چكيده لاتين :
Introduction
Soil is regarded as one of the natural slow biodegradable source which plays an important role in
the cycle of mineral and organic elements. As a dynamic ecosystem, it provides the life for big and
small creatures. So, removing its pollution needs considerable attention. The pollution of heavy
metals not only affects directly the physical and chemical features of soil and reduces biological
activities and access to nutrition materials in soil, but also is considered as a serious danger for
human health. In fact, they can enter food chain or penetrate underground water sources. Iran is one
of the oil-rich countries in the world in which high amount of oil is extracted in southern regions
and refined in other places, yearly. Once oil is extracted, transmitted and refined, its release in the
soil causes pollution. A group of soil pollutant sources is related to oil discoveries, production,
saving, transmission, distribution and final burial of wastes. If these industries are pollutants, they
will cause dangers. The increase of soil pollution by heavy metals has led to a lot of research.
Materials and Methods
Kermanshah province is located to the west of Iran sharing borders with Lorestan, Kurdistan, Ilam
and Hamedan and an international border with Iraq. Its geographical coordinate is between 33˚37 to
35˚17 northern longitude and 45˚20 to 48˚01 eastern longitude. Since Kermanshah refinery is built
on alluvial terraces, fans of new low foothills and inceptisols and vertisols, 15 samples of
surrounded soil were collected by an iron shovel from the depth of 15 to 25 cm. ICP-MS method
were used to analyze and determine the density of heavy elements in of the samples. Grinded to the
sizes less than 4 mm by crusher, the samples were become powder to the size of 75 microns (200
mesh) by disc mill. Weighing the samples by Teflon pipes in digest 4 acid, hydrochloric, perchloric,
nitric and choloridric acid were added to the samples equally. All samples were kept in Hot Box
case. After complete digest operations, the samples were cold in the environment temperature and
achieved volume by distilled water.
Discussion and Results
The findings from geo-accumulation index shows that the intensity of Refinery soil is classified in
the range of no pollution to average regarding chromium and nickel. Besides, enrichment index
indicates average enrichment for cadmium (station 14), copper (stations 13, 11, 2 and 14), lead
(stations 6 and 13), zinc (stations 11, 6, 2, and 13) and chromium (the stations from 6 to 15). In
addition, pollution bar index of chromium, copper, nickel, zinc and lead is more than 1 proving the dried at 70˚ and dried bulk sediment was sieved to separate various fractions using wet sieving
(based on standard test ASTM for determining average grain size). Grain size analysis of the 44
surficial sediment samples performed by Analysette 19 wet sieving instrument. Therefore, samples
grouped into mud, sand and gravel fraction according to Udden and Wentworth. A detailed
description of grain size <63 μm fractions was executed by Laser Particle Seizer (model analysette
22). Collected samples analyzed for granolometery and it calculated same statistical parameters
such as mean, sorting, skewness, and kurtosis. Moreover, X-Ray diffractions in 44 sediment
samples in the area have been performed using an automatic powder EQUINOX 3000 X-ray
diffract meter. I geophysical studies Geoelectric and ground penetration radar techniques was used
to determine the depth and material of surrounding sediments and checking sub-surface
discontinuities existence and connection of this marsh in Gohar Rood river.
Discussion and Results
Mineralogical and physical characteristics of the sediments in Eynak marsh can be influenced by
rock assemblages in upstream such as basaltic-andesitic lava, dark grey limestone, slate and
Arkozic sandstone which has been subjected into weathering, eroded and transported to
downstream. In fact, due to terrestrial sources of sediments in Eynak marsh, it is characterized by
similar mineralogical and physical features. According to grading studies, 13 sedimentary types
existed in surface sediments including gravelly mud, muddy gravel, gravelly sand, muddy sandy
gravel, gravelly muddy sand, muddy sand with a little gravel, sandy mud with a little gravel, mud
with a little gravel, silty sand, muddy sand, sandy silt, silt, sandy mud. Various statistical
parameters of Eynak marsh sediments were computed. Different values obtained for textural
statistical parameters varying from minimum 1.5 to maximum 6.6; thus it falls between coarse sand
and medium silt. In the study area sediments range in 3 sorts: poorly sorted, very poorly sorted, and
moderately sorted. The closer to Gohar Rood, the sorting number increases and sediments poorly
sorted. In the present study, skewness values ranges −0.43 to 0.68 with an average −0.02 represents
five sorts: strongly fine skewed, fine skewed, near symmetrical, coarse skewed, strongly coarse
skewed. Many curves designated to minute Kurtosis and it varies from platy Kurtic to Mesokurtic.
Also, the values are among 0.5 to 2 with an average of 0.99. Scatter plot with mean, standard
deviation and skewness can be used successfully for the distinction of the sedimentary
environments, always using a large number of samples for each sedimentary body sampled
(Martins, 1997). The scatter diagram proved that the distribution of grains belongs to fluvial and
riverine sediments.
Conclusions
The results of granolometery show thirteen dispositional types in the region. The major component
minerals were quartz, calcite, feldspar, and mica and minor minerals were pyroxene, evaporates
along with some heavy minerals. Bad sorting in Eynak Marsh shows that the source of sediments
near the basin passes through a short transportation route. Skewness was generally seen as near
symmetrical shows the abundance of coarse grains in an energetic environment, whereas Kurtosis is
generally seen as Platykurtic and Mesokurtic. The essence is revealed between the Eynak Marsh
and Gohar Rood River exists a high resistive anomaly due to Rasht fault on the sidelines of Marsh
and change the kind of sediments in this area. Therefore, sedimentary statistical parameters and
geophysical studies show that the Eynak Marsh Tributary of Gohar Rood river were cut-off by
Rasht fault and it has shaped in current form.
