Journal article
Effects of thermal drying on phosphorus availability from iron-precipitated sewage sludge
Thermal drying of sewage sludge implies sanitation and improves practical handling options of the sludge prior to land application. However, it may also affect its value as a fertilizer. The objective of this study was to assess whether thermal drying of sewage sludge, as well as drying temperature, affects plant P availability after application to soil.
The experiment included dewatered sewage sludge (20% DM) and thermally dried sewage sludge (95% DM) collected at a Danish wastewater treatment plant, as well as laboratory oven-dried (70, 130, 190, and 250°C; DM > 95%) subsamples of the dewatered sludge, and a triple superphosphate as a reference. Plant P availability was studied in a 197 d soil incubation experiment, with sampling for Diffusive Gradients in Thin films (DGT) and water extractable P (WEP) analyses over time, and in a pot experiment with spring barley (Hordeum vulgare L.).
In both experiments, thermal drying reduced P availability, as shown by 37 and 23% lower DGT and WEP values, respectively, and a 16% lower P uptake by barley in the pot experiment. The specific drying temperature did not appear to have much effect. Overall, our results suggest that thermal drying of iron-precipitated sewage sludge is not an optimal treatment option if the aim is to optimize plant P availability.
Language: | English |
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Year: | 2017 |
Pages: | 720-728 |
ISSN: | 15222624 and 14368730 |
Types: | Journal article |
DOI: | 10.1002/jpln.201700070 |
ORCIDs: | Scheutz, Charlotte , 0000-0003-2997-4434 , 0000-0002-2233-5122 , 0000-0002-1446-2084 and 0000-0001-5867-0910 |
DGT Hordeum vulgare Incubation Pot experiment SDG 2 - Zero Hunger Spring barley Water-extractable P
incubation pot experiment spring barley water-extractable P water‐extractable P