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

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 similar to 806.45 mg g(-1) for the removal of MnO4- (99.9%) from aqueous system at ambient temperature, neutral pH in 70 min. The adsorption of MnO(4)(- )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 MnO(4)(- )removal was tested in tap water, river water, and dam water. With all these observed results, CNOs show promise for practical water remediation applications.

Automated summary

The increasing threats of oxo-anions in drinking water have prompted the development of cost-effective and sustainable nanomaterials for water remediation. Carbon nano-onions derived from flaxseed oil have been found to be efficient adsorbents for toxic oxo-anions removal, with high adsorption efficiency and recyclability. They show promise for practical water remediation applications.