%A Jing Li, Haiqin Yu, Xue Zhang, Rixin Zhu, Liangguo Yan %T Crosslinking acrylamide with EDTA-intercalated layered double hydroxide for enhanced recovery of Cr(VI) and Congo red: Adsorptive and mechanistic study %0 Journal Article %D 2020 %J Front. Environ. Sci. Eng. %J Frontiers of Environmental Science & Engineering %@ 2095-2201 %R 10.1007/s11783-020-1229-x %P 52- %V 14 %N 3 %U {https://journal.hep.com.cn/fese/EN/10.1007/s11783-020-1229-x %8 2020-06-15 %X

• Functional groups of AM and EDTA in composite increased removal of Cr(VI) and CR.

• Removal process reached equilibrium within 30 min and was minimally affected by pH.

• Elimination of Cr(VI) was promoted by coexisting CR.

• Adsorption process of CR was less influenced by the presence of Cr(VI).

• Mechanisms were electrostatic attraction, surface complexation and anion exchange.

We prepared ethylenediaminetetraacetic acid (EDTA)-intercalated MgAl-layered double hydroxide (LDH-EDTA), then grafted acrylamide (AM) to the LDH-EDTA by a cross-linking method to yield a LDH-EDTA-AM composite; we then evaluated its adsorptive ability for Congo red (CR) and hexavalent chromium (Cr(VI)) in single and binary adsorption systems. The adsorption process on LDH-EDTA-AM for CR and Cr(VI) achieved equilibrium quickly, and the removal efficiencies were minimally affected by initial pH. The maximum uptake quantities of CR and Cr(VI) on LDH-EDTA-AM were 632.9 and 48.47 mg/g, respectively. In mixed systems, chromate removal was stimulated by the presence of CR, while the adsorption efficiency of CR was almost not influenced by coexisting Cr(VI). The mechanisms involved electrostatic attraction, surface complexation, and anion exchange for the adsorption of both hazardous pollutants. In the Cr(VI) adsorption process, reduction also took place. The removal efficiencies in real contaminated water were all higher than those in the laboratory solutions.