Naabtaler Milchwerke Bechtel OHG, Schwarzenfeld, Germany
After an extension of prodction the processing of milk to cheese and milk products produces up to 1,100 m³ waste water daily. The existing biological aerobic waste water treatment plant (WWTP) is
designed for 600 m³/d.
EnviroChemie extended the existing WWTP with an anaerobic Biomar® AFB WWT unit for a capacity of 1,500 m³/d.
Features of this concept are small area requirement, low operation cost as well as gain of fermentation gas and reduced excess sludge.
The waste water from several production departments is collected in the central pumppit. After separation of big parts in the fine-meshed sieve the waste water is pumped to the preacidification, which also works as a buffer. Before the preacidified waste water enters the Biomar® AFB reactor the flotation separates fats and cheese particles. In the Biomar® AFB reactor organic waste water constituents, like lactic acid, alcohols and other organic compounds are digested by micro organisms into methane and carbon dioxide (fermentation gas).  COD and BOB load of the waste water strongly decreases (approx. 80%). The final polishing treatment is made by the existing aerobic waste water treatment unit.
The fermentation gas is taken off and used in a high-speed steam generator.
 

capacity	1,500 m³/d
COD-load	5,250 kg/d
COD-Concentration	3,500 mg/l
COD-reduction,anaerobic	75 %

Anaerobic pretreatment
Space requirements	approx. 250 m²
control system	programmable control,
	process visualization
methane reactor
volume	approx. 900 m³
material	stainless steel, isolated
operating temperature	30-35 °C
fermentation gas removal	approx. 2000 m³/d

Mr Thomas H. Weißer
thomas.weißer(at)envirochemie.com
phone: +49 (0) 61 54 / 69 98 - 28