Indice fisicoquímico de la calidad de agua para el manejo de lagunas tropicales de inundación

Abstract

Physicochemical water quality index, a management tool for tropical-flooding lagoons. We propose ICA-L, a wetland physicochemical water quality index (WWQI), to be used as a management tool for seasonal-flooding lagoons in Palo verde National Park, Guanacaste, Costa Rica. The goal is to preserve their natural role for native plants as well as migrants and local animal species. The index was developed in four steps: parameter selection, assignment of parameter weight, transformation of data to their corresponding sub indices and selection of an appropriate aggregation function. In this process, the following criteria were used as a reference: WQI from the National Sanitation Foundation, WQI for the Des Moines River, Escribano and De Frutos WQI, the international legislation on maximum acceptable concentration for different water quality variables, and the authors' personal criteria. The index includes the following parameters: dissolved oxygen percent saturation, pH, nitrate concentration, total phosphorus concentration, chemical oxygen demand, concentration of suspended solids, electrical conductivity and temperature. The index sets itself to zero if the concentration of some toxic substance exceeds the maximum allowed limit. The adjustment values were based on "weights" defined in the National Sanitation Foundation Water quality Index (ICA-NSF). In this study, the weight of fecal coliforms count was excluded, the values of turbidity and the one for total solids were integrated into one (suspended solids) and a factor of 0.08 was assigned to the conductivity parameter. The sub indices associated to suspended solids were obtained from the quality of Kahler-Royer variation graph; the values for pH and the nitrate concentration from the graphs constructed for ICA-NSF. The percentage of dissolved oxygen saturation, in sites like irrigation channels, was evaluated directly from the quality variation graph constructed for ICA-NSF, whereas the same parameter for the flooding lagoons required an adjustment based on the optimal value for similar non contaminated ecosystems. The conductivity was evaluated from adjustments in the qualification functions commented by Escribano & De Frutos. Chemical oxygen demand, total phosphorus and temperature, were qualified based on the functions developed for the ICA-L.

Inconvenientes del uso de promedios de parámetros fisicoquímicos no conservativos, ejemplos de caso lagunas costeras mexicanas

“…En el caso del cálculo del porcentaje de saturación, dado que se basa en la solubilidad de este gas según temperatura y salinidad fundamentalmente, este parámetro es aplicable para estimar los límites de tolerancia de peces y algunos organismos bentónicos. Pérez y Rodríguez (2008) emplearon este porcentaje y calcularon el índice de calidad del agua-Fundación Nacional de Salud (ICA-NSF) y consideraron que se ajustaba, en general, a la realidad de las especies tropicales, donde el porcentaje ideal para muchos peces es mayor a 67 %, mientras que las concentraciones de oxígeno disuelto menores a 55 % afectan adversamente la biodiversidad y la supervivencia de la comunidad biótica. Adicionalmente, concentraciones superiores a 100 % de saturación de oxígeno disuelto pueden resultar peligrosas para la vida acuática, pues facilitan que burbujas de oxígeno bloqueen el flujo sanguíneo (Chapman, 1996).…”

Evaluación de la calidad del ecosistema urbano río Torres, San José Costa Rica

“…Así mismo, los valores de sólidos totales y coliformes fecales obtenidos en este estudio, no fueron los adecuados para la conservación de la vida acuática y la estabilidad de los ecosistemas, según la legislación nacional (La Gaceta, 2007). Por otro lado, el oxígeno disuelto se mantuvo dentro del rango permitido (>5,0mg/L) para garantizar la supervivencia de las comunidades biológicas (Pérez-Castillo & Rodríguez, 2008;Mena-Rivera, Salgado-Silva, Benavides-Benavides, Vega-Guzmán, & Coto-Campos, 2015); a excepción de la ZR3, donde se reflejó una disminución del parámetro, producto de las actividades antrópicas (Kannel, Lee, Lee, Kanel, & Khan, 2007).…”

“…Por otro lado, el pH se ajustó a los niveles permitidos (6,5-8) en la reglamentación nacional (La Gaceta, 2007); a excepción de la ZR2, donde se observó un aumento considerable en el pH, posiblemente producto del aporte de aguas residuales cercanas (Pérez-Castillo & Rodríguez, 2008;Abril Saltos, Rodríguez Badillo, Sucoshañay Villalba, & Bucaram Visuma, 2017).…”

Removing Organic Matter and Nutrients from Swine Wastewater after Anaerobic–Aerobic Treatment

“…This variable is an indicator of water quality for the wellbeing of different aquatic organisms. Concentrations below 3 mg L −1 reduce the chances of survival of biotic communities and represent an imminent threat to the conservation of biodiversity in aquatic ecosystems [25]. Dissolved oxygen is also important for the efficient operation of the trickling filter, in which the bacteria aerobically degrades the organic matter in the wastewater under treatment [8].…”