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2019

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Civil Engineering

Disinfection

Articles 1 - 4 of 4

Full-Text Articles in Engineering

Electrocoagulation As A Pretreatment For Electroxidation Of E. Coli, William Lynn, Joe Heffron, Brooke Mayer Dec 2019

Electrocoagulation As A Pretreatment For Electroxidation Of E. Coli, William Lynn, Joe Heffron, Brooke Mayer

Civil and Environmental Engineering Faculty Research and Publications

Insufficient funding and operator training, logistics of chemical transport, and variable source water quality can pose challenges for small drinking water treatment systems. Portable, robust electrochemical processes may offer a strategy to address these challenges. In this study, electrocoagulation (EC) and electrooxidation (EO) were investigated using two model surface waters and two model groundwaters to determine the efficacy of sequential EC-EO for mitigating Escherichia coli. EO alone (1.67 mA/cm2, 1 min) provided 0.03 to 3.9 logs mitigation in the four model waters. EC alone (10 mA/cm2, 5 min) achieved ≥1 log E. coli mitigation in all …


Mechanisms Of Virus Mitigation And Suitability Of Bacteriophages As Surrogates In Drinking Water Treatment By Iron Electrocoagulation, Joe Heffron, Brad Mcdermid, Emily Maher, Patrick J. Mcnamara, Brooke K. Mayer Oct 2019

Mechanisms Of Virus Mitigation And Suitability Of Bacteriophages As Surrogates In Drinking Water Treatment By Iron Electrocoagulation, Joe Heffron, Brad Mcdermid, Emily Maher, Patrick J. Mcnamara, Brooke K. Mayer

Civil and Environmental Engineering Faculty Research and Publications

Emerging water treatment technologies using ferrous and zero-valent iron show promising virus mitigation by both inactivation and adsorption. In this study, iron electrocoagulation was investigated for virus mitigation in drinking water via bench-scale batch experiments. Relative contributions of physical removal and inactivation, as determined by recovery via pH 9.5 beef broth elution, were investigated for three mammalian viruses (adenovirus, echovirus, and feline calicivirus) and four bacteriophage surrogates (fr, MS2, P22, and ΦX174). Though no one bacteriophage exactly represented mitigation of the mammalian viruses in all water matrices, bacteriophage ΦX174 was the only surrogate that showed overall removal comparable to that …


Sequential Electrocoagulation-Electrooxidation For Virus Mitigation In Drinking Water, Joe Heffron, Donald R. Ryan, Brooke K. Mayer Sep 2019

Sequential Electrocoagulation-Electrooxidation For Virus Mitigation In Drinking Water, Joe Heffron, Donald R. Ryan, Brooke K. Mayer

Civil and Environmental Engineering Faculty Research and Publications

Electrochemical water treatment is a promising alternative for small-scale and remote water systems that lack operational capacity or convenient access to reagents for chemical coagulation and disinfection. In this study, the mitigation of viruses was investigated using electrocoagulation as a pretreatment prior to electrooxidation treatment using boron-doped diamond electrodes. This research is the first to investigate a sequential electrocoagulation-electrooxidation treatment system for virus removal. Bench-scale, batch reactors were used to evaluate mitigation of viruses in variable water quality via: a) electrooxidation, and b) a sequential electrocoagulation-electrooxidation treatment train. Electrooxidation of two bacteriophages, MS2 and ΦX174, was inhibited by natural organic …


Bacteriophage Inactivation As A Function Of Ferrous Iron Oxidation, Joe Heffron, Brad Mcdermid, Brooke K. Mayer Jul 2019

Bacteriophage Inactivation As A Function Of Ferrous Iron Oxidation, Joe Heffron, Brad Mcdermid, Brooke K. Mayer

Civil and Environmental Engineering Faculty Research and Publications

Iron-based disinfection has been promoted as a potential low-cost, low-byproduct means of virus mitigation. This research is the first to establish that virus inactivation due to ferrous iron is impacted both by the extent of iron oxidation (from ferrous to ferric iron) and the rate of iron oxidation. Log inactivation of bacteriophages increased linearly with ferrous iron concentration at low doses (< 3 mg/L Fe), but higher doses limited disinfection, likely due to floc formation. The rate of iron oxidation was controlled by independently varying pH and dissolved oxygen concentration. Bacteriophage inactivation increased with the inverse of ferrous oxidation rate, suggesting that slower iron oxidation rates allow better contact between viruses and reactive ferrous iron. Ferrous iron showed potential for disinfection in conditions of low pH and dissolved oxygen, though these conditions preclude effective iron coagulation/flocculation.