Circular Economy
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Erscheinungsjahr
- 2021 (45) (entfernen)
Dokumenttyp
Schlagworte
- Klärschlammverordnung (6)
- Phosphor (5)
- Phosphorrückgewinnung (5)
- BOFS (4)
- Bottom ash (4)
- Phosphorus (4)
- Rostasche (4)
- Circular Economy (3)
- Circular economy (3)
- Hydraulic reactivity (3)
- Klärschlamm (3)
- Metrology (3)
- Recycling (3)
- Abwasserbehandlung (2)
- Alkali-activated materials (2)
- Analytik (2)
- Carbon Fibers (2)
- Electric Arc Furnace (2)
- Fertilizer (2)
- Flame retardancy (2)
- Phosphorus recovery (2)
- Portland Cement (2)
- Pyrometallurgy (2)
- Recovery (2)
- Ringversuch (2)
- Sewage sludge (2)
- Steelmaking (2)
- TCE (2)
- X-ray diffraction (2)
- Air pollution control (1)
- Ammonium (1)
- Antimon (1)
- Ashdec (1)
- Aufbereitungstechnik (1)
- Auslaugverfahren (1)
- Bauxite Residue (1)
- Bio-based (1)
- Blast-furnace sludge (1)
- Brown Coal Fly Ash (1)
- CFRP (1)
- Calcium alkali phosphate (1)
- Calcium silicate (1)
- Charring (1)
- Chromium (1)
- Clean steel (1)
- Composite recycling (1)
- Crystalline phase identification (1)
- Design of experiments (1)
- Dichtesortierung (1)
- Diffusive gradients in thin-films (DGT) (1)
- Dry treatment (1)
- EVA (1)
- Elektroofenstaub (1)
- Emission (1)
- Environmental evaluation (1)
- Epoxy (1)
- Ersatzbaustoffe (1)
- Fibre/matrix bonding (1)
- Fire protection (1)
- Flotation (1)
- Geopolymers (1)
- Gichtgasschlamm (1)
- Gipsabfälle (1)
- Gipsrecycling (1)
- Green Deal (1)
- Gypsum plasterboards (1)
- Gypsum waste (1)
- Heavy metal removal (1)
- Hydration products (1)
- Insects (1)
- Intumescence (1)
- Landwirtschaftliche Klärschlammverwertung (1)
- Leaching of waste materials (1)
- Leather waste (1)
- Leichte Gesteinskörnung (1)
- Lignite Coal (1)
- Limit values (1)
- Lysimeter (1)
- Mauerwerkbruch (1)
- Mineralwolle (1)
- NIR (1)
- Nachhaltigkeit (1)
- Nitrate (1)
- Papierasche (1)
- Phosphorbestimmung (1)
- Phosphorus availability (1)
- Potential toxic elements (1)
- Prallzerkleinerungsverfahren (1)
- Process upscaling (1)
- RFA (1)
- Raman spectroscopy (1)
- Recycled gypsum (1)
- Recycling fertiliser (1)
- Recycling fertilizer (1)
- Red Mud (1)
- Reference material (1)
- Regulation (1)
- Ressourcenrückgewinnung (1)
- Reststoffe (1)
- Rhenanite (1)
- Rohstoffliches Recycling (1)
- Salts (1)
- Sc recovery (1)
- Scandium (1)
- Secondary Recources (1)
- Secondary building materials (1)
- Selective chlorination (1)
- Silicate (1)
- Speichermaterial (1)
- Steelmaking residues (1)
- Tannery industry (1)
- Technology-critical elements (1)
- Thermal analysis (1)
- Thermal treatment (1)
- Thermoplastic matrix (1)
- Thermosetting resin (1)
- Traceability (1)
- Uncertainty (1)
- Waste incineration (1)
- Waste-to-energy (1)
- X-ray absorption near-edge structure (XANES) spectroscopy (1)
- XANES (1)
- XANES spectroscopy (1)
- Zentrifugalsortierer (1)
- Zinc chloride (1)
- Zink (1)
- microspectroscopy (1)
- soil (1)
- x-ray diffraction (1)
Organisationseinheit der BAM
- 4 Material und Umwelt (35)
- 4.4 Thermochemische Reststoffbehandlung und Wertstoffrückgewinnung (26)
- 4.3 Schadstofftransfer und Umwelttechnologien (14)
- 7 Bauwerkssicherheit (9)
- 7.4 Baustofftechnologie (7)
- 1 Analytische Chemie; Referenzmaterialien (4)
- 1.1 Anorganische Spurenanalytik (3)
- 7.1 Baustoffe (3)
- 7.5 Technische Eigenschaften von Polymerwerkstoffen (2)
- 1.4 Prozessanalytik (1)
Eingeladener Vortrag
- nein (22)
Steelmaking slags are a by-product of steel production, that are currently used primarily in road construction, earthwork, and hydraulic engineering. In this use, the iron bound in the steelmaking slags (< 30 wt.%) is lost.
Recovery of iron from steelmaking slags is possible by thermochemical reductive treatment. The reductive treatment of liquid steelmaking slags causes iron oxides to be reduced to metallic iron, which separates from the mineral phase due to its higher density. The chemical composition of the mineral phase is thus adapted to that of the Portland cement clinker and the mineral alite, the most important component of Portland cement, is formed. This way, crude iron can be recovered, and at the same time a hydraulic binder can be produced.
This process, however, is uneconomical due to the high temperatures required (~1800 °C). In the current project, the process is to be adapted so that the reduction of liquid steelmaking slag can be carried out at ~1600 °C. The chemical composition is to be modified in such a way that the melting temperature of the slags as well as their viscosity are in a technically suitable range and still a product with good cementitious properties is obtained.
Thermochemische Behandlung von Klärschlammaschen - Phosphorrückgewinnung mit dem AshDec Prozess
(2021)
Klärschlammaschen können eine hohe Phosphatkonzentration aufweisen und stellen damit einen geeigneten Sekundärrohstoff für die Produktion von Phosphatdüngemitteln dar. Bisher wird dieses Potential der Klärschlammaschen für die Phosphor-Rückgewinnung jedoch kaum genutzt, da die in den Aschen enthaltenen Phosphate für Pflanzen kaum verfügbar und die Aschen teilweise mit toxischen Schwermetallen belastet sind.
Im AshDec®-Verfahren wird die Klärschlammaschen im Drehrohrofen im Temperaturbereich 800-1000°C unter Zugabe von Alkali-Additiven (bsp. Na2CO3) thermochemisch behandelt, um ein wirksames und schadstoffarmes Phosphatdüngemittel herzustellen. Aktuell bereitet die Firma Emter GmbH den Bau der ersten großtechnischen AshDec®-Anlage mit einer Kapazität von 30.000 Jahrestonnen Klärschlammasche am Standort ihrer Klärschlammverbrennungsanlage (Altenstadt / Oberbayern) vor. Die erste Ausbaustufe dieser Anlage wird durch das BMBF-Projekt R-Rhenania im Rahmen der Förderinitiative RePhoR begleitet.
Agricultural sewage sludge utilization becomes less important in Germany. In 2017, new fertilizer and waste laws caused the agricultural sewage sludge utilization to collapse by more than a quarter. From 2029, in German wastewater treatment plants (WWTPs) phosphorus (P) must be recovered from sewage sludge ifit contains more than 2 wt % P. Agricultural utilization will be prohibited for large WWTPs > 100,000 population equivalents (pe) from 2029 and > 50,000 pe from 2032. In Germany, each federal state must annually report amounts and quality of agriculturally utilized sewage sludge which was 17 % of the total disposal in 2019. The reports of 10 States were evaluated for 2016 and 2017 representing approx. 60 % ofthe total agriculturally used sludge volume. Whereas phosphorus recovery is mandatory this does not apply to other nutrients. However, many P recovery processes recover other nutrients, too.
Considering three differentscenariosfor future German sewage sludge disposal Shows that 70 - 77 % ofthe P load in sewage sludge will probably be recovered in the future.
At the same time, this applies for about 0 - 16 % of nitrogen, 36 - 52 % of calcium, 31-53 % of potassium, and 40 - 52 % of magnesium. However, these recovered nutrient loads can substitute only 1 % or less ofthe commercial fertilizer demand except from phosphorus which is about 45 % ofthe demand.
Gleichwertigkeit der nach AbfKlärV zulässigen Verfahren zur Phosphorbestimmung in Klärschlamm
(2021)
In dem Meeting wurde den Notifizierern und Ausrichtern des jährlichen länderübergreifenden Ringversuchs Klärschlamm die Ergebnisse zu Untersuchungen hinsichtlich der Gleichwertigkeit verschiedener nach AbfKlärV zulässiger Verfahren zur Phosphorbestimmung in Klärschlamm vorgestellt. Die Untersuchungen an 15 Klärschlammproben ergaben die höchsten Ergebnisse für das Messverfahren ICP-OES und das Aufschlussverfahren in der Mikrowelle. Diese Ergebnisse wurden im Ringversuch bestätigt.
Die Ergebnisse des extraWERT-Vorhabens wurden Vertreter*innen des Umweltministeriums von Bund und Ländern vorgestellt und im Zusammenhang mit dem Vollzug der AbfKlärV diskutiert. Es ging um die Phosphorschwankungen in kommunalem Klärschlamm und eine Empfehlung der Untersuchungshäufigkeit, um den Phosphorgehalt rechtssicher festzustellen. Des weiteren wurde die Performance verschiedener nach Verordnung gleichwertiger Analyseverfahren für Phosphor in Klärschlamm diskutiert anhand von Ringversuchsergebnissen und Eigenuntersuchungen an 15 Klärschlammproben.
Agricultural sewage sludge utilization becomes less important in Germany. In 2017, new fertilizer and waste laws caused the agricultural sewage sludge utilization to collapse by more than a quarter. From 2029, in German wastewater treatment plants (WWTPs) phosphorus (P) must be recovered from sewage sludge ifit contains more than 2 wt % P. Agricultural utilization will be prohibited for large WWTPs > 100,000 population equivalents (pe) from 2029 and > 50,000 pe from 2032. In Germany, each federal state must annually report amounts and quality of agriculturally utilized sewage sludge which was 17 % of the total disposal in 2019. The reports of 10 States were evaluated for 2016 and 2017 representing approx. 60 % ofthe total agriculturallyused sludge volume. Whereas phosphorus recovery is mandatory this does not apply to other nutrients. However, many P recovery processes recover other nutrients, too. Considering three differentscenariosfor future German sewage sludge disposal shows that 70 - 77 % ofthe P load in sewage sludge will probably be recovered in the future. At the same time, this applies for about 0 - 16 % of nitrogen, 36 - 52 % of calcium, 31-53 % of potassium, and 40 - 52 % of magnesium. However, these recovered nut rient loads can substitute only 1 % or less ofthe commercial fertilizer demand except from phosphorus which is about 45 % ofthe demand.
Rückgebaute Mineralwolledämmstoffe und Baustellenverschnitte werden in der Regel deponiert und damit als Rohstoffe dem Markt entzogen. Ziel dieses Projektes ist es darzulegen, dass das Recycling von Glas- und Steinwolle im großmaßstäblich volumenrelevanten Umfang für das Schmelzwannenverfahren technisch umsetzbar und ökonomisch und ökologisch vorteilhaft ist. Neben verfahrenstechnischen Herausforderungen, gilt es die wirtschaftliche in-situ-Identifikation unbekannter Mineralwolle zu ermöglichen. Dazu wird auf erste erfolgversprechende Tastversuche mit spektroskopischen Methoden weiter aufgebaut.
The concept of circular economy supports mitigation of climate change and other environmental pressures to the planet. Circulating materials in anthropogenic processes come with the risk of accumulating hazardous substances and compounds. In this concept, waste incineration or waste-to-energy (WtE) is a necessary technology to remove these compounds from the life cycle. In this mini-review, contaminants of major importance in the flue gas from waste incineration plants and their environmental impact are discussed. Air pollution of WtE is often seen as the most relevant environmental impact of this treatment option. The emission values parameter set for different countries is presented and compared. The most stringent legally set of emission values could be found in parts of Europe and South Korea. Japan also permits similar strict values when authorising individual incineration plants. In North America, the values are partially less strict as the best available technologies in Europe suggest being possible. Emerging economies, such as India and China, have shown efforts to improve their environmental protection standards but still have room to improve. This could be set in relation to other industrial emitting processes and therefore could be used to assess the relevance of this industry sector to the national emission inventories.
Phosphorus (P) resource availability and quality is declining and recycling P-fertilizers from waste materials are becoming increasingly important. One important secondary P resource is sewage sludge (SSL) where P is often bound as aluminum phosphate (Al-P), iron phosphate (Fe-P) and polyphosphate (poly-P), respectively. Thermal treatment in different ways is a promising way in P recycling to produce highly plant-available P-fertilizers. To investigate mechanisms behind transformation of hardly available P-species toward plant-available P forms we treated a model SSL containing different kinds of defined P sources by low-temperature conversion (LTC) at 500 °C and subsequent thermochemical treatment of the LTC product with Na additives (TCT) at 950 °C, respectively. Pot experiments with ryegrass were carried out to determine the plant availability of P of the different treatments. The poly-P (here pyrophosphates) based fertilizers had a very high plant availability after both thermal treatments. During LTC treatment the plant availability of the Fe-P and Al-P variants increased because of the Formation of Fe(II) phosphates and/or pyro-/polyphosphates. Especially the formation of Al-polyphosphate shows a high plant availability. The subsequent TCT further increased strongly the plant availability of the Fe-P variants because of the formation of highly plant-available CaNaPO4. Thus, a direct TCT without prior LTC probably also produce CaNaPO4 and is recommended for Fe-P based SSL. However, a molar Ca/P ratio of 1 in the fertilizer is favorable for CaNaPO4 formation. Thus, the knowledge on the source of primary P in SSL is essential for choosing the accurate thermal treatment method to produce highly plant-available P-fertilizers from SSL.
Phosphorus (P) fertilizers from secondary resources became increasingly important in the last years. However, these novel P-fertilizers can also contain toxic pollutants. Chromium in its hexavalent state (Cr(VI)) is regulated with low limit values for agricultural products due to its high toxicity, but the determination of Cr(VI) in these novel fertilizer matrices can be hampered by redox processes that lead to false results. Thus, we applied the passive sampler technique Diffusive Gradients in Thin-films (DGT) for the determination of Cr(VI) in fertilizers and compared the results with the standard wet chemical extraction method (German norm DIN EN 15192) and Cr K-edge X-ray absorption near-edge structure (XANES) spectroscopy. We determined an overall good correlation between the wet chemical extraction and the DGT method. DGT was very sensitive and in most cases selective for the analysis of Cr(VI) in P-fertilizers. However, hardly soluble Cr(VI) compounds cannot be detected with the DGT method since only mobile Cr(VI) is analyzed. Furthermore, Cr K-edge XANES spectroscopy showed that the DGT binding layer also adsorbs small amounts of mobile Cr(III) compounds which leads to overestimated Cr(VI) values. The results of certain types of P-fertilizers containing mobile Cr(III) or partly immobile Cr(VI), showed that optimization of the DGT method is required to avoid over- or underestimation of Cr(VI).