Filtern
Erscheinungsjahr
- 2017 (4) (entfernen)
Dokumenttyp
- Zeitschriftenartikel (4) (entfernen)
Schlagworte
- Bottom ash (BA) (1)
- Column percolation tests (1)
- Cost benefit analysis (1)
- Cumulative energy demand (1)
- Eco-efficiency analysis (1)
- Exergie (1)
- Ferrous metals (1)
- Hausmüllverbrennungsasche (1)
- Heavy metals (1)
- Hydrometallurgie (1)
Für die Herstellung von Kupfer aus Primär- und Sekundärressourcen wurde eine Exergieanalyse der Aufbereitungs- und Gewinnungsverfahren durchgeführt. Für die Stoffgemische Kupfererz, Kupferkonzentrat und Hausmüllverbrennungsasche wurden die Exergien tabellarisch berechnet. Die Exergieaufwände der technischen Prozesse zur Kupferherstellung wurden mit den thermodynamisch minimal notwendigen Aufwänden verglichen. Die Nutzung von Sekundärrohstoffen aus Abfällen ist über weite Bereiche vorteilhaft, insb. wenn das Kupfer bereits in der metallischen Form vorliegt.
Decision makers for waste management are confronted with the problem of selecting the most economic, environmental, and socially acceptable waste treatment process. This paper elucidates evaluation methods for waste treatment processes for the comparison of ecological and economic aspects such as material flow analysis, statistical entropy analysis, energetic and exergetic assessment, cumulative energy demand, and life cycle assessment.The work is based on the VDI guideline 3925. A comparison of two thermal waste treatment plants with different process designs and energy recovery systems was performed with the described evaluation methods. The results are mainly influenced by the type of energy recovery, where the waste-to-energy plant providing district heat and process steam emerged to be beneficial in most aspects. Material recovery options from waste incineration were evaluated according to sustainability targets, such as saving of resources and environmental protection.
Recycled plastic granules of high-density polyethylene, polyvinyl chloride and polystyrene the size of microplastics were exposed to artificial aging conditions (2000 h; photooxidative and thermo-oxidative) to simulate their fate outdoors. Their potential to leach into water during the aging process was investigated using column percolation tests.
Aging-related changes on the surface of the material were characterised by IR measurements indicating oxidation reactions with the formation of new adsorption bands (C=O, C–O and OH), especially in the case of photooxidative aging.
These findings were confirmed by the identification of leachable organic compounds. Leaching of total organic carbon, Cl, Ca, Cu and Zn is clearly affected by changes due to aging, and their release is increased after photooxidative aging.
In general, exposure to photooxidative conditions shows a greater influence on aging and thus on leaching and seems to be the more important mechanism for the aging of microplastic in the environment. Comparison with the total content of inorganic species revealed that, for most elements, less than 3% of the total content is released after 2000 h of photooxidative aging.
The industrial sector of bottom ash (BA) treatment from municipal solid waste incineration (MSWI) in Germany is currently changing. In order to increase the recovery rates of metals or to achieve a higher quality of mineral aggregates derived from BA, new procedures have been either implemented to existing plants or completely new treatment plants have been built recently. Three treatment trains, which are designated as entire sequences of selected processing techniques of BA, are introduced and compared. One treatment train is mainly characterized by usage of a high speed rotation accelerator whereas another is operating completely without crushing. In the third treatment train the BA is processed wet directly after incineration. The consequences for recovered metal fractions and the constitution of remaining mineral aggregates are discussed in the context of legislative and economical frameworks. Today the recycling or disposal options of mineral residues still have a high influence on the configuration and the operation mode of the treatment trains of BA despite of the high value of recovered metals.