An investigation of primary water sources in two Bolivian basins identified the presence of heavy metals toxic to health that exceeded the permissible limits for drinking water. Lead deposited in the San Jacinto and Huacata–Tarija reservoirs within the Guadalquivir basin and arsenic in the Milluni–La Paz basin were identified. The work studies reverse osmosis (RO) to remove Pb and As. The main contribution of this research is the development and construction of a mathematical model based on the Spiegler–Kedem concentration polarization model using different concentrations of Pb and As. The model makes it possible to design high conversion facilities (>80%) and optimize the process from the point of view of energy efficiency in future works. The model was developed to also include an Arrhenius temperature adjustment factor that allows for an accurate prediction of the process performance. The experimentation was carried out in two RO pilot plants using polyamide membranes. The model fits correctly with a maximum relative error between the experimental and theoretical flows of 5.4% and 4.4%. Among the benefits of the study, it guarantees the rejection of metals greater than 99%, even at low pressures.

Like other Latin American countries, Bolivia is in the race towards development, which has caused many economic activities to be carried out without due consideration for the care of the environment. At this point, it is essential to carry out environmental inventories to preserve the quality of ecosystems and natural resources, such as water. As water is vital, it needs to be adequately monitored and managed to prevent its degradation. This research presents the results of monitoring the main sources of water supply in two continuously growing departments of Bolivia, La Paz, and Tarija. The main objective of this study was to evaluate the suitability of the water to which the population has access, with particular attention to heavy metals with concentrations that exceed the permitted limits. The metals found were arsenic, chromium, mercury, manganese, iron, zinc, and tin in the Milluni area, and lead, iron, and manganese in the Guadalquivir area. Exposing the presence of metals in water sources implies immediate attention by decision-makers to take action to reduce the risk to public health. In addition, this study exposes a Bolivian reality that could encourage other countries in similar contexts to conduct similar studies on their water sources.