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

Omed Mohammed Mustafa
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.

Key Words:
Karstic water,
Speciation, Makook
system, DOC,
Kurdistan Region


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