About this Research Topic
The waste hierarchy has been fundamental in designing national strategies and policies that move the countries away from its dependence on landfilling. After minimizing the amount of waste that is produced in the first place through waste prevention and reuse, the next priority is to recycle as much useful material as possible from the waste that is unavoidably generated.
Respecting the waste hierarchy means that energy is recovered from waste after secondary materials have been removed for recycling. Only after extracting the maximum value from waste (both materials and energy) should the remaining waste be disposed of safely.
The organic wastes that are generated in different production processes are increased in diversity and quantity creating challenges for management and treatment. For food production systems, this sort of problem is also recurrent and the complexity to handle this waste is increasing rapidly around the world. Sometimes the treatment of waste generated in these production systems is an alternative that must be considered. The big question to be answered is how to reduce residues’ environmental impact, decrease the treatment costs and add value to the organic waste. Different processes can be chosen to reach this goal looking for the possibility to generate byproducts that can be used inside or outside the productive process that is one of the principles of circular economy. In a circular economy, bio-waste is not landfilled. Instead, it forms a resource for organic soil improvers, fertilizers, growing media component and bio-based products. The reintroduction of these materials into the agroecosystems reduces environmental impact and costs of production. After use, the residues of these products can flow back safely into the biosphere, thereby closing carbon and nutrient cycles.
Bio-organic waste has immense potential for green energy recovery. Energy can be recovered from the organic fraction of waste or by-product (biodegradable as well as non-biodegradable) through thermal, thermo-chemical and biochemical methods. Energy that is produced in the form of electricity, heat or fuel using combustion, pyrolysis, gasification or anaerobic digestion is clean and renewable energy, with reduced carbon emissions and minimal environmental impact than any other form of energy. The development of technologies for the recovery of energy from organic wastes is becoming an ever-more important challenge due to the eventual depletion of fossil fuel resources and global warming. This research topic will highlight the knowledge regarding to treatment processes for organic waste looking for energy recovery processes (substrates preparation, characterization, innovative treatment processes) and how these processes can be applied and used considering the possibilities of recovery of resources from waste. Respecting circular economy principles, the topic covers also the by-products valorization or safe disposal after energy recovery from organic wastes.
Keywords: energy recovery, biogas, pyrolysis, gasification, by-products valorization and disposal, substrate characterization and preparation, circular economy, organic waste, sustainability, solid waste, liquid waste, innovative treatment processes, waste management.