Electrochemical treatment of sewage sludge and pathogen inactivation


Treatment and disposal of sewage sludge is still a worldwide challenging problem. Improper sludge treatment results in severe environmental impact and endangering public health. Moreover, sewage sludge disposal is a cost-intensive process. Therefore, pathogen removal and solid reduction are indispensable for sludge disposal management. In this study, a novel electrochemical method in alkaline media was developed to break down the sludge structure at room temperature. A reduction of 24.85% in total solids and 46.42% in volatile solids was achieved, which represents approximately a 25% reduction in the sludge disposal cost when compared to conventional treatment methods. Also, a 90% reduction in energy consumption was demonstrated when compared to other electrochemical methods. The post-processed samples characterization showed that a large quantity of organic material was released from the sludge samples into the liquid phase, which indicates the potential to reduce the residence time in anaerobic digesters and to generate more biogas. The proposed treatment demonstrated the feasibility of pathogen removal and biosolid production for safe landfilling or agriculture applications such as fertilizers.

Graphic abstract

This is a preview of subscription content, access via your institution.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7


  1. 1.

    Ahn Y, Im S, Chung J-W (2017) Optimizing the operating temperature for microbial electrolysis cell treating sewage sludge. Int J Hydrog Energy 42(45):27784–27791. https://doi.org/10.1016/j.ijhydene.2017.05.139

    CAS  Article  Google Scholar 

  2. 2.

    Southern Research Institute (2012) Technology assessment report aqueous sludge gasification technologies. Southern Research Institute, Birmingham

    Google Scholar 

  3. 3.

    Kroiss H (2004) What is the potential for utilizing the resources in sludge? Water Sci Technol J Int Assoc Water Pollut Res 49(10):1–10

    CAS  Article  Google Scholar 

  4. 4.

    Zhang Q, Hu J, Lee D-J, Chang Y, Lee Y-J (2017) Sludge treatment: current research trends. Bioresour Technol 243:1159–1172. https://doi.org/10.1016/j.biortech.2017.07.070

    CAS  Article  PubMed  Google Scholar 

  5. 5.

    Lowman A, McDonald MA, Wing S, Muhammad N (2013) Land application of treated sewage sludge: community health and environmental justice. Environ Health Perspect 121(5):537–542. https://doi.org/10.1289/ehp.1205470

    Article  PubMed  PubMed Central  Google Scholar 

  6. 6.

    Oladejo J, Shi K, Luo X, Yang G, Wu T (2019) A review of sludge-to-energy recovery methods. Energies. https://doi.org/10.3390/en12010060

    Article  Google Scholar 

  7. 7.

    Yuan H, Chen Y, Zhang H, Jiang S, Zhou Q, Gu G (2006) Improved bioproduction of short-chain fatty acids (SCFAs) from excess sludge under alkaline conditions. Environ Sci Technol 40(6):2025–2029. https://doi.org/10.1021/es052252b

    CAS  Article  PubMed  Google Scholar 

  8. 8.

    Mizoguchi T, Watanabe K, Kobori T, Fujimoto T, Kumagai H, Sasaki K (2008) Solubilization and reduction of activated sludge from petroleum refinery using high speed mixer and alkaline treatment. J Jpn Pet Inst 51(4):245–251. https://doi.org/10.1627/jpi.51.245

    CAS  Article  Google Scholar 

  9. 9.

    Kim T-H et al (2007) Solubilization of waste activated sludge with alkaline treatment and gamma ray irradiation. J Ind Eng Chem 13:1149–1153

    CAS  Google Scholar 

  10. 10.

    Ma X et al (2019) Alkaline fermentation of waste activated sludge with calcium hydroxide to improve short-chain fatty acids production and extraction efficiency via layered double hydroxides. Bioresour Technol 279:117–123. https://doi.org/10.1016/j.biortech.2019.01.128

    CAS  Article  PubMed  Google Scholar 

  11. 11.

    Jin B, Wang S, Xing L, Li B, Peng Y (2016) Long term effect of alkali types on waste activated sludge hydrolytic acidification and microbial community at low temperature. Bioresour Technol 200:587–597. https://doi.org/10.1016/j.biortech.2015.10.036

    CAS  Article  PubMed  Google Scholar 

  12. 12.

    Kim J, Park C (2003) Effects of various pretreatments for enhanced anaerobic digestion with waste activated sludge. J Biosci Bioeng 95(3):271–275. https://doi.org/10.1016/S1389-1723(03)80028-2

    CAS  Article  PubMed  Google Scholar 

  13. 13.

    Chen Y, Jiang S, Yuan H, Zhou Q, Gu G (2007) Hydrolysis and acidification of waste activated sludge at different pHs. Water Res 41(3):683–689. https://doi.org/10.1016/j.watres.2006.07.030

    CAS  Article  PubMed  Google Scholar 

  14. 14.

    Su G, Huo M, Yuan Z, Wang S, Peng Y (2013) Hydrolysis, acidification and dewaterability of waste activated sludge under alkaline conditions: combined effects of NaOH and Ca(OH)2. Bioresour Technol 136:237–243. https://doi.org/10.1016/j.biortech.2013.03.024

    CAS  Article  PubMed  Google Scholar 

  15. 15.

    Ruffino B et al (2016) Preliminary technical and economic analysis of alkali and low temperature thermo-alkali pretreatments for the anaerobic digestion of waste activated sludge. Waste Biomass Valorization 7(4):667–675. https://doi.org/10.1007/s12649-016-9537-x

    CAS  Article  Google Scholar 

  16. 16.

    Feng L, Wang H, Chen Y, Wang Q (2009) Effect of solids retention time and temperature on waste activated sludge hydrolysis and short-chain fatty acids accumulation under alkaline conditions in continuous-flow reactors. Bioresour Technol 100(1):44–49. https://doi.org/10.1016/j.biortech.2008.05.028

    CAS  Article  PubMed  Google Scholar 

  17. 17.

    Wonglertarak W, Wichitsathian B (2014) Alkaline pretreatment of waste activated sludge in anaerobic digestion. J Clean Energy Technol 2:118–121. https://doi.org/10.7763/JOCET.2014.V2.104

    CAS  Article  Google Scholar 

  18. 18.

    García Becerra FY, Acosta EJ, Allen DG (2010) Alkaline extraction of wastewater activated sludge biosolids. Bioresour Technol 101(18):6972–6980. https://doi.org/10.1016/j.biortech.2010.04.021

    CAS  Article  Google Scholar 

  19. 19.

    Zeng Q et al (2019) Electrochemical pretreatment for stabilization of waste activated sludge: simultaneously enhancing dewaterability, inactivating pathogens and mitigating hydrogen sulfide. Water Res 166:115035. https://doi.org/10.1016/j.watres.2019.115035

    CAS  Article  PubMed  Google Scholar 

  20. 20.

    Ye C, Yuan H, Dai X, Lou Z, Zhu N (2016) Electrochemical pretreatment of waste activated sludge: effect of process conditions on sludge disintegration degree and methane production. Environ Technol 37(22):2935–2944. https://doi.org/10.1080/09593330.2016.1170209

    CAS  Article  PubMed  Google Scholar 

  21. 21.

    Cui X, Quicksall AN, Blake AB, Talley JW (2013) Electrochemical disinfection of Escherichia coli in the presence and absence of primary sludge particulates. Water Res 47(13):4383–4390. https://doi.org/10.1016/j.watres.2013.04.039

    CAS  Article  PubMed  Google Scholar 

  22. 22.

    Song L-J, Zhu N-W, Yuan H-P, Hong Y, Ding J (2010) Enhancement of waste activated sludge aerobic digestion by electrochemical pre-treatment. Water Res 44(15):4371–4378. https://doi.org/10.1016/j.watres.2010.05.052

    CAS  Article  PubMed  Google Scholar 

  23. 23.

    Yu B, Xu J, Yuan H, Lou Z, Lin J, Zhu N (2014) Enhancement of anaerobic digestion of waste activated sludge by electrochemical pretreatment. Fuel 130:279–285. https://doi.org/10.1016/j.fuel.2014.04.031

    CAS  Article  Google Scholar 

  24. 24.

    American Public Health APHA (2005) Standard methods for the examination of water & wastewater. American Public Health Association APHA, Washington, DC

    Google Scholar 

  25. 25.

    Jin X, Botte GG (2010) Understanding the kinetics of coal electrolysis at intermediate temperatures. J Power Sources 195(15):4935–4942. https://doi.org/10.1016/j.jpowsour.2010.02.007

    CAS  Article  Google Scholar 

  26. 26.

    Jin X, Botte GG (2007) Feasibility of hydrogen production from coal electrolysis at intermediate temperatures. J Power Sources 171(2):826–834. https://doi.org/10.1016/j.jpowsour.2007.06.209

    CAS  Article  Google Scholar 

  27. 27.

    Sheets BL, Botte GG (2018) Electrochemical nitrogen reduction to ammonia under mild conditions enabled by a polymer gel electrolyte. Chem Commun. https://doi.org/10.1039/c8cc00657a

    Article  Google Scholar 

  28. 28.

    Vitse F, Cooper M, Botte GG (2005) On the use of ammonia electrolysis for hydrogen production. J Power Sources 142(1–2):18–26. https://doi.org/10.1016/j.jpowsour.2004.09.043

    CAS  Article  Google Scholar 

  29. 29.

    Nabi M et al (2019) Contribution of solid and liquid fractions of sewage sludge pretreated by high pressure homogenization to biogas production. Bioresour Technol 286:121378. https://doi.org/10.1016/j.biortech.2019.121378

    CAS  Article  PubMed  Google Scholar 

  30. 30.

    Otieno B, Apollo S, Kabuba J, Naidoo B, Simate G, Ochieng A (2019) Ozonolysis pre-treatment of waste activated sludge for solubilization and biodegradability enhancement. J Environ Chem Eng 7(2):102945. https://doi.org/10.1016/j.jece.2019.102945

    CAS  Article  Google Scholar 

  31. 31.

    Fang W et al (2014) Effect of alkaline addition on anaerobic sludge digestion with combined pretreatment of alkaline and high pressure homogenization. Bioresour Technol 168:167–172. https://doi.org/10.1016/j.biortech.2014.03.050

    CAS  Article  PubMed  Google Scholar 

  32. 32.

    Bastian RK (2003) Biosolid management handbook. Office of Wastewater Management US Environmental Protection Agency, Washington, DC

    Google Scholar 

  33. 33.

    Feki E, Sayadi S, Loukil S, Dhouib A, Khoufi S (2019) Comparison between thermo-alkaline and electro-fenton disintegration effect on waste activated sludge anaerobic digestion. BioMed Res Int. https://doi.org/10.1155/2019/2496905

    Article  PubMed  PubMed Central  Google Scholar 

  34. 34.

    Park SK, Jang HM, Ha JH, Park JM (2014) Sequential sludge digestion after diverse pre-treatment conditions: sludge removal, methane production and microbial community changes. Bioresour Technol 162:331–340. https://doi.org/10.1016/j.biortech.2014.03.152

    CAS  Article  PubMed  Google Scholar 

  35. 35.

    Zhao Z, Zhang Y, Yu Q, Ma W, Sun J, Quan X (2016) Enhanced decomposition of waste activated sludge via anodic oxidation for methane production and bioenergy recovery. Int Biodeterior Biodegrad 106:161–169. https://doi.org/10.1016/j.ibiod.2015.10.020

    CAS  Article  Google Scholar 

  36. 36.

    Subhedar PB, Gogate PR (2014) Alkaline and ultrasound assisted alkaline pretreatment for intensification of delignification process from sustainable raw-material. Ultrason Sonochem 21(1):216–225. https://doi.org/10.1016/j.ultsonch.2013.08.001

    CAS  Article  PubMed  Google Scholar 

  37. 37.

    Grigatti M, Montecchio D, Francioso O, Ciavatta C (2015) Structural and thermal investigation of three agricultural biomasses following Mild-NaOH pretreatment to increase anaerobic biodegradability. Waste Biomass Valorization 6(6):1135–1148. https://doi.org/10.1007/s12649-015-9423-y

    CAS  Article  Google Scholar 

  38. 38.

    Bykov I (2008) Characterization of natural and technical lignins using FTIR spectroscopy

  39. 39.

    Jiang J, Zhao Q, Wei L, Wang K, Lee D-J (2011) Degradation and characteristic changes of organic matter in sewage sludge using microbial fuel cell with ultrasound pretreatment. Bioresour Technol 102(1):272–277. https://doi.org/10.1016/j.biortech.2010.04.066

    CAS  Article  PubMed  Google Scholar 

  40. 40.

    Punyamurthy R, Sampathkumar D, Ranganagowda RP, Bennehalli B, Badyankal P, Venkateshappa SC (2014) Surface modification of abaca fiber by benzene diazonium chloride treatment and its influence on tensile properties of abaca fiber reinforced polypropylene composites. Ciênc Tecnol Mater 26:142–149. https://doi.org/10.1016/j.ctmat.2015.03.003

    Article  Google Scholar 

  41. 41.

    Navab Daneshmand T, Beton R, Hill RJ, Gehr R, Frigon D (2012) Inactivation mechanisms of bacterial pathogen indicators during electro-dewatering of activated sludge biosolids. Water Res 46(13):3999–4008. https://doi.org/10.1016/j.watres.2012.05.009

    CAS  Article  PubMed  Google Scholar 

  42. 42.

    United States Environmental Protection Agency (2003) Control of patoghens and vector attraction in sewage sludge, EPA 625-R-92-013. 186 pp. https://www.epa.gov/biosolids/control-pathogens-and-vector-attraction-sewage-sludge

  43. 43.

    Wang Q, Ye L, Jiang G, Jensen PD, Batstone DJ, Yuan Z (2013) Free nitrous acid (FNA)-based pretreatment enhances methane production from waste activated sludge. Environ Sci Technol 47(20):11897–11904. https://doi.org/10.1021/es402933b

    CAS  Article  PubMed  Google Scholar 

  44. 44.

    Bonnin EP, Biddinger EJ, Botte GG (2008) Effect of catalyst on electrolysis of ammonia effluents. J Power Sources 182(1):284–290. https://doi.org/10.1016/j.jpowsour.2008.03.046

    CAS  Article  Google Scholar 

  45. 45.

    Cooper M, Botte GG (2006) Hydrogen production from the electro-oxidation of ammonia catalyzed by platinum and rhodium on raney nickel substrate. J Electrochem Soc 153(10):A1894. https://doi.org/10.1149/1.2240037

    CAS  Article  Google Scholar 

Download references


The authors would like to acknowledge the personnel from the Lubbock Municipal Wastewater Treatment Plant for the analytical test support for nitrate and phosphorous analysis, the support of Dr. Calle for the E. coli analysis at the experimental science building, and the help of Dr. Surowiec for the elemental analysis, in the Department of Chemistry and Biochemistry, Texas Tech University. TGA and FTIR measurements were performed at the Materials Characterization Center, Edward E. Whitacre Jr. College of Engineering, Texas Tech University. Financial support was provided by the Department of Chemical Engineering and the Chemical and Electrochemical Technology and Innovation Laboratory (CETI) in the Whitacre College of Engineering at Texas Tech University.

Author information



Corresponding author

Correspondence to Gerardine G. Botte.

Additional information

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Jafari, M., Botte, G.G. Electrochemical treatment of sewage sludge and pathogen inactivation. J Appl Electrochem 51, 119–130 (2021). https://doi.org/10.1007/s10800-020-01481-6

Download citation


  • Sludge electrolysis
  • Alkaline treatment
  • Electrochemical pathogen deactivation
  • Ammonia production
  • Agricultural grade biosolids