Abstract
AbstractCo-composting is a technique that allows the aerobic degradation of organic waste mixtures, primarily aiming at obtaining compost that can be used as fertiliser or soil amendment. As compared to the typical composting activity, the main difference is not merely the use of more than one feedstock to start and sustain the biodegradation process, but also the possibility of combining various kinds of waste to obtain ‘tailored’ products with designed properties, or to reclaim and valorise natural resources, such as degraded soils or polluted soils and sediments. Set up of appropriate co-composting protocols can be a way to optimise the management of waste produced by different sectors of agriculture and industry and also from human settlements. Different formulations can not only optimise the biodegradation process through the adjustment of nutrient ratios, but also lead to the formation of products with innovative properties. Moreover, co-composting can be a technique of choice for the reclamation of soils degraded by intensive agriculture or contaminated soils and sediments. In fact, an appropriate mix of organic waste and soils can restore the soil structure and induce fertility in nutrient-depleted soils, and also remediate polluted soils and sediments through degradation of organic pollutants and stabilisation of heavy metals. While the selection of different mixes of organic waste may lead to the design of composts with specific properties and the potential valorisation of selected waste materials, there are still several factors that hamper the development of co-composting platforms, mainly insufficient knowledge of some chemical and microbiological processes, but also some legislative aspects. This chapter illustrates the progress achieved in co-composting technology worldwide, some key legislative aspects related to the co-composting process, the main scientific and technical aspects that deserve research attention to further develop co-composting technology, and successful applications of co-composting for the reclamation of soils and sediments, allowing their use for cultivation or as growing media in plant nurseries. A specific case study of the production of fertile plant-growing media from sediment co-composting with green waste is also illustrated.
Highlights
Co-composting is the process of the aerobic degradation of organic compounds using more than one feedstock
Since ever, composting of organic solid waste was directed towards the sanitation and volume reduction of municipal waste, with extensive efforts directed to mechanical innovations, the reduction of emissions and odours during the composting process, and speeding up of compost maturation through the achievement of a sustained thermophilic phase
Similar results were reported by Wan et al (2003), who compared various mixes of pig manure, sewage sludge and soybean refuse to enhance the degradation of polycyclic aromatic hydrocarbon (PAH) in a polluted soil, reaching a maximum of 90% of removal with pig manure, and for removal of total petro hydrocarbons during a co-composting of a diesel oil-contaminated soil mixed with sewage sludge (Namkoong et al 2001)
Summary
Co-composting is the process of the aerobic degradation of organic compounds using more than one feedstock. With rapid urbanisation occurring globally, organic waste represents the majority of the municipal waste in emerging countries. In this context, composting systems can play an important role in managing waste as well as creating employment and creating products that contribute to food security, in developing countries. Organic solid waste collected from households and institutions is composted either at decentralised (community-based) or centralised composting plants. Community-based decentralised composting systems can generally process about 2–50 tonnes per day of organic waste, whereas centralised composting facilities are capable of receiving 10–200 tonnes per day. Proper management of the plant and marketing of the compost are key factors to ensure the sustainability of such systems
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call