Evaporative water from the concentration of yeast slurry is a potential raw material for water recovery. It is characterized by low pH (4.6–6.3), increased turbidity (3.65–13.7 NTU), and high content of total organic carbon (356–754 mg/L). Its treatment in the volume coagulation process using NaOH and coagulant PIX 111, was studied. Water turbidity was lowered to a value below 1 NTU, but coagulation did not allow for the removal of organic compounds. Coagulation was effective at temperatures of 20 and 40°C. Pre- -treatment of the feed water for RO included alkalization, coagulation, sedimentation, and 5 μm fine filtration (variant I), as well as single 5 μm fine filtration (variant II as a blank). In variant I the feed with improved properties was achieved. Membrane filtration allowed for effective desalination of evaporative water, 98 and 73% conductivity retention was obtained, depending on the method of the feed pre-treatment. The organic compounds were removed less effi ciently, at 94 and 84%, respectively.
The meat industry is characterized by high water consumption. Since this wastewater is highly loaded, it should be thoroughly pre-treated prior to its discharge into receiving water. Our investigations revealed that a hybrid system of ultrafiltration and reverse osmosis is a promising purification method. Its application resulted in a 100% and 98.8% removal of phosphorus and nitrogen compounds, respectively. The efficiency of COD and BOD removal exceeded 99%.