Source identification of high glyme concentrations in the Oder River. 
The objective of the following study was to identify the source of high concentrations of glycol diethers (diglyme, triglyme, and tetraglyme) in the Oder River.  Altogether four sampling campaigns were conducted and over 50 surface samples collected.  During the first two samplings of the Oder River in the Oderbruch region (km 626-690), glymes were detected at concentrations reaching 0.065 μg L(-1) (diglyme), 0.54 μg L(-1) (triglyme) and 1.7 μg L(-1) (tetraglyme).  The subsequent sampling of the Oder River, from the area close to the source to the Poland-Germany border (about 500 km) helped to identify the possible area of the dominating glyme entry into the river between km 310 and km 331.  During that sampling, the maximum concentration of triglyme was 0.46 μg L(-1) and tetraglyme 2.2 μg L(-1); diglyme was not detected.  The final sampling focused on the previously identified area of glyme entry, as well as on tributaries of the Oder River.  Samples from Czarna Woda stream and Kaczawa River contained even higher concentrations of diglyme, triglyme, and tetraglyme, reaching 5.2 μg L(-1), 13 μg L(-1) and 81 μg L(-1), respectively.  Finally, three water samples were analyzed from a wastewater treatment plant receiving influents from a Copper Smelter and Refinery; diglyme, triglyme, and tetraglyme were present at a maximum concentration of 1700 μg L(-1), 13,000 μg L(-1), and 190,000 μg L(-1), respectively.  Further research helped to identify the source of glymes in the wastewater.  The gas desulfurization process Solinox uses a mixture of glymes (Genosorb(®)1900) as a physical absorption medium to remove sulfur dioxide from off-gases from the power plant.  The wastewater generated from the process and from the maintenance of the equipment is initially directed to the wastewater treatment plant where it undergoes mechanical and chemical treatment processes before being discharged to the tributaries of the Oder River.  Although monoglyme was also analyzed, it was not detected in any of the water samples.