Evaluación Comparativa del funcionamiento de dos líneas de tratamiento de agua residual basadas en humedales construidos en la concesión minera Sacachispas el Oro, Ecuador.

Abstract

The study evaluates the operational performance of two treatment lines (P-L1-E and P-L2-E) employed to manage the liquid waste of the Sacachispas mining company over a period of 8 years. The performance and behavior were studied through water quality variables, considering macro-parameters (COD, oils and greases, pH, TSS), nitrogen forms (NO3, NO2), and metals (Al, As, Cd, Cu, Fe, Mn, Pb). For this analysis, statistical tools were used, which initially involved developing a comparative analysis for the influent (P-GL-A), effluents (P-L1-E and P-L2-E), and between them. Additionally, their evolutionary behavior was studied by dividing the analysis into two operating periods: less than or equal to 4 years and greater than 4 years. On the other hand, to determine the similarity or difference between the two treatment lines depending on the normality of the data using Shapiro-Wilk, the following were applied: a) for data with normal distribution (paired t-test) and b) for data without normal distribution (Wilcoxon test). Finally, an evaluation of the removal efficiency and compliance with the environmental regulations applied in Ecuador (Ministerial Agreement No. 097-A) was performed. For data processing and analysis, the InfoStat 2020 software was used, employing a 95% confidence level (Alpha=0.05). The results, after evaluating the performance of the treatment lines, did not show evolutionary changes in the effluents or between them (p>0.05), meaning that both treatment lines functioned similarly over the eight years analyzed. Despite this, the P-L2 line showed a certain trend of improvement compared to the P-L1 line. Also, in general, both treatment lines significantly reduced the influent concentration, presenting some degree of removal and/or reduction of the evaluated water quality parameters. These results become an important milestone for the world of research in constructed wetlands, as they have achieved significant environmental performance in reducing contaminants present in the effluents in both treatment lines, complying with the current environmental legislation in Ecuador.