Open Access
Municipal solid waste management in a decentralized composting scenario: assessment of the process reproducibility and quality of the obtained composts
(MDPI, 2024) Álvarez-Alonso, Cristina; Pérez-Murcia, María Dolores; Sánchez-Méndez, Silvia; Martínez-Sabater, Encarnación; Irigoyen Iriarte, Ignacio; López, Marga; Nogués, Isabel; Paredes, Concepción; Orden, Luciano; García-Rández, Ana; Bustamante, María Ángeles; Agronomía, Biotecnología y Alimentación; Agronomia, Bioteknologia eta Elikadura; Institute for Multidisciplinary Research in Applied Biology - IMAB
Over the last several years, the models for organic waste management have changed to implement circular economy in the productive cycle. In this context, new scenarios have emerged, where the management of different organic waste streams by composting is conducted with decentralized models that manage organic wastes in a more local way. However, in these new models, the standardization of the process control and of the end-product characteristics is necessary to guarantee the quality and agronomic value of the compost obtained, avoiding potential risks for human health and the environment. Thus, the aim of this work was to study two different scenarios of community composting of the organic fraction of municipal solid waste separately collected in order to guarantee the effectiveness and reproducibility of the composting processes and the quality of the composts obtained. For this, the development of the process and the characteristics of the composts at agronomic, hygienic–sanitary and environmental levels were assessed in real conditions and during three cycles of the process. The results obtained show high similarity among the different composting cycles, indicating an important degree of reproducibility among the processes. In addition, the composts obtained showed a good sanitary quality, absence of phytotoxicity and low contents of potentially toxic elements, which guarantee their use in agriculture without posing any risk to human health and to the environment.
Open Access
Quality assessment of composts officially registered as organic fertilisers in Spain
(Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), 2019) Puyuelo, Belén; Sánchez Arizmendiarrieta, Joseba; Irigoyen Iriarte, Ignacio; Plana, Ramón; Agronomía, Biotecnología y Alimentación; Agronomia, Bioteknologia eta Elikadura; Gobierno de Navarra / Nafarroako Gobernua
Composting of organic wastes is a management strategy linked to circular economy models through the transformation of these wastes into an organic product, compost, which can be used as fertiliser, soil amendment or growing media. However, the concept of ‘compost quality' is not enough defined to take a technical decision about which is its best use or application. In the last decade, different guidelines and regulations about organic fertilisers have been developed. For instance, in Spain the Fertilisers Regulation categorises compost under five kinds according to the raw materials used - organic amendment compost (OaC), manure compost (MaC), green compost (GrC), vermicompost (VC), ‘alperujo' compost (AlC) -, and under three quality levels (A, B or C) depending exclusively on the heavy metals content. This work analyses the national database of all composts (307) marketed in Spain, considering the analytical parameters declared, with the objective of proposing a methodology to define a global quality index. For this assessment, two indicators are employed: a fertility indicator, related to the nutrients content, and a clean indicator, related to the heavy metals content. Results show an average compost formulation 2.5:2.5:2.5 (N:P 2 O 5 :K 2 O). MaC and OaC present the highest fertility indicator, whereas VC the lowest. Regarding the clean indicator, GrC, MaC and VC are cleaner than OaC. In the future, this new quality assessment should be completed by including other indicators related to physical and biological characteristic (e.g. porosity, stability/maturity, phytotoxicity) that could determine the most proper use of compost.
Open Access
Integrated biowaste management by composting at a university campus: process monitoring and quality assessment
(MDPI, 2025-03-07) Álvarez-Alonso, Cristina; Pérez-Murcia, María Dolores; Martínez-Sabater, Encarnación; Irigoyen Iriarte, Ignacio; Sánchez Arizmendiarrieta, Joseba; Plana, Ramón; López, Marga; Nogués, Isabel; Bustamante, María Ángeles; Agronomía, Biotecnología y Alimentación; Agronomia, Bioteknologia eta Elikadura; Institute for Multidisciplinary Research in Applied Biology - IMAB
The sustainable management of biowaste, mainly food and pruning waste, is currently a challenge due to the increase in its production. The CaMPuSTAJE program, which has been implemented on the campus of the Public University of Navarre (UPNA) since 2019, is an excellent example of how the institution is addressing its strategic interests in sustainable waste management. The principal aim of this program is to manage the biowastes generated by the campus canteens through a simple community composting facility, involving UPNA students and graduates. This program aims to promote experiential learning and applied research in sustainability and circular economy, managing their own waste in a circular and local way. Thus, four composting sets of the CaMPuSTAJE program were evaluated by monitoring the process and the main chemical properties of the composting samples. Also, final composts were fully characterized to ensure the process reproducibility and efficiency and the absence of any hazard in the end-products. The final composts showed a significant agronomic quality, had low content of potentially toxic elements, and were free from phytotoxicity, thus being able to be reintroduced as an organic amendment at the university campus itself.
Open Access
Rational application of treated sewage sludge with urea increases GHG mitigation opportunities in Mediterranean soils
(Elsevier, 2017-02-01) Calleja Cervantes, María Eréndira; Aparicio Tejo, Pedro María; Villadas Latorre, Pablo José; Irigoyen Iriarte, Ignacio; Irañeta, Iosu; Fernández-González, A.J.; Fernández-López, M.; Menéndez, S.; Producción Agraria; Nekazaritza Ekoizpena; Ciencias del Medio Natural; Natura Ingurunearen Zientziak; Institute for Multidisciplinary Research in Applied Biology - IMAB
Open Access
Effect of feeding regime on composting in bins
(Taylor & Francis, 2017) Storino, Francesco; Menéndez Villanueva, Sergio; Muro Erreguerena, Julio; Aparicio Tejo, Pedro María; Irigoyen Iriarte, Ignacio; Natura Ingurunearen Zientziak; Nekazaritza Ekoizpena; Ciencias del Medio Natural; Producción Agraria; IdAB. Instituto de Agrobiotecnología / Agrobioteknologiako Institutua
Composting in bins is one of the most practical home composting methods. There is currently a need for greater information to improve the management of the composting process and to create home composting programs, which ensure sustainable production of high quality compost. This study investigates how two aspects of the bin feeding regime—the feeding frequency and the amount of waste applied at each feed—influence the process's evolution and the quality of the compost. Compost bins were assayed after introducing the same amount of kitchen and garden waste according to three different frequencies: in a single batch, weekly, or every 3 weeks. A fourth treatment was applied to calculate the potential waste reduction achieved by the composting process, filling the bins to the brim on a weekly basis. Temperature, mass, and volume changes; the microbial diversity (by Biolog); and gas emissions (CO2, CH4, N2O, and NH3) were all determined during the process. At the end of the experiment, all of the composts were weighed and characterized. Results show that the main differences were very dependent on the quantity of waste provided. Large amounts of waste were added increasing the compost's temperature and maturity during the process, while slightly affecting the salinity and phytotoxicity of the final compost but without any clear effects on microbial diversity and gas emission. Therefore, from a technical point of view, the shared use of compost bins among several households (community composting) is preferable to individual us
Open Access
Meat waste as feedstock for home composting: effects on the process and quality of compost
(Elsevier, 2016) Storino, Francesco; Sánchez Arizmendiarrieta, Joseba; Irigoyen Iriarte, Ignacio; Muro Erreguerena, Julio; Aparicio Tejo, Pedro María; Ciencias del Medio Natural; Natura Ingurunearen Zientziak; Producción Agraria; Nekazaritza Ekoizpena
Home composting is a powerful tool, which is spreading in different parts of the world, to reduce the generation of municipal waste. However, there is debate concerning the appropriateness, in terms of domestic hygiene and safety, of keeping a composter bin in the household deputed to kitchen waste of animal origin, such as meat or fish scraps and pet droppings. The purpose of our work was to study how the addition of meat scraps to household waste influences the composting process and the quality of the final compost obtained. We compared four raw material mixtures, characterized by a different combination of vegetable and meat waste and different ratios of woody bulking agent. Changes in temperature, mass and volume, phenotypic microbial diversity (by Biolog TM) and organic matter humification were determined during the process. At the end of the experiment, the four composts were weighed and characterized by physicochemical analysis. In addition, the presence of viable weed seeds was investigated and a germination bioassay was carried out to determine the level of phytotoxicity. Finally, the levels of pathogens (E. coli and Salmonella spp.) were also determined in the final compost. Here we show that the presence of meat waste as raw feedstock for composting in bins can improve the activity of the process, the physicochemical characteristics and maturity of the compost obtained, without significantly affecting its salinity, pH and phytotoxicity. Pathogen levels were low, showing that they can be controlled by an intensive management and proper handling of the composter bins.
Open Access
Integration of a communal henhouse and community composter to increase motivation in recycling programs: overview of a three-year pilot experience in Noáin (Spain)
(MDPI, 2018) Storino, Francesco; Plana, Ramón; Aparicio Tejo, Pedro María; Muro Erreguerena, Julio; Irigoyen Iriarte, Ignacio; Ciencias del Medio Natural; Natura Ingurunearen Zientziak; Producción Agraria; Nekazaritza Ekoizpena
This paper presents a three-year pilot experience of a new municipal waste management system developed in Navarre, Spain that integrates composting and hens. The aim of this new system is to motivate the general public to participate more in waste prevention programs. The Composter-Henhouse (CH) is a compact facility comprised of a henhouse and three composters. This is shared by 30 families who provide the organic part of their kitchen waste to feed the hens. Hens help speed up the composting process by depositing their droppings and turning the organic residue into compost. This study assesses the CH in terms of treatment capacity, the technical adequacy of the composting process, the quality and safety of the compost obtained and some social aspects. Over three years, the CH has managed nearly 16.5 tons of organic waste and produced approximately 5600 kg of compost and more than 6000 high-quality fresh eggs. No problems or nuisances have been reported and the level of animal welfare has been very high. The follow up of the composting process (temperature, volume reduction and compost maturity) and a physicochemical and microbiological analysis of the compost have ensured the proper management of the process. The level of involvement and user satisfaction has been outstanding and the project has presented clear social benefits.
Open Access
Business models of composting for a circular economy
(Elsevier, 2022-09-16) Mihai, Florin Constantin; Plana, Ramón; Sánchez Arizmendiarrieta, Joseba; Irigoyen Iriarte, Ignacio; Agronomía, Biotecnología y Alimentación; Agronomia, Bioteknologia eta Elikadura
A linear economy based on the “take-make-use-dispose” model disregards the role of composting in bio-waste diversion from landfills or dumpsites with repercussions to human settlements and the natural environment. Bio-waste is a key fraction of municipal solid waste and agricultural waste flows which must be properly managed under the “zero-waste” scenario promoted by the circular economy framework. This chapter argues the role of composting as a sound circular mechanism in bio-waste management. Best practices from Spain and Romania are revealed through cost-efficient and innovative projects which integrate the composting, multi-stakeholders cooperation (local authorities, waste operators, Non-Governmental Organizations, researchers, consultants, citizens, etc) business opportunities, and social inclusion (vulnerable individuals and marginalized communities) in line with circular economy principles. Examples from urban, rural and touristic regions show how composting could play a catalyzing role in human, natural, and economical regeneration of communities which could be further adjusted to other territories of the world to support the transition towards the circular economy.
Open Access
Addressing the gaseous and odour emissions gap in decentralised biowaste community composting
(Elsevier, 2024) González, Daniel; Barrena, Raquel; Moral-Vico, Javier; Irigoyen Iriarte, Ignacio; Sánchez, Antoni; Agronomía, Biotecnología y Alimentación; Agronomia, Bioteknologia eta Elikadura
Composting has demonstrated to be an effective and sustainable technology to valorise organic waste in the framework of circular economy, especially for biowaste. Composting can be performed in various technological options, from full-scale plants to community or even individual composters. However, there is scarce scientific information about the potential impact of community composting referred to gaseous emissions. This work examines the emissions of methane and nitrous oxide as main GHG, ammonia, VOC and odours from different active community composting sites placed in Spain, treating kitchen, leftovers and household biowaste. Expectedly, the gaseous emissions have an evident relation with the composting progress, represented mainly by its decrease as temperature or biological activity decreases. GHG and odour emission rates ranged from 5.3 to 815.2 mg CO2eq d-1 kg-1VS and from 69.8 to 1088.5 ou d-1 kg-1VS, respectively, generally being lower than those find in open-air full-scale composting. VOC characterization from the community composting gaseous emissions showed a higher VOC families’ distribution in the emissions from initial composting phases, even though terpenes such as limonene, α-pinene and β-pinene were the most abundant VOC along the composting process occurring in the different sites studied. The results presented in this study can be the basis to evaluate systematically and scientifically the numerous current projects for a worldwide community composting implementation in decentralised biowaste management schemes.
Open Access
El compostaje descentralizado de los desechos de cocina como herramienta agroecológica: influencia de las políticas públicas en la comarca de Sakana (Navarra)
(Sociedad Española de Agricultura Ecológica (SEAE), 2017-06-01) Sánchez Arizmendiarrieta, Joseba; Iso Tinoco, Andoni; Irigoyen Iriarte, Ignacio; Plana, Ramón; Sociología; Soziologia; Producción Agraria; Nekazaritza Ekoizpena
Se muestra la exitosa experiencia de ayuntamientos navarros que trasforman mediante compostaje in situ los desechos orgánicos generados por su población en un recurso local al servicio de la agroecología.