Analysis of operational parameters, reactor kinetics, and floc characterization for the removal of estrogens via electrocoagulation

Maher, Emily K.; O’Malley, Kassidy; Heffron, Joe; Huo, Jingwan; Mayer, Brooke K.; Yin, Wang

doi:10.1016/j.chemosphere.2018.12.161

Cited by 46 publications

(21 citation statements)

References 38 publications

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“…The electrodes were rinsed with Milli-Q water and exposed to UV light for approximately 30 min per side. During tests, electrode polarity was reversed every 30 s to limit the formation of a passivation layer on the cathode, as described by Maher et al (2019) [36].…”

Section: Electrocoagulationmentioning

confidence: 99%

Electrocoagulation as a Pretreatment for Electroxidation of E. coli

Lynn

Heffron

Mayer

2019

Water

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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 model waters. Sequential EC-EO did not achieve greater mitigation than EC alone. To enhance removal of natural organic matter, the initial pH was decreased. Lower initial pH (pH 5–6) improved E. coli mitigation during both stages of EC-EO. EC-EO also had slightly greater E. coli mitigation than EC alone at lower pH. However, EO alone provided more energy efficient E. coli mitigation than either EC or EC-EO.

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Section: Electrocoagulationmentioning

confidence: 99%

Electrocoagulation as a Pretreatment for Electroxidation of E. coli

Lynn

Heffron

Mayer

2019

Water

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“…S1, Section S1 in the Supplementary Data). EC and EO experiments were performed in 250-mL glass Berzelius beakers with a 3Dprinted plastic cap designed to fit two electrodes at an interelectrode distance of 1 cm (Naje et al, 2015;Maher et al, 2019aMaher et al, , 2019b. Power was supplied using a benchtop DC power supply (Sorensen XPH75-2D, 300W, 0-75W, 0-2A, dual output, universal input 110VAC to 240VAC).…”

Section: Reactor Operationmentioning

confidence: 99%

“…Iron electrodes (1020 steel, fabricated by VMetals, Franklin, WI) with an active anode surface area of 18 cm 2 were used as the anode and cathode in EC experiments. In EC experiments, the power supply was used in conjunction with a current alternator (kindly provided by A/O Smith Corporation, Brookfield, WI) using a 30-s polarity reversal to reduce electrode passivation and improve efficiency (Maher et al, 2019a). EC was conducted in 250 mL volume with coagulation at a rapid mix stir rate of 120 rpm [velocity gradient (G) is 117 s -1 ], followed by 15 min of slow mixing flocculation (40 rpm, G value of 23 s -1 ) with no power.…”

Section: Reactor Operationmentioning

confidence: 99%

“…All glassware for DOC testing were acid washed in 5% HCl solution and baked at 550°C (Mayer et al, 2019). The iron electrodes were acid washed (2 M sulfuric acid), rinsed with water, washed with Alconox Ò , and wet sanded with 320 grit fine sandpaper (Maher et al, 2019a(Maher et al, , 2019b (Panizza, 2010;Macpherson, 2015), and extremely high oxygen evolution overpotential (Panizza, 2010). BDD electrodes underwent anodic polarization for 10 min in 0.1 M H 2 SO 4 at 50 mA current between each experiment to remove any surface contamination or deposition (Murugananthan et al, 2007).…”

Section: Reactor Operationmentioning

confidence: 99%

“…Electrochemical treatment technologies have been used in industrial wastewater treatment processes and have recently gained attention for drinking water treatment based on their ability to provide efficient, safe, and effective removal of a variety of pollutants (Heffron et al, 2019;Maher et al, 2019a;Ö ztürk et al, 2019). Electrooxidation (EO) employs inert electrodes that indirectly oxidize contaminants through the generation of oxidants in solution and directly oxidize contaminants on the surface of the electrode (Chen, 2004;Heffron et al, 2019).…”

Section: Introductionmentioning

confidence: 99%

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Removal of Estrogenic Compounds from Water Via Energy Efficient Sequential Electrocoagulation-Electrooxidation

Maher

O’Malley

Dollhopf

et al. 2020

Environmental Engineering Science

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The purpose of this study was to investigate energy reduction using electrocoagulation (EC) followed by electrooxidation (EO) targeting initial removal of dissolved organic carbon (DOC) during EC and subsequent removal of estrogenic compounds in EO. EC offers benefits over conventional coagulation such as in situ generation of coagulant but is not practical for removing estrogenic compounds. Advanced oxidation processes, including EO, can effectively remove micropollutants such as estrogenic compounds but are hindered by the presence of bulk organic matter. This study investigated four estrogenic compounds from the U.S. EPA's Contaminant Candidate List: estrone (E1), 17b-estradiol (E2), estriol (E3), and 17a-ethynylestradiol (EE2). First, EC (iron electrodes) was employed to remove humic acid and improve downstream removal of estrogenic compounds while reducing overall energy consumption in EO (boron-doped diamond electrodes). The sequential EC and EO system effectively reduced overall electrical energy per order (EEO) by more than half compared with EO alone for each estrogenic compound. The system also effectively removed humic acid and estrogenic compounds. An EC current density of 8.88 mA/cm 2 and electrolysis time of 8 min with a flocculation stir rate of 40 rpm (G = 23 s-1) achieved the greatest DOC and UV-VIS 254 removal. EO treatment achieved the highest estrogenic compound removal at a current density of 22.2 mA/cm 2. Initial humic acid sodium salt concentration (0-60 mg/L C) had an effect on EC iron dose and estrogenic compound removal. The EEO for EC-EO treatments was lower than EC alone, EO alone, UV photolysis, UV photocatalysis, and ozone but was higher than a photocatalytic reactor membrane and UV/H 2 O 2. Overall, the EC-EO system was effective at removing bulk organic matter during EC and estrogenic compounds during EO. EC-EO reduced overall energy demand, indicating that this system should be developed further as an advanced technology that could efficiently remove micropollutants.

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Electrochemical technologies for per‐ and polyfluoroalkyl substances mitigation in drinking water and water treatment residuals

et al. 2021

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Water treatment technologies are needed that can convert per-and polyfluoroalkyl substances (PFAS) into inorganic products (e.g., CO 2 , F À ) that are less toxic than parent PFAS compounds. Research on electrochemical treatment processes such as electrocoagulation and electrooxidation has demonstrated proof-of-concept PFAS removal and destruction. However, research has primarily been conducted in laboratory matrices that are electrochemically favorable (e.g., high initial PFAS concentration [μg/L-mg/L], high conductivity, and absence of oxidant scavengers). Electrochemical treatment is also a promising technology for treating PFAS in water treatment residuals from nondestructive technologies (e.g., ion exchange, nanofiltration, and reverse osmosis). Future electrochemical PFAS treatment research should focus on environmentally relevant PFAS concentrations (i.e., ng/L), matrix conductivity, natural organic matter impacts, short-chain PFAS removal, transformation products analysis, and systems-level analysis for cost evaluation.

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Analysis of operational parameters, reactor kinetics, and floc characterization for the removal of estrogens via electrocoagulation

Cited by 46 publications

References 38 publications

Electrocoagulation as a Pretreatment for Electroxidation of E. coli

Electrocoagulation as a Pretreatment for Electroxidation of E. coli

Removal of Estrogenic Compounds from Water Via Energy Efficient Sequential Electrocoagulation-Electrooxidation

Electrochemical technologies for per‐ and polyfluoroalkyl substances mitigation in drinking water and water treatment residuals

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