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Conference paper, 2004

Urine, faeces, greywater, greywater and biodegradable solid waste as potential fertilisers

Palmquist, Helena; Luleå, universitet; Jönsson, Håkan

Abstract

To increase the knowledge concerning the flows and compositions of wastewater fractions, field measurements were performed on the Gebers wastewater system (80 residents), which source separates the flow into four fractions of urine, dry collected faeces, greywater, and solid biodegradable waste. The flows were 1.77; 0.22; 110 and 0.18 kg per person and day respectively. The chemical compositions were reported for the following compounds: TS, COD, BOD7, N-tot, P-tot, K, S, Ag, B, Bi, Cd, Co, Cr, Cu, Hg, Mn, Mo, Ni, Pb, Pd, Pt, Rh, Sb, Se, Sn, Sr, Te, W and Zn. The NPKS relationships of urine mixture, faeces, and biodegradable solid waste at Gebers corresponded well to the crop uptake of macronutrients, which make them to potential fertilisers from a plant nutrients pont of view. A ratio of hazardous elements vs. nutrients was calculated to evaluate the potential for nutrient recycling. The lower the quotient, the better quality of the fertiliser. Obtained ratios were compared to the analogous ratios for wastewater sludge and a chemical fertiliser. The ratios of 12 non-essential elements to phosphorus and nitrogen were lower in the urine than in all of the other fractions. The fertilising potential for the sludge, greywater and biodegradable solid waste was questioned in the long term perspective due to higher ratios of hazardous elements contra nutrients than the plant uptake, which implies that an accumulation of these metals may occur in the fields. To reach a mass balance on the field the fertiliser should contain lower or the same ratios than the food. Since the food is the main source of the discussed metals in urine and faeces these fractions could be potential fertilisers, provided that external sources can be restricted

Keywords

Wastewater fractions; urine; faeces; greywater; potential fertiliser; metals; nutrients

Published in

Title: Ecosan - closing the loop : proceedings of the 2nd international symposium, 7th - 11th april 2003, Lübeck, Germany
ISBN: 3-00-012791-7
Publisher: The 2nd International Symposium on Ecological Sanitation, Incorporating the 1st IWA Specialist Group Conference on Sustainable Sanitation

Conference

The 2nd International Symposium on Ecological Sanitation, Incorporating the 1st IWA Specialist Group Conference on Sustainable Sanitation

    UKÄ Subject classification

    Agricultural Science
    Environmental Sciences related to Agriculture and Land-use

    Permanent link to this page (URI)

    https://res.slu.se/id/publ/4203