TY - JOUR
T1 - Inactivation of Escherichia coli and somatic coliphage ΦX174 by oxidation of electrochemically produced Fe2+
AU - Bicudo, Bruno
AU - Medema, Gertjan
AU - van Halem, Doris
PY - 2022
Y1 - 2022
N2 - Electrochemical ferrous iron (Fe2+) wastewater treatment is gaining momentum for treating municipal wastewater due to its decreasing costs, environmental friendliness and capacity for removal of a wide range of contaminants. Disinfection by iron electrocoagulation (Fe-EC) has been occasionally reported in full scale industrial applications, yet controversy remains regarding its underlying elimination mechanisms and kinetics. In this study, it was demonstrated that substantial inactivation can be achieved for Escherichia coli WR1 (5 log10) and somatic coliphage ΦX174 (2–3 log10). Electrochemically produced Fe2+ yielded similar inactivation as chemical Fe2+. Reactive oxygen species (ROS)-quenching experiments with TEMPOL confirmed that E. coli inactivation was related to the production of Fenton-like intermediates during Fe2+ oxidation. The observed E. coli disinfection kinetics could be mathematically related to Fe-EC current intensity using a Chick-Watson-like expression, in which the amperage is surrogate for the disinfectant's concentration. We hereby show that it is possible to mathematically predict disinfection based on applied Fe dosage and dosage speed. Phage ΦX174 inactivation could not be described in a similar way because at higher Fe dosages (>20 mg/l), little additional inactivation was observed. Also, ROS-quencher TEMPOL did not completely inhibit phage ΦX174 removal, suggesting that additional pathways are relevant for its elimination.
AB - Electrochemical ferrous iron (Fe2+) wastewater treatment is gaining momentum for treating municipal wastewater due to its decreasing costs, environmental friendliness and capacity for removal of a wide range of contaminants. Disinfection by iron electrocoagulation (Fe-EC) has been occasionally reported in full scale industrial applications, yet controversy remains regarding its underlying elimination mechanisms and kinetics. In this study, it was demonstrated that substantial inactivation can be achieved for Escherichia coli WR1 (5 log10) and somatic coliphage ΦX174 (2–3 log10). Electrochemically produced Fe2+ yielded similar inactivation as chemical Fe2+. Reactive oxygen species (ROS)-quenching experiments with TEMPOL confirmed that E. coli inactivation was related to the production of Fenton-like intermediates during Fe2+ oxidation. The observed E. coli disinfection kinetics could be mathematically related to Fe-EC current intensity using a Chick-Watson-like expression, in which the amperage is surrogate for the disinfectant's concentration. We hereby show that it is possible to mathematically predict disinfection based on applied Fe dosage and dosage speed. Phage ΦX174 inactivation could not be described in a similar way because at higher Fe dosages (>20 mg/l), little additional inactivation was observed. Also, ROS-quencher TEMPOL did not completely inhibit phage ΦX174 removal, suggesting that additional pathways are relevant for its elimination.
KW - Disinfection
KW - Electrocoagulation
KW - Reactive oxygen species
KW - TEMPOL
KW - Water reclamation
UR - http://www.scopus.com/inward/record.url?scp=85125715997&partnerID=8YFLogxK
U2 - 10.1016/j.jwpe.2022.102683
DO - 10.1016/j.jwpe.2022.102683
M3 - Article
AN - SCOPUS:85125715997
SN - 2214-7144
VL - 47
JO - Journal of Water Process Engineering
JF - Journal of Water Process Engineering
M1 - 102683
ER -