Desarrollo de un prototipo de desinfección a escala de laboratorio para la inactivación de bacterias y virus en muestras de agua cruda superficial

Abstract

In this project, a laboratory-scale prototype was developed, which, through the combination of disinfection methods by chlorination and oxidation by peroxide, allows the inactivation of bacteria and viruses in samples of raw surface water. This arises as a preventive response to the current Colombian regulations on drinking water and wastewater, which does not consider specific requirements for the control and / or treatment of viruses and some bacteria in water, which is of concern when the world checks for the presence of the SARS-CoV-2 virus in wastewater samples representing a health risk (Lodder & De Roda Husman, AM, 2020). For this, four phases were developed in which tests were carried out with the samples obtained from the sampling point in the Bogotá River located between the municipality of Cota in the department of Cundinamarca and the town of Suba in the city of Bogotá in the sector of Puente la Virgen, these were transported for the disinfection procedure in the water treatment laboratory of the Santo Tomás University using the aforementioned methodology.

Through these tests it was possible to determine the most suitable conditions and the optimal dose for disinfection of the samples. Once the tests had been carried out and the appropriate conditions and optimal dose were clear, a laboratory-scale disinfection prototype was developed that guarantees high efficiency (> = 99%) in inactivating bacteria and viruses. For this reason, the method of the most probable or best-known number “Poisson's zeros” was used as an indicator, which allowed quantifying the microbial density with a 95% confidence interval for the determination of total coliforms. This method also allowed identify the physicochemical characteristics of the water that most favor disinfection. In order to confirm the disinfection results and the optimal dose, tests were carried out using colitag as the presence-absence and detection method. Finally, a single somatic coliphage test was performed as indicators of fecal contamination and a validation test in an external laboratory.

With the help of these results, it is intended to contribute to reducing the risk to the health of people, who may have contact with different sources of water that contain viruses and bacteria. In the same way, the development of the prototype is intended to be an important input in the field of research, which in the future could serve as an instrument to improve the quality of water during its treatment.