Dairy effluents from the dairy industries are organically heavily loaded and consequently more difficult to decompose in biological treatment processes. This is the reason that they cause malfunctions on the treatment plants. In case of release into the environment, they can even cause eutrophication of stagnant waters. Significantly higher concentrations of organic pollution are found in cheese whey, which is the main component of dairy wastewater. Lactose is the major part of cheese whey dry matter and some proteins and fats are also found. These specific features offer many opportunities for further exploitation and will be presented below.
The theoretical part of this master thesis presents the characteristics of ovine and caprine cheese whey, which were obtained from the literature. We also described a process for the production of protein powder and then focused on using cheese whey as a cosubstrate in anaerobic digestion for biogas production. Biochemical processes and process parameters of anaerobic degradation were presented. In the experimental part, several different sheep and goat cheese wheys were sampled. We measured their physicochemical properties, and also the properties of the inoculum and cow slurry, as these were the three substrates added to the fermenters for anaerobic digestion at the beginning of the test. The experiment was performed with an automatic methane potential test system (AMPTS II). Based on the quantities of whey produced in the area of Bovec, two different reactors (UASB and AnFBR) were dimensioned in the last part of the thesis. The UASB reactor would be filled with wastewater from the treatment plant with primary cheese whey and cow slurry at a ratio of 283: 10: 3. AnFB reactor would be filled with primary and secondary sludge, primary cheese whey and cow slurry at a ratio of 10:5:1.