Evaluation of Chloroquine Drug Degradation by Combined Adsorption Process and Fenton-Like Reaction Based on Mixed-Valence Mil-100 (Fe) Without Energy Assistance and Metal Doping

Abstract

Chloroquine phosphate (CQP) has posed significant hazards and risks to ecological environment. This study evaluated the chloroquine drug degradation by combined adsorption process and Fenton-like reaction based on mixed-valence MIL-100 (Fe) without energy assistance and metal doping. Adsorption tests and the Fenton-like reaction were carried out. CQP removal rate was about 96 % within 60 min with 5 mM of H2O2 and 30 mg/L of CQP. The pseudo-second-order rate equation and Langmuir model are more suitable for the adsorption behavior of CQP. Pore adsorption, electrostatic interaction, Lewis acid-base interaction, π-π interaction, and hydrogen bonding can explain the adsorption mechanism. Fe (II) substitution in Fe-MOFs materials can accelerate the Fe(III)/Fe(II) redox cycle and the Fenton-like oxidation rate. CQP degradation was found to occur mainly by the heterogeneous Fenton-like process. Four free radicals (•OH, electron, 1O2, and O2•–) are involved in the Fenton-like catalytic oxidation of CQP. The fixed-bed reactor based on mixed-valence MIL-100 (Fe) and PVA gel has excellent properties for continuous removal of CQP. The above results confirm the potential application of mixed-valence MIL-100 (Fe) as an effective adsorbent and Fenton-like catalyst for the continuous removal of CQP from wastewater.

Keywords: Chloroquine, Fe (III)/Fe (II) cycle, Fenton-Like Degradation, MIL-100 (Fe), adsorption