Lake Sajószöged


Our customer the TVK MALI Triathlon Club has organized the International Triathlon World Cup in August 2007. The scene of the swimming race was the Sajószöged Lake. The company has taken contact with us 1 month before the event to improve the water quality of the lake, and making it available for an international sport event. The lake was highly loaded with nutrients and rotting organic material, it had been struggling with heavy algae blooms during every summer in the past years.

The short deadline was the biggest difficulty of the project, we have had 1 month till the start of the Triathlon event. Furthermore according to our survey the DO levels were very low in every part of the lake in every segment of the water column, and high pathogenic count was measured. Besides continuous fish kills was observed, various species were dying due to lack of DO, and various infections like Spherosporosis, Aeromonas Hydrophila and various worms.

The project concluded with an outstanding success due to the very intensive treatment. For the start of the Triathlon race the water quality has become first class, Secchi depth increased, there were no algae blooms, fish kills stopped on the first week after the first treatment. The change in the trophic state defining parameters are shown in tables below as well as the pathogenic counts.

Lake Sajószöged
Pathogenic survey before treatment: after treatment:
Fecal Coliform: 702 db / 100 ml 270 db / 100 ml
Enterococcus: 180 db / 100 ml 2 db / 100 ml
Clostridium: 200 000 / 50 ml – / 50 ml
SAJÓSZÖGED 06th July 2007 07th September 2007.
Ammonium mg/l 0,39 0,13
Free Ammonia mg/l 0,02
Nitrite mg/l 0,21 0,04
Nitrate mg/l 19,5 5,8
Ortophosphate mg/l 0,43 0,20
Total Algae Count / ml 24 230 8 210