scholarly journals Assessment of Disintegration of Compostable Bioplastic Bags by Management of Electromechanical and Static Home Composters

2020 ◽  
Vol 13 (1) ◽  
pp. 263
Author(s):  
Lorenzo Maria Cafiero ◽  
Margherita Canditelli ◽  
Fabio Musmeci ◽  
Giulia Sagnotti ◽  
Riccardo Tuffi

Interest in small scale composting systems is currently growing, and this in turn raises the question of whether the compostable bags are as suitable as in industrial composting facilities. In this work the physical degradation percentage of compostable lightweight bioplastic bags in two types of composter was examined. The main goal was to understand whether the mild biodegrading conditions that occur in electromechanical or static home composters are sufficient to cause effective bag degradation in times consistent with the householders’ or operators’ expectations. Bags, which complied with standard EN 13432, were composted in a number of 600 L static home composters, which were run in different ways (e.g., fed only with vegetables and yard waste, optimizing the humid/bulking agent fraction, poorly managed) and a 1 m3 electromechanical composter. Six months of residence time in static home composters resulted in 90–96 wt% degradation depending on the management approach adopted, and two months in the electromechanical composter achieved 90 wt%. In the latter case, three additional months of curing treatment of the turned heaps ensured complete physical degradation. In conclusion, in terms of the level and times of physical degradation, the use of compostable bioplastic bags appeared promising and consistent with home composting practices.

Detritus ◽  
2020 ◽  
pp. 3-10
Author(s):  
Roberto Guião de Souza Lima Jr. ◽  
Claudio Fernando Mahler

This study involves the evaluation of new composting systems for the treatment of organic solid waste that has low environmental impact. Two composting devices were developed, with four types of management. Their behavior was analyzed regarding temperature, gas production, moisture, leachate and percolated water production, compost maturation, nutrient presence, pH and water heating, which can be seen as an energy gain in addition to the economic viability of the process. The proposed composting techniques kept the waste at thermophilic temperatures for more than 20 days, with no significant emission of CH4, under aerobic conditions by passive aeration, without leachate generation. These results can be partially attributed to the suspension of the compost on pallets, the residue composition chosen in the experiments and the boundary conditions of the compartments. The energy recovery test, through water recirculation inside the compost, presented temperatures that reached 51°C after 24 h of recirculation, and were maintained throughout the process, 20 days, demonstrating its effectiveness. The proposed models are environmentally viable, minimizing gas emissions and leachate generation compared to landfill or industrial composting plants. They can be used in industrial kitchens, residential complexes, shopping malls and other small and medium solid waste generators. In addition, the solution presented in this study avoids the transportation of waste over medium and long distances, which also brings a significant reduction in energy expenses, and in the case of landfills, it avoids occupation for long periods, thus reducing emissions of gases and leachate, whose control and treatment are expensive.


2020 ◽  
Vol 18 (2) ◽  
pp. 31-48 ◽  
Author(s):  
Amadou Sidibé ◽  
Gennifer Meldrum ◽  
Harouna Coulibaly ◽  
Stefano Padulosi ◽  
Issa Traore ◽  
...  

AbstractFonio (Digitaria exilis (Kippist) Stapf) and Bambara groundnut (Vigna subterranea (L.) Verdc.) are native crops grown at a small scale in Mali that have potential to support agricultural productivity under climate change. A community biodiversity management approach was explored in this study as a means to reinforce the cultivation of these crops by increasing farmers' access to intraspecific diversity and developing capacities of community institutions for their management. The research involved six communities in Ségou and Sikasso regions. Multiple varieties of fonio (10–12) and Bambara groundnut (8–12) were established in diversity fields in each site over 2 years where farmers engaged in experiential learning over the crop cycle. Significant adoption of fonio and Bambara groundnut was detected in several study sites. The precise drivers of adoption cannot be definitively determined but likely include increased seed access and awareness gained through the diversity field fora, seed fairs and community seed banks. No significant yield advantage was detected for any of the varieties in the diversity fields, which showed variable performance by site and year. The number of varieties registered and managed by community seed banks in each site increased from 1–5 varieties of each crop to 11–12 varieties following the interventions. The number of Bambara groundnut varieties cultivated in farmers' fields also increased, while there was evidence of a slight decline in fonio diversity in some communities. The results of this study can inform efforts to strengthen seed systems and cultivation of neglected and underutilized species in Africa.


2019 ◽  
Vol 134 ◽  
pp. 134-143
Author(s):  
Dae-Yun Ji ◽  
Won-Ki Hwang ◽  
Hyun Ku Kim ◽  
Kwon-Yeong Lee

2021 ◽  
Vol 617 ◽  
pp. 118625 ◽  
Author(s):  
Minyoung Kim ◽  
Negin Nejatishahidein ◽  
Ehsan Espah Borujeni ◽  
David J. Roush ◽  
Andrew L. Zydney ◽  
...  

2020 ◽  
Author(s):  
Maria Wirth ◽  
Johannes Kisser

<p>The present-day urban system is characterised by a one-directional flow of resources from the rural environment into cities. Cities are centres of human and economic activity, but also of resource use and waste. Therefore, they play both a critical and promising role to support the transition to a circular economy, by keeping incoming products, materials and resources in use. This requires a redesign of biological and technical material cycles in a way that their value can be maintained at the highest possible level for as long as possible, while at the same time natural systems are restored. How can we rethink urban infrastructures to transform cities from resource sinks into circular resource transformation hubs? And how can nature-inspired systems help us to create circular cities?</p><p>alchemia-nova is developing integrated, regenerative systems to close water, nutrient, material and energy cycles in cities, centred around buildings as multifunctional service providers. They include building-integrated nature-based solutions for small-scale on-site wastewater treatment, combined with organic solids management to platform chemicals, biogas and nutrients. This approach can enable the efficient valorisation of the high resource potential of urban nutrient flows, with near zero-energy and chemical input. This way, they provide a more efficient, robust and resilient alternative to the predominant chemical and energy-intensive end-of-pipe approaches to circular cities. Water and nutrients can be safely reused in urban and peri-urban agriculture, renewable energy produced on site, biomass and other solid waste further processed to secondary materials, while also gaining the multifunctional benefits of urban greening. These systems are being demonstrated through the EU H2020 HOUSEFUL project in Austria and Spain, complimented by demonstration sites in Greece (EU H2020 HYDROUSA project), thus ensuring their applicability in highly industrialised infrastructure and temperate climatic conditions, as well as in less developed communal infrastructure and Mediterranean arid climatic conditions. HOUSEFUL’s integrated management approach includes circular materials management along the entire housing value chain, e.g. to enable local sourcing of building materials. Together, the robust, low-maintenance technologies and circular materials management contribute to the creation of distributed resource transformation hubs across cities, where value is maintained, and secondary resources captured and recirculated where they occur, creating more efficient and more resilient circular cities, and a wider circular economy.</p><p>The research conducted in preparation of this presentation as well as the participation at NGU 2020 is funded by the EU-funded HOUSEFUL project (Grant Agreement number 776708).</p><p>HOUSEFUL online: http://houseful.eu/solutions/searching-local-building-material/</p>


2000 ◽  
Vol 2000 (3) ◽  
pp. 386-395 ◽  
Author(s):  
Michael K. Peterson ◽  
Dina L. Johnson ◽  
Richard C. Pleus

2014 ◽  
Vol 34 (7) ◽  
pp. 1109-1116 ◽  
Author(s):  
Raquel Barrena ◽  
Xavier Font ◽  
Xavier Gabarrell ◽  
Antoni Sánchez

2008 ◽  
Vol 35 (5) ◽  
pp. 385 ◽  
Author(s):  
Michael F. Clarke

Ecological fire management in Australia is often built on an assumption that meeting the needs of plant species will automatically meet the needs of animal species. However, the scarcity of ecological data on the needs of fauna in relation to fire undermines the confidence managers should place in current popular frameworks for planning ecological burning. Such frameworks are built almost entirely around the goal of maintaining plant community diversity. They provide little guidance to managers regarding the characteristics of desirable ‘mosaics’ (e.g. patch size, connectivity or composition of age-since-burnt classes) or the timing of fires in relation to faunal population trends linked to other cycles (e.g. El Niño events). Claims by agencies of adopting an adaptive management approach (‘learning by doing’) to cope with a dearth of knowledge are credible only if monitoring and evaluation are carried out and future actions are modified in light of new evidence. Much monitoring of fauna is of such a small scale and short duration that the statistical likelihood of detecting a positive or negative effect of the management regime is minute. Such shortcomings will only be overcome through broad-scale and/or long-term studies of fauna. The funding for such research is unlikely to be forthcoming if fire ecologists and land managers convey the impression that the current data are adequate for the implementation of the current planning frameworks.


Author(s):  
Vaughn M. Emmerson ◽  
Gerardo Diaz

Biomass is essentially organic garbage obtained from many sources of dead or live vegetation including yard waste. According to recent data, approximately sixty million bone dry tons of biomass are produced in California each year [1]. Of this, only five million tons are used for the generation of electricity. At a global scale, 8700 Tg of biomass (dry matter) were burned without energy recovery in 1991. This number has increased especially in developing countries with the main sources being the savannas, agricultural waste, tropical forests, and fuel wood. Inefficient burning of waste, through combustion in open-air or in open dumps are a significant source of pollutants leading to possible health effects. An alternative to open air combustion is gasification, which involves the conversion of biomass to generate synthesis gas (syngas) by adding heat and limited amounts of oxygen. Several gasifying agents can be utilized, but air is commonly used in small-scale gasifiers. The use of air causes a large molar fraction of nitrogen in the syngas composition. This papers shows the experimental results obtained with a commercially available small-scale downdraft gasifier. Woodchips obtained from a nearby landfill are used as input to the gasifier and temperatures, flow rates, and syngas composition are reported and analyzed.


2022 ◽  
Vol 10 (1) ◽  
pp. 69
Author(s):  
Soukaina Elyaagoubi ◽  
Georg Umgiesser ◽  
Mehdi Maanan ◽  
Francesco Maicu ◽  
Jovita Mėžinė ◽  
...  

The finite element model SHYFEM was used to study the hydrodynamics and variability of water level, salinity, temperature, and water residence time (WRT) in the Oualidia lagoon located on the Moroccan Atlantic coast. The lagoon hosts a RAMSAR convention-protected area and also offers a set of valuable ecosystem services providing the source of income for the local population. To assess the effects of submarine groundwater discharge (SGD) inputs in the study area, four simulations were set up using different SGD inputs estimates in addition to tidal forcing, bathymetry, meteorological data including solar radiation, rain, and wind, in addition to boundary conditions in the Atlantic such as salinity, water level, and water temperature. The model was calibrated and validated using hydrodynamic measurements of previous studies in 2012 and 2013. The final results from the model are in good agreement with measured data. The simulation with SGD input ~0.05 m3 s−1 produced salinity values closest to the observed ones. Calculated spatial distribution of WRT, temperature, and salinity reduced to coordinates in two PCA axes is consistent with lagoon zones developed earlier using the benthic macroinvertebrate distribution. The calculated spatial distribution of WRT allowed us to evaluate the placement of oyster aquaculture farms and small-scale fisheries in relation to water quality issues existing in the lagoon.


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