Integrating of electrocoagulation process with submerged membrane bioreactor for wastewater treatment under low voltage gradients

Khalid Bani-Melhem; Maria Elektorowicz; Muhammad Tawalbeh; Abeer Al Bsoul; Ahmed El Gendy; Hesam Kamyab; Mohammad Yusuf

doi:10.1016/j.chemosphere.2023.139693

Integrating of electrocoagulation process with submerged membrane bioreactor for wastewater treatment under low voltage gradients

Chemosphere. 2023 Oct:339:139693. doi: 10.1016/j.chemosphere.2023.139693. Epub 2023 Aug 1.

Authors

Khalid Bani-Melhem¹, Maria Elektorowicz², Muhammad Tawalbeh³, Abeer Al Bsoul⁴, Ahmed El Gendy⁵, Hesam Kamyab⁶, Mohammad Yusuf⁷

Affiliations

¹ Water Technology Unit (WTU), Center for Advanced Materials (CAM). Qatar University, P.O. Box 2713, Doha, Qatar. Electronic address: kmelhem@qu.edu.qa.
² Dept. of Building, Civil and Environmental Engineering, Concordia University, 1455 Blvd de Maisonneuve W., Montreal, Quebec, H3G 1M8, Canada.
³ Sustainable and Renewable Energy Engineering Department, University of Sharjah, Sharjah, P.O. Box 27272, United Arab Emirates; Sustainable Energy & Power Systems Research Centre, RISE, University of Sharjah, P.O. Box 27272, Sharjah, United Arab Emirates.
⁴ Al-Balqa Applied University, Al-Huson University College, Department of Chemical Engineering, Jordan.
⁵ Environmental Engineering Program, Department of Construction and Architectural Engineering, School of Sciences and Engineering, The American University in Cairo, New Cairo, Egypt.
⁶ Faculty of Architecture and Urbanism, UTE University, Calle Rumipamba S/N and Bourgeois, Quito, Ecuador; Department of Biomaterials, Saveetha Dental College and Hospital, Saveetha Institute of Medical and Technical Sciences, Chennai, 600 077, India; Process Systems Engineering Centre (PROSPECT), Faculty of Chemical and Energy Engineering, Faculty of Engineering, Universiti Teknologi Malaysia, Skudai, Johor, Malaysia.
⁷ Institute of Hydrocarbon Recovery, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, Perak, 32610, Malaysia. Electronic address: yusufshaikh.amu@gmail.com.

PMID: 37536541
DOI: 10.1016/j.chemosphere.2023.139693

Abstract

Treating and reusing wastewater has become an essential aspect of water management worldwide. However, the increase in emerging pollutants such as polycyclic aromatic hydrocarbons (PAHs), which are presented in wastewater from various sources like industry, roads, and household waste, makes their removal difficult due to their low concentration, stability, and ability to combine with other organic substances. Therefore, treating a low load of wastewater is an attractive option. The study aimed to address membrane fouling in the submerged membrane bioreactor (SMBR) used for wastewater treatment. An aluminum electrocoagulation (EC) device was combined with SMBR as a pre-treatment to reduce fouling. The EC-SMBR process was compared with a conventional SMBR without EC, fed with real grey water. To prevent impeding biological growth, low voltage gradients were utilized in the EC deviceThe comparison was conducted over 60 days with constant transmembrane pressure and infinite solid retention time (SRT). In phase I, when the EC device was operated at a low voltage gradient (0.64 V/cm), no significant improvement in the pollutants removal was observed in terms of color, turbidity, and chemical oxygen demand (COD). Nevertheless, during phase II, a voltage gradient of 1.26 V/cm achieved up to 100%, 99.7%, 92%, 94.1%, and 96.5% removals in the EC-SMBR process in comparison with 95.1%, 95.4%, 85%, 91.7% and 74.2% removals in the SMBR process for turbidity, color, COD, ammonia nitrogen (NH₃-N), total phosphorus (TP), respectively. SMBR showed better anionic surfactant (AS) removal than EC-SMBR. A voltage gradient of 0.64 V/cm in the EC unit significantly reduced fouling by 23.7%, while 1.26 V/cm showed inconsistent results. Accumulation of Al ions negatively affected membrane performance. Low voltage gradients in EC can control SMBR fouling if Al concentration is controlled. Future research should investigate EC-SMBR with constant membrane flux for large-scale applications, considering energy consumption and operating costs.

Keywords: Electrocoagulation; Grey water; Membrane fouling; PAHs; Submerged membrane bioreactor.

MeSH terms

Bioreactors
Electrocoagulation
Environmental Pollutants*
Membranes, Artificial
Waste Disposal, Fluid / methods
Wastewater
Water / chemistry
Water Purification* / methods

Substances

Wastewater
Membranes, Artificial
Environmental Pollutants
Water