Manure processing into granular fertilizers using additional additives

Abstract

According to the project of the EU Commission (Circular Economy Package Document) currently only 5 % of bio-waste in the European Union is recycled. The EU imports around 6 million per year tons of phosphates, but up to 30 % of this amount could be replaced by substances received from organic waste (manure and others). Organic fertilizers are the only alternative for organic farms. The additional value is received by replacing mineral fertilizers with organic ones: reduced energy consumption for fertilizer production and transportation, less environment pollution, improved soil properties. In addition to this, recycled biomass is more homogeneous and more even spread in the fields. The aim of the work is to determine the possibilities of processing of manure compost and other waste into granular organic fertilizers, the physical-mechanical properties of granules. The physical mechanical properties of raw material for granular organic fertilizers with various additives molasses, defecate (lime sludge), which have a significant influence on the quality of granules, are discussed in the article. The fertilizer granules must be sufficiently resistant for transporting, storing and spreading in the soil. Properties such as the raw material fractional composition, material and granules moisture, strength of the granules and others were investigated. It has been determined that compaction of milled manure without additives requires 42.6 kJ•t-1 of energy, the mass with molasses additive 44.8 kJ•t-1 and with defecate additive 53.0 kJ•t-1 energy, while estimating the pressure function parameters and the density of the required granules.

Physical mechanical properties evaluation of experimental granulated poultry manure fertilizer

“…Bulk density of poultry manure with litter raw material was 647.1 ± 4.05 kg•m -3 . This is a higher rate compared to cattle manure compost raw material bulk density (556.4 ± 5.81 kg•m -3 ) [13], or composted pig manure raw material (525.8 ± 56.06 kg•m -3 ) [14]. Average moisture content of the prepared mill after artificially drying in the ventilation canal was 11.2 ± 1.4% (Table 2).…”

“…Compared to previous studies of cattle manure compost granules, it may be seen that granules under the force of 425 N in horizontal compression disintegrated totally. Granules with molasses addition reached 491 N in horizontal direction [13], average pig manure compost granule strength was 628.3 ± 38.9 N [14]. Poultry manure with litter granules has shown better results.…”

Granulation of poultry manure and biochar for production of organic fertilizers

“…Milling quality was determined, the mass fraction composition of these manure types and biochar was determined using a sieve shaker Retsch AS 200 (Germany) and sieves with holes of various diameters: 0.25 mm, 0.5 mm, 0.63 mm, 1 mm, 2 mm, 3.15 mm, 4 mm and 5 mm. The mass remaining on the sieves is weighted, and the sample part of every fraction in percentage is calculated [7].…”

“…Cylindrical granule volume was calculated using the granule size (diameter and length). After determination of the granule volume and weight, the density of all investigated granule samples was calculated [7]. Each test was repeated 3 times.…”

“…The cylindrical granules were horizontally placed between two anvils and a compressive force was applied to the side of the granule. The tester was run at a compression rate of 20 mm•min -1 and was stopped after the granule had broken [7]. Each test was performed 5 times per granule type sample.…”