Performance and mechanistic study on electrocoagulation process for municipal wastewater treatment based on horizontal bipolar electrodes

Abstract

• EC modified with BPEs enhances pollutant removal and reduce energy consumption.

• Increasing BPE number cannot increase flocculants yield exponentially.

• Simulations help to predict the distribution of electrochemical reactions on BPEs.

The design of electrodes is crucial to electrocoagulation process (EC), specifically, with respect to pollutant removal and energy consumption. During EC, the mechanisms for interaction between different electrode arrangement and electrode reactions remain unclear. This work presents an integrated EC process based on horizontal bipolar electrodes (BPEs). In the electrochemical cell, the graphite plates are used as driving cathode while either Fe or Al plates serves as driving anode and BPEs. The BPEs are placed horizontally between the driving electrodes. For municipal wastewater treatment, the pollutant removal efficiency and energy consumption in different configurations of two-dimension electrocoagulation (2D-EC) system with horizontal BPEs were investigated. The removal efficiency of turbidity, total phosphorus and total organic carbon increased significantly with the number of BPEs. Noted that the energy consumption for TP removal decreased by 75.2% with Fe driving anode and 81.5% with Al driving anode than those of 2D-EC, respectively. In addition, the physical field simulation suggested the distributions of potential and current in electrolyte and that of induced charge density on BPE surface. This work provides a visual theoretical guidance to predict the distribution of reactions on BPEs for enhanced pollutant removal and energy saving based on electrocoagulation process for municipal wastewater treatment.

Graphical abstract

Keywords

Electrocoagulation / Bipolar electrodes / Municipal wastewater / Simulations

References

[1] Al-Shannag M, Bani-Melhem K, Al-Anber Z, Al-Qodah Z (2013). Enhancement of COD-nutrients removals and filterability of secondary clarifier municipal wastewater influent using electrocoagulation technique. Separation Science and Technology, 48(4): 673–680

[2] Bani-Melhem K, Al-Shannag M, Alrousan D, Al-Kofahi S, Alqodah Z, Al-Kilani M R (2017). Impact of soluble COD on grey water treatment by electrocoagulation technique. Desalination and Water Treatment, 89: 101–110

[3] Barker D, Walsh F C (1991). Applications of Faraday’s laws of electrolysis in metal finishing. Transactions of the IMF, 69(4): 158–162

[4] Bhatti M S, Reddy A S, Kalia R K, Thukral A K (2011). Modeling and optimization of voltage and treatment time for electrocoagulation removal of hexavalent chromium. Desalination, 269(1–3): 157–162

[5] Bhatti M S, Reddy A S, Thukral A K (2009). Electrocoagulation removal of Cr(VI) from simulated wastewater using response surface methodology. Journal of Hazardous Materials, 172(2–3): 839–846

[6] Bonnor W B (1953). Certain exact solutions of the equations of general relativity with an electrostatic field. Proceedings of the Physical Society. Section A, 66(2): 145

[7] Chang B Y, Chow K F, Crooks J A, Mavré F, Crooks R M (2012). Two-channel microelectrochemical bipolar electrode sensor array. Analyst (London), 137(12): 2827–2833

[8] Chavalparit O, Ongwandee M (2009). Optimizing electrocoagulation process for the treatment of biodiesel wastewater using response surface methodology. Journal of Environmental Sciences (China), 21(11): 1491–1496

[9] Cho K, Kwon D, Hoffmann M R (2014). Electrochemical treatment of human waste coupled with molecular hydrogen production. RSC Advances, 4(9): 4596–4608

[10] Chow K F, Mavré F, Crooks J A, Chang B Y, Crooks R M (2009). A large-scale, wireless electrochemical bipolar electrode microarray. Journal of the American Chemical Society, 131(24): 8364–8365

[11] Daneshvar N, Ashassi Sorkhabi H, Kasiri M B (2004). Decolorization of dye solution containing Acid Red 14 by electrocoagulation with a comparative investigation of different electrode connections. Journal of Hazardous Materials, 112(1–2): 55–62

[12] Gao S, Yang J, Tian J, Ma F, Tu G, Du M (2010). Electro-coagulation–flotation process for algae removal. Journal of Hazardous Materials, 177(1–3): 336–343

[13] Garcia-Segura S, Eiband M M S, de Melo J V, Martínez-Huitle C A (2017). Electrocoagulation and advanced electrocoagulation processes: A general review about the fundamentals, emerging applications and its association with other technologies. Journal of Electroanalytical Chemistry, 801: 267–299

[14] Ghosh D, Medhi C R, Purkait M K (2008). Treatment of fluoride containing drinking water by electrocoagulation using monopolar and bipolar electrode connections. Chemosphere, 73(9): 1393–1400

[15] Hakizimana J N, Gourich B, Chafi M, Stiriba Y, Vial C, Drogui P, Naja J (2017). Electrocoagulation process in water treatment: A review of electrocoagulation modeling approaches. Desalination, 404: 1–21

[16] Jiang J Q, Graham N, André C, Kelsall G H, Brandon N (2002). Laboratory study of electro-coagulation–flotation for water treatment. Water Research, 36(16): 4064–4078

[17] Jiménez C, Sáez C, Cañizares P, Rodrigo M A (2016). Optimization of a combined electrocoagulation-electroflotation reactor. Environmental Science and Pollution Research International, 23(10): 9700–9711

[18] Jüttner K, Galla U, Schmieder H (2000). Electrochemical approaches to environmental problems in the process industry. Electrochimica Acta, 45(15–16): 2575–2594

[19] Keddam M, Nóvoa X R, Vivier V (2009). The concept of floating electrode for contact-less electrochemical measurements: Application to reinforcing steel-bar corrosion in concrete. Corrosion Science, 51(8): 1795–1801

[20] Kobya M, Bayramoglu M, Eyvaz M (2007). Techno-economical evaluation of electrocoagulation for the textile wastewater using different electrode connections. Journal of Hazardous Materials, 148(1–2): 311–318

[21] Li M, Liu S, Jiang Y, Wang W (2018). Visualizing the zero-potential line of bipolar electrodes with arbitrary geometry. Analytical Chemistry, 90(11): 6390–6396

[22] Mahvi A H, Ebrahimi S J A D, Mesdaghinia A, Gharibi H, Sowlat M H (2011). Performance evaluation of a continuous bipolar electrocoagulation/electrooxidation–electroflotation (ECEO–EF) reactor designed for simultaneous removal of ammonia and phosphate from wastewater effluent. Journal of Hazardous Materials, 192(3): 1267–1274

[23] Mansouri K, Ibrik K, Bensalah N, Abdel-Wahab A (2011). Anodic dissolution of pure Aluminum during electrocoagulation process: Influence of supporting electrolyte, initial pH, and current density. Industrial & Engineering Chemistry Research, 50(23): 13362–13372

[24] Marcus R A (1956). On the theory of oxidation-reduction reactions involving electron transfer. I. Journal of Chemical Physics, 24(5): 966–978

[25] Martinez-Delgadillo S, Mollinedo-Ponce H, Mendoza-Escamilla V, Gutiérrez-Torres C, Jiménez-Bernal J, Barrera-Diaz C (2012). Performance evaluation of an electrochemical reactor used to reduce Cr(VI) from aqueous media applying CFD simulations. Journal of Cleaner Production, 34: 120–124

[26] Mavré F, Anand R K, Laws D R, Chow K F, Chang B Y, Crooks J A, Crooks R M (2010). Bipolar electrodes: A useful tool for concentration, separation, and detection of analytes in microelectrochemical systems. Analyst (London), 82: 8766–8774

[27] Modirshahla N, Behnajady M A, Mohammadi-Aghdam S (2008). Investigation of the effect of different electrodes and their connections on the removal efficiency of 4-nitrophenol from aqueous solution by electrocoagulation. Journal of Hazardous Materials, 154(1–3): 778–786

[28] Mollah M Y A, Schennach R, Parga J R, Cocke D L (2001). Electrocoagulation (EC)—Science and applications. Journal of Hazardous Materials, 84(1): 29–41

[29] Mollah M Y, Morkovsky P, Gomes J A, Kesmez M, Parga J, Cocke D L (2004). Fundamentals, present and future perspectives of electrocoagulation. Journal of Hazardous Materials, 114(1–3): 199–210

[30] Moussa D T, El-Naas M H, Nasser M, Al-Marri M J (2017). A comprehensive review of electrocoagulation for water treatment: Potentials and challenges. Journal of Environmental Management, 186: 24–41

[31] Olmez-Hanci T, Kartal Z, Arslan-Alaton İ (2012). Electrocoagulation of commercial naphthalene sulfonates: process optimization and assessment of implementation potential. Journal of Environmental Management, 99: 44–51 doi:10.1016/j.jenvman.2012.01.006

[32] Pébère N, Vivier V (2016). Local electrochemical measurements in bipolar experiments for corrosion studies. ChemElectroChem, 3(3): 415–421

[33] Peel J W, Reddy K J, Sullivan B P, Bowen J M (2003). Electrocatalytic reduction of nitrate in water. Water Research, 37(10): 2512–2519

[34] Qi Z, You S, Ren N (2017). Wireless electrocoagulation in water treatment based on bipolar electrochemistry. Electrochimica Acta, 229: 96–101

[35] Qi Z, Zhang J, You S (2018). Effect of placement angles on wireless electrocoagulation for bipolar aluminum electrodes. Frontiers of Environmental Science & Engineering, 12(3): 9

[36] Reddy K J, Lin J (2000). Nitrate removal from groundwater using catalytic reduction. Water Research, 34(3): 995–1001

[37] Ryder E J(1953). Mobility of holes and electrons in high electric fields. Physical Review, 90(5): 766 doi:10.1103/PhysRev.90.766

[38] Sahu O, Mazumdar B, Chaudhari P K (2014). Treatment of wastewater by electrocoagulation: A review. Environmental Science and Pollution Research International, 21(4): 2397–2413

[39] Sun Y, Chen Z, Wu G, Wu Q, Zhang F, Niu Z, Hu H Y (2016). Characteristics of water quality of municipal wastewater treatment plants in China: Implications for resources utilization and management. Journal of Cleaner Production, 131: 1–9

[40] Szabó T, Tombácz E, Illés E, Dékány I (2006). Enhanced acidity and pH-dependent surface charge characterization of successively oxidized graphite oxides. Carbon, 44(3): 537–545

[41] Vázquez A, Nava J L, Cruz R, Lázaro I, Rodríguez I (2014). The importance of current distribution and cell hydrodynamic analysis for the design of electrocoagulation reactors. Journal of Chemical Technology and Biotechnology (Oxford, Oxfordshire), 89(2): 220–229

[42] Vázquez A, Rodríguez I, Lázaro I (2012). Primary potential and current density distribution analysis: A first approach for designing electrocoagulation reactors. Chemical Engineering Journal, 179: 253–261

[43] Walsh F C (1991). The overall rates of electrode reactions: Faraday’s laws of electrolysis. Transactions of the IMF, 69(4): 155–157

[44] Zhang X, Shang C, Gu W, Xia Y, Li J, Wang E (2016). A renewable display platform based on the bipolar electrochromic electrode. ChemElectroChem, 3(3): 383–386

RIGHTS & PERMISSIONS

Higher Education Press and Springer-Verlag GmbH Germany, part of Springer Nature