4 Material und Umwelt
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- 2021 (115) (entfernen)
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- Biocides (8)
- Antimicrobial resistance (7)
- Microbiologically influenced corrosion (6)
- Bottom ash (5)
- Evolution (5)
- Phosphorus (5)
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- BOFS (4)
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Organisationseinheit der BAM
- 4 Material und Umwelt (115)
- 4.1 Biologische Materialschädigung und Referenzorganismen (38)
- 4.2 Material-Mikrobiom Wechselwirkungen (24)
- 4.3 Schadstofftransfer und Umwelttechnologien (23)
- 4.4 Thermochemische Reststoffbehandlung und Wertstoffrückgewinnung (18)
- 6 Materialchemie (15)
- 4.0 Abteilungsleitung und andere (11)
- 4.5 Kunst- und Kulturgutanalyse (9)
- 1 Analytische Chemie; Referenzmaterialien (8)
- 6.2 Material- und Oberflächentechnologien (8)
Paper des Monats
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Eingeladener Vortrag
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Emission testing of volatile organic compounds (VOC) from materials and products is commonly based on emission test chamber measurements. To ensure the comparability of results from different testing laboratories, their measurement performance must be verified. For this purpose, Bundesanstalt für Materialforschung und -prüfung (BAM) organizes an international proficiency test (round robin test, RRT) every two years using well-characterized test materials (one sealant, one furniture board, and four times a lacquer) with defined VOC emissions. The materials fulfilled the requirements of homogeneity, reproducibility, and stability. Altogether, 36 VOCs were included of which 33 gave test chamber air concentrations between 13 and 83 µg/m3. This is the typical concentration range to be expected and to be quantified when performing chamber tests. Three compounds had higher concentrations between 326 and 1105 µg/m3. In this paper, the relative standard deviations (RSD) of BAM round robin tests since 2008 are compared and the improvement of the comparability of the emission chamber testing is shown by the decrease of the mean RSD down to 28 % in 2018. In contrast, the first large European interlaboratory comparison in 1999 showed a mean RSD of 51 %.
In Europe, nearly 19 Mt/y of bottom ash (BA) are produced. Of this quota, only 46 %wt. was treated, often in poorly performing plants, leaving behind 10 Mt of untreated and unrecovered BA, destined to landfill. The resulting 2.14 Mt loss of valuable materials included 1 Mt mineral fraction and 0.97 Mt ferrous metals, mostly from untreated BA, and 0.18 Mt non-ferrous metals, mostly from unrecovered BA. For the coarser fractions, the main obstacle to BA being used as recycling aggregate is the content of salts and potential toxic elements (PTEs), concentrated in a layer that coats BA particles. For the fine BA fractions, usually underexploited and landfilled, it is estimated that up to 0.95 Mt/y of ferrous and non-ferrous metals are not recovered in Europe.
During the workshop, the key results of BASH Treat project will be presented: the results of 2 industrial tests performed in BA treatment plants in Germany and Sweden; a novel dry treatment for the removal of salts and PTEs from BA coarse particles; a wet process for the recovery of heavy metal compounds from the fine fraction; a technical-economic assessment of the EU potential for the optimization of BA management.
In this study, nanoscopic particles of magnesium Fluoride (MgF2) and calcium fluoride (CaF2) also known as nano metal fluorides (NMFs), were evaluated for their potential to improve wood durability. Even though these fluorides are sparingly soluble, their synthesis in the form of nano-sized particles turns them into promising candidates for wood preservation. Their distinct property of low-water solubility is proposed to maintain long-lasting protection of treated wood by reducing the leaching of fluoride. Analytical methods were used to characterize the synthesized NMFs and their distribution in treated wood specimens. Transmission electron microscopy images showed that these fluoride particles are smaller than 10 nm. In nano metal fluoride (NMF) treated specimens, aggregates of these particles are uniformly distributed in the wood matrix as confirmed with scanning electron microscopy images and their corresponding energy-dispersive X-ray spectroscopy maps. The fluoride aggregates form a protective layer around the tracheid walls and block the bordered pits, thus reducing the possible flow path for water absorption into wood. This is reflected in the reduced swelling and increased hydrophobicity of wood treated with NMFs. The biocidal efficacy of NMFs was tested against brown-rot fungi (Coniophora puteanaand Rhodonia placenta), white-rot fungus (Trametes versicolor), and termites (Coptotermes formosanus). The fungal and termite tests were performed in accordance with the EN 113 (1996) and EN 117 (2012) standards, respectively. Prior to fungal tests, the NMF treated wood specimens were leached according to the EN 84 (1997)standard. Compared to untreated specimens, the NMF treated wood specimens have a higher resistance to decay caused by brown-rot fungi, white-rot fungus, and termites. Although all NMF treatments in wood reduce the mass loss caused by fungal decay, only the combined treatment of MgF2 and CaF2 has efficacy against both brown-rot fungi and white-rot fungus. Similarly, wood treated with the combined NMF formulation is the least susceptible to attack by C. formosanus.It is proposed that combining MgF2 and CaF2changes their overall solubility to promote the release of fluoride ions at the optimal concentration needed for biocidal efficacy against fungi and termites. In this thesis, it was proven that even after leaching, sufficient fluoride was present to protect NMF treated wood from fungal decay. This shows that NMFs are robust enough for above ground contact outdoor applications of wood, where permanent wetness cannot be avoided according to Use Class 3.2, as per the EN 335 (2013) standard. Also, they pose a low risk to human health and the environment because they are sparingly soluble. Since NMFs significantly reduce the decay of wood, the CO2 fixed in it will be retained for longer than in unpreserved wood. Overall, the novel results of this study show the potential of NMFs to increase the service life of building materials made from non-durable wood.
Scientific material analysis of the elemental composition of inks from different strata of a manuscript has the potential to complement scholarly observations using palaeography and philology in reconstructing the history of the manuscript’s production, correction and repair.
There are three typologically different classes of black writing inks: soot inks consist of carbon particles.
The first manuscripts from the Qumran caves were found in 1947. Within the following 10 years, clandestine and legal excavations revealed some 900 highly fragmented manuscripts from the late Second Temple period. This collection is generally known as Scrolls of the Judea Desert or Dead Sea Scrolls (DSS). For many years after their discovery, text analysis and fragmeents attribution were the main concern of the scholars dealing with the scrolls. The uncertain archaeological provenance of the larger part of the collection added an additional difficulty to the formidable task of sorting some 19000 fragments. After 60 years of scholar research the question of origin, archaeological provenance and correct attribution of the fragmenst are still hotly debated. To dtermine a possible contribution to the debate from the point of view of writing materials, we used otpical and electron microscopy, various X-ray based techniques as well as vibratiional sprectroscopy. We validated our approach with SY - based studies using the advantages of the synchroton radiation source with respect to the benchtop devices. Our laboratory studies showed that often production and storage locality could be distinguished thenks to the specific residues ("fingerprint") they left on the material. Moreover, we have diescovered that diferrent parchment production processses coexisted in the antiquity, and the resulting writing materials can readily be distinguished.