Influence of cations on As(III) removal from simulated groundwaters by double potential step chronoamperometry (DPSC) employing polyvinylferrocene (PVF) functionalized electrodes
| Autor: | Shikha Garg, Zhao Song, T. David Waite, Jinxing Ma |
|---|---|
| Rok vydání: | 2022 |
| Předmět: |
Environmental Engineering
Cations Divalent Health Toxicology and Mutagenesis Inorganic chemistry chemistry.chemical_element 02 engineering and technology 010501 environmental sciences 01 natural sciences Arsenic Water Purification Divalent Solution of Schrödinger equation for a step potential Neutral Charge Environmental Chemistry Ferrous Compounds Electrodes Groundwater Waste Management and Disposal 0105 earth and related environmental sciences chemistry.chemical_classification Sorption Chronoamperometry 021001 nanoscience & nanotechnology Pollution 6. Clean water chemistry Electrode Polyvinylferrocene Polyvinyls Adsorption 0210 nano-technology Water Pollutants Chemical |
| Zdroj: | Journal of Hazardous Materials. 424:127472 |
| ISSN: | 0304-3894 |
| DOI: | 10.1016/j.jhazmat.2021.127472 |
| Popis: | As(III) removal from groundwaters is challenging because of its neutral charge and low surface affinity under circumneutral pH conditions. In this work, we investigate the influence of Ca2+ and Mg2+ on the removal of As(III) by a redox active polyvinylferrocene (PVF) functionalized electrode in a modified double potential step chronoamperometry (DPSC) setup. In the absence of divalent cations, nearly 90% As(III) removal is achieved over ten continuous cycles by single-pass DPSC, even in the presence of competing anions, however the presence of divalent cations at concentrations ≥ 1.25 mM significantly inhibits As(III) removal. The divalent cations enhance arsenic removal in the first (removal) step but suppress electrode regeneration in the 2nd step. Our results suggest that Ca2+/Mg2+ either acts as a bridge between the electrode surface and As anions or the sorption of Ca2+/Mg2+ increases the positive charge on the electrode surface thereby facilitating As(V) sorption. We show that effective electrode regeneration can be achieved using an NaOH wash however the overall complexity of the process increases. Overall, we conclude that the influence of divalent cations on As removal by electro-sorption processes needs to be taken into consideration for application of this technology for real groundwater treatment. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect