Effect of biochar addition to metal-contaminated soil on Phaseolus vulgaris

The soil of the Campine region in Belgium is polluted with metals such as cadmium (Cd), copper (Cu) and zinc (Zn) due to past industrialization (Schreurs et al., 2011). When this soil is used for agriculture, these metals can accumulate in crops and cattle. To enlarge the available land to produce safe crops with high productivity, addition of biochar to the soil is considered a possible solution. Biochar has been proven to possess many advantages. When added to the soil, it can adsorb metals like Cd and hence reduce its bioavailability for plants (Li et al., 2017). Pig manure is an interesting feedstock to pyrolyze into biochar because it is highly abundant in Belgium. To investigate the capability of this biochar type, pot experiments were performed to study the effect of biochar addition to polluted soil on Phaseolus vulgaris. The environmental norms of the Flemish government indicate the safe and allowed quantity (mg.kg-1 dry matter) of metals in a reference soil (10% clay, 2% organic matter). A metal-contaminated soil exceeding these guidelines for Cd, Cu and Zn for at least eighty percent was mixed with 0%, 1% or 2% pig manure-derived biochar. On the one hand, this experiment showed that the biomass of P. vulgaris (stems, leaves and beans) was dose-dependently enhanced by biochar application. On the other hand, metal determination in beans and leaves showed an opposite relation, mainly a biochar-related decrease in metal concentration. The latter was in most cases reflected in higher remains of metals in the soil. In conclusion, P. vulgaris grown on metal-contaminated soil mixed with pig manure-derived biochar showed a higher crop yield than plants without biochar. This enhanced growth seemed to be dose-dependent within the concentration range tested, but this should be further researched in other plant species and substrates. In addition, pig manure-derived biochar diminished the translocation of Cd, Cu and Zn to the aboveground parts of the plant. These results indicate that pig manure-derived biochar could be used to enhance the growth of crops and diminish the uptake and accumulation of metals, although further research on other feedstock-derived biochar is necessary. References Li, H., Dong, X., da Silva, E., de Oliveira, L., Chen, Y., & Ma, L. (2017). Mechanisms of metal sorption by biochars: Biochar characteristics and modifications. Chemosphere, 178, 466-478. Elsevier Ltd. Schreurs, E., Voets, T., & Thewys, T. (2011, 10 15). GIS-based assessment of the biomass potential from phytoremediation of contaminated agricultural land in the Campine region in Belgium. Biomass and Bioenergy, 35(10), 4469-4480

Activated Carbon by Co-pyrolysis and Steam Activation from Particle Board and Melamine Formaldehyde Resin: Production, Adsorption Properties and Techno Economic Evaluation

One of the top strategic objectives and research areas in Europe is recovering wood from processing and end of life products. However, there are still several "contaminated" wood products that are not or only partly reused/recycled. Particle board waste which is contaminated with aminoplasts is one of these products. In addition, a considerable amount of aminoplast waste resinis produced for the production of particle board that cannot be re-used or recycled. The chemical properties of these wastes (high nitrogen content of 5.9 wt% and 54.1 wt% for particle board and melamine formaldehyde respectively) make them ideal precursors for the production of nitrogenised activated carbon. The profitability of the produced activated carbon is investigated by calculating the net present value, the minimum selling price and performing a Monte Carlo sensitivity analysis. Encouraging results for a profitable production are obtained even though the current assumptions start from a rather pessimistic scenario

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

Deciphering the morphology of motor evoked potentials

Motor Evoked Potentials (MEPs) are used to monitor disability progression in multiple sclerosis (MS). Their morphology plays an important role in this process. Currently, however, there is no clear definition of what constitutes a normal or abnormal morphology. To address this, five experts independently labeled the morphology (normal or abnormal) of the same set of 1,000 MEPs. The intra- and inter-rater agreement between the experts indicates they agree on the concept of morphology, but differ in their choice of threshold between normal and abnormal morphology. We subsequently performed an automated extraction of 5,943 time series features from the MEPs to identify a valid proxy for morphology, based on the provided labels. To do this, we compared the cross-validation performances of one-dimensional logistic regression models fitted to each of the features individually. We find that the approximate entropy (ApEn) feature can accurately reproduce the majority-vote labels. The performance of this feature is evaluated on an independent test set by comparing to the majority vote of the neurologists, obtaining an AUC score of 0.92. The model slightly outperforms the average neurologist at reproducing the neurologists consensus-vote labels. We can conclude that MEP morphology can be consistently defined by pooling the interpretations from multiple neurologists and that ApEn is a valid continuous score for this. Having an objective and reproducible MEP morphological abnormality score will allow researchers to include this feature in their models, without manual annotation becoming a bottleneck. This is crucial for large-scale, multi-center datasets. An exploratory analysis on a large single-center dataset shows that ApEn is potentially clinically useful. Introducing an automated, objective, and reproducible definition of morphology could help overcome some of the barriers that are currently obstructing broad adoption of evoked potentials in daily care and patient follow-up, such as standardization of measurements between different centers, and formulating guidelines for clinical use

Verwijdering van restconcentratie zware metalen uit afvalwater met geactiveerde biokool van organische probleemstromen (Biosorb)

status: publishe

Combining Monte Carlo simulations and experimental design for incorporating risk and uncertainty in investment decisions for cleantech: a fast pyrolysis case study

The value of phytoextracting crops (plants cultivated for soil remediation) depends on the pro tability of the sequential investment in a conversion technology aimed at the economic valorization of the plants. However, the net present value (NPV) of an investment in such an innovative technology is risky due to technical and economic uncertainties. Therefore, decision makers want to dispose of information about the probability of a positive NPV, the largest possible loss, and the crucial economic and technical parameters in uencing the NPV. This paper maps the total uncertainty in the NPV of an investment in fast pyrolysis for the production of combined heat and power from willow cultivated for phytoextraction in the Belgian Campine. The probability of a positive NPV has been calculated by performing Monte Carlo simulations. Informa- tion about possible losses has been provided by means of experimental design. Both methods are then combined in order to identify the key economic and technical parameters in uencing the project’s pro tability. It appears that the case study has a chance of 87% of generating a positive NPV with an expected value of 3 million euro (MEUR), while worst-case scenarios predict possible losses of 7 MEUR. The amount of arable land, the biomass yield, the purchase price of the crop, the policy support, and the product yield of fast pyrolysis are identi ed as the most in uential parameters. It is concluded that both methods, i.e., Monte Carlo simulations and experimental design, provide decision makers with complementary information with regard to economic risk

Monitoring the Chloride Concentration in International Scheldt River Basin District Water Using a Low-Cost Multifunction Data Acquisition Board

In analytical chemistry laboratories, to gather in the shortest time as many data as possible with the utmost accuracy and precision, high throughput automated setups are indispensable. In the present study, to determine the chloride concentration in the international Scheldt river basin district, experiments are carried out utilizing a thermostatically controlled semi-automated setup. A novel ICT-based method is developed using a low-cost multifunction Data Acquisition Board (DAQ) controlled by a homebuilt LabVIEW™ program. Specifically, this approach enables a correlation between different parameters i.e., droplet volume, temperature, A/D voltage conversions. Here, processing experimental data of a potentiometric precipitation titration utilizing a silver nitrate standard solution as titrant in a manual burette equipped with a controllable electronic valve allows for a preliminary indication of the titration end point via the Virtual Instrument (VI) numerical first derivative tool in the LabVIEW software. The LabVIEW tool is compared with the well-known Gran method implemented in the LabVIEW program, emphasizing an accurate performance of the setup to determine the chloride concentration in fresh river water. We are confident that our findings are evidence of the versatile and powerful features of the LabVIEW controlled DAQ in the analytical chemistry laboratory

Valorisation of heavy metals enriched tobacco biomass through slow pyrolysis and steam activation

BACKGROUND The disposal of metal-enriched plant biomass is an important and still unresolved issue associated with phytoextraction. Therefore, the aim of this study was to valorise these contaminated biomasses into valuable products, i.e. bio-chars and activated carbons (ACs), through slow pyrolysis followed by steam activation. The effects of pyrolysis/steam activation on metal availability in the chars/ACs were also evaluated. In addition, Cr(VI) adsorption by these ACs in aqueous solutions was studied. RESULTS Relevant chars/ACs yields were obtained due to applied thermochemical treatments. Leachability of heavy metals from those products was limited indicating that they may be safely applied as adsorption media. Prepared ACs demonstrated good Cr(VI) adsorption capacities occurring through a ‘coupled adsorption–reduction’ mechanism. It was found that Cr(VI) removal strongly depended on pH of Cr(VI) solutions and was higher for ACs activated at 800 °C. Among applied isotherm adsorption models, i.e. Langmuir and Freundlich, a better fit was obtained with the Langmuir model corresponding to monolayer coverage sorption of Cr(VI) on ACs surface. CONCLUSIONS Heavy metals enriched biomass can be successfully valorised through slow pyrolysis/steam activation into value added products, i.e. ACs that can be used as efficient and safe adsorbents for Cr(VI) removal