عنوان مقاله [English]
Pollutants that leak and spread in the ground causing harm. They move with the ground waters and can be seen in wells farther than the original location of pollution. If mineral or chemical materials or bacteria disturb the water quality in this research, environmental hazards of natural and industrial pollutants of Mehriz area are studied and the pollutions caused by them affecting the ground water resources of the Yazd-Ardakan plain which encompass 80% of Yazd water resources have been examined.
In this research in order to choose wells for sampling, water well location maps, resulting from visiting and the location of pollutants were considered. In the studied area 10 wells were chosen for sampling and the sampling method used was casual sampling. According to the circumstances, characteristics of ground waters and level of solubility and the mobility of pollutants in ground waters were the chemical and biological parameters chosen for experiment and the prepared samples were tested with standard methods.
According to the results from geological and geomorphological studies of the area and the effects of it on the ground water quality we cannot relate the high level of some parameters or fluctuations in the studied area to natural pollutions. The concentration maps prepared based on the experiment results of the water sample of the studied area show that the level of COD and nitrate increase in the direction which the ground water flow. Appearance of toxic and heavy metals of lead in some samples show that pollution has entered from an unnatural source. High amounts of chromium (Cr+6) in some samples is a result of industrial or agricultural waste entering the water resources. By using the results of this research ecological and biological problems of this exquisite area can be solved and decisions can be made regarding the establishment of clean industries which produce no pollution. In this way economic development and environmental issues are both considered important.