Regeneration and reuse of microbial extracellular polymers immobilised on a bed column for heavy metal recovery

WATER RESEARCH

卷:171

Article

Ajao, Victor^1,2  Nam, Kang³  Chatzopoulos, Paraschos¹  Spruijt, Evan⁴  Bruning, Harry²  Rijnaarts, Huub²  Temmink, Hardy^1,2 

[1] Wetsus European Ctr Excellence Sustainable Water, Oostergoweg 9, NL-8911 MA Leeuwarden, Netherlands

[2] Wageningen Univ & Res, Subdept Environm Technol, Bornse Weilanden 9, NL-6708 WG Wageningen, Netherlands

[3] Avans Univ Appl Sci, Sch Life Sci & Environm Technol, Breda, Netherlands

[4] Radboud Univ Nijmegen, Inst Mol & Mat, Heyendaalseweg 135, NL-6525 AJ Nijmegen, Netherlands

关键词: Biosorption;    Column;    Extracellular polymeric substances;    Ion exchange mechanism;    Metal adsorption;   

DOI  :  10.1016/j.watres.2020.115472

来源: Elsevier

【 摘 要 】

Microbial extracellular polymeric substances (EPS) have gained increasing attention for various water treatment applications. In this study, EPS produced from nitrogen-limited glycerol/ethanol-rich wastewater were used to recover Cu2+ and Pb2+ from aqueous solutions. Continuous flow-through tests were conducted on a column packed with silica gel coated with polyethyleneimine, to which EPS were irreversibly attached as shown by optical reflectometry. These immobilised EPS excellently adsorbed Cu2+ and Pb2+, with 99.9% of influent metal adsorbed before the breakthrough points. Metal desorption was achieved with 0.1M HCl, with an average recovery of 86% for Cu2+ and 90% recovery for Pb2+. For the first time, we successfully showed the possibility to regenerate and reuse the immobilised EPS for five adsorption-desorption cycles (using Cu2+ as an example) with no reduction in the adsorbed amount at the breakthrough point (q(bp)). Based on the mass balance of the associated metal ions participating in the adsorption process, ion exchange was identified as the major mechanism responsible for Cu2+ and Pb2+ adsorption by EPS. The results demonstrate the potential of wastewater-produced EPS as an attractive and perhaps, cost-effective biosorbent for heavy metal removal (to trace effluent concentrations) and recovery (86-99%). (C) 2020 The Author(s). Published by Elsevier Ltd.

【 授权许可】

Free