Fertiliser Properties of Wastewater Sludge and Sludge Ash - A Case Study from the Finnish Forest Industry
Loading...
Access rights
openAccess
URL
Journal Title
Journal ISSN
Volume Title
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
This publication is imported from Aalto University research portal.
View publication in the Research portal (opens in new window)
View/Open full text file from the Research portal (opens in new window)
Other link related to publication (opens in new window)
View publication in the Research portal (opens in new window)
View/Open full text file from the Research portal (opens in new window)
Other link related to publication (opens in new window)
Authors
Date
2023-03-01
Department
Major/Subject
Mcode
Degree programme
Language
en
Pages
16
63-78
63-78
Series
Ecological Chemistry and Engineering S, Volume 30, issue 1
Abstract
In this case study we compared the fertiliser properties of an industrial wastewater treatment sludge and a sludge ash to the requirements of the Finnish Fertiliser Product Decree. The sludge was obtained from the activated sludge wastewater treatment plant of a Finnish non-integrated pulp mill. The sludge was furthermore incinerated at a laboratory in a muffle furnace (850 °C) to obtain sludge ash. The total Cd (4.9 mg/kg d.m.) concentration in the pulp sludge exceeded the Finnish limit value (1.5 mg/kg d.m.) for fertiliser products used in agriculture. In the sludge ash, the total concentration of Cd (39 mg/kg; d.m.) exceeded the Finnish limit value (25 mg/kg d.m.) for ash fertilisers used in forestry. These results restrict the potential reuse options of these residues. However, from the utilisation point of view, the enrichment of essential plant macro-nutrients was most notable, resulting to the following total concentrations of these elements in the sludge ash: P (26,000 mg/kg d.m.), S (40,000 mg/kg d.m.), K (11,000 mg/kg d.m.), Ca (83,000 mg/kg d.m.) and Mg (10,000 mg/kg d.m.). Therefore, we conclude that, the converting of sludge into ash may promote the reuse of this wastewater treatment residue to a more value-adding fertiliser by-product to be used as a soil improver and growing medium in landscaping or landfills sites or other closed industrial areas, where heavy metal limit values for fertilisers are not applied in Finland.Description
Publisher Copyright: © 2023 Juha Oksanen et al., published by Sciendo.
Keywords
ash, circular economy, extraction, fertiliser, pulp mill, sludge, waste, wastewater treatment
Other note
Citation
Oksanen, J, Pöykiö, R & Dahl, O 2023, ' Fertiliser Properties of Wastewater Sludge and Sludge Ash - A Case Study from the Finnish Forest Industry ', Ecological Chemistry and Engineering S, vol. 30, no. 1, pp. 63-78 . https://doi.org/10.2478/eces-2023-0004