Sequential electrocoagulation-electrooxidation for virus mitigation in drinking water.

Area of Science:

• Environmental Science
• Water Treatment Technologies
• Electrochemistry

Background:

• Electrochemical water treatment offers a viable solution for remote and small-scale systems lacking chemical reagents.
• Virus mitigation is crucial for safe drinking water, especially where conventional methods are challenging.

Purpose of the Study:

• To investigate the efficacy of sequential electrocoagulation-electrooxidation for virus removal.
• To evaluate the performance of this novel treatment train across different water qualities.
• To compare electrochemical methods with conventional water treatment.

Main Methods:

• Bench-scale batch reactors were utilized to assess virus mitigation.
• Electrooxidation and a sequential electrocoagulation-electrooxidation treatment were compared.
• Two bacteriophages (MS2, ΦX174) and human echovirus were used as surrogates in model surface and groundwaters with varying turbidity and organic matter.

Main Results:

• Electrooxidation alone was inhibited by natural organic matter and turbidity, highlighting the need for pretreatment.
• The sequential electrocoagulation-electrooxidation train was effective in model surface waters but not superior to electrocoagulation alone in model groundwaters.
• Bacteriophage ΦX174 proved a more reliable surrogate than MS2 in the presence of contaminants.
• The electrochemical system showed varied effectiveness compared to conventional ferric salt coagulation and chlorine disinfection.

Conclusions:

• Sequential electrocoagulation-electrooxidation is a potentially beneficial water treatment strategy, particularly for surface water applications.
• Electrocoagulation alone can be effective for groundwater treatment.
• The choice of virus surrogate is critical and depends on water matrix characteristics.
• While promising, practical implementation challenges for the sequential electrochemical system remain.