Evaluación de la eficiencia de Brassica rapa subsp. oleífera (nabo silvestre) en la reducción de Plomo y Cadmio en los lodos residuales de la planta de tratamiento de aguas del cantón Penipe.

Abstract

The purpose of the research was to evaluate the efficiency of wild turnip greens (Brassica rapa subsp. oleífera) in the reduction of lead and cadmium in the sewage sludge at the water treatment plant located in Penipe County, Chimborazo Province as well as the physical and chemical characterization of de sewage sludge in three experimental unit (UE) before, while and after the reduction process with Brassica rapa subsp. oleífera. This research applied a previous treatment for the sewage sludge to be separated into three built cages called: UE1 (sludge), UE2 (sludge + plant tissue) and UE3 (sludge + plant tissue + fertile soil). The descriptive observation and the behavior of the phenomenon to be studied were the predominant aspects where some parameters such as humidity, temperature, pH, and organic matter were controlled as well as the vegetative growth of the species. Through the atomic absorption spectrophotometry, it was possible to analyze the heavy metals like cadmium and lead (Cd and Pb) in the plant tissue and the soil of the experimental units. It was possible to identify that the plant species studied reduced the levels of cadmium in a 46.09% and lead in 5.92% in a 247 – treatment – day in the experimental unit number 2, the one that contained sewage sludge and the plant species germination. In addition, it generated less amount of leached from the pollutant since its concentration of organic matter was lower, humidity was considered relatively optimal, this prevented the dissolution of the pollutants and made cadmium and lead move into the plant tissue. Therefore, it is recommended to use the plant species in an in-situ environment since it allows reducing the control cost and environmental monitoring, besides providing a spontaneous vegetative growth.