Characterization and evaluation of the distribution of sediments in urban surfaces

Abstract

Urban sediments are potentially polluting because of their capacity to associate with pollutants such as heavy metals, increasing the chance of contamination of water bodies in urban environment. The little amount of studies related to composition of urban sediments, this article aims to analyze the particle size distribution, organic / inorganic fraction and quantify the load and accumulation of sediments collected at each point by checking its relation to vehicle flow and the occurrence of precipitation. To this end, three streets were selected with different flows of vehicles, where sediments were collected in the gutters by brushing and vacuuming method. Also filters of a high volume sampler particles were analyzed. Laser diffraction analyzes were performed to determine the particle size and the load and accumulation were determinaded by weighing in analytical precision balance. The results show that the sediment load has an inverse relationship with the occurrence / intensity precipitation and the traffic flow. It was possible to verify that the street with greater afforestation shows a bigger organic fraction, and the sediments of streets have a bigger organic fraction than “white” sediments. The medium diameter of particles show an increasing trend with occurency of precipitation, and a direct relation with the flow of vehicles, where the route with greater flow of vehicles had the highest grain sizes.