Dr. Salgado-Mendoza, Pablo

The Coronel aquifer, located in Chile (36°S – 37°S), has experienced significant water quality deterioration, primarily due to environmental factors and anthropogenic pressures, including increased industrial activities, rising temperatures, and reduced precipitation. These factors synergistically contribute to higher pollutant concentrations. Fluctuations in metal ion levels, particularly total iron and total manganese, have frequently exceeded the regulatory limits for human consumption (0.3 mg L−1 and 0.1 mg L−1, respectively). In response, companies exploiting these aquifers have intensified the search for alternative water sources with better quality. This study analyzed the interannual and seasonal patterns of water quality in the Coronel aquifer, focusing on the hydrogeological sectors of common use (HSCU) in North and South Coronel, alongside hydrogeological measurements and environmental variables. The findings revealed that the North Coronel HSCU is predominantly affected by allochthonous organic pollutants (NO3−), whereas the South Coronel HSCU is impacted by metal pollutants (Fe and Mn). Metal ion concentrations exhibited pronounced interannual and seasonal dynamics, peaking during the summer when precipitation drops below 100 mm month−1 and average monthly temperatures exceed 14 °C. In contrast, NO3− levels did not demonstrate a clear interannual or seasonal pattern. The study suggests that anthropogenic pressures in both HSCU may facilitate the presence of these contaminants.

In pursuit of a more sustainable construction material with the potential to improve bioreceptivity in marine environments, this study investigates the feasibility of incorporating three industrial residues—steel sludge (“Conox”), mytilid mussel shells, and wheat straw fibers—as partial substitutes for cement and sand. The research focuses on evaluating the physical and mechanical properties of mortar and concrete mixtures containing these residues, both individually and in combination. Additionally, it assesses the metal leaching potential of concrete incorporating Conox sludges into the environment. The results show that mixture containing 10% Conox sludges as a sand substitute exhibit the highest mechanical strength but also increased porosity, water absorption, and chloride ion diffusion. The addition of mussel shells and straw fibers generally reduced mechanical properties and increased porosity in mortars, though a 20% mussel shell substitution maintained mechanical strength and chloride ion diffusion in the concrete. The combination of mussel shells with Conox sludges allowed the concrete to retain its mechanical properties, although it also increased porosity and chloride ion penetration, which may limit its use where impermeability is key. However, this increased porosity could benefit coastal erosion control structures like breakwaters and revetments, and sea walls. Moreover, metal leaching from concrete incorporating Conox sludges remained within established safety limits. Despite these challenges, the materials show promise for non-structural applications or projects where sustainability is prioritized. Our research lays the foundation and opens new possibilities for future investigations that innovate in the combination of industrial wastes, aiming to create more sustainable construction materials with a reduced impact on biodiversity.