Dairy processing and technology Milk Science International (69) 2016 15 Method for the determination of product losses in dairy processes

  • Jan Hesse
  • Hans-Peter Ohlinger
  • Saskia Schwermann
Keywords: product loss, rinse milk, rinse water, wastewater, COD, chemical oxygen demand


The chemical oxygen demand (COD) in the wastewater of the dairy industry is high. A high COD demand has two problems: First, it could
lead to problems with the sewage treatment plant; second, it means a loss of product. It is well-known that approximately 90 % of the
COD load is milk components, but it is difficult to specify how much effluents occur from the different processes. Thus, it is necessary to
develop a method to determine product losses. This paper shows a possibility of determining product losses and provides information on
where, why and how many COD-loaded wastewaters occur. Here, the first rinse water of the cleaning process in a dairy is collected and the
COD is analysed. In relation to the COD of the pure product, one can determine the product loss. The presented method was reproducible
with a variation coefficient of < 3.6 %, except for cream, which had a variation coefficient of approximately 6.5 %. This method allows for
the optimization of processes and the reduction of the COD load of wastewater.


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