Environmental Engineering Reference
In-Depth Information
From the metal chemical element groups, the most aggressive impact belongs to lead.
This is due to the use as an antiknock additive in some gasoline compositions
[3]
.
The lead originating from gasoline combustion has been polluting all environment
components, including inhabitants
[4, 5]
. Today, despite of the unleaded gasoline
preponderant use, the historical impact of gasoline with lead additives during the last
decades is still observable on soil. Other heavy metals from the gasoline, diesel and
tire compositions have gotten into the soil because of fuels burning and wear of auto
tires. Industrial emissions have a considerable contribution to urban soils pollution,
including those located along roads. This paper presents the heavy metals abundance
in the soils located along the main roads from three large Romanian cities, which are
different in both dimension and industrial capacity.
Experimental Method
Soil samples from superior horizon (0-20 cm depth) of urban soils situated length-
ways the main streets were sampled. Soil samples have been analyzed from a chemi-
cal point of view: soil reaction (pH in aqueous solution), carbonates content, argyle
<2 mm content, organic carbon for soil type and subtype establishing. The results
are presented in
[6]
. Heavy metals content determinations (Cd, Co, Cr, Cu, Mn, Ni,
Pb and Zn) were performed by means of absorption spectrometry in an air-acetylene
flame. After soil samples mineralization, using a mixture of HNO3 and HClO4,
the total heavy metals content was determined in a hydrochloric solution. Soil
mobile heavy metals were extracted with an EDTA-CH3COONH4 solution at pH
7.0. The heavy metals were fractioned by soil components, using a method devel-
oped by
[7]
. Results were analyzed statistically, for grouping centre parameters
(arithmetic mean, geometric mean, median), and scattering parameters (standard
deviation, minimum and maximum values). Moreover, correlative links were estab-
lished between some of the chemical elements. Pedogeochemical abundance index
(PAI) and geochemical abundance index (GAI) values have been calculated using a
methodology elaborated by
[8]
.
Results and Discussion
The Nature of Urban Soils from Bucharest, Iassy and Baia Mare
The Romanian metropolis Bucharest, with a surface area of about 228 km
2
and over a
billion inhabitants, is located in a plane zone in the southeastern part of the country. The
development of the city has occurred on natural soils belonging to different types: that
is Chernozems and Brown Reddish types. By anthropogenic action, these natural soils
have become urban soils as Urbic Regosols, Regosols and Humic Regosols.
