Method for the determination of product losses in dairy processes

J. Hesse1, H.-P. Ohlinger1, S. Schwermann2

1 Hochschule Hannover - University of Applied Sciences and Arts, Faculty II – Bioprocess Engineering, Heisterbergallee 12,
30453 Hannover, Germany
2 Hochschule Fulda – Fachbereich Lebensmitteltechnologie, Leipziger Straße 123, 36037 Fulda, Germany

Date submitted:18/06/2015    Date accepted: 11/02/2016                                                 Volume/Page(s): 69/15-17

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.

Keywords: Product loss, rinse milk, rinse water, wastewater, COD, chemical oxygen demand, dairy