Continuous electrodeionization on the removal of toxic pollutant from aqueous solution

Area of Science:

• Environmental Science
• Water Treatment Technology
• Analytical Chemistry

Background:

• Arsenic is a toxic pollutant causing severe public health issues even at low concentrations in water.
• Groundwater contamination by arsenic is a global concern requiring efficient removal methods.

Purpose of the Study:

• To investigate the efficacy of Electrodeionization (EDI) for removing arsenic ions from groundwater.
• To evaluate the performance of an EDI system in terms of removal efficiency, operational parameters, and energy consumption.

Main Methods:

• Utilized an Electrodeionization system, combining electrodialysis and ion exchange, to remove and concentrate arsenic ions.
• Conducted batch recirculation and continuous column analyses with varying arsenic concentrations (5-25 ppm), voltages (5-20 V), and flow rates (5-20 mL/min).
• Determined breakthrough curves and measured energy consumption per kilogram of removed arsenic.

Main Results:

• EDI achieved up to 100% ion removal at low voltages (5-20 V).
• Arsenic removal efficiency reached 98.8% in the conducted trials.
• Energy consumption ranged from 3.88 to 60.7 kWh/kg of removed arsenic.

Conclusions:

• Electrodeionization is a highly effective and productive technology for removing arsenic from aqueous solutions.
• The study demonstrates EDI's capability to significantly reduce arsenic levels in groundwater, addressing a critical public health challenge.