New spin on cutting dairy effluent costs
Most water that is used in milk production ends up as effluent containing a milk loss of up to 3%. Depending on the capability of local wastewater treatment facilities, effluent discharge may in some cases be impractical.
The answer is often to dispose of this material directly to land, which has both advantages and disadvantages. Similarly, disposal to sewer can be an expensive option.
To help solve the problem, Westfalia Separator uses its centrifugal technology to remove fine suspended solid products from the water.
This significantly reduces the chemical and biological oxygen demand (COD/BOD) level to reduce the cost of disposal of the liquid phase. But it also converts the nutritionally-rich solid phase into a cake that is simple to transport, easy to spread on land and is not subject to the same stringent European Union regulations.
This dewatering technology uses either centrifugal decanters or, if appropriate, downstream disc bowl clarifiers to remove fine organic matter to reduce the COD/BOD as far as possible. This may in some circumstances be used in addition to the dairy's own dissolved air flotation (DAF) waste treatment plant to reduce contaminants to a minimum.
Centrifugal technology has the ability to lower the cost of disposal of the liquid phase to sewer and reduce the cost and effectiveness of disposal to land too.
Another way to reduce costs is to reduce the amount of effluent produced by the manufacturing processes in the first place.
Westfalia's Sludge Reduction System (SRS), also called 'Protein Plus', can reduce the discharge from bacterial clarifiers by up to six times, returning some 80% back into the process as valuable skim milk and protein.
In SRS separators, the feed system has been redesigned, with the rotating bowl re-engineered to retain the protein element within the skim product. This, in turn, enhances the quality of the milk and reduces the number of desludge operations typically between four and six times. This advance has been realised without affecting the separation efficiency of the separator.
Contact: Westfalia Separator, Tel: 08708 305512
