Efecto del sulfato de cobre como germicida en aguas residuales domésticas tratadas en humedales artificiales

Abstract

In many rural areas, domestic wastewater treatment remains a pending task due to structural and social constraints. This situation represents a risk to both public health and the environment due to the presence of pathogenic microorganisms in the effluents. In this context, this research evaluated the use of copper sulfate as a germicidal agent in a real-life treatment system that includes a septic tank, a coagulation process, and a subsurface flow constructed wetland. In the laboratory, jar tests were conducted with different copper sulfate concentrations (1–5%) and doses between 150 and 400 mg/L to determine the most effective. The optimal dose (250 mg/L at 3%) was subsequently applied to the full-scale system. The results showed high removal efficiencies for turbidity (90%), BOD (93%), COD (95%), phosphates and nitrates (97%), and fecal coliforms (>95%). However, an increase in ammoniacal nitrogen was detected (up to 34.78%), possibly due to the inhibition of nitrifying bacteria. Furthermore, the effectiveness of copper sulfate was compared with chlorine and aluminum sulfate. Chlorine was the most effective (99.9% coliform removal), followed by copper sulfate (80.4%) and aluminum sulfate (47.6%). Overall, the results support the use of copper sulfate as a viable alternative to improve water quality in rural communities where access to conventional technologies is limited.