Recycling of Wash Water as a Way to Reduce the Environmental Load and Increase the Utilization Rate of Raw Materials

Far Eastern State Technical Fisheries University, Engineering Disciplines Department, 52 B Lugovaya Str., Vladivostok 690087, Russia

^* Corresponding author: boytsova.tm@dgtru.ru

Abstract

The problem of recovering the protein and other valuable components from wash water (low-concentrated suspensions) exists in almost all areas of the food industry. Research in this field is quite successful and is mainly based on the processes of evaporation, flotation, the use of force fields, and other physical and chemical methods. The variety of proposed methods for extracting the protein substances, the permanent search for new methods confirm the incompleteness and urgency of the problem under study. The possibility was demonstrated and the conditions for purification of wash waters of minced meat production and technological liquids for processing the algae were determined. The use of an acidic solution of chitosan was proposed for cleaning the wash water of minced meat production. Considering the ability of chitosan to sediment from solutions having a pH in the range of 5,6, crystalline sodium bicarbonate was used to adjust the pH value. The calculation showed that 0,66 g of sodium bicarbonate was required to neutralize a 2% solution of chitosan in 2% acetic acid. The largest mass of the sediment was obtained at the ratio of wash water / chitosan solution as 25/2 – 25/4. Ultrafiltration was used for the purification of technological waters for processing the algae. The results of the study showed that after passing through the filtration bed, the purified water contained 4 times less mineral components and organic substances compared to the original content.