Biochar characterization of raw versus spent common ivy: Inorganic nutrient behavior

Hedera sp., common Ivy, a lignocellulosic evergreen vine, is commonly seen in gardens and yards all over the globe. It is an excellent candidate to be applied in vertical green walls to improve ecosystems in future green cities (e.g. fine particulate matter adsorption). These green walls need to be trimmed regularly, thus leaving a major residue stream which could be promising as biomass feedstock for biochar fertilizer production. However, common Ivy contains valuable compounds (e.g. etheric oils and triterpene saponins) increasing the process’ added value. These should preferably be extracted prior to thermal conversion. The aim of this study is therefore to investigate the influence of extraction methods on the final properties of common ivy’s biochar using conventional pyrolysis. Investigated extraction methods include a Soxhlet ethanol extraction and a steam distillation, to obtain respectively a triterpene saponin and volatile oil extract. The influence of these extractions on the biochar properties was studied by comparing the thermal conversion and biochar properties of spent, extracted, biomass with raw biomass. Studied properties include biochar yield, elemental composition (CHNO), amount of inorganic nutrients, specific surface area, and presence of harmful heavy metals. The guidelines of the European Biochar Certificate are used to evaluate said properties. Furthermore, the pyrolysis process parameters, temperature and heating rate, were optimized to improve said biochar properties for application as fertilizer. Tested pyrolysis temperatures were 400, 550 and 700 °C. Results show that biochar yield from raw ivy was inversely proportional with pyrolysis temperature ranging from 29.6 ± 0.6% at 400 °C, 25.4% ± 0.03 at 550 °C and 23.0 ± 0.06 % at 700 °C. It was found that steam distillation lowers the amount of heavy metals in the material, whilst the inorganic nutrients are retained, thus enhancing the biochar’s potential as fertilizer. Furthermore, nitrogen content remained constant, around 2%, before and after pyrolysis both for raw and spent ivy, these results indicate that high-quality biochars were produced. To further understand biochar’s chemical behavior in soils, structural properties and morphology are being investigated further, specific surface area via BET, general pore structure using SEM, surface functional groups with FT-IR and, aromaticity with CP/MAS 13C NMR results will be presented accordingly

CoMix: comparing mixing patterns in the Belgian population during and after lockdown.

The COVID-19 pandemic has shown how a newly emergent communicable disease can lay considerable burden on public health. To avoid system collapse, governments have resorted to several social distancing measures. In Belgium, this included a lockdown and a following period of phased re-opening. A representative sample of Belgian adults was asked about their contact behaviour from mid-April to the beginning of August, during different stages of the intervention measures in Belgium. Use of personal protection equipment (face masks) and compliance to hygienic measures was also reported. We estimated the expected reproduction number computing the ratio of [Formula: see text] with respect to pre-pandemic data. During the first two waves (the first month) of the survey, the reduction in the average number of contacts was around 80% and was quite consistent across all age-classes. The average number of contacts increased over time, particularly for the younger age classes, still remaining significantly lower than pre-pandemic values. From the end of May to the end of July , the estimated reproduction number has a median value larger than one, although with a wide dispersion. Estimated [Formula: see text] fell below one again at the beginning of August. We have shown how a rapidly deployed survey can measure compliance to social distancing and assess its impact on COVID-19 spread. Monitoring the effectiveness of social distancing recommendations is of paramount importance to avoid further waves of COVID-19

De eurocrisis in het nieuws. Een framinganalyse van de verslaggeving in Vlaamse kranten

This research examines the news frames used in the news coverage about the European debt crisis. The mainstream media are the main source of information for the European citizens concerning this crisis in the Eurozone. Therefore, it is interesting to research the news coverage through an in-depth content analysis. First, we conducted an inductive analysis to recognize the dominant news frames about this issue. Three dominant frames were identified: conflict, disease and natural disaster. Secondly, we executed a deductive analysis to measure the frequency of these frames. The conflict frame appeared the most, followed by the disease frame and the natural disaster frame. In this article we studied the news coverage in Flemish newspapers. However, this research is the first part of a larger study that will analyze more EU member states.status: publishe

Framingonderzoek voor het ministerie van Buitenlandse Zaken

In dit rapport wordt aangegeven welke frames en counterframes intern door het Nederlandse ministerie van Buitenlandse Zaken gebruikt worden, en in welke mate deze overeenstemmen met het gebruik door externe stakeholders en de pers. Daarnaast wordt er communicatieadvies geformuleerd.nrpages: 65status: publishe

An Experimentally Validated Selection Protocol for Biochar as a Sustainable Component in Green Roofs

Green roofs contribute to more sustainable cities, but current commercial substrates suffer from important limitations. If carefully selected, biochar could serve as a viable option for a more sustainable green roof substrate. We propose a protocol to select an optimal biochar for green roof substrate amendment. Coffee husks, medium-density fiberboard, palm date fronds, and a mixture of waste wood, tree bark, and olive stone kernels are selected as residues for biochar production to develop a selection protocol. The residues are pyrolyzed at 350, 450, 500, and 550 °C in a lab-scale reactor. A pyrolysis temperature of 450 °C is selected for upscaling and is based on biochar yield, pH, salinity, and elemental composition. From evaluating the biochar characteristics after upscaling, it can be concluded that the biochar’s carbonization degree is mainly controlled by pyrolysis temperature, while yield, pH, and salinity are more dependent on the biomass properties. Ultimately, our procedure evaluates the presence of important contaminants, the biochar’s water holding capacity, salinity, pH, and carbonization degree. To validate the developed protocol, plant coverage experiments on green roofs are performed, which are quantified using a novel digital image processing method, demonstrating its efficient use to facilitate future biochar selection in substrates

Social contact data from CoMix survey (Belgium)

Individual contacts from the Belgian CoMix survey

Common Ivy (<i>Hedera Helix</i> L.) as a Novel Green Resource in an Urban Biorefinery Concept

Common ivy (CI) or Hedera Helix L., is a clinging evergreen vine that can be cultivated on any vertical surface (walls, fences, tree trunks, etc.). In Europe, CI has been recommended by governments to plant in urban areas because it lowers urban heat island effects and improves urban air quality. Regular trimmings of these vertical greenery systems would be necessary, which would yield a potentially interesting novel biomass resource for urban biorefinery concepts. Furthermore, CI extracts contain pharmaceutically active compounds (e.g., hederacoside C and α-hederin), which constitute the active components of commercially available cough syrups. Moreover, research on their suitability to treat (lung) inflammations and suppress cancer tumor growth is ongoing and shows promise. CI extracts also have demonstrated potential for their application in the agricultural industry to serve as antifungal agents. Recently, postextracted residues of CI have shown to be a promising feedstock for green fertilizer production via slow pyrolysis. Moreover, a provisional sustainability assessment indicated that the proposed process would be both carbon- and energy-negative. Therefore, a novel circular biorefinery approach is proposed, which entails the lifecycle of CI, from cultivation in vertical ecosystems via refinery into bioproduct(s) and valuable nutrients, and then back into soil