Trilite adsorption characteristics for perchlorate from Korean military facilities

Abstract

Perchlorate is used as an oxidizer in solid propellants for rockets, missiles, and fireworks. It is not classified as a carcinogen according to the US EPA, EU, and WHO; however, it affects the respiratory system and skin. Perchlorate removal is not very effectively achieved by biological processes with coagulation and activated carbon. At present, relatively efficient removal methods, which have been tested and backed by study, include ion exchange and membrane processes. Ion exchange is the most commonly used method, and it has proven to be the most effective. The maximum perchlorate concentrations in Korea and USA were 107.7 μg/L and 2600 mg/L, respectively, exceeded the Drinking Water Equivalent Level (DWEL) by the US EPA (24.5 μg/L). The perchlorate removal method was tested using an isothermal adsorption experiment that determined the characteristics of perchlorate adsorption onto Trilite. Evaluation of these results suggests a potential for local application of Trilite for perchlorate removal. The parameters and coefficients for adsorption isotherms were determined with linear and non-linear regression methods. The coefficient of determination of the Langmuir-1 isotherm was the highest (R2 = 0.998), and the maximum adsorption was 145 mg/ml, which was higher than reported for other anion exchange resins. The non-linear regression analysis showed the highest coefficient of determination (R2 = 0.968) for both the Langmuir and Redlich-Peterson isotherms. The optimal adsorption isotherms with the non-linear regression method were the Langmuir and Redlich-Peterson isotherms. The potential for local application of Trilite was evaluated via the Langmuir isotherm, which has a relatively simple formula. The value of R s was 0.028 (between 0< R s ≪1) or “very favorable.” Therefore, Trilite appeared to be among the desirable alternatives for the effective removal of perchlorate.