The use of nanofiltration to regulate the properties of secondary products of processing animal raw materials

The problem of processing secondary material resources of the dairy industry, in particular buttermilk, is closely related to environmental issues. Nanofiltration is an energy-saving alternative to demineralization by ion exchange and electrodialysis. The purpose of the article is to study the membrane concentration process using nanofiltration flat membranes of the OPMN-P and OPMN-K brands for ultrafiltration of buttermilk. In order to achieve the set goal, two brands of nanofiltration membranes were tested during the experiment. The experimental study of the NF-UV process of oil pan permeate was carried out with the help of a laboratory installation, the parts of which included a container with a pressure gauge; thermostat; pump; manometers; counter (rotameter); membrane module; measuring capacity; valve; cylinder with CO2. To identify the main filtration dependencies, two types of Vladipor OPMN nanofiltration membranes were studied. For each type, pressure in the range from 0.5 to 2.0 MPa and temperature from 20 to 40°C were used. The results show that both types of membranes effectively retain lactose at a pressure of 2.0 MPa, a temperature of 40°C, and a concentration factor of about 2. Changing the flow velocity over the membrane from 0.5 m/s to 1.5 m/s allows obtaining increase in specific productivity by 15% from the initial one. The effect of concentration polarization effects on the specific performance of nanofiltration membranes was established. The limitation of the concentration coefficient due to the increase in the osmotic pressure of the solution was determined.A conclusion was made regarding the possibility of large-scale implementation of nanofiltration of secondary material resources of milk processing in the study of membrane regeneration processes. The practical significance of the work lies in helping to solve environmental problems through the use of the nanofiltration method, which has a number of advantages over other processing mechanisms. In addition, such a process will make it possible to obtain new valuable liquids that can be used during the production of a number of dairy products, in particular lactose-free