Honeycomb-like magnetic cornstalk for Cr(VI) removal and ammonium release

• Published in: Bioresource technology 2019-11, Vol.291, p.121856-121856, Article 121856
• Main Authors: Ren, Jingya, Zhang, Guilong, Wang, Dongfang, Cai, Dongqing, Wu, Zhengyan
• Format: Article
• Language: English
• Subjects: Ammonium Compounds - chemistry; Ammonium sulfite; Chromium - isolation & purification; Cornstalk; Hexavalent chromium; High energy electron beam; Magnetics; Polyvinyl Alcohol - chemistry; Water
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2019.121856

[Display omitted] •A honeycomb-like magnetic composite named as OPCS-AS@PVA-Fe3O4 was fabricated.•OPCS-AS@PVA-Fe3O4 consisted of cornstalk, (NH4)2SO3, polyvinyl alcohol and Fe3O4.•OPCS-AS@PVA-Fe3O4 could reduce Cr(VI) to Cr(III) and adsorb Cr(III).•OPCS-AS@PVA-Fe3O4 could release ammonium to favor plant growth.•OPCS-AS@PVA-Fe3O4 was stable against coexisting ions. In this work, cornstalk (CS) was irradiated by high energy electron beam to obtain honeycomb-like porous CS (PCS). The PCS was loaded with ammonium sulfite (AS) and then coated by polyvinyl alcohol (PVA)-Fe3O4 to obtain PCS-AS@PVA-Fe3O4. The PCS-AS@PVA-Fe3O4 could reduce hexavalent chromium (Cr(VI)) to trivalent chromium (Cr(III)) by SO32−, then the Cr(III) combined with PCS-AS@PVA-Fe3O4 through hydrogen bonds. The resulting PCS-AS@PVA-Fe3O4/Cr with a high magnetism could be conveniently separated from water via a magnet. PCS-AS@PVA-Fe3O4/Cr showed a high performance on controlling Cr(VI) migration in soil and uptake by plant. Meanwhile, ammonium could be released from PCS-AS@PVA-Fe3O4, favoring plant growth. Therefore, this work not only provides a promising and low-cost approach to remove Cr(VI) and promote plant growth simultaneously, but also provides a new route for CS recycling, which might have a potential application value.