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Nitro-oxidized carboxycellulose nanofibers from moringa plant: effective bioadsorbent for mercury removal
- Source :
- Cellulose. 28:8611-8628
- Publication Year :
- 2021
- Publisher :
- Springer Science and Business Media LLC, 2021.
-
Abstract
- Mercury contamination in drinking water is a worldwide problem due to its severely harming effects on the human body. A nanostructured natural bioadsorbent, carboxycellulose nanofiber extracted from raw moringa plant using the nitro-oxidation method (termed NOCNF), capable of effectively remediating this problem has been demonstrated. Nitro-oxidation is a simple approach that can extract carboxylated nanocellulose directly from raw biomass. In this study, the produced NOCNF contained a large density of carboxylate groups on the cellulose surface (0.97 mmol/g), capable of removing Hg2+ ions by simultaneous electrostatic-interactions and mineralization processes. Using the Langmuir analysis, the adsorption results indicated that the highest Hg2+ removal capacity of this NOCNF was 257.07 mg/g, which is higher than most of the reported values. The interactions between Hg2+ and NOCNF were further characterized by Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS), transmission electron microscopy (TEM) with electron diffraction and wide-angle X-ray diffraction (WAXD) methods, suggesting the existence of two distinct removal mechanisms: predominant adsorption at low Hg2+concentrations (< 250 ppm) and predominant mineralization at high Hg2+ concentrations (> 1000 ppm). The applications of NOCNF were illustrated in both suspension form, as an adsorbent/coagulant, and dry powder form using filtration column. The results indicated that NOCNF in suspension exhibited a higher maximum removal efficiency of 81.6 % as compared to the dry state of 74.3 %. This work demonstrated the feasibility of extracting nanostructured adsorbents from biomass feedstocks to tackle the Hg2+ contamination problem in drinking water.
Details
- ISSN :
- 1572882X and 09690239
- Volume :
- 28
- Database :
- OpenAIRE
- Journal :
- Cellulose
- Accession number :
- edsair.doi.dedup.....6b86d3381f169905d67a131f22f4caa9