Performance evaluation of fixed bed anaerobic baffled reactor and its upgrading by integrated electrocoagulation process for municipal wastewater treatment

Document Type : Original Article


1 Department of Environmental Health Engineering, Khoy university of Medical Science, Khoy, Iran

2 Department of Environmental Health Engineering, Qom university of Medical Science, Qom, Iran


Anaerobic baffled reactor is efficient for wastewater treatment, while it lacks efficient nutrient removal and must be upgraded. The present study aimed to evaluate performance of fixed-bed media anaerobic baffled reactor (FABR) for municipal wastewater treatment. The performance of the integrated electrocoagulation process in the FABR (E-FABR) was also investigated. The large bench-scale five of sectional FABR reactor was assessed continually to the hydraulic retention times (HRTs) of 40, 30, and 20 hours, respectively to meet the effluent disposal standards using the HDPE-2H media in the FABR. After determining the optimum HRT, EP was integrated in 4th section of the FABR to improve the performance. At the E-FABR, the steel-steel and aluminum electrode pair (Al-Al) was evaluated at the current densities of 0.05-0.5 mA/cm2 (HRT=20 hours). The performance of FABR decreased with reduced HRT from 40 to 30 and 20 hours. At the optimum HRT (30 hours), the reactor met the TSS, COD, and BOD effluent discharge standards. The mean steady-state removal of TSS, COD, BOD5, total nitrogen, and total phosphorus was 93±0.5%, 91±0.8%, 93.4±1%, 16±1%, and 28±0.7%, respectively. The E-FABR with the steel and aluminum electrodes at the current densities of 0.3 and 0.1 mA/cm2 and HRT of 20 hours decreased the TSS, COD, BOD, SO4, and TP concentrations to the effluent discharge standard limits. Therefore, the FABR is an efficient system for municipal wastewater treatment, and E-FABR with aluminum electrodes and extremely low current density could easily treat wastewater to the effluent discharge standards.


1. Stuckey DC. Anaerobic baffled reactor (ABR) for wastewater treatment. Environmental Anaerobic Technology: Applications and New Developments 2010: 163-84.
2. Liu R, Tian Q, Chen J. The developments of anaerobic baffled reactor for wastewater treatment: a review. African Journal of Biotechnology 2010; 9(11): 1535-42.
3. Bodkhe S. A modified anaerobic baffled reactor for municipal wastewater treatment. Journal of environmental management 2009; 90(8): 2488-93.
4. Moussavi G, Khosravi R, Farzadkia M. Removal of petroleum hydrocarbons from contaminated groundwater using an electrocoagulation process: Batch and continuous experiments. Desalination 2011; 278(1-3): 288-94.
5. Moussavi G, Majidi F, Farzadkia M. The influence of operational parameters on elimination of cyanide from wastewater using the electrocoagulation process. Desalination 2011; 280(1-3): 127-33.
6. Bisschops I, Kok DK, Seghezzo L, Zeeman G. Anaerobic treatment as core technology for more sustainable sanitation.  2019.
7. Moradgholi M, Massoudinejad M, Aghayani E, Yazdanbakhsh A. Performance of electrical stimulated anaerobic baffled reactor for removal of typical pollutants from low-strength municipal wastewater at low temperatures. Environment health management and engineering 2019; 6(2):121-8.  
8. Stazi V, Tomei MC. Enhancing anaerobic treatment of domestic wastewater: State of the art, innovative technologies and future perspectives. Science of The Total Environment 2018; 635: 78-91.
9. Eaton AD, Clesceri LS, Greenberg AE, Franson MaH. Standard methods for the examination of water and wastewater. American public health association 2005; 1015: 49-51.
10. Schalk T, Marx C, Ahnert M, Krebs P, Kühn V. Operational experience with a full‐scale anaerobic baffled reactor treating municipal wastewater. Water Environment Research 2019; 91(1): 54-68.
11. Yulistyorini A, Camargo-Valero MA, Sukarni S, Suryoputro N, Mujiyono M, Santoso H, et al. Performance of Anaerobic Baffled Reactor for Decentralized Wastewater Treatment in Urban Malang, Indonesia. Processes 2019; 7(4): 184.
12. Nasr FA, Doma HS, Nassar HF. Treatment of domestic wastewater using an anaerobic baffled reactor followed by a duckweed pond for agricultural purposes. The Environmentalist 2009; 29(3): 270-9.
13. Hahn MJ, etueroa LA. Pilot scale application of anaerobic baffled reactor for biologically enhanced primary treatment of raw municipal wastewater. Water research 2015; 87: 494-502.
14. Kuscu ÖS, Sponza DT. Effects of nitrobenzene concentration and hydraulic retention time on the treatment of nitrobenzene in sequential anaerobic baffled reactor (ABR)/continuously stirred tank reactor (CSTR) system. Bioresource technology 2009; 100(7): 2162-70.
15. Lv L, Li W, Bian J, Yu Y, Li D, Zheng Z. Evaluation of phase separation in a single-stage vertical anaerobic reactor: Performance and microbial composition analysis. Bioresource technology 2018; 261: 370-8.
16. Sung H-N, Katsou E, Statiris E, Anguilano L, Malamis S. Operation of a modified anaerobic baffled reactor coupled with a membrane bioreactor for the treatment of municipal wastewater in Taiwan. Environ technol 2018: 1-6.
17. Jiang H, Nie H, Ding J, Stinner W, Sun K, Zhou H. The startup performance and microbial distribution of an anaerobic baffled reactor (ABR) treating medium-strength synthetic industrial wastewater. J Environ Sci Health A Tox Hazard Subst Environ Eng 2018; 53(1): 46-54.
18. Thanwised P, Wirojanagud W, Reungsang A. Effect of hydraulic retention time on hydrogen production and chemical oxygen demand removal from tapioca wastewater using anaerobic mixed cultures in anaerobic baffled reactor (ABR). International Journal of Hydrogen Energy 2012; 37(20): 15503-10.
19. Adhanom G, Hughes J, Odindo A. The effect of anaerobic baffled reactor effluent on nitrogen and phosphorus leaching from four soils in a laboratory column experiment. Water SA 2018; 44(1): 1-12.
20. Azhdarpoor A, Abbasi L, Samaei MR. Investigation of a new double-stage aerobic-anoxic continuous-flow cyclic baffled bioreactor efficiency for wastewater nutrient removal. Journal of environmental management 2018; 211: 1-8.
21. Jiang Y, Li H, Qin Y, Liang Y, Wu C, Liu K, et al. Spatial separation and bio-chain cooperation between sulfidogenesis and methanogenesis in an anaerobic baffled reactor with sucrose as the carbon source. International Biodeterioration & Biodegradation 2019; 138: 99-105.
22. Elreedy A, Tawfik A. Effect of hydraulic retention time on hydrogen production from the dark fermentation of petrochemical effluents contaminated with Ethylene Glycol. Energy Procedia 2015; 74: 1071-8.
23. Khalekuzzaman M, Hasan M, Haque R, Alamgir M. Hydrodynamic performance of a hybrid anaerobic baffled reactor (HABR): effects of number of chambers, hydraulic retention time, and influent temperature. Water Science and Technology 2018; 78(4): 968-81.
24. Elazzouzi M, Haboubi K, Elyoubi M. Enhancement of electrocoagulation-flotation process for urban wastewater treatment using Al and Fe electrodes: techno-economic study. Materials Today: Proceedings 2019; 13: 549-55.
25. Moussavi G, Aqanaghad M. Performance evaluation of electro-Fenton process for pretreatment and biodegradability improvement of a pesticide manufacturing plant effluent. Sustain Environ Res 2015; 25: 249e254.
26. Tezcan Un U, Filik Iscen C, Oduncu E, Akcal Comoglu B, Ilhan S. Treatment of landfill leachate using integrated continuous electrocoagulation and the anaerobic treatment technique. Environmental Progress & Sustainable Energy 2018; 37(5): 1668-76.
27. Elyasi S, Amani T, Dastyar W. A comprehensive evaluation of parameters affecting treating high-strength compost leachate in anaerobic baffled reactor followed by electrocoagulation-flotation process. Water, Air, & Soil Pollution 2015; 226(4): 116.
28. Yılmaz S, Gerek EE, Yavuz Y, Koparal AS. Treatment of vinegar industry wastewater by electrocoagulation with monopolar aluminum and iron electrodes and toxicity evaluation. Water Science and Technology 2019.