50 crop residues carbonatation mud from the sugar beet industry (i.e. calcium carbonate residue that remains after raw sugar beet juice has been clariï¬ed) compost (including black earth) sewage sludge One very important source of phosphorus is human urine. The ï¬rst pilot projects to separate urine collection and treatment have been started. The ï¬rst treatment plant for human urine, which recovers the phosphate as struvite, has opened in Zutphen. Most phosphate that is currently recycled in the Netherlands originates from manure (section 6.2). Next is phosphate from by-products of food production and animal by-products. Other secondary products and waste are re-used, although in relatively small amounts compared with the phosphate from manure, plant and animal by-products. Phosphate recycled from manure and compost is still mostly used as a nutrient source for crop production, and to a much lesser extent as a secondary phosphate ore by Thermphos. Other uses are currently being investigated. Plant by-products are mainly used as feed, as there is limited use as fuel. Crop residues were traditionally used as soil amendments. Nowadays, biogas production plants are a secondary and growing market for these residues. Carbonatation mud is primarily used as a lime, but it also contains phosphate from the sugar beet and it is therefore also a nutrient source. Other wastes are recycled as raw material for the production of fertiliser or dietary phosphates, or serve as primary products for the chemical industry. The estimated quantities of phosphate from these sources that are re-used in the Netherlands are given in Table 6.1. Table 6.1: Re-use of phosphate from diï¬erent sources in the Netherlands in Gg P2O5. 29 Bouwmeester, H., M.H. BokmaBakker, N. Bondt, J. van der Roest, 2006. Alternatieve aanwending van (incidentele) reststromen buiten de diervoedersector. RIKILT rapport 2006.008. Vis et al., 2003 De diervoederketen en zijn witte vlekken in kaart gebracht. â door de bomen het bos zienâ. Tussenrapport Ketenanalyse Diervoedersector. Deelproject 1 en 2. Den Haag, VWA/RVV, 16-122003. Bouwmeester, H., M.H. BokmaBakker, N. Bondt & J. van der Roest, 2005. Risicobeheersing bij gebruik van reststoï¬en in diervoeders, RIKILT, rapport 2005.001. Source Animal manure By-products of food production, plant by-products Animal by-products Crop residues Compost Carbonatation mud Sewage sludge Estimated quantity 165.0 113.2 42.7 9.2 2.5 1.5 0.2 30 Animal manure By far the largest amount of phosphate is recycled by using animal manure as a nutrient source. In 2005, 149 Gg P2O5 was reused in the Netherlands and 16 Gg P2O5 was exported. By-products of food production, plant by-products Food production (cereal processors, bakeries, breweries, fruit and vegetable processors, cacao processors, fermentation industries, cheese production etc.) also leads to residues that are all valorised to plant by-products, although the distinction between by-product and waste is not always clearly given (Bouwmeester et al., 200629). Most plant by-products are re-used as feed (intensive livestock and pets). Vis et al., 200330, Bouwmeester et al., 200531, Bouwmeester et al., 2006, give 31 Pagina 59
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