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Yang B, Han F, Li Y, Bai Y, Xie Z, Yang J, Liu T. Phosphate removal mechanism of a novel magnesium slag-modified coal gasification coarse slag adsorbent. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:60607-60617. [PMID: 37036649 DOI: 10.1007/s11356-023-26667-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Accepted: 03/21/2023] [Indexed: 05/10/2023]
Abstract
We used magnesium slag (MS) as a calcium source for modifying coal gasification coarse slag (CGCS) in the presence of NaOH to prepare a novel phosphate adsorbent (MS-CGCS). Ca2SiO4 in MS reacts with NaOH during the high-temperature synthesis process, with sodium displacing a part of the calcium content in Ca2SiO4 and entering the mineral lattice to form Na2CaSiO4. Hydroxide ions reacted with calcium in Ca2SiO4 to generate Ca(OH)2 and decomposed into CaO at a high temperature. The two newly formed species participated in the phosphate removal. The MS-CGCS adsorbent showed good phosphate removal performance over a wide pH range, with a maximum phosphate adsorption capacity of 50.14 mg/g, which was significantly higher than that of other reported adsorbents. The Langmuir and pseudo-second-order models described the adsorption process well, indicating it being a monolayer and chemisorption process. The main mechanisms of phosphate removal are as follows: electrostatic interaction between the positively charged MS-CGCS and negatively charged phosphate ions; the inner-sphere complexation of oxides of metal, such as magnesium, aluminum, and calcium, with phosphate ions; and the precipitation of phosphate ions with calcium ions. Precipitation contributes to ~ 32% of the phosphate removal. This study provides a new method for the development of phosphate adsorbents while recycling CGCS and MS.
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Affiliation(s)
- Baoguo Yang
- Hubei Key Laboratory of Yangtze River Basin Environmental Aquatic Science, School of Environmental Studies, China University of Geosciences, NO. 68 Jincheng Street, East Lake High-Tech Development Zone, Wuhan, 430078, People's Republic of China
- Ningxia Institute of Geophysical and Geochemical Survey (Autonomous Regional Deep Earth Exploration Center), Yinchuan, 750001, China
| | - Fenglan Han
- School of Materials Science and Engineering, North Minzu University, Yinchuan, 750021, China.
| | - Yilian Li
- Hubei Key Laboratory of Yangtze River Basin Environmental Aquatic Science, School of Environmental Studies, China University of Geosciences, NO. 68 Jincheng Street, East Lake High-Tech Development Zone, Wuhan, 430078, People's Republic of China
| | - Yadong Bai
- Ningxia Institute of Geophysical and Geochemical Survey (Autonomous Regional Deep Earth Exploration Center), Yinchuan, 750001, China
| | - Zuoming Xie
- Hubei Key Laboratory of Yangtze River Basin Environmental Aquatic Science, School of Environmental Studies, China University of Geosciences, NO. 68 Jincheng Street, East Lake High-Tech Development Zone, Wuhan, 430078, People's Republic of China
| | - Jing Yang
- Ningxia Institute of Geophysical and Geochemical Survey (Autonomous Regional Deep Earth Exploration Center), Yinchuan, 750001, China
| | - Tengteng Liu
- School of Materials Science and Engineering, North Minzu University, Yinchuan, 750021, China
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Nasir A, Inaam-Ul-Hassan M, Raza A, Tahir M, Yasin T. Removal of copper using chitosan beads embedded with amidoxime grafted graphene oxide nanohybids. Int J Biol Macromol 2022; 222:750-758. [PMID: 36167100 DOI: 10.1016/j.ijbiomac.2022.09.188] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 07/15/2022] [Accepted: 09/21/2022] [Indexed: 11/05/2022]
Abstract
This study explores a biopolymer-based composite system for metal decontamination of water using copper {Cu (II)} as a model pollutant. Novel composite beads of chitosan and amidoxime grafted graphene oxide (AOGO) were successfully prepared and used for the Cu (II) removal from aqueous solutions. For this purpose, acrylonitrile was first polymerized onto a gamma-irradiated and silanized graphene oxide substrate. The nitrile groups of polyacrylonitrile grafted graphene oxide (GO-g-PAN) were then chemically modified into amidoxime groups to form AOGO nanohybrids. These nanohybrids were mixed with a blend of chitosan (CS) and polyvinyl alcohol (PVA) and crosslinked using tetraethylorthosilicate (TEOS) to form composite CP/AOGO beads. Fourier transform infrared spectroscopy (FTIR) was used to study the structural changes at each step during the formation of composite beads. Scanning electron microscopic (SEM) analysis demonstrated that the beads had a well-developed spherical structure. The adsorption of Cu (II) onto CP/AOGO composite beads was studied under different conditions (initial concentration, pH, and contact time). The results revealed the potential of composite beads in copper removal from aqueous solutions.
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Affiliation(s)
- Amara Nasir
- Pakistan Institute of Engineering and Applied Sciences (PIEAS), Islamabad 45650, Pakistan.
| | | | - Asif Raza
- Pakistan Institute of Engineering and Applied Sciences (PIEAS), Islamabad 45650, Pakistan
| | - Mehwish Tahir
- Pakistan Institute of Engineering and Applied Sciences (PIEAS), Islamabad 45650, Pakistan
| | - Tariq Yasin
- Pakistan Institute of Engineering and Applied Sciences (PIEAS), Islamabad 45650, Pakistan.
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