Sustainable removal of arsenate, arsenite and bacterial contamination from water using biochar stabilized iron and copper oxide nanoparticles and associated mechanism of the remediation process
| Autor: | Nagahanumaiah, Nripen Chanda, Nivedita Priyadarshni, Peuli Nath |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Environmental remediation
Process Chemistry and Technology Inorganic chemistry Arsenate chemistry.chemical_element Portable water purification 02 engineering and technology 010501 environmental sciences 01 natural sciences Arsenic contamination of groundwater chemistry.chemical_compound Adsorption 020401 chemical engineering chemistry Freundlich equation 0204 chemical engineering Safety Risk Reliability and Quality Waste Management and Disposal Arsenic 0105 earth and related environmental sciences Biotechnology Arsenite |
| Zdroj: | Journal of Water Process Engineering. 37:101495 |
| ISSN: | 2214-7144 |
| Popis: | Iron and copper oxide nanoparticles have proven the capability of arsenic remediation, but their use in community-level water purification processes becomes limited due to their irreversible aggregation property. This behavior decreases the active surface area and lowers its effectiveness in the removal of arsenic contamination. In the present study, novel rice-husk biochar stabilized iron and copper oxide nanoparticles (biochar@Fe and biochar@Cu) were developed for efficient removal of total arsenic (arsenite + arsenate, AsIII+V) and microbial contaminants from water. The composites were synthesized by treating microporous rice-husk char with FeCl3 and CuCl2 and their subsequent reaction with NaOH and drying at 90 °C. The mixture of composites, i.e. biochar@Fe and biochar@Cu showed high arsenic removal efficiency, > 95 %, which is dependent on the contact time, pH, and the co-existing anions. The efficiency was examined with a real groundwater sample which showed 92 % removal. The analysis of arsenic speciation after adsorption revealed that the removal process occurs with the oxidation of most of the AsIII to AsV in the presence of CuO, followed by the adsorption of AsV and residual AsIII by Fe2O3 and CuO nanoparticles. The adsorption process followed the pseudo-second-order kinetic model and Freundlich adsorption isotherm with a maximum capacity of 20.32 mg/g. Based on these results, a mechanism of arsenic adsorption was established where it is proposed that arsenic is adsorbed by electrostatic and covalent type interactions between Fe/Cu–OH/OH2+ groups of the composites and AsIII/V–OH/AsVO– of arsenic species. These multiple interactions make the combined biochar@Fe and biochar@Cu system efficient and robust for arsenic filtration compared to any other reported platform. |
| Databáze: | OpenAIRE |
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