Speciation of U, Se, As and Sr in Makook Karstic water system, Kurdistan Region, Iraq

Volume 1 , Issue 1 , January 2016 , Pages 471-480

Authors

¹ Department of General Sciences, College of Basic Education, Charmo University, Kurdistan Region, Iraq

Speciation of trace elements in water system is essential for understanding of the

mobility, toxicity, bioavailability and transport characteristics of these elements. This

study presents an evaluation of different factors affecting speciation of uranium (U),

selenium (Se), arsenic (As) and strontium (Sr) in Makook Karstic water system. Results

show a temporal variability of U, Se, As and Sr species within the different karst

aquifers. The abundant species are U(VI), U(IV), Se(IV), Se(VI), As(V), As(III), Sr2+

and SrHCO3+. It is observed that these species are significantly controlled by pH, redox

(pE), temperature (T), dissolved organic carbon (DOC), dissolution of calcite and

dolomite minerals and variation of springs discharge. Mineralogical content of the host

rocks controls the speciation of the studied elements as well. Therefore, different

aquifers show different speciation responses for the same element. This study illustrates

the speciation mechanism in karstic waters.

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