فهرست مطالب hojatallah joghatayi

Joghatay plain is located in Sabezvar Ophiolitic Zone and next to the chromite mine. In this research, the soil pollution by heavy metals have been investigated with respect to geochemical, statistical and environmental indicators in Joghatay plain.Material and

Samples were collected seasonally from soil in Joghatay plain within May 2014, and the concentration of heavy metals were measured using ICP-MS method. To the geochemical phases of metals in soil were determined using BCR sequential extraction method.

The result of the analysis of heavy metals in soil samples has shown high concentrations of some elements such as Chromium, Nickel and Cobalt in the southern part of the region. Assessment and correlation of heavy metals in Joghatay region soils by multivariate statistical methods (Pearson correlation, cluster analysis and principal component analysis) show a strong positive correlation between Cobalt, Nickel, Chromium, Iron, Manganese and Magnesium due to the same source  (ophiolitic unit area).

The pollution index (geoaccumulation index, enrichment factor, contamination factor and modified contamination degree) indicates that soil has strongly polluted with regard to Chromium and Nickel and moderately polluted to Cobalt. Sequential extraction method has indicated that more than 50% of Nickel and Chromium concentration in intercahnageable phase. On the other hand ophiolitic rocks and Chromit mining leads releasing of these elements in the area. Though, as far as it gets away from ophiolitic rocks these elements concentration will be decreased. Also element speciation in different phases reveals that the rest elements have concentrated in residual phases and have a lithogenic source.

Water quality assessment and identification of contaminants and contaminated area where groundwater is used for drinking is very important. The present study aimed at evaluation of the groundwater quality of Joghatay plain using GQI as an indicator of groundwater quality. GQI is a suitable tool to synthesize different available quality data into easily understood format. For this reason the concentration of anions and cations in water including Na, K, Mg, Ca, SO4 -2, Cl- and TDS were analyzed. Based on the measured parameters the groundwater quality distribution map of Joghatay was provided and the groundwater quality index (GQI) was determined by GIS. GQI index value in the study area changes between 81.3 to 88.1 and it is in the acceptable range. GQI index assessment reveals that according to the distance and passing through the different formations the water quality in the northern parts of Joghaty plain is lower.