Enhanced separation of europium radionuclides from active solutions using a novel sorbent of gadolinium metal–organic framework

Abstract

Preserving environmental quality when disposing of hazardous waste, especially radioactive waste, is a relevant research area that attracts the interest of global scientists. The separation of harmful species on the surface of novel adsorbent metal–organic frameworks (MOFs) is a promising and effective method for achieving this goal. This study identifies a new metal–organic framework known as melamine–terephthalic acid (MTGd MOF) that was synthesized and then treated with oxalic acid to produce modified MTGd–OX MOF that has been characterized. The MOFs were formed successfully based on the characterization results. BET results show that MTGd MOF and MTGd–OX MOF have surface areas of 1857.40 and 1955.16 m² g⁻¹, respectively. The prepared materials were used in batch studies to explore the sorption behavior of Eu radionuclides onto unmodified and modified MOFs. The results indicate that MTGd–OX MOF had a more effective sorption capacity than MTGd MOF. Several variables, including the pH, ionic strength, initial concentration of ^152+154Eu ions, contact time, and optimal conditions for separating ^152+154Eu onto MTGd–OX MOF, were examined, including temperature. The MTGd–OX MOF capacity is about 37.22 mg g⁻¹ at pH 3.5, and the equilibrium was reached after 4 hours. The efficiency of MTGd–OX MOF as a sorbent was assessed by analyzing a real waste sample, which showed it had significant sorption efficiency.