RESUMO
Food waste is one of the main obstacles to transitioning to sustainable and circular food systems. Food waste-reducing platforms (FWRPs) have emerged as low-cost alternatives by donating or commercializing surpluses and non-commercial food. However, as a recent phenomenon, little is known about their actual contribution to the fight against food waste. This study aims to employ a systematic review of the literature to understand the main issues of FWRPs. Our results indicate that technology plays multiple roles in FWRPs: enabling the sharing of surpluses by connecting supply and demand, monitoring and generating data on waste, among others. However, technology is insufficient for food recovery. FWRPs' business models must be aligned with the sustainability concept, encompassing environmental, economic and social benefits. Innovators must design and prototype solutions to address these various intended functions. This study points out many barriers to implementing these digital platforms, such as delivering multiple benefits for heterogeneous actors. Other barriers involve building trust and changing the behaviour of actors concerning their food habits. The scarcity of empirical studies has limited a better understanding of FWRPs and their actual ability to tackle food waste on a large scale. Despite the limitations found in the literature, digital platforms are an interesting solution to food waste management by promoting food waste prevention and reduction strategies at the source.
Assuntos
Eliminação de Resíduos , Gerenciamento de Resíduos , Alimentos , Abastecimento de Alimentos , Gerenciamento de Resíduos/métodosRESUMO
The leachate treatment by nanofiltration (NF) process has received much attention over the last two decades. Previous studies focused on the investigation of the technical feasibility of NF. However, there are a limited number of works that examined leachate treatment costs. On the other hand, in a landfill management system, the economic component is an imperative factor for the decisions of all operations. Thereby, this work aimed to investigate the technical feasibility and economic parameters involved in a full-scale NF plant for the treatment of leachate previously treated by the physicochemical process. The average quality of the pre-treated leachate was 2258 ± 230 mg L-1 chemical oxygen demand (COD) and 821 ± 86 mg L-1 humic substances (HS). NF was performed using a bench-scale filtration module with commercial polymeric membranes SR100 and NP030. At the end of each filtration, a cleaning protocol was applied to recover the initial membrane permeability. The concentration of recalcitrant compounds, expressed as HS, was reduced to 84 ± 8 mg L-1 in the permeate, and COD complies with the wastewater discharge standards imposed by local legislation. The capital costs for a full-scale NF was estimated at MUS$ 0.772, and specific total cost, treated leachate per volume unit, has been estimated at US$ 8.26 m-3.
Assuntos
Poluentes Químicos da Água , Análise da Demanda Biológica de Oxigênio , Filtração , Substâncias Húmicas/análise , Poluentes Químicos da Água/análiseRESUMO
Landfill leachate consists mostly of a high content of refractory organic matter, ammonia and toxic compounds. All these compounds, regardless of their nature, have a potential pollution effect on local ground and surface waters. In this context, the purpose of the present study was to evaluate a treatment process (coagulation-flocculation with lime coupled with nanofiltration) applied to landfill leachate from Seropédica, Rio de Janeiro (Brazil). Jar tests were conducted to determine the optimum dosage of lime (ranged from 0 to 10 g L-1) and, at optimum lime dose, ammonia nitrogen was removed during coagulation-flocculation process due to high pH. The process was settled for 6 h with slow stirring (50 rpm) to promote air entrainment and NH3-N stripping before using the final treatment step of nanofiltration at 8 bar. After ammonia stripping, NH3-N was reduced from 1,236 mg L-1 to 353 mg L-1 (71% removal efficiency). At the end of the combined treatment, TOC (total organic carbon), HS (humic substances) and COD (chemical oxygen demand) removals were 89%, 80% and 94%, respectively. The results showed that the combined process was effective in the removal of recalcitrant compounds and NH3-N.
Assuntos
Compostos de Cálcio/química , Filtração , Floculação , Óxidos/química , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Amônia/análise , Análise da Demanda Biológica de Oxigênio , Brasil , Substâncias Húmicas/análise , Modelos TeóricosRESUMO
This paper proposes a framework with six dimensions that can be useful for evaluating the potential and the current stage of a bio-based platform chemical. The framework considers the technological and strategic challenges to be fulfilled by a company that intends to lead a platform based on a bio-based chemical. A platform chemical should be an intermediate molecule, with a structure able to generate a number of derivatives, that is produced at a competitive cost, capable of allowing exploitation of the scale and scope economies, and inserted within a complete innovation ecosystem that is able to create value with governance mechanisms that are capable of allowing coordination of the innovation process and facilitation of the value capture by the focal company leading the platform, in our case the producer of the platform molecule. Based on these six dimensions, three potential platform chemicals - succinic acid, butanol and farnesene - are compared and discussed. It is possible to identify important differences concerning the technological dimensions and the strategic dimensions as well. Two of the molecules - farnesene and succinic acid - adhere to most of the conditions required to structure a platform chemical. However, the innovation ecosystem is not complete and the governance mechanisms are still under development, so it is not clear if they will be capable of allowing a favorable position for value capture by the platform leader. Butanol structuring for a platform does not seem promising. The potential of the molecule is apparently not high and the strategic initiatives are in general not focused on innovation ecosystem structuring.