Continuous-flow electrocoagulation (EC) process for iron removal from water: Experimental, statistical and economic...

Area of Science:

• Environmental Engineering
• Water Treatment Technologies
• Electrochemistry

Background:

• Electrocoagulation (EC) is a widely used, cost-effective water treatment method due to its chemical additive-free nature.
• Existing EC units face limitations, particularly in reactor design, impacting efficiency and power consumption.

Purpose of the Study:

• To develop and validate a new electrocoagulation (EC) unit design.
• The new design utilizes drilled plates as electrodes to enhance mixing and reduce external power requirements.
• To optimize iron removal from water using the novel EC reactor.

Main Methods:

• A new EC reactor with drilled plate electrodes was designed and implemented for continuous flow treatment.
• The Box-Behnken model was employed to optimize key operational parameters: applied current density (ACD), pH of water (PoW), initial iron concentration (IC), and treatment time (TT).
• Synthetic water samples with varying iron concentrations were treated to assess the reactor's performance.

Main Results:

• The optimized EC process achieved a 99.9% removal of iron from water.
• Optimal conditions were identified as PoW of 7, ACD of 3 mA/cm², IC of 10 mg/l, and TT of 50 min.
• The performance of the EC unit was accurately simulated with an R² value of 0.9788.
• The cost-effectiveness of iron removal using the proposed EC unit was determined to be £0.623/m³.

Conclusions:

• The developed EC unit with drilled plate electrodes offers an efficient and cost-effective solution for iron removal from water.
• The novel design successfully addresses limitations of conventional EC units by integrating mixing within the electrode structure, thereby minimizing power consumption.
• The study demonstrates the potential of this optimized EC system for practical water and wastewater treatment applications.