title: Greenhouse gas emissions during composting of two-phase olive mill wastes with different agroindustrial by-products.
abstract: The evolution of CO(2), CH(4) and N(2)O were monitored in five composting mixtures prepared from two-phase olive mill waste (TPOMW) and different agroindustrial by-products in order to assess the effect of the initial composition and the N source on greenhouse gas emission. Surface gas fluxes were measured using a closed static chamber and compared to the changes in different organic matter fractions (organic and watersoluble C) and N forms (NH(4)(+) and NO(3)(-)). CH(4) emissions depended on the organic matter mineralisation dynamics and the incorporation of manure in the starting mixture. The highest CH(4) fluxes were registered during the intense degradation at early stages of the process (up to 100 g Cm(-2)d(-1)). The emission of N(2)O (0-0.9 g Nm(-2)d(-1)) occurred from 6th to 10th wk of composting (bioxidative phase), coinciding with an intense nitrification in the pile. The use of urea enhanced the N(2)O emission up to 3.7 g Nm(-2)d(-1), due to an increase in available mineral N in the pile. Even though well managed TPOMW composting piles only represent a minor source of CH(4) and N(2)O emissions, the addition of urea and easily available C fractions to the starting mixtures can significantly increase the environmental impact of TPOMW composting as far as greenhouse gas emissions are concerned.
authors: Department of Soil and Water Conservation and Organic Waste Management, CEBAS-CSIC, PO Box 164, 30100 Murcia, Spain. monedero@cebas.csic.es
authors: Miguel A
authors: MA
authors: Sánchez-Monedero
authors: Nuria
authors: N
authors: Serramiá
authors: Concepción García-Ortiz
authors: CG
authors: Civantos
authors: Antonia
authors: A
authors: Fernández-Hernández
authors: Asunción
authors: A
authors: Roig
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D002244:Carbon / Q000737:chemistry; D002245:Carbon Dioxide / Q000032:analysis; D019649:Food Industry; D017752:Greenhouse Effect; D007220:Industrial Waste / Q000032:analysis*; D008697:Methane / Q000032:analysis; D009584:Nitrogen / Q000737:chemistry; D009585:Nitrogen Dioxide / Q000032:analysis; D031658:Olea; D012037:Refuse Disposal
chemical_list: D000393:Air Pollutants; D007220:Industrial Waste; D002245:Carbon Dioxide; D002244:Carbon; D009584:Nitrogen; D008697:Methane; D009585:Nitrogen Dioxide