article
Tropical climate effect on the toxic heavy metal pollutant course of road-deposited sediments
Registro en:
0269-7491
1873-6424
10.1016/j.envpol.2019.05.043
Autor
Santos, Paula R. S. dos
Fernandes, Glauber J. T.
Moraes, Edgar Perin
Moreira, Lúcio Flávio Ferreira
Resumen
In modern society, the intense vehicle traffic and the lack of effective mitigating strategies may adversely
impact freshwater systems. Road-deposited sediments (RDS) accumulate a variety of toxic substances
which are transported into nature during hydrologic events, mainly affecting water bodies through stormwater runoff. The aim of this study was to evaluate the RDS metal enrichment ratio between the end of wet season and the middle of the dry season for Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn in samples from Natal, Brazil. Twenty RDS, drainage system and river sediment samples were collected in the wet and dry seasons using a stainless-steel pan, brush and spatula. In the laboratory, the samples were submitted to acid digestion and heavy metal concentrations were measured by atomic absorption spectrometry (AAS). A consistent RDS enrichment by heavy metals in dry season samples was followed by an increase in the finest particle size fraction (D < 63 mm). Maximum concentrations were 5, ND, 108, 23810, 83, ND, 77 and 150mg kg-1 for Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn, respectively. The RDS enrichment ratio was Cr(1.3 ), Cu(2.6 ), Fe(3.3 ), Mn(1.5 ), Pb(1.5 ) and Zn(2.1 ). The Geo-accumulation Index values showed that RDS were moderately polluted for Cu and slighted polluted for Zn and Pb. Principal Component Analysis (PCA) showed that the accumulation of toxic heavy metals decreased according to water flow