Selectivity of S 930 ion exchange resin regarding Ca2+ and Ni2+ ions from aqueous solutions

The natural water usually contents a series of the metallic ions, such as: Ca2+, Mg2+, K+ and Na+ that confer the test and quality of water, and also some heavy metals in trace like Ni2+, Al3+, Zn2+, Cd2+, Cu2+ etc that determine the toxicity of water. For obtaining potable water with quality according to European legislation is necessary to apply adequate methods to remove the heavy metals. Water pollution by toxic metals remains an important environmental issue having a major impact on the public health and the economy. This paper present a comparative study of Ca2+ and Ni2+ ions sorption from aqueous solutions on S 930 ion exchange resin. The ion exchange capacity toward Ca2+ and Ni2+ ions depends on the pH values of the aqueous solution, increasing with the increase of pH value in the range of 2 – 6.5 pH unities. Simultaneous sorption on S 930 E of Ca2+ and Ni2+ ions from their binary mixed solutions was studied, the weight ratios between the two metals in the binary systems being 1:2, 1:1; 2:1 and 5:1, by the means of batch experiments performed at 20.0 0.1o C, at different pH values. Among the studied systems, Ni seems to have the strongest affinity for S930 ion exchange resin.