ng’hong’hona, Kisasa, and Swaswa of Dodoma municipal were analyzed by the EDTA titrimetric method. The results showed the highest hardness of 547 mg/L in the water sample of Ng’hong’hona from which hardness was removed. The maximum percentage removal of 74.50% was achieved at 80 minutes of optimum contact time. The optimum adsorbent dose is 3.5 g at which 80.7% of removal was achieved. The optimum temperature was 80°C at which 75.8% of removal achieved. An increase in pH increased the percentage of removal up to a pH of 12 with 71.1%. The data obtained showed that the adsorption process fitted Langmuir type II isothermal model and pseudo-second-order kinetic model with correlation coefficients of 0.9994 and 0.9940, respectively. Grafted potato starch has shown higher efficiency in hardness removal, and hence, this adsorbent is highly recommended for the treatment of hard water