Synthesis of Pyridine Dicarboxylic Acid Functionalized and Crosslinked to Polyvinyl Alcohol/polyamide for Thorium Capturing From Aqueous Solution

Abstract

AbstractThorium harms humans and the environment. Mining can release thorium‐containing waste. This study aims to simplify the production of a novel poly‐adsorbent by mixing pyridine dicarboxylic acid, polyvinyl alcohol, and polyamide and first removing thorium from the solution. Various analytical methods were used to characterize the produced dicarboxylic acid/polyvinyl alcohol/polyamide poly‐adsorbent. The practical conditions on adsorption effectiveness evaluated to pH 3.5, 60 mg poly‐adsorbent, 60 min. Th(IV) uptake for poly‐adsorbent is 107.3 mg/g. The linear and nonlinear uptake for the pseudo‐second‐order is closer to the practical uptake (107.71 mg/g). Hence, the kinetic analysis verified the sorption mechanism. Also, the uptake of linear (107.64 mg/g) and nonlinear (108.63 mg/g) types for the Langmuir isotherm is closer to the practical uptake (107.71 mg/g); thus, the sorption isotherm was suitably utilizing Langmuir modeling. Thermodynamic studies proved that the sorption is spontaneous, exothermic, and random due to the negative ΔG°, negative ΔH°, and positive ΔS° during the thorium adsorption process on poly‐adsorbent. In addition, the regeneration ability of poly‐adsorbent was tested utilizing 1.5 M H2SO4. After six cycles, the poly‐adsorbent showed about 83 % regeneration efficacy. The results confirmed that the dicarboxylic acid/polyvinyl alcohol/polyamide poly‐adsorbent might be effective in removing Th(IV) from the watery solution.