Fig.2. trend of major and trace metals in 5 cores
The value of the enrichment factor (EF) for the main elements in the surface samples is 1 and
lower because of less human activities and natural entrance. While enrichment factor for
chromium, lead and zinc in the eastern part of study area (stations 1 to 5) is more than 2 to 4
times higher. Also, the molybdenum with a different trend is mostly enriched in the western
parts, and its highest value is related to samples from stations 11, 12 and 13 in the west of the
Gorgan Bay, that concentration is more than 3 times over the concentration of the element in
natural samples. Nickel, cobalt, copper and arsenic are also contaminated in most samples,
upstream sediments of the region and erosion of formations in the south and southeastern
part of the region by seasonal and permanent rivers is probably the main factor for their
enrichment in the environment, another factor is that local contaminants are probably due to
repair of the fishing boats that have been poured into the sediments. The values of the
enrichment factor for the main and trace elements in the core samples K1, K3, K5, N1 are
generally in the range of 1, which indicates the natural source of the elements in the sediment,
while in the core K7 for zinc, lead, and arsenic, moderate to high enrichment suggests that with
regard to the Behshahr industrial town and entry of wastewater into this environment could
cause contamination and pollution (Figure.3).
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Fig 3. Trend of enrichment factor in K7
Finally, the comparison of variations in the concentration of selected elements in the study
area (surface and core sediments) with the American and Canadian sediment quality guidelines
showed that the amount of these elements in the sediments of this region is less than
dangerous and harmful and is in the range between the two guideline but because of
ecosystem condition, tourism and aquatic resources, this area, must be prevented, managed
and monitored properly before they constitute a serious threat to the health of the
environment and the organisms .
Table 2. Comparison of this study (surface and core sediments) with other studies and quality guidelines
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Heavy Metal Pollution in Water and Heavy
Metal
Poisoning
S.R.Hajieva
1
, H.L.Rafieva
2
, U.N.Abdullaeva
3
1
Baku State University, Faculty of Ecology, Head of the department "Enviromental Chemistry", Doctor of
Chemistry, Professor
2
Baku State University, Faculty of Ecology, Teacher at the department " Enviromental chemistry", PhD in
Chemistry
3
Baku State University, Faculty of Ecology, Master student of the department of " Enviromental
chemistry"
Keywords: Toxic metal , Heavy metals, Pollution
INTRODUCTION
Water pollution is contamination of water by foreign matter that deteriorates the quality of the
water. Water pollution covers pollutions in liquid forms like ocean pollution and river pollution. As the
term applies, liquid pollution occurs in the oceans, lakes, streams, rivers, underground water and bays,
in short liquid-containing areas.
It involves the release of toxic substances, pathogenic germs, substances that require much oxygen
to decompose, easy-soluble substances, radioactivity, etc. that becomes deposited upon the bottom
and their accumulations will interfere with the condition of aquatic ecosystems. For example, the
eutrophication: lack of oxygen in a water body caused by excessive algae growths because of
enrichment of pollutants. According to the water cycle, naturally, water around us will be absorbed to
the land (soil) and rivers will stream from the upstream to the downstream and released to the sea. In
normal situation organic pollutants are biodegraded by microbes and converted to a form that brings
benefits to the aquatic life. And for the inorganic pollutants, in the same situation, don't bring to much
hazards because they are widely dispersed and have almost no effect to the environment which they are
released to.
Some of the pollutants like lead (Pb), arsenic (As), mercury (Hg), chromium (Cr) specially hexavalent
chromium, nickel (Ni), barium (Ba), cadmium (Cd), cobalt (Co), selenium (Se), vanadium (V), oils and
grease, pesticides, etc are very harmful, toxic and poisonous even in ppb (parts per billion) range. There
are some minerals which are useful for human and animal health in small doses beyond which these are
toxic. Zinc (Zn), copper (Cu), iron (Fe), etc fall into this category. For agriculture, some elements like zinc,
copper, manganese (Mn), sulphur (S), iron, boron (B), together with phosphates, nitrates, urea,
potassium, etc are useful in prescribed quantities. There are some compounds like cyanides,
thiocyanides, phenolic compounds, fluorides, radioactive substances, etc which are harmful for humans
as well as animals.
Methods and materials
Atomic Absorption Spectrometry (AAS) is a technique for measuring quantities of chemical elements
present in environmental samples by measuring the absorbed radiation by the chemical element of
interest. This is done by reading the spectra produced when the sample is excited by radiation. The
atoms absorb ultraviolet or visible light and make transitions to higher energy levels. Atomic absorption
methods measure the amount of energy in the form of photons of light that are absorbed by the
sample.
Flame atomic absorption methods are referred to as direct aspiration determinations. They are
normally completed as single element analyses and are relatively free of interelement spectral
interferences. For some elements, the temperature or type of flame used is critical. If flame and
analytical conditions are not properly used, chemical and ionization interferences can occur. Different
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