Characterization of influent and effluent at a wastewater treatment plant with trickling filters in the high Andean region of PeruCharacterization of influent and effluent at a wastewater treatment plant with trickling filters in the high Andean region of Peru
Introduction: The Yauli wastewater treatment plant, located in the high Andean region of Huancavelica, Peru (~3,383 m), faces environmental conditions that limit the efficiency of biological processes.
Objective: To determine the concentrations of key parameters in the influent and effluent of the Yauli WWTP, including oils and fats (O&F), thermotolerant coliforms (TC), BOD₅, chemical oxygen demand (COD), total suspended solids (TSS), pH, and temperature.
Materials and methods: Using a descriptive cross-sectional design, 8 sampling campaigns were conducted for influent and effluent between October 2019 and February 2020. O&F, TT, BOD₅, COD, TSS, pH, and temperature were analyzed. The results were compared with the Maximum Permissible Limits (MPLs) established by Peruvian regulations. Normality tests and Student’s t-tests (p < 0.05) were applied, with 95% confidence intervals and effect size (Cohen’s d).
Results: The effluent complied with the MPLs for BOD₅, COD, TSS, pH, and temperature. However, BOD₅ exceeded the limit (732.9 mg/L vs. 100 mg/L). Higher removal efficiency was observed for SST (73.15%), and lower for BOD₅ (3.95%). Organic overload was also evident, which affected the system’s efficiency.
Conclusion: The study highlights the limitations of biological treatment in high-Andean conditions. It is necessary to adapt technologies to local environmental and operational conditions to protect water resources and ensure effluent quality.
Ramírez Arbieto KM, Alva Huapaya CA. Technical efficiency for the treatment of domestic wastewater in the removal of Biochemical Oxygen Demand and Eschericia coli by applying artificial wetland, Lima, Peru, 2023. In: Proceedings of the LACCEI international Multi-conference for Engineering, Education and Technology [Internet]. Latin American and Caribbean Consortium of Engineering Institutions; 2024 [citado 2026 Abr 9]. DOI: 10.18687/LACCEI2024.1.1.713
Baquero-Rodríguez GA, Martínez S, Acuña J, Nolasco D, Rosso D. How elevation dictates technology selection in biological wastewater treatment. J Environ Manage [Internet]. 2022 Abr 1; 307:114588. DOI: 10.1016/j.jenvman.2022.114588
Guo M, Wang J, You J, Zong Y, Fu C. The influence of DO on the microbiological community of the A2O treatment of municipal wastewater in alpine regions. Water Air Soil Pollut [Internet]. 2022;233:470. DOI: 10.1007/s11270-022-05943-9
Feng Z, Liu X, Wang L, Wang Y, Yang J, Wang Y, et al. Comprehensive efficiency evaluation of wastewater treatment plants in northeast Qinghai–Tibet Plateau using slack–based data envelopment analysis. Environ Pollut [Internet]. 2022; 311:120008. DOI: 10.1016/j.envpol.2022.120008
Jerves-Cobo R, Maldonado E, Hidalgo-Cordero JF, García-Herazo H, Mora-Serrano D. Comparative assessment of wastewater treatment technologies for pollutant removal in high-altitude Andean sites. Water [Internet]. 2025; 17(12):1800. DOI: 10.3390/w17121800
Haque A. Water and wastewater treatment; Challenge: Resource recovery in water and wastewater treatment (SDG 6). SSRN [Internet]. 2024 [citado 2026 Abr 9]. DOI: 10.2139/ssrn.4758952
Ministerio del Ambiente. Decreto Supremo N° 003-2010-MINAM que Aprueba los Límites Máximos Permisibles de efluentes de plantas de tratamiento de aguas residuales domésticas o municipales [Internet]. Lima (PER); MinAm: 2010 [citado 2026 Abr 12]. Disponible en: https://www.gob.pe/institucion/minam/normas-legales/317434-003-2010-minam
American Public Health Association, Americal Water Works Association, Water Environment Federation. Standard Methods for the Examination of Water and Wastewater. 23rd ed. Washington (USA): APHA, AWWA, WEF; 2022. Disponible en: https://www.standardmethods.org/doi/book/10.2105/smww.2882
Metcalf & Eddy Inc. Ingeniería de aguas residuales. Tratamiento, vertido y reutilización. 3rd ed. Aravaca: McGraw Hill; 1995.
United States Environmental Protection Agency. Wastewater treatment/Environmental design manual: Trickling filter design. Washington (USA): EPA; 1993.
Gonzales Ccanto EM. Informe visita técnica planta de tratamiento de agua residual de la municipalidad del distrito Yauli de la provincia de Huancavelica [Internet]. Universidad Nacional de Huancavelica; 2018 [citado 2026 Abr 12]. Disponible en: https://es.scribd.com/document/519937219/Petar-Yauli-Informe
International Organization for Standardization. ISO/IEC 17025:2017. General requirements for the competence of testing and calibration laboratories. Geneva (CHE): ISO; 2017. Disponible en: https://www.iso.org/standard/66912.html
Echeverría I, Vargas V. Coagulación-floculación como estrategia de pulimento para efluentes secundarios en plantas de tratamiento municipales. I&D [Internet]. 2025 Aug 25; 25(1):43–54. DOI: 10.23881/idupbo.025.1-4i
Echeverría I, Aliaga G, Saavedra O. Evaluación de la calidad de agua residual tratada para riego en el Valle Alto de la ciudad de Cochabamba. I&D [Internet]. 2024 Jul 31; 24(1):35–45. DOI: 10.23881/idupbo.024.1-3i
Xu J, Wang P, Li Y, Niu L. Performance and characterization of the microbial community structures in the activated sludge from wastewater treatment plant at high altitudes in tibet of China. Desalination Water Treat [Internet]. 2018 Feb 1; 106:108–115. DOI: 10.5004/dwt.2018.21995
Zhang R, Liu Y, Li H, Xiong J, Zhang Q, Li P, et al. Metagenomic Analysis of Bacterial Community Structure and Pollutant Removal Process in High-Altitude Municipal Wastewater Treatment Plants of Tibet, China. Water [Internet]. 2025 May 1; 17(9):1284. DOI: 10.3390/w17091284
Braz GHR, Fernandez-Gonzalez N, Lema JM, Carballa M. Organic overloading affects the microbial interactions during anaerobic digestion in sewage sludge reactors. Chemosphere [Internet]. 2019 May 1; 222:323–332. DOI: 10.1016/j.chemosphere.2019.01.124
Jwara TYS, Musonge P, Bakare BF. Effects of hydraulical overload on biological nutrient removal efficiencies in wastewater treatment systems. In: 18th SOUTH AFRICA Int’l Conference on Agricultural, Chemical, Biological & Environmental Sciences (ACBES-20). Johannesburg (ZAF): Universal Researchers; 2020. p. 272–275. DOI: 10.17758/eares10.eap1120128
Zhang C, Li S, Sun H, Li X, Fu L, Zhang C, et al. Assessing the impact of low organic loading on effluent safety in wastewater treatment: Insights from an activated sludge reactor study. J Hazard Mater [Internet]. 2024; 465:133083. DOI: 10.1016/j.jhazmat.2023.133083
Ali I, Khan ZM, Peng C, Naz I, Sultan M, Ali M, et al. Identification and elucidation of the designing and operational issues of trickling filter systems for wastewater treatment. Pol J Environ Stud [Internet]. 2017; 26(6):2431–2444. DOI: 10.15244/pjoes/70627
de Oliveira-Avellar BR, Marçal K, dos Santos GA, Bogo CR, Ribeiro RP, Aisse MM. Low-rate trickling filter with natural ventilation: Diagnosis in a full-scale WWTP set in southern Brazil. Environ Sci Pollut Res [Internet]. 2025; 32:27037–27051. DOI: 10.1007/s11356-025-36921-3
Abyar H, Nowrouzi M. Trickling filter systems for sustainable water supply: An evaluation of eco-environmental burdens and greenhouse gas emissions. Environ Res [Internet]. 2023; 237:117011. DOI: 10.1016/j.envres.2023.117011