A Sandwich Structure of Fulvic Acid and PMIDA-Modified LDHs for the Simultaneous Removal of Cu²⁺ and Aniline in Multicomponent Solutions

Abstract

The coexistence of organic and inorganic pollutants in industrial wastewater has emerged as a concerning environmental issue worldwide due to the critical levels of biological toxicity of these pollutants. In this context, the present study proposes a sandwich structure of fulvic acid and PMIDA-modified LDHs (FA/PMIDA-LDHs) for the simultaneous removal of Cu2+ and aniline from wastewater. The specific structure was synthesized using a combination of coprecipitation and impregnation methods. Abundant benzene rings and oxygen-containing functional groups greatly increased the number of sites for the adsorption of both Cu2+ and aniline. The maximum adsorption capacity of Cu2+ and aniline in solution with initial pH 5.0 at 25 °C could reach 221.24 and 132.28 mg/g, respectively. Cu2+ could be chelated by the functional groups in the FA/PMIDA-LDHs structure, and a coupled reduction–complexation mechanism was proposed for this process. The uptake of aniline on FA/PMIDA-LDHs was demonstrated to be a result of the combination of coordination forces, hydrophobic effects, π–π interactions, and hydrogen bonds. In a multicomponent solution, FA/PMIDA-LDHs exhibited excellent salt tolerance of up to 1000 mg/L of Na+ or Ca2+. The effects of Fe3+, Ni2+, Cl–, Cr2O7 2–, SO4 2–, and H2PO4 – on the uptakes of Cu2+ and aniline were also investigated.

Pore Regulation of Carboxyl-Functionalized Hyper-Crosslinked Polymers and Their Efficient Aniline Adsorption

“…The utilization of aniline, a basic aromatic amine, has been extensively employed across various industrial sectors including the manufacture of dyes, pharmaceuticals, and polymers. , Nevertheless, its widespread application has raised significant concerns regarding occupational exposure and environmental contamination. , Furthermore, the International Agency for Research on Cancer (IARC) has categorized aniline as a group 2B carcinogen, underscoring its potential harm to humans health. , Therefore, the rapid and efficient elimination of aniline in water holds immense significance and has attracted more and more attention in recent years. , …”