title: Relevance of organic matter fractions as predictors of wastewater sludge mineralization in soil.
abstract: Seventeen different wastewater sludges were characterized using both chemical and organic matter fractionation methods (water extraction, Van Soest method, and acid hydrolysis) and 6-mo incubation studies to assess their decomposition in soil. Simple correlation and multiple factor analysis (MFA) were then performed to establish relationships between composition and C and N mineralization of sludges. Carbon and N concentrations covered a wide range of values, but organic carbon (C(o)) to organic nitrogen (N(o)) ratios were relatively low (from 5 to 19). Carbon and N were mainly distributed in the most soluble fractions of the Van Soest method and in the water-insoluble fraction at 100 degrees C. Carbon mineralization varied from 180 to 661 g C kg(-1) organic C added during the 168-d incubation. The addition of sludges led to different inorganic N dynamics: from -3.3 to +120.0 g N kg(-1) sludge organic C mineralized after the 168-d incubation. Fractionation studies showed that the most discriminating method was acid hydrolysis. Carbon mineralization was linked with the proportion of sludge N and C present in the lignin-like fraction (r = -0.68 and -0.65, respectively). Significant relationships were established between N mineralization and N(o) to C(o) ratio (0.88 < r < 0.95) and the C(o) to N(o) ratio of sludges, the C to N ratio of the soluble fraction obtained by the Van Soest method, the water-soluble fraction at 100 degrees C, and the C and N present in the acid-hydrolyzable fraction. Finally, multiple factor analysis also enabled establishing a sludge typology using five clusters based on composition and mineralization characteristics.
authors.affiliation: INRA, Unité d'Agronomie de Laon-Reims-Mons, 2 esplanade R. Garros, BP 224, 51686 Reims cedex 2, France. Virginie.Parnaudeau@reims.inra.fr
authors.forename: Virginie
authors.initials: V
authors.lastname: Parnaudeau
authors.forename: Bernard
authors.initials: B
authors.lastname: Nicolardot
authors.forename: Jérôme
authors.initials: J
authors.lastname: Pagès
mesh_terms: D002244:Carbon / Q000032:analysis / Q000737:chemistry*; D005544:Forecasting; D009584:Nitrogen / Q000032:analysis / Q000737:chemistry*; D012722:Sewage / Q000737:chemistry*; D012987:Soil; D012995:Solubility; D014865:Waste Disposal, Fluid / Q000379:methods*
chemical_list: D012722:Sewage; D012987:Soil; D002244:Carbon; D009584:Nitrogen