Smithfield in Timisoara, belonging to the largest meat chain industry of the world, with the headquarters in USA, decided in 2004 to purchase the Comtim slaughterhouse and to reconstruct it in order to become the biggest slaughterhouse in Romania and one of the biggest in Europe. The slaughtering line reaches the capacity of 8000 pigs/day resulting into an amount of waste water produced of 2000 cm/day. Due to the fact that the treated water shall be disposed to the Bega river, the local authorities required that the treatment efficiency of all parameters should be more than 95%. The main problem of the influent is the presence of the nitrogen, which has to reach an effluent value of less than 10 mg/l. The unique design that Hydrotech has applied consists of,
1) coarse and fine screening;
2) buffer tank which operates as oxidation ditch in order for the biological nitrification/denitrification to begin before the waste water to reach the main treatment steps;
3) dissolved air flotation for the removal of the solids and the fats as well as for the removal of the biological excess sludge;
4) biological phosphorus removal;
5) plug flow biological nitrification - denitrification process which is flexible to operate in three different ways according to the parameters of the inlet.
6) secondary clarification zone with integrated rectangular sedimentation tanks supplied by the Swedish company Zickert;
7) dewatering of the homogenized excess sludge removed by the dissolved air flotation unit by decanter centrifuge .