ANALYSIS OF NUTRITIONAL PARAMETERS OF BIOGAS SLURRY

Abstract

Large amount of waste and by-products generated during livestock processes requires urgent treatment and disposal. The energy recovery of wastes and by-products can be a solution for the problem, since the biogas production is an obvious way of recovery. As a by-product of biogas production biogas slurry is produced and it is to be suitable for nutrient supply. The samples of the biogas slurry originate from the Nyírbátor Regional Biogas Plant. The plant is used for the disposal and recovery of plant residues, manure of cattle and poultry, poultry slaughterhouses and other animal wastes. The organic matter from the fermenter is separated. After separation, the dilute phase is transferred to the manure storage and the solid phase is transferred to a drying plant or composting plant. Aims of the study were the analysis of filtering efficiency of the separator, comparison of properties of the pre-separator and the separated fermentation residue, since the company wants to spread the biogas slurry to arable land and pasture in a frame of complex precision irrigation system. For this reason, the sampling points were planned to set both before and after separator processes. Samples were taken twelve times between February and June 2018. Among other properties, the dry matter content of the biogas slurry, C and N content, element content, pH, conductivity, biological and chemical oxygen demand were measured. Based on the element content and the N content, the biogas slurry is suitable for nutrient supply. The average dry matter content values of the samples show that the result of the separation process the dry matter content is significantly reduced (P<0.05). The salt content was very high in the samples both before and after separation. In order to prevent environmental stress, it is recommended to reduce the salt content before applying the biogas slurry.

Keywords

• biogas slurry
• nutritional parameters
• separator
• precision irrigation