298 94 307/02 Untersuchungen zum Stand der Umsetzung des ...

Teil 3 Seite 7-6
Table 7-4: Composition of the entire production wastewater in a TBA without processing
of blood, feathers, or bones
Parameter Unit Average Range
pH-value - - 6,0-9,7
Specific conductivity mS/cm 4,0 3,0-8,0
Hydrogen carbonate mmol/l 20 14-44
Entire water density (Ca, Mg) mmol/l - 0,4-1,4
Settleable solids ml/l 17 0,1-60
Filterable solids mg/l 1500 1200-2000
COD homogenised mg/l 5600 564-23000
BOD5 homogenised mg/l 3500 330-14000
Carbon acids C1 - C6 (as COD) mg/l 3800 450-12000
Acetic acid mg/l - 1100-3600
Propion acid mg/l - 670-1700
n-Butyric acid mg/l - 700-2200
Lipophile substances mg/l - 25-23000
Ammonium-N mg/l 790 50-3000
org.-N mg/l 120 50-350
P total mg/l 15 0,5-50
Sulphide mg/l 5 10-25
Sulphates mg/l 40 5-45
Chloride mg/l 150 20-300
COD : BOD5 mg/l - 1,3 : 1-1,6 : 1
BOD5 : N : P mg/l 100 : 26 : 0,3 -
BOD5 : N mg/l 3,8 : 1 -
COD : N mg/l 6,2 : 1 -
Table 7-4 also shows that the wastewater from plants without processing of blood has a
lack of trace elements and micro-nutrients. For the feather processing, one has mainly to
consider the additional high concentrations of hydrogen sulphide. In the wastewater of the
blood processing, one can expect high concentrations of phosphoroustotal.
One must also pay attention to undesirable concomitant substances from the raw mate-
rial or from the operation chemicals, particularly:
- Disinfection agents (mainly cationic tensides)
- Chemicals from the exhaust air cleaning (sodium hypochlorite, sulphuric acid, soda
lye)
- Chemicals from the production water and cooling water processing and conditioning
(sodium sulphite, tri-sodium phosphate, etc.)
- Cleaning agents (tensides)
Relevant heavy metals could as yet not been proven in the wastewater of the meat meal
industry. AOX can as a rule be found if sodium hypo-chlorite is used for exhaust vapour
treatment or if halogenous-separating products are used as disinfection agents.