INTENSIFICATION OF BIOMETRIC MANURE STABILIZATION PROCESS

Abstract

An increase in pig livestock and their housing system’s changing led to the liquid manure amount increasing, both in Russia and around the world. The greatest difficulties arise at disposal manure with moisture content of 92-97 %. All of well-known technologies of liquid manure preparation for using have low technical and economic indicators due to high costs for structures construction, purchasing and equipments operating and low quality obtained organic fertilizers. It is possible to increase efficiency of such manure disposal improving  by the biothermal stabilization technology improving, based on the liquid manure saturation with oxygen from the air. The results of the pre-tests had showed that process intensity is largely determined by the initial manure’s granulometric composition. The mathematical model of a manure biothermal stabilization process is presented in the form of differential equations system and it describes in time four main changing parameters: treated manure’s temperature, substrate’s concentrations, thermophilic microorganisms and oxygen in treated manure. It was found that with in increase in the manure moisture content from 90 to 96% increasing ash-free substance decomposition intensity decreases, the maximum temperature reduces from 70 to 51 °C and the exposure time is increased from 8 to 14 days. The most stable a decomposition process of ash-free substance occurs at initial manure humidity of 92 %, when the maximum temperature in the manure processed on a mechanical shredder and apparatus of vortex layer of  more than 70 °C and it is reached on the third day. Applying only mechanical shredder for manure pretreatment is impractical due to the insignificant of this type of treatments influence on the biothermal stabilization process intensity.