Mechanisms of arsenic removal from simulated surface water based on As(III) retention on thiol chelating resins
| Autor: | Virginia S.T. Ciminelli, Mônica Cristina Teixeira, Sunday J. Olusegun, Graziele Duarte |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
inorganic chemicals
chemistry.chemical_classification Aqueous solution Ion exchange Materials Science (miscellaneous) Inorganic chemistry Langmuir adsorption model chemistry.chemical_element Management Monitoring Policy and Law Pollution Ferrous symbols.namesake chemistry medicine Thiol symbols Ferric Chelation Waste Management and Disposal Arsenic Water Science and Technology medicine.drug |
| Zdroj: | Environmental Nanotechnology, Monitoring & Management. 16:100532 |
| ISSN: | 2215-1532 |
| Popis: | A novel system for arsenic speciation in the aqueous environment has been developed based on the high affinity of As(III) for the sulfhydryl groups present in thiol resins (R-S). The performance of tailor-made cartridges filled with the thiol resin was then compared with a commercial silica-based anion exchange cartridge with a quaternary ammonium group (R-N) typically used for As(V) speciation. Both were able to separate arsenic species efficiently, As(V) and As(III), within a broad pH range using flow rates of up to 5 ml min−1. The R-S resin was shown to be suitable for the inorganic arsenic speciation in aqueous systems containing calcium, magnesium, ferrous and ferric ions. The R-S selectivity for As(III) was affected only at sulfate or phosphate/As mass ratio > 500, in a behavior similar to R-N for As(V). The thiol resin's selectivity for As(III) and its immobilization mechanism were investigated through X-ray Absorption Spectroscopy. At pH 5, each arsenic atom bounds to three sulfur atoms, with an As-S inter-atomic distance of 2.26 ± 0.01 A, and a coordination number (CN) of 2.8 ± 0.3. The separation of the neutral As(III) species by a thiol resin presents itself as an alternative to the available anion exchange methods. The sorption of As(III) on the thiol resin followed a pseudo-second-order kinetic model and can be described by the Langmuir isotherm. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect