Effective removal of silica and sulfide from oil sands thermal in-situ produced water by electrocoagulation

Chow, Héline; Pham, Anh Le‐Tuan

doi:10.1016/j.jhazmat.2019.120880

Cited by 36 publications

(6 citation statements)

References 48 publications

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“…This type of water has been selected as a produced water treatment and recycling is a major challenge for the oil and gas industry. Electrocoagulation can potentially be used to treat produced water on-site, to reduce costs, and to increase recycle rates. , The pH of each water sample was determined and adjusted using HCl or NaOH for all experiments, where the influence of pH was studied (i.e., calibration). Further materials used and the chemical composition of SPW and FPW are shown in the Supporting Information and Table S1.…”

Section: Methodsmentioning

confidence: 99%

Mechanistic Insight into Electrode Processes by Operando Visualization of Interfacial pH Using Fluorescent Nanosensors

Elsutohy

Fuladpanjeh-Hojaghan

Roberts

et al. 2023

Environ. Sci. Technol.

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Operando visualization of interfacial pH is crucial, yet challenging in electrochemical processes. Herein, we report the fabrication and utilization of ratiometric, fluorescent pH-sensitive nanosensors for operando quantification of fast-dynamic, interfacial pH changes in electrochemical processes and environments where unprotected fluorescent dyes would be degraded. Spatiotemporal pH changes were detected using an electrochemically coupled laser scanning confocal microscope (EC-LSCM) during the electrocoagulation treatment of model and field samples of oilsands-produced water. Operando visualization of interfacial pH provided new insights into the electrode processes, including ion speciation, electrode fouling, and Faradaic efficiency. We provide compelling evidence that formed metal complexes precipitate at the edge of the pH boundary layer and that there is a strong coupling between the thickness of the interfacial pH layer and the electrode fouling. Furthermore, these findings provide a powerful pathway for optimizing the operating conditions, minimizing electrode passivation, and enhancing the efficiency of electrochemical processes, e.g., electrocoagulation, flow batteries, capacitive deionization, and electrolyzes.

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Section: Methodsmentioning

confidence: 99%

Mechanistic Insight into Electrode Processes by Operando Visualization of Interfacial pH Using Fluorescent Nanosensors

Elsutohy

Fuladpanjeh-Hojaghan

Roberts

et al. 2023

Environ. Sci. Technol.

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“…195−198 Chow and Pham investigated electrocoagulation with Fe 0 anodes to treat SAGD produced water at 22 ± 1 °C. 198 Their results showed over 60% of silica concentration could be removed. However, two common drawbacks including high energy consumption and the need to replace the sacrificed anodes inhibit the application of EC in the actual plants.…”

Section: Treatment Technologies For Removal Of Organics and Silicamentioning

confidence: 99%

“…In recent decades, electrocoagulation (EC) has received growing attention due to its brief retention times, easy operation, and simple equipment . It has been proved to efficiently remove suspended particles, organics, and dissolved silica in different types of wastewater. − Chow and Pham investigated electrocoagulation with Fe 0 anodes to treat SAGD produced water at 22 ± 1 °C . Their results showed over 60% of silica concentration could be removed.…”

Section: Treatment Technologies For Removal Of Organics and Silicamentioning

confidence: 99%

Treatment Technologies for Organics and Silica Removal in Steam-Assisted Gravity Drainage Produced Water: A Comprehensive Review

How

Zeng

et al. 2022

Energy Fuels

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Produced water from steam-assisted gravity drainage (SAGD) operations is a complex mixture of inorganic and organic constituents. Silica, carbonate and bicarbonate, and hardness are three inorganic constituents of interest, whereas the organic contaminants are composed of free and emulsified oil (F&EO) and water-soluble organic (WSO) fractions. Although the current warm lime softening (WLS) and hot lime softening (HLS) in SAGD operations are able to remove particles, silica, and organics, improving the removal efficiency of organics and silica still faces technical and operational challenges given their complex chemistry in produced water. Much effort has been put toward developing effective and cost-efficient treatment processes to handle organics and silica. In this work, we have systematically reviewed the properties of silica and the characteristics of dissolved organics in SAGD produced water, as well as the working principle and removal mechanisms of several techniques, including membrane technology, adsorption, coagulation–flocculation, and hybrid processes. Different analytical techniques for characterizing dissolved organics have been assessed, and the dominant and representative organic species in produced water have been identified. The advantages and limitations, impact factors, application performance, and effectiveness of each technology have been discussed in terms of the removal efficiency for silica and organics. Some remaining challenges and perspectives for future research are also presented. This work provides an improved understanding of the characteristics of silica and organics in SAGD produced water, as well as different treatment technologies, with useful implications for developing effective, feasible, and cost-efficient treatment processes with the objective of enhancing the removal of silica and organics from produced water, thereby leading to economic and environmental performance improvements.

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“…Scientific and industrial communities have considered electrocoagulation (EC) as an alternative electrochemical process for water and wastewater treatment. − The EC process invariably removes the suspended solids, heavy metals, organic dyes, and natural organic matter. Electrochemically formed coagulants (metal oxyhydroxides) can remove the particulate pollutants via charge neutralization and physical enmeshment and dissolved contaminants by adsorption, coprecipitation, and complexation phenomena. , In particular, the dissolved organics removal by EC processes undergoes two major mechanistical pathways: (i) removal of organic compounds by coagulation, binding between the anionic sites of organics and electrocoagulants surface; (ii) neutralizing their charge and resulting in reduced solubility and the adsorption of organic substances on amorphous metal oxyhydroxides precipitates.…”

Section: Introductionmentioning

confidence: 99%

Electrocoagulants Characteristics and Application of Electrocoagulation for Micropollutant Removal and Transformation Mechanism

Govindan

Arumugam

Manda

et al. 2019

ACS Appl. Mater. Interfaces

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Predominantly, the removal of dissolved contaminates via the Fe electrocoagulation (EC) process depends on the electrocoagulants stability, specific area, porosity, dissolution rate, and phase transformation kinetics. The present investigation elucidates the role of applied currents and electrolyte counteranions on the crystalline phase and surface topography of electrocoagulants generated from Fe EC. Moreover, the dissolved contaminant micropollutant removal efficiency was also evaluated by electrochemically produced coagulants. This study confirms that mixed-phase iron (oxyhydr) oxide nanostructures were consistently produced from Fe EC with predominant formation of the goethite phase. The applied current controls the morphology of the coagulants, with flake-like morphology observed with currents at and below 100 mA and spherical morphology observed with currents above 100 mA. The counteranions in the electrolyte also impacted the morphology with spherical, nanosheet, and nanorod morphologies produced by Cl− or SO4 2–, CO3 2–, and HCO3 – counteranions, respectively. BET analysis revealed the formation of electrocoagulants with micro-, meso-, and macropores. Surface area was markedly reduced from 142.85 to 41.96 m2 g–1 by incident coagulation resulting from increased anodic dissolution. Applicability of the electrocoagulant was examined by different micropollutants (acetaminophen (AC), antipyrine (AT), and atenolol (AT)). Results suggest that >90% and >80% TOC reduction were achieved with Na2CO3 and NaHCO3 as electrolyte media. The lower TOC reduction was rationalized by the identified intermediate products, and possible micropollutant degradation pathways were proposed based on LC-MS/MS analysis.

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Effective removal of silica and sulfide from oil sands thermal in-situ produced water by electrocoagulation

Cited by 36 publications

References 48 publications

Mechanistic Insight into Electrode Processes by Operando Visualization of Interfacial pH Using Fluorescent Nanosensors

Mechanistic Insight into Electrode Processes by Operando Visualization of Interfacial pH Using Fluorescent Nanosensors

Treatment Technologies for Organics and Silica Removal in Steam-Assisted Gravity Drainage Produced Water: A Comprehensive Review

Electrocoagulants Characteristics and Application of Electrocoagulation for Micropollutant Removal and Transformation Mechanism

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