Evaluación de la eficiencia de un vermifiltro como tratamiento secundario, aplicado en una vivienda de la parroquia Baños, para la remoción de amebas de aguas residuales domésticas y su posible uso en la agricultura

Abstract

In this study, a comparative evaluation of the efficiency of three systems for the elimination of contaminants and microorganisms was carried out, with emphasis on the removal of pathogenic amoebae. For this purpose, the performance of a filter without worms, a vermifilter with Eisenia fetida worms and 15 cm of coconut fiber, and another vermifilter with 30 cm of coconut fiber thickness were compared. These systems, installed in a single-family house in the parish of Baños in the city of Cuenca, achieved removals in BOD5 and COD (13.40% - 55.77%), NO3- (18.43% - 40.12%), NH4 + (17.62% - 60.22%), fecal coliforms (29.17% - 31.25%) and amoebae (29.94% - 70.42%), with the vermifilter with 30 cm of coconut fiber being the most efficient. However, parameters such as OD, EC, SDT, PO4 3- and NO2 - increased with respect to the influent. On the other hand, two laboratory-scale activated carbon filters were constructed with 25 cm and then 10 cm of vegetable and mineral carbon, as tertiary treatment. Total coliforms (14.12% - 38.67%), fecal coliforms (13.33% - 20%) and amoebae (47.12% - 62.89%) were removed, with the 10 cm charcoal filter standing out in the removal of amoebae. The persistence of coliforms and amoebae prevents the use of treated water for irrigation of hydroponic crops or any irrigation that involves direct contact with food or animal pastures. Therefore, a more efficient tertiary treatment or disinfection with chlorine is recommended.