%0 Journal Article
%T Characterisation of Organomineral Fertilisers Derived from Nutrient-Enriched Biosolids Granules
%A Diogenes L. Antille
%A Ruben Sakrabani
%A Sean F. Tyrrel
%A Minh S. Le
%A Richard J. Godwin
%J Applied and Environmental Soil Science
%D 2013
%I Hindawi Publishing Corporation
%R 10.1155/2013/694597
%X Organomineral fertilisers (OMFs) were produced by coating biosolids granules with urea and potash. Two OMF formulations with N£¿:£¿P2O5£¿:£¿K2O compositions: 10£¿:£¿4£¿:£¿4 (OMF10) and 15£¿:£¿4£¿:£¿4 (OMF15) were developed for application in grassland and arable crops. Routine fertiliser analyses were conducted on four batches of OMF and biosolids granules and compared with a sample of urea to determine key physical and chemical properties of the materials which affect handling and spreading, soil behaviour, and fertiliser value. Bulk and particle densities were in the range of 608 to 618£¿kg£¿m£¿3, and 1297 to 1357£¿kg£¿m£¿3, respectively. Compression tests showed that OMF particles undergo deformation followed by multiple failures without disintegration of the granules when vertical load was applied. Static particle strength was between 1.18 and 4.33£¿N£¿mm£¿2 depending on the particle diameter. The use of a model for fertiliser particle distribution studies showed that OMF granules should be between 1.10 and 5.50£¿mm in diameter with about 80% of the particles in the range of 2.25 to 4.40£¿mm to enable application at 18£¿m tramline spacing. This research utilises novel technology to improve the fertiliser value of biosolids, reduce disposal costs, and deliver a range of environmental benefits associated with recycling. 1. Introduction 1.1. The Need for Recycling The production of sewage sludge (biosolids) in England and Wales is estimated to be 1.6 million tonnes (dry solids) per year [1] while this amount exceeds 10 million tonnes (dry solids) per year in the European Union (EU) [2]. Current levels of sludge production are set to increase due to the growth of the population and continuous adoption of improved technologies which are introduced to comply with standards required for the treatment of effluents. The quantity of sewage sludge recycled to agriculture varies considerably between EU member states. The UK and Ireland recycle approximately 70% and 90%, respectively, while Finland, Slovenia, Sweden, Holland, Greece, and Belgium recycle very low quantities or no sewage sludge to agriculture [3]. Conventional routes for disposal of sewage sludge include landfill and incineration which are considered to be unsustainable and therefore being progressively restricted. In this respect, the EU Landfill Directive 99/31/EC [4] requires reduction of 35% of biodegradable waste by 2020 of that generated in 1995 while the UK Government is committed to cut back CO2 emission by 20% [5] which narrows the opportunities for increased disposal through incineration. Expanding incineration
%U http://www.hindawi.com/journals/aess/2013/694597/