Triethylene tetramine-modified crosslinked acrylonitrile as Cu(II) ion adsorbent by photo-induced precipitation polymerization

• Published in: Iranian polymer journal 2021-07, Vol.30 (7), p.685-695
• Main Authors: Zeng, Lelin, Zhou, Feixiang, Zhan, Xuehui, Zhang, Yusheng, Xie, Wanyun, Wang, Guoxiang, Liang, Enxiang
• Format: Article
• Language: English
• Subjects: Adsorbents; Adsorption; Ceramics; Chemistry; Chemistry and Materials Science; Composites; Crosslinking; Glass; Heavy metals; Methylene bisacrylamide; Natural Materials; Original Research; Photoinitiators; Polyacrylonitrile; Polymer Sciences; Polymerization; Regeneration; Room temperature; Wastewater treatment
• ISSN: 1026-1265; 1735-5265
• DOI: 10.1007/s13726-021-00923-y

Heavy metal pollution is a serious environmental problem, and adsorption is regarded as an effective technology for metal ions removal. A new absorbent triethylene tetramine (TETA)-modified crosslinked polyacrylonitrile (TETA-modified XL-PAN) was prepared by photo-induced precipitation polymerization of acrylonitrile in water at room temperature using FeC 2 O 4 as photoinitiator and N , N′ -methylenebisacrylamide as crosslinking agent. The TETA provided amidogens, to bond Cu(II) ions and the crosslinking agent was used to improve the stability of adsorbent. FTIR, SEM, BET, and TG were used to characterize the TETA-modified XL-PAN. The FTIR results demonstrate that the XL-PAN was successfully modified by TETA. The SEM images show that TETA-modified XL-PAN powders were agglomerated from 100 to 200 nm spherical particles. TETA-modified XL-PAN was used as an adsorbent to remove Cu(II) ion from wastewater. The effects of contact time, pH, Cu(II) concentration, temperature, and reuse cycles on adsorption were investigated, respectively. Experimental results showed that the adsorption isotherms agreed well with the Langmuir model and a chemical adsorption between TETA-modified XL-PAN and Cu(II) was inferred. After optimizing the experimental conditions, the maximum adsorption capacity of TETA-modified XL-PAN for Cu(II) was 46.6 mg/g with an adsorption time of 8 h. Furthermore, the TETA-modified XL-PAN adsorbent can be well regenerated by acid solutions. After eight regeneration and adsorption processes, the adsorption capacity still reached more than 90% of the first adsorption capacity. These results demonstrated the potential use of TETA-modified XL-PAN as an effective adsorbent for Cu(II) ions removal from wastewater.