Published Feb 24, 2020


Google Scholar
Search GoogleScholar

José Castellanos-Rozo

Jaqueline A. Galvis-López

Nuri A. Merchán Castellanos

Elsa H. Manjarres-Hernández

Alex L. Rojas



Wastewater sludge is a by-product of waste water treatment; it is often employed in agricultural processes following appropriate microbiological stabilization. In this study, we evaluated two methods of sludge stabilization in the waste water treatment plant of Sotaquirá, Colombia. The two assessed stabilization methods were dewatering on drying beds and alkaline stabilization. The stabilization through dewatering on drying bed was carried out for five months. Alkaline stabilization was conducted for 96 hours with three concentrations of calcium oxide, 7%, 9%, and 13% w/w. Humidity, pH, organic carbon, phosphorus, organic nitrogen, fecal coliforms, somatic phages, total helminth eggs, and Salmonella sp. were monitored monthly for the sludge under dewatering treatment and at 0, 12, 24 hours for sludge under alkaline stabilization treatment. Both treatments succeded in eliminating Salmonella sp. Helminth eggs were eliminated by alkaline stabilization, whereas it was reduced to one or zero helminth eggs with the dewatering treatment. Somatic phages were eliminated with alkaline stabilization but were only reduced to 3.52 log CFU/g with the dewatering method. Dewatering on drying beds produced biosolids that can be used for soil restoration. Whereas alkaline stabilization produced biosolids that can be used for agricultural purposes. Alkaline stabilization with 9% and 13 % calcium oxide ostensibly reduced nitrogen and phosphorus contents in the sludge, whereas 7 % calcium affected less the phosphorus concentration of the sludge. These results indicate that sludge dewatering on drying beds is an effective sludge sanitation protocol to be implemented in small waste water treatment plants, such that in Sotaquirá, Colombia.


Drying beds, alkaline stabilization, waste water sludge, biosolids, pathogens, organic carbon

[1] Clarke R, Peyton D, Healy MG, Fenton O, Cummins E. A quantitative microbial risk assessment model for total coliforms and E. coli in surface runoff following application of biosolids to grassland. Environmental Pollution, 224: 739- 750, 2017.
doi: 10.1016/j.envpol.2016.12.025

[2] Semblante GU, Hai FI, Huang X, Ball AS, Price WE, Nghiem L.D. Trace organic contaminants in biosolids: Impact of conventional wastewater and sludge processing technologies and emerging alternatives. Journal of Hazardous Materials, 300: 1-17, 2015.
doi: 10.1016/j.jhazmat.2015.06.037

[3] Anjum M, Al-Makishaha NH, Barakat MA. Wastewater sludge stabilization using pre-treatment methods, Process Safety and Environmental Protection, 102:615-632, 2016.
doi: 10.1016/j.psep.2016.05.022

[4] Colombia (2014) Ministerio de Vivienda, Ciudad y Territorio. Decreto 1287 del 10 de julio de 2014. Criterios para el uso de biosólidos generados en plantas de tratamiento de aguas residuales municipales.
Retrieved from: Vivienda/1287%20-%202014.pdf

[5] Bittencourt S, Serrat BM, Aisse MM, Gomes D. Sewage sludge usage in agriculture: A case study of its destination in the Curitiba metropolitan region, Paraná, Brazil. Water, Air, and Soil Pollution, 225: 2014.
doi: 10.1007/s11270-014-2074-y

[6] Mattsson A, Finnson A, I’Ons D. Heavy metal content of Swedish municipal wastewater sludge - status and goals. Water Science & Technology, 76(3-4):869-876, 2017.
doi: 10.2166/wst.2017.277

[7] Superintendencia de Servicios Públicos Domiciliarios. Estudio Sectorial de los servicios Públicos domiciliarios de Acueducto y Alcantarillado - 2016.
Retrieved from: SSPD%20Publicaciones/Publicacione /2018/Oct/estudio_ sectorial-compilado-26-12-2017-vbibiana.pdf.

[8] Pilli S, Yan S, Tyagi, RD, Surampall, RY. Overview of fenton pre-treatment of sludge aiming to enhance anaerobic digestion, Reviews in Environmental Science and Biotechnology, 14: 453-472, 2015.
doi: 10.1007/s11157-015-9368-4

[9] Gontijo JC, Wagner LG, Souza ME de, Possetti GRC. Sanitation and drying of sewage sludge on radiant floors using solar energy and biogas: comparison between different thicknesses of deposited mass. Brazilian Archives of Biology and Technology, 61: 2018.
doi: 10.1590/1678-4324-smart-2018000037

[10] Pompeo RP, Andreoli CV, De Castro EA, Aisse MM. Influence of long-term storage operating conditions on the reduction of viable ascaris eggs in sewage sludge for agricultural reuse. Water, Air, and Soil Pollution, 227:144, 2016.
doi: 10.1007/s11270-016-2816-0

[11] Santos DS, Teshima E, Furiam DSM, Araújo RA, Rodrigues da Silva, CM. Effect of bed drying on the physicochemical and microbiological characteristics of sludge from upflow anaerobic blanket reactor used in sewage treatment. Engenharia Sanitária e Ambiental, 22(1): 341-349, 2017.
doi: 10.1590/S1413-41522016100531

[12] Awasthi MK, Wang Q, Chen H, Awasthi SK, Wang M, Ren X, Zhao J, Zhang Z. Beneficial effect of mixture of additives amendment on enzymatic activities, organic matter degradation and humification during biosolids co-composting, Bioresource Technology, 247: 138-146, 2018.
doi: 10.1016/j.biortech.2017.09.061

[13] Lopes BC, Machado EC, Rodrigues HF, Leal CD, de Araújo JC, de Matos AT. Effect of alkaline treatment on pathogens, bacterial community and antibiotic resistance genes in different sewage sludges for potential agriculture use. Environmental Technology, 0: 1-10, 2018.
doi: 10.1080/09593330.2018.1505960

[14] Romero-Flores A, McConnell LL, Hapeman CJ, Ramirez M, Torrents A. Evaluation of an electronic nose for odorant and process monitoring of alkaline-stabilized biosolids production. Chemosphere, 186: 151-159, 2017.
doi: 10.1016/j.chemosphere.2017.07.135

[15] Bittencourt S, Aisse MM, Serrat, BM. Agronomic and inorganic parameters of sewage sludge sanitized by alkaline stabilization: A case study of the state of Paraná, Brazil. Scientia Agraria, 17(2): 1-13, 2016.
Retrieved from:

[16] Zhen G, Lu X, Kato H, Zhao Y, Li YY. Overview of pretreatmentstrategies for enhancing sewage sludge disintegration and subsequent anaerobic digestion: Current advances, full-scale application and future perspectives. Renewable and Sustainable Energy Reviews, 69: 559-577, 2017.
doi: 10.1016/j.rser.2016.11.187

[17] R Core Team R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria, 2018.
Retrieved from:

[18] Bedoya-Urrego K, Acevedo-Ruíz J, Peláez-Jaramillo C, Agudelo-López S. The characterization of biosolids produced by the San Fernando wastewater treatment plant in Itagui, Antioquia, Colombia. Revista de Salud Pública, 15(5):778-790, 2013.
Retrieved from: h t t p : / / w w w. s c i e l o . o r g . c o / s c i e l o . p h p ? s c r i p t = s c i _ arttext&pid=S0124-00642013000500013

[19] Cota-Espericueta A, Ponce-Corral C. Elimination of pathogenic bacteria in residual sludge during solar drying. Revista Internacional de Contaminación Ambiental, 24 (4): 161-170, 2008.
Retrieved from:

[20] Correia, JE. Caracterização físico-química e microbiológica do lodo gerado na estação de tratamento de esgoto contorno. Feira de Santana, BA. Revista eletrônica de gestão e tecnologia ambiental, 2: 2, 2014.
doi: 10.17565/gesta.v2i2.12789

[21] Goberna M, Simón P, Hernández MT, García, C. Prokaryotic communities and potential pathogens in sewage sludge: Response to wastewaster origin, loading rate and treatment technology. Science of the Total Environment, 615: 360-368, 2018.
doi: 10.1016/j.scitotenv.2017.09.240

[22] Belloulid MO, Hamdi H, Mandi L, Ouazzani N. Solar drying of wastewater sludge: a case study in Marrakesh, Morocco. Environmental Technology, 1-7, 2018.
doi: 10.1080/09593330.2017.1421713

[23] Torres L P, Madera PCA, Silva J. Eliminating pathogens in biosolids by alkaline stabilization. Acta Agronomica, 58(3):197-205, 2009.
Retrieved from:

[24] Shanahan E, Roiko A, Tindale N, Thomas M, Walpole R, Kurtböke I. Evaluation of pathogen removal in a solar sludge drying facility using microbial indicators. International Journal of Environmental Research and Public Health, 7: 565-582, 2010.
doi: 10.3390/ijerph7020565

[25] Ellis S, Tyrrel S, O’Leary E, Richards K, Griffiths B, Ritz, K. Proportion of sewage sludge to soil influences the survival of Salmonella Dublin and Escherichia coli. Clean - Soil, Air, Water, 46(4): 2018.
doi: 10.1002/clen.201800042

[26] Campos MC, Medina LK, Fuentes NP, García GI. Assessment of indicators of fecal contamination in soils treated with biosolids for growing grasses. Universitas Scientiarum, 20 (2): 217-227, 2015.
doi: 10.11144/Javeriana.SC20-2.aifc

[27] Al-Gheethi AA, Efaq AN, Bala JD, Norli I, Abdel-Monem MO, Kadir MO Ab. Removal of pathogenic bacteria from sewagetreated effluent and biosolids for agricultural purposes. Applied Water Science, 8: 74, 2018.
doi: 10.1007/s13201-018-0698-6

[28] Torres LP, Madera CA, Silva J. Microbiological quality improvement of biosolids from domestic wastewater treatment plants. Escuela de Ingenieria de Antioquia EIA, 11: 21-37, 2009.
Retrieved from:

[29] Silva-Leal J, Bedoya-Ríos D, Torres-Lozada P. Effect of thermal drying and alkaline treatment on the microbiological and chemical characteristics of biosolids from domestic wastewater treatment plants. Quimica Nova, 36(2):207-214, 2013.
Retrieved from:
How to Cite
Castellanos-Rozo, J., Galvis-López, J. A., Merchán Castellanos, N. A., Manjarres-Hernández, E. H., & Rojas, A. L. (2020). Assessment of two sludge stabilization methods in a wastewater treatment plant in Sotaquirá, Colombia. Universitas Scientiarum, 25(1), 17–36.