Abstract:
In this research, the commercial chitosan with degree of deacetylation 96 percent, ashcontent 1 percent, CaCO, content 0.08 percent, molecular weight 300,000 glmole and mean powdersize in range of 0.297-0.590 mm was used. Chitosan porous bead was developed by dropping 4percent chitosan solution in 2 percent acetic acid. The obtained chitosan porous bead was sphericalwith white color like a glutinous pallet, soft, and sturdy. The surface area, porosity, density, moisturecontent and mean outside diameter of chitosan porous bead were 2,850 mm2/mg, 0.159 cm31g, 0.16063 glcm ,97 percent and 3.43 mm, respectively.The results show that 120 g of chitosan porous bead was able to remove hardness fromCaCl,, CaSO,, MgC12, MgSO, solutions at 36, 38, 28 and 29 percent, respectively. The absorptioncapacity of chitosan porous bead for calcium from CaC1, and CaSO, were 7.35 mglg and 9.75 mglgrespectively, where as for magnesium from MgC1, and MgSO, were 6.58 mglg and 7.33 mglgrespectively. Among these hardness ions, the absorption rate of CaCl, solution was the most rapid.The results also indicate that lower concentration of absorbents is the better condition for hardnessabsorption.