Synthesis of low-density polyethylene derived carbon nanotubes for activation of persulfate and degradation of water organic micropollutants in continuous mode

J Environ Manage. 2022 Apr 15:308:114622. doi: 10.1016/j.jenvman.2022.114622. Epub 2022 Feb 3.

Abstract

Plastic derived carbon nanotubes (CNTs) were tested as catalysts in persulfate activation for the first time. Four catalysts were prepared by wetness impregnation and co-precipitation (using Al2O3, Ni, Fe and/or Al) and implemented to grow CNTs by chemical vapour deposition (CVD) using low-density polyethylene (LDPE) as carbon feedstock. A catalyst screening was performed in batch mode and the best performing CNTs (CNT@Ni+Fe/Al2O3-cp) led to a high venlafaxine mass removal rate (3.17 mg g-1 h-1) in ultrapure water after 90 min (even with a mixture of micropollutants). Its degradation increased when the matrix was replaced by drinking water and negligibly affected in surface water. A composite polymeric membrane was then fabricated with CNT@Ni+Fe/Al2O3-cp and polyvinylidene fluoride (PVDF), a high venlafaxine mass removal rate in surface water being also observed in 24 h of continuous operation. Therefore, the results herein reported open a window of opportunity for the valorisation of plastic wastes in this catalytic application performed in continuous mode.

Keywords: Advanced oxidation processes (AOPs); Chemical vapour deposition (CVD); Composite polymeric membranes; Contaminants of emerging concern (CECs); Waste management.

MeSH terms

  • Catalysis
  • Nanotubes, Carbon*
  • Polyethylene
  • Water
  • Water Pollutants, Chemical* / analysis

Substances

  • Nanotubes, Carbon
  • Water Pollutants, Chemical
  • Water
  • Polyethylene