The effect of stabilization on the utilization of municipal sewage sludge as a soil amendment
•Stabilization procedures affect nutrient and inorganic contaminant concentrations.•Anaerobic sludge has the highest levels of metals and radionuclides.•High P and N contents in sludge are a measure of its potential as a fertilizer.•Adsorption of metals and radionuclides to sludge biomass increases...
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Published in: | Waste management (Elmsford) Vol. 94; pp. 27 - 38 |
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Main Authors: | , , , , , , , , , , , , , , |
Format: | Journal Article |
Language: | English |
Published: |
United States
Elsevier Ltd
01-07-2019
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Subjects: | |
Online Access: | Get full text |
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Summary: | •Stabilization procedures affect nutrient and inorganic contaminant concentrations.•Anaerobic sludge has the highest levels of metals and radionuclides.•High P and N contents in sludge are a measure of its potential as a fertilizer.•Adsorption of metals and radionuclides to sludge biomass increases with nutrient content.•Soil amendment with sewage sludge is a promising strategy for nutrient recovery.
This study assesses the potential use of different types of stabilized sewage sludge as a soil amendment by considering their physicochemical characteristics, nutritional status, and their trace metal and radionuclide content. The concentrations of trace metals and radionuclides were determined using ICP-OES and gamma-ray spectrometry, respectively. For determining nutritional status and chemical characterization, this study followed standard ISO-recommended procedures. Data analysis revealed that anaerobic sludge contains higher concentrations of Cr, Hg, and Ni compared to aerobic and non-biologically stabilized sludge. A similar observation was observed in the case of 226Ra, 210Pb, 228Ra, and 228Th. Furthermore, the high levels of P and N in aerobic sludge suggest that biologically stabilized sludge has the potential to be a good fertilizer. In addition, the study finds strong evidence that nutrients are involved in the adsorption of metals and radionuclides onto sludge biomass. Overall, eight of the nine studied sludge samples are safe for agricultural use since the concentrations of trace metals fall well below the limits set by Croatian legislation (NN 38/08). In addition, the levels of radionuclides do not pose a radiological risk. This means that soil conditioning with sewage sludge remains a viable strategy for nutrient recovery from municipal waste, although long-term impact assessments of repeated applications are necessary. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0956-053X 1879-2456 |
DOI: | 10.1016/j.wasman.2019.05.032 |