The presence of cations such as calcium and magnesium led to increased hardness of water. The hardness of water is undesirable for some industries such as leather and dyeing. Also, the presence of Ca2+ , Mg2+ and Na+ in water stream has the most influence for the increasing of conductivity of water [1]. Electrical conductivity (EC) is an important parameter in water quality assessments for drinking and irrigation, since it is related to the concentration of charged particles in the water like Ca2+, Mg2+ , and Na+ ions. The common methods used for softening of water and reduction of conductivity are chemical precipitation, ion exchange and reverse osmosis (RO) [2]. The sono-sorption method is appropriate, efficient, and environmentally friendly approach to complete and rapid removal of cations from aqueous solution [3-5]. In this study, the combination of moss as a biomass and anionic resin as a synthetic matter were used for the removal of Ca (II), Mg (II), and Na (I) as a mixture. This removal led to the reduction of conductivity from aqueous solutions and softening of water. The efficiency of the removal was studied using batch adsorption technique under different experimental conditions such as resin/moss ratio, initial metal-ion concentration, and contact time. Chemical treatment was carried out for the activation of the moss. The optimum amount of resin/moss ratio was one for different metal-ion concentrations. The adsorption of Mg (II) on the treated moss was higher than the other ions and it was completed after 3 minutes. Adsorption of calcium and sodium ions reached to a maximum amount after 5 minutes. Different kinetic models were applied for the sorption process and the sorption of ions followed pseudo-second order model. From the BET analysis, the specific surface area of treated and untreated moss was 5.0 and 0.18 m2/g, respectively. The present study revealed that moss as a low cost material could be a proper case for replacing with cationic resin and it can be used as an efficient adsorbent for the removal of alkali and alkali earth metal ions from water streams.

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