The background content of heavy metals in the water of small rivers in the Nadym – Pur interfluvial area

This article considers the problem of the formation of the microelement water composition of the small rivers not directly affected by the oil and gas industrial complex in the Nadym-Pur interstream area. Physicochemical characteristics and ionic composition of the natural water samples are determined by chemical aqueous method, the total content of heavy metals is analyzed by inductively coupled plasma atomic emission spectrometry (ICP-AES) and inductively coupled plasma mass spectrometry (ICP-MS). More than 99% of the sum of all the heavy metal mass with concentration above 0,1 mcg/dm3 is defined by the presence of fourteen metals ranged as following: Fe>>Mn>>Sr>Ba>Zn>Rb>Cu>Co>Ni>V>Ce>Zr>Pb>La. Groups of such metals as manganese and strontium, nickel and cobalt, lead, zinc and copper, vanadium and zirconium, cerium and lanthanum form the concentration сlusters. In comparison to large and average rivers, water samples from small rivers contain higher concentrations of iron and manganese, and lower concentrations of zinc. The Fe and Mn content may vary depending on such characteristics as water color index and water turbidity. The significant exceedance of MACf of Fe and Mn is observed everywhere. The excess of zinc, caused by natural factors is occasionally fixed. The defined variability ranges for the heavy metal contents in water of small rivers located beyond the reach of the oil and gas industrial complexes effects are suggested to consider as modern background regional values of the heavy metal concentrations throughout water-collecting area of Nadym and Pur rivers in Yamalo-Nenets Autonomous Okrug of Tyumen region.