title: Anomalous but massive removal of two organic dye pollutants simultaneously.
abstract: A one-pot method to remove two organic dye contaminants and alkali simultaneously from alkaline wastewater was developed by forming Zn-Al layered double hydroxide (ZnAl-LDH). Using this process, not only alkali but also methyl orange (MO), an anionic contaminant was totally removed from wastewater. In addition, cationic contaminant, methylene blue (MB) was also removed effectively while maintaining the high removal efficiency of MO. The removal efficiency of MO was almost 100% and the pH of the treated wastewater decreased from 12 to 7.38. The charge-limited removal process, molecular arrangement of the contaminants in LDHs, and the anomalous removal mechanism were analyzed experimentally and through simulation. After MO accumulated in the interlayers of LDH by electrostatic interaction, MB entered and trapped by hydrophobic interaction.
authors.affiliation: Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes, National Laboratory of Mineral Materials, School of Materials Science and Technology, China University of Geosciences, Beijing 100083, China; Department of Ecosystem Science and Management, Materials Research Institute, Materials Research Laboratory, the Pennsylvania State University, University Park, PA 16802, United States.
authors.forename: Zilin
authors.initials: Z
authors.lastname: Meng
authors.affiliation: Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes, National Laboratory of Mineral Materials, School of Materials Science and Technology, China University of Geosciences, Beijing 100083, China. Electronic address: zyh@cugb.edu.cn.
authors.forename: Yihe
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Drilling Research Institute, CNPC, Beijing, China.
authors.forename: Zhilei
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes, National Laboratory of Mineral Materials, School of Materials Science and Technology, China University of Geosciences, Beijing 100083, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Department of Physics & Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong, China.
authors.forename: Paul K
authors.initials: PK
authors.lastname: Chu
authors.affiliation: Department of Ecosystem Science and Management, Materials Research Institute, Materials Research Laboratory, the Pennsylvania State University, University Park, PA 16802, United States. Electronic address: Komarneni@psu.edu.
authors.forename: Sridhar
authors.initials: S
authors.lastname: Komarneni
authors.affiliation: Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes, National Laboratory of Mineral Materials, School of Materials Science and Technology, China University of Geosciences, Beijing 100083, China. Electronic address: lfz619@cugb.edu.cn.
authors.forename: Fengzhu
authors.initials: F
authors.lastname: Lv
keywords: Alkali; Methyl orange; Molecular simulation; Organic contaminants; ZnAl-LDH