Evaluation of physical mechanical properties of experimental granulated cattle manure compost fertilizer

Abstract

Currently, there are searches for new and more rational ways to use biological waste for new forms of energy, creating fertilizers, building materials and other products. One kind of this biodegradable waste management is pelleting as the processing of recyclable materials into organic products. In the EU today only 5 % of bio-waste is recycled. According to estimates, if more bio-waste was recycled, it could replace up to 30 % of non-organic fertilizers. Currently, the EU imports around 6 million tons of phosphates a year but could replace up to 30 % of this total by extraction from sewage sludge, biodegradable waste, meat and bone meal or manure. According to the EU legal requirements manure is considered to be waste that the livestock owner has to account for and eliminate using as crop fertilizer and not polluting the environment. Manure compost pelleting can increase the bulk density, improve storability, reduce transportation costs, and make these materials easier to handle using the existing handling and storage equipment. Granulation process parameters and factors affecting the manure-based compost of organic granular fertilizer physical-mechanical properties were investigated. Manure raw material samples were dried naturally till 42 % humidity. Before pelletizing the samples were dried artificially till 28 % humidity. There were prepared 5 experimental manure samples in laboratory conditions and pelletized mixtures of manure waste with molasses and lime sludge add. For pellet production a small capacity 7.5 kW granulator was used, with a horizontal granulator matrix, the diameter of the pellets was 6 mm. During the researches there were estimated various physical – mechanical characteristics: biometric indicators (dimensions, mass), raw material and pellet volume and density, material and pellet humidity, pellet strength.