This review goal is to reflect on the challenges and prospects for water quality in the face of the pandemic caused by the new SARS-CoV-2 coronavirus (COVID-19). Based on the information available so far, the detection of SARS-CoV-2 RNA in wastewater has raised interest in using it as an early warning method, to detect the resurgence of infections and to report the risk associated with contracting SARS-CoV-2 in contact with untreated water or inadequately treated wastewater is discharged. The wastewater-based epidemiological approach can be used as an early indicator of infection within a specific population. On the other hand, it is necessary to collect information from the managers of drinking water supply companies and professionals who are related to water quality, to know SARS-CoV-2 data and information, and its influence on drinking water quality. The basic purpose of this review article is to try to provide a valuable and quick reference guide to COVID-19. Important topics were discussed, such as detection of SARS-CoV-2 in wastewater in various parts of the world; wastewater screening to monitor COVID-19; persistence of SARS-CoV-2 in aquatic systems; the presence of SARS-CoV-2 in drinking water; clean water as a mechanism to deal with the COVID-19 pandemic; chlorine as a disinfectant to eliminate SARS-CoV-2 and damage to ecosystems by the use of chlorine. Currently does not exist extensive literature on the effectiveness of water and wastewater treatment processes that ensure the correct elimination of SARS-CoV-2. Excessive use of disinfectants such as chlorine is causing effects on the environment. This document highlights the need for further research to establish the behavior of the SARS-CoV-2 virus in aquatic systems. This study presents an early overview of the observed and potential impacts of COVID-19 on the environment.

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Due to the outbreak of the novel coronavirus disease there is a need for public water supply of the highest quality. Adequate levels of chlorine allow immediate elimination of harmful bacteria and viruses and provide a protective residual throughout the drinking water distribution network (DWDN). Therefore, a residual chlorine decay model was developed to predict chlorine levels in a real drinking water distribution network. The model allowed determining human exposure to drinking water with a deficit of residual chlorine, considering that it is currently necessary for the population to have clean water to combat coronavirus Covid 19. The chlorine bulk decay rates (kb) and the reaction constant of chlorine with the pipe wall (kw) were experimentally determined. Average kb and kw values of 3.7 d− 1 and 0.066 m d− 1 were obtained, respectively. The values of kb and kw were used in EPANET to simulate the chlorine concentrations in a DWDN. The residual chlorine concentrations simulated by the properly calibrated and validated model were notably close to the actual concentrations measured at different points of the DWDN. The results showed that maintaining a chlorine concentration of 0.87 mg L− 1 in the distribution tank, the residual chlorine values in the nodes complied with the Ecuadorian standard (0.3 mg L− 1); meanwhile, about 45% of the nodes did not comply with what is recommended by the WHO as a mechanism to combat the current pandemic (0.5 mg L− 1). This study demonstrated that residual chlorine modeling is a valuable tool for monitoring water quality in the distribution network, allowing to control residual chlorine levels in this pandemic season.

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Los métodos tradicionales de producción de cueros en el Perú consumen en promedio entre el 60 al 80% del cromo utilizado para el proceso de curtido, generando aguas residuales con altas concentraciones de cromo total que deben ser tratadas para poder cumplir con los Valores Máximos Admisible (VMA) establecidos por el DS 029-2009-Vivienda. El uso de agentes acomplejantes de cromo en el proceso de curtido permite reducir la oferta de cromo incrementando la absorción en la piel. El objetivo de la presente investigación fue evaluar la tratabilidad por precipitación química de las aguas residuales de los procesos tradicionales y alternativos de curtido, además de comparar las condiciones de tratamiento de los efluente de curtido de un proceso tradicional, con procesos alternativos que utilizan agentes acomplejantes y basificantes. Se determinó que el pH óptimo para la precipitación estuvo entre 7,36 y 9,99; además, las dosis utilizadas de hidróxido de sodio estuvieron entre 0,5 y 5,5 g/L, siendo el proceso tradicional el que requiere mayor dosis. Se determinó que el costo de los insumos empleados en la producción del cuero a wet blue es mayor al costo de insumos empleados en el tratamiento de las aguas residuales de curtido, cuando los valores de cromo total son menores a 650 mg/L.

This article presents data on corrosion and dissolved copper in copper tubes that transport drinking water in domiciles of the Azogues city, Ecuador. Corrosion tests were performed using copper coupons exposed to water with different concentrations of free chlorine for 30, 60, 90 and 180 days. The determination of the copper corrosion rate exposed in chlorine was carried out by means of gravimetric tests. With weight loss data, the corrosion rate was determined. By means of static immersion tests, copper release of coupon surface was determined. In the obtained data it was observed that the corrosion rate and the release of copper increases with the chlorine concentration. This data is beneficial for drinking water companies and building builders by providing information on the corrosion and leaching behavior of copper pipes when exposed to chlorine and is useful for predicting the service life copper pipes. In addition, it could allow assessing the health risk by consuming water with copper in solution.

Contamination of drinking water supplies by arsenic is a world-wide problem. Total arsenic measurements are commonly used to investigate and regulate arsenic in water, but it is well understood that arsenic occurs in several chemical forms, and these exhibit different toxicities. It is problematic to use laboratory-based speciation techniques to assess exposure as it has been suggested that the distribution of species is not stable during transport in some types of samples. A method was developed in this study for the on-site speciation of the most toxic dissolved arsenic species: As (III), As (V), monomethylarsonic acid (MMA) and dimethylarsenic acid (DMA). Development criteria included ease of use under field conditions, applicable at levels of concern for drinking water, and analytical performance.The approach is based on selective retention of arsenic species on specific ion-exchange chromatography cartridges followed by selective elution and quantification using graphite furnace atomic absorption spectroscopy. Water samples can be delivered to a set of three cartridges using either syringes or peristaltic pumps. Species distribution is stable at this point, and the cartridges can be transported to the laboratory for elution and quantitative analysis. A set of ten replicate spiked samples of each compound, having concentrations between 1 and 60 µg/L, were analyzed. Arsenic recoveries ranged from 78-112 % and relative standard deviations were generally below 10%. Resolution between species was shown to be outstanding, with the only limitation being that the capacity for As (V) was limited to approximately 50 µg/L. This could be easily remedied by changes in either cartridge design, or the extraction procedure. Recoveries were similar for two spiked hard groundwater samples indicating that dissolved minerals are not likely to be problematic. These results suggest that this methodology can be use for analysis of the four primary arsenic species of concern in drinking water supplies. Keywordsanalysis; solid-phase extraction; speciation; As (III); As (V); monomethylarsonic acid (MMA); dimethylarsenic acid (DMA)