Effects of direct and alternating current on the treatment of oily water in an electroflocculation process

Cerqueira, Alexandre Andrade; Souza, Paulo Sérgio de; Marques, Mônica Regina da Costa

doi:10.1590/0104-6632.20140313s00002363

Cited by 37 publications

(26 citation statements)

References 26 publications

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“…Contrariwise, adopting AC can be the best solution for this problem thanks to the periodicity of this current that prevents the oxide layer formation and accelerates the reaction speed. and Cerqueira et al (2014) showed the importance of alternating current (AC) in the removal of pollutants by the electrocoagulation (EC) process through the dissolution of different electrode, such as Mg, Al, Fe and Zn. Achieving maximum pollutant removal in a minimum time was the common goal of all these researches.…”

Section: Introductionmentioning

confidence: 99%

The alternating and direct current effect on the elimination of cationic and anionic dye from aqueous solutions by electrocoagulation and coagulation flocculation

Othmani

Kesraoui

Seffen

2017

Euro-Mediterr J Environ Integr

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In this study, we investigated the effect of alternating current (AC) and direct current (DC) on the elimination of methylene blue (MB) and indigo carmine (IC) by the electrocoagulation process using two Pb electrodes in comparison with the coagulation-flocculation process. Different parameters influencing the elimination of these dyes were studied, namely initial dye concentration, initial pH, voltage, temperature, coagulant and flocculant concentration and current density. The elimination of MB reached 98.8% with AC and 97.3% with DC at current density of 0.5 A/m 3 and pH of 7.0. However, the energy consumed was lower in the case of AC (4.89 9 10 -6 kWh/m 3 ) than DC (7.6 9 10 -6 kWh/m 3 ). The elimination was also faster in the case of AC (0.47 mg L -1 /min) than the DC (0.066 mg L -1 /min). The same behavior was observed with the IC where the effectiveness of dye elimination was, respectively, 98.5 and 100% with an energy consumed (E c ) of 4.35 9 10 -5 and 2.03 9 10 -6 kWh/m 3 , respectively, with DC and AC. The adsorption kinetic data were obtained using pseudo-firstorder and pseudo-second-order models. The pseudo-second-order was more appropriate describing the adsorption kinetics of methylene blue and the pseudo-first-order was more appropriate describing the adsorption kinetics of indigo carmine. Langmuir, Freundlich and Sips models were used to optimize the elimination dye process. The Sips model displayed the best fit of the equilibrium data.

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Section: Introductionmentioning

confidence: 99%

The alternating and direct current effect on the elimination of cationic and anionic dye from aqueous solutions by electrocoagulation and coagulation flocculation

Othmani

Kesraoui

Seffen

2017

Euro-Mediterr J Environ Integr

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“…Several researchers, as Un et al (2009), Canizares et al (2007, Yang (2007), Bensadok et al (2008), Cerqueira et al (2014), and Karhu et al (2012), have reported high efficiency in removing chemical oxygen demand (COD), oil and grease (O&G), color, and turbidity, indicating that it is a promising alternative in treatment of oily emulsion for oil industry such as oilfield-produced water.…”

Section: Introductionmentioning

confidence: 99%

Effects of untreated and treated oilfield-produced water on seed germination, seedling development, and biomass production of sunflower (Helianthus annuus L.)

Marques

Souza

Rigo

et al. 2015

Environ Sci Pollut Res

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This study aims to evaluate possible toxic effects of oil and other contaminants from oilfield-produced water from oil exploration and production, on seed germination, and seedling development of sunflower (Helianthus annuus L.). In comparison, as treated by electroflocculation, oilfield-produced water, with lower oil and organic matter content, was also used. Electroflocculation treatment of oilfield-produced water achieved significant removals of chemical oxygen demand (COD) (94 %), oil and grease (O&G) (96 %), color (97 %), and turbidity (99 %). Different O&G, COD, and salt levels of untreated and treated oilfield-produced water did not influence germination process and seedling biomass production. Normal seedlings percentage and vigor tended to decrease more intensely in O&G and COD levels, higher than 337.5 mg L(-1) and 1321 mg O2 L(-1), respectively, using untreated oilfield-produced water. These results indicate that this industrial effluent must be treated, in order to not affect adversely seedling development. This way, electroflocculation treatment appears as an interesting alternative to removing oil and soluble organic matter in excess from oilfield-produced water improving sunflower's seedling development and providing a friendly environmental destination for this wastewater, reducing its potential to harm water resources, soil, and biota.

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“…Finally, they had precipitated to the bottom [14][15][16]. Additionally, AC was applied to reduce corrosion of electrodes that can impact to efficiency loss of current transfer [17]. The product mixture of biodiesel and glycerol was prepared with the same procedure as mentioned in the previous section.…”

Section: Electrocoagulation Separation Processmentioning

confidence: 99%

“…Glycerol and other contaminants would receive charges between electrode points afterwards they were linked to large molecules and settled to the bottom [21]. Therefore, high voltage can excite electron movement around the electric field and several aluminum hydroxide species were produced [25].…”

Section: Effect Of Methyl Ester Contentmentioning

confidence: 99%

Electrocoagulation with AC Electrical Current at Low Voltage for Separation of Crude Glycerol from Biodiesel Product Mixture

et al. 2020

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Electrocoagulation with AC electrical current at low voltage was implemented to remove crude glycerol from biodiesel which was produced via transesterification reaction of refined palm oil (RPO) as feedstock with methanol in the presence of sodium hydroxide derivative-catalyst at 60°C for 2 hr using the conventional heating in the water bath. Effects of point-to-point electrode configuration, electrode materials, inter-electrode distances, optimized AC low voltages, molar ratios of glycerol and biodiesel product mixture on the separation time and the separation efficiency were studied. Electrocoagulation process with applied AC at 96 V and using Al point-to-point electrodes at the inter-electrode distance of 0.1 cm could efficiently remove free glycerol more than the gravitation settling for the separation time of 120 s. The separation efficiency was over 99.99%. Even though the clear interface between biodiesel and glycerol was firstly observed after applying the electrocoagulation for 30 s, the separation time had to proceed for additional 90 s to eliminate unreacted catalyst. The methyl ester content of 98.56±0.47 wt% was obtained after purification with 2 times of water-washing. This process can be achieved by shortening the separation time and could significantly reduce the water consumption during the purification process.

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Effects of direct and alternating current on the treatment of oily water in an electroflocculation process

Cited by 37 publications

References 26 publications

The alternating and direct current effect on the elimination of cationic and anionic dye from aqueous solutions by electrocoagulation and coagulation flocculation

The alternating and direct current effect on the elimination of cationic and anionic dye from aqueous solutions by electrocoagulation and coagulation flocculation

Effects of untreated and treated oilfield-produced water on seed germination, seedling development, and biomass production of sunflower (Helianthus annuus L.)

Electrocoagulation with AC Electrical Current at Low Voltage for Separation of Crude Glycerol from Biodiesel Product Mixture

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