MODELING PROCESSES OF СENTRIFUGAL SEPARATION AND ULTRAFILTRATION OF WASTEWATER ON LIVESTOCK FARMS

Ecologization of animal husbandry is determined by the effi ciency of manure disposal in agricultural fi elds. Manure effl uents are formed as a result of livestock keeping without litter and they contain pathogenic bacteria, helminth eggs and larvae. For the treatment of manure effl uents as multicomponent substances, the authors have proposed a technology including their separation into solid and liquid fractions in a precipitation centrifuge with a screw sediment discharge and subsequent deworming of the liquid fraction in an ultrafi ltration installation. To evaluate the effectiveness of the technology, the methods of mathematical modeling were applied. The methods are based on both original approaches to the centrifugation process with the determination of local fractional degrees of capturing and the integral degree of cleaning, and conventional ones consisting in the ultrafi ltration process based on the diffusing of a substance through a semipermeable partition under the action of a pressure gradient. The research was carried out in a livestock breeding farm enterprise. According to the results of mathematical modeling, it was established that for a given performance
of 3…4 m3/h all considered centrifuges of the ОГШ type provide 97% degree of manure removal from the solid fraction, while according to the energy effi ciency criterion, it is advisable to recommend the ОГШ-202K-03 machine with the drive power of 5.5 kW. It was found that to clean the liquid fraction from pathogenic microorganisms, an increase in the operating pressure p from 0.1 to 0.7 MPa is accompanied by a decrease in the area F of the membrane fi lter partition of the МФАС-Б-4 and МФАС-П-2 type from 78.2 to 11.2 m2 for membrane type МФАС-МА-6 – respectively from 33.0 to 4.7 m2. It was found that at an operating pressure
of 0.2 MPa, according to the criteria of energy intensity of the process and material capacity of the ultrafi ltration installation, it is advisable to use a МФАС-П-3 membrane type with a fi lter partition area of 2.73 m2.