Sustainable carbon nano-onions as an adsorbent for the efficient removal of oxo-anions

Environ Sci Pollut Res Int. 2023 Feb;30(6):15480-15489. doi: 10.1007/s11356-022-22883-3. Epub 2022 Sep 28.

Abstract

The increasing threats of oxo-anions in drinking water have posed a serious threat to human health, aquatic environment, ecology, and sustainability. Accordingly, developments of cost-effective and sustainable nanomaterials for water remediation are on top priority and highly sought in global research community. Carbon nano-onions (CNOs) are one of the emerging nanomaterials for water purification because of its unique morphology, surface reactivity, high density of surface-active sites, and microporous structure. Herein, flaxseed oil-derived CNOs are utilized as efficient adsorbent for the removal of toxic oxo-anions. Aside from the green and economic nature, CNOs provide high adsorption efficiency ~ 806.45 mg g-1 for the removal of [Formula: see text] (99.9%) from aqueous system at ambient temperature, neutral pH in 70 min. The adsorption of [Formula: see text] onto CNOs was well fitted in pseudo-second order kinetics and followed the Langmuir adsorption isotherm model. The adsorption process was determined to be exothermic and spontaneous from the resulting thermodynamic characteristics. Furthermore, the high hydrophobic nature of CNOs make it recycling simpler. The real-life applicability of CNOs towards [Formula: see text] removal was tested in tap water, river water, and dam water. With all these observed results, CNOs show promise for practical water remediation applications.

Keywords: Adsorption; Flame pyrolysis; Green synthesis; Oxo-anions removal; Sustainable carbon nano onions; Water remediation.

MeSH terms

  • Adsorption
  • Anions
  • Carbon / chemistry
  • Humans
  • Hydrogen-Ion Concentration
  • Kinetics
  • Onions
  • Thermodynamics
  • Water / chemistry
  • Water Pollutants, Chemical* / analysis
  • Water Purification* / methods

Substances

  • Carbon
  • Anions
  • Water
  • Water Pollutants, Chemical