Selenium in wastewater: fast analysis method development and advanced oxidation treatment applications.
Dipti Prakash Mohapatra1, Deepak M Kirpalani1
1National Research Council of Canada, Energy Mining and Environment Portfolio, 1200 Montreal Road, Ottawa, ON, K1A 0R6, Canada
Summary
This study presents a UV-Vis spectrophotometer method for measuring selenium in wastewater, achieving a 2 mg/L detection limit. Advanced oxidation processes, particularly low-frequency ultrasound, effectively removed selenium, showing promise for environmental remediation.
Area of Science:
- Environmental Chemistry
- Analytical Chemistry
- Water Treatment Technologies
Background:
- Selenium contamination poses ecological risks due to bioaccumulation.
- Increasing regulations necessitate efficient selenium measurement and removal methods.
- Selenate is particularly challenging to remove using conventional techniques.
Purpose of the Study:
- To develop a UV-Vis spectrophotometer method for quantifying selenium in wastewater.
- To investigate the efficacy of advanced oxidation processes (AOPs) for selenium removal.
- To optimize AOP parameters for maximum selenium removal efficiency.
Main Methods:
- Colorimetric analysis using malachite green and azure blue indicators with UV-Vis spectrophotometry.
- Application of advanced oxidation processes (AOPs), including ultrasound, for selenium treatment.
- Determination of the lower limit of detection for the UV-Vis selenium analysis.
Main Results:
- The UV-Vis method with malachite green demonstrated effective selenium quantification with a lower detection limit of 2 mg/L.
- All AOP-treated samples showed significant selenium removal.
- Low-frequency ultrasound (40 kHz) yielded the highest chemical cavitation and selenium removal efficiency.
Conclusions:
- The developed UV-Vis method is suitable for monitoring selenium in wastewater.
- AOPs, especially ultrasound, are effective for removing challenging selenium species like selenate.
- Optimized ultrasound parameters enhance selenium removal efficiency in water treatment.
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