Abstract

This paper reports a very high capacity and recyclable Mg-Co-Al-layered double hydroxide@ g - C3N4 nanocomposite as the new adsorbent for remediation of radioisotope-containing medical-based solutions. In this work, a convenient solvothermal method was employed to synthesize a new nano-adsorbent, whose features were determined by energy dispersive X-ray (EDS/EDX), XRD, FESEM, TEM, TGA, BET, and FT-IR spectroscopy. The as-prepared nano-adsorbent was applied to capture the radioisotope iodine-131 mainly from the medicalbased wastewater under different conditions of main influential parameters, (i.e. adsorbent dose, initial I-2 concentration, sonication time, and temperature). The process was evaluated by three models of RSM, CCD-ANFIS, and CCD-GRNN. Furthermore, comprehensive kinetic, isotherm, thermodynamic, reusability cycles and optimization (by GA and DF) studies were conducted to evaluate the behavior and adsorption mechanism of I-2 on the surface of Mg-Co-Al-LDH@ g - C3N4 nanocomposite. High removal efficiency (95.25) of I-131 in only 30 min (i.e. during 1/384 its half-life), along with an excellent capacity that has ever been reported (2200.70 mg/g) and recyclability (seven times without breakthrough in the efficiency), turns the nanocomposite to a very promising option in remediation of I-131-containing solutions. Besides, from the models studied, ANFIS described the process with the highest accuracy and reliability with R-2 > 0.999.