Effect of anion co-existence on ionic organic pollutants removal over Ca based layered double hydroxide

摘要

The effects of co-existing anions (NO3- or SO42-) on the removal of sodium dodecylsulfate (SDS), representing anionic organic pollutants, by Ca-based layered double hydroxide (CaAI-LDH-Cl) are investigated to provide fundamental insights on the ionic surfactant removal in the presence of co-existing anions, and facilitate the establishment of a practical and advanced water treatment for environmental remediation. The SO42- system shows higher adsorption capacity (4.43 mmol-g(-1)) and larger d-spacing of adsorption resultant (3.4 nm) than the control system with no co-existing anion (3.64 mmol-g(-1), 3.25 nm) and the NO3- system (3.82 mmol-g(-1), 3.27 nm). The macroscopic and microscopic analyses reveal that, NO3- had a little influence on the SDS removal due to strong electrolysis, while SOi(3)(2-) could significantly promote the SDS removal. Moreover, the reaction mechanism varies under different molar ratios of DS-/SO42- (C) 2018 Elsevier Inc. All rights reserved.