Influence of pyrolysis on evaporation and solubility of heavy metals in sewage sludge

• Published in: Journal of physics. Conference series Vol. 1556; no. 1; pp. 12017 - 12025
• Main Authors: Larina, O M, Zaichenko, V M
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 01.05.2020
• Subjects: Ashes; Heavy metals; Physics; Pollutants; Pyrolysis; Residues; Sewage disposal; Sewage sludge; Sludge; Solubility; Synthesis gas
• ISSN: 1742-6588; 1742-6596
• DOI: 10.1088/1742-6596/1556/1/012017

One of the sewage sludge characteristics is the presence of various pollutant types. This is both pathogenic microflora and chemical pollutants. For example, it is heavy metals. When using the pyrolysis process up to 800 °C with thermal cracking of volatile products, as a method of sewage sludge treatment, in addition to synthesis gas a solid residue is formed. It is about 40% by weight of the initial sewage sludge and has an ash content of 58.2% (on dry state). With this amount of ash, the use of solid residue for energy purposes is not appropriate. Such material is subject to disposal. In this connection, the question arises, what proportion of heavy metals remains in the solid residue and goes into syngas. This paper presents the study results of the effects of pyrolytic processing conditions on the behavior of heavy metals in the composition of sewage sludge. The gross content and solubility in neutral and acidic media of heavy metals in the sewage sludge and the solid residue after pyrolysis are determined. The hazard class according to the content of heavy metals of the sewage sludge and the solid residue is calculated.