Determinação da quantidade de óleo na água de escoamento superficial: Simulação física de evento pluviométrico e da poluição por óleo lubrificante

Abstract

The whole urbanization process is antagonistic to environmental sustainability, which promotes the development of environmentally sound technologies, and minimizes the negative environmental impacts of human activities. The landscape changes caused by urbanization are characterized by a considerable increase in the presence of impervious areas that are susceptible to contamination. When rainwater falls on contaminated surfaces, specifically in car parks, runoff can carry off a variety of contaminants. Focusing on lubricating oils, Brazilian legislation stipulates that oil-containing effluent must be treated before being discharged into the environment. With the assumption that the oil concentration in the effluent decreases over increased rain time, which is similar qualitative behavior to rainwater runoff from roofs, the present study aims to quantify the concentration / pollutant load of oil in simulated rainwater, time of pollutant maximum and the effect of chemical and mechanical treatment of the surface. In order to achieve this objective, it was necessary to develop an experimental model of an impervious surface, runoff, testing methodologies and experimental design. The contents of the sample oils were analyzed using the standard Soxhlet extraction method, defining the concentration per liter (mg / L) and the pollutant load (mg / min). The results observed with respect to the concentration demonstrate that there are peaks between 3 and 4 minutes and stabilization after 10 minutes. Flow influences the efficiency of cleaning from surface runoff, and 75% of the load is removed in the first 10 minutes, and contaminant removal efficiency is not improved by chemical and mechanical cleaning.