A novel N-(2-acetamido)-2-aminoethanesulfonic acid (AASA) and Zr3C2Tx MXene-modified organosolv lignin (OL) (AASA@ Zr3C2Tx @OL) composite for simultaneous adsorption of tetracycline and U(VI)

Abstract

Hospital wastewater contains two dangerous contaminants that coexist: tetracycline (TC) and uranium (U(VI)). Comprehensive studies on the simultaneous removal of U (VI) and TC with potential mechanisms have not yet been conducted. Therefore, a novel N-(2-acetamido)-2-aminoethanesulfonic acid (AASA) and Zr₃C₂T_x MXene-modified organosolv lignin (OL) (AASA@Zr₃C₂T_x@OL) composite was facilely synthesized as a model adsorbent for demonstrating its simultaneous adsorption capability and mechanism for tetracycline (TC) and uranium (U (VI). The adsorption performance of the AASA@Zr₃C₂T_x@OL ternary composite was examined at various temperatures (2938.15, 308.15, 318.15K, and 328.15 K), pH values (1–9 for U(VI) and 1–12 for TC), and starting adsorbent concentrations (1–100 mg/L for U(VI) and 1–150 mg/L for TC) in this work. In a single pollutant system, it was discovered that the as-resultant adsorbent demonstrated remarkable sorption capability toward TC and U (VI), with q_max values of 563.93 and 454.27 mg/g, respectively. Adsorption of TC and U (VI) can attain equilibrium in 3 and 6 min, respectively, because of the participation of several mechanisms, such as hydrogen bonding, π-π interaction, electrostatic attraction, and complexation It is interesting to note that, in the TC-U (VI) binary system, the complex (AASA@Zr₃C₂T_x@OL adsorbent-U (VI)-TC or AASA@Zr₃C₂T_x@OL adsorbent-TC-U (VI)) formed when U (VI) or TC coexisted, significantly promoting each other's removal efficiency. The results of XPS and FTIR studies indicated that the uptake mechanisms were primarily due to hydrogen bonding, π-π interaction, electrostatic attraction, and complexation.