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Spectroscopic study of Se(IV) removal from water by reductive precipitation using sulfide
Bahngmi Jung1, Aya Safan1, Bill Batchelor2
1Chemical Engineering Program, Texas A&M University at Qatar, PO BOX 23874, Doha, Qatar.
Chemosphere
|August 24, 2016
Summary
Selenium (IV) removal from water was achieved via reductive precipitation with sodium sulfide. UV light did not improve removal efficiency but altered the resulting solid
Area of Science:
- Environmental Chemistry
- Water Treatment Technologies
- Inorganic Chemistry
Background:
- Selenium (IV) poses environmental and health risks.
- Effective removal of selenium from water is crucial for environmental protection.
- Reductive precipitation is a promising method for selenium remediation.
Purpose of the Study:
- To investigate selenium (IV) removal from water using sodium sulfide.
- To evaluate the impact of UV light on reductive precipitation of selenium.
- To analyze the effects of sulfide dose and pH on selenium reduction.
Main Methods:
- Reductive precipitation using sodium sulfide.
- Application of UV light irradiation.
- Analysis of solid products using Scanning Electron Microscopy with Energy Dispersive X-ray Spectroscopy (SEM/EDS) and X-ray Photoelectron Spectroscopy (XPS).
- X-ray Diffraction (XRD) analysis.
Main Results:
- Selenium (IV) was effectively removed at neutral and acidic pH.
- UV irradiation did not enhance selenium removal efficiency but modified precipitate morphology and composition.
- SEM/EDS and XPS confirmed the reduction of selenite to elemental selenium or selenium-sulfide precipitates (SenS8-n).
- XRD revealed elemental selenium solids without UV and orange Se3S5 precipitates with UV.
Conclusions:
- Sodium sulfide is effective for selenium (IV) removal across a range of pH.
- UV light influences the characteristics of selenium precipitates rather than removal efficiency.
- The study identified elemental selenium and various selenium-sulfide compounds formed during the process.
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