Calcium loading onto granular activated carbon with salicylate or phthalate

In order to evaluate the effects of complexation on calcium loading in the presence of organic compounds, the calcium-salicylate and calcium-phthalate systems were examined. These compounds were chosen as models to evaluate the role of carboxyl and hydroxyl groups in otherwise similar compounds. Batch tests were conducted at varying pH. Total organic carbon (TOC) loading onto granular activated carbon (GAC) was evaluated in the presence and absence of calcium. Calcium loading onto GAC significantly increased in systems that contained salicylate. Salicylate adsorption onto GAC also increased in the presence of calcium. In comparison, calcium loading onto GAC was only slightly enhanced in the presence of phthalate, and phthalate loading onto GAC was not substantially increased in the presence of calcium.