Studying Hydro-Geochemistry and Pollution of Underground Water

Category Environmetal Geology
Group GSI.IR
Location The 25 Symposium of Geosciences
Author F.Rahmani-A.Yaghub pour-A.Aftabi-A.Haj hariri-P.Behnia-R.Noubari-E.Izadi
Holding Date 02 July 2007
 

Studying Hydro-Geochemistry and Pollution of Underground Water

In Tehran (wells & reservoirs) 1:50000 Sheet (stressted on Medical Geology) Executive Division of Geomedical Researches

 (Geology and Mineral Exploitation Organization)

 

Water is a substance which is found in nature numerously. Despite its abundance, different natural factors cause limitation in drinking water. One of these factors is antropogenic and geologic pollution of water resources which has direct relation with general health of the society. This problem appears more in large cities due to high population and contaminating industries. Tehran industrial and urban development has been so fast within the last 2 decades, and it has brought several dangers one of which is underground water pollution.

The factors of Tehran water wells pollution:

1- Natural pollution: it is due to ground type and existence of ore mineral veins.

In places located on volcanic rock beds, the amount of some elements, Nitrate, and Nitrite may be much in underground water. The metals in the earth crust are also effective in such pollution.

- Pollution by human sources: industrial and agricultural developments are other water contaminating toxic elements and heavy metals in residues of industries, fertilizers, and pesticides may cause pollution in underground water. Therefore the results show over existence of Nitrate in Tehran water wells which can cause respiratory diseases especially in under one year old children as well as digestive diseases in adults. Furthermore, same scale maps show the concentration of Sodium, Magnesium, Manganese, Iron, Zinc, Cobalt, Chrome, Ammonia, Sulphate, Sodium and Chloride in South and South east of Tehran. Consequently, total water hardness is more in these regions and needs more consideration in respect of kidney diseases and urine ducts.

The studies indicate that the quality of underground water is higher due to special geological status, type of geologic formations in the plain, and aquifer hydraulic and hydrogeologic features in northern, central, and western part. Moving toward south eastern parts, the quality is lower, out it should be considered in determining the place of drilling new wells. A significant part of ground and deep water pollution comes from detergents, Nitrates, and nitrites. The nitrate density is more than 45 mg/L (standard limit) in most samples, due to urban sewerage. Heavy metals and poisons such as mercury, and Arsenic are also observed in samples which are the results of textile, leather, detergent and welding industries. To get more details, we should study water resources more.                                                         

 

tags: QAZVIN