Abstract
The hydrothermal carbonization of sewage sludge has been studied as an alternative technique for the conversion of sewage sludge into value-added products, such as soil amendments. We tested the toxicity of biosolid hydrochar (Sewchar) to earthworms. Additionally, the toxicity of Sewchar process water filtrate with and without pH adjustment was assessed, using brine shrimps as a model organism. For a Sewchar application of 40 Mg ha−1, the earthworms significantly preferred the side of the vessel with the reference soil (control) over side of the vessel with the Sewchar treatments. There was no acute toxicity of Sewchar to earthworms within the studied concentration range (up to 80 Mg ha−1). Regarding the Sewchar process water filtrate, the median lethal concentration (LC50) to the shrimps was 8.1% for the treatments in which the pH was not adjusted and 54.8% for the treatments in which the pH was adjusted to 8.5. The lethality to the shrimps significantly increased as the amount of Sewchar process water filtrate increased. In the future, specific toxic substances in Sewchar and its process water filtrate, as well as their interactions with soil properties and their impacts on organisms, should be elucidated. Additionally, it should be identified whether the amount of the toxic compounds satisfies the corresponding legal requirements for the safe application of Sewchar and its process water filtrate.
Original language | English |
---|---|
Pages (from-to) | 1351-1364 |
Number of pages | 14 |
Journal | Environmental geochemistry and health |
Volume | 39 |
Issue number | 6 |
DOIs | |
Publication status | Published - 2017 Dec 1 |
Externally published | Yes |
Bibliographical note
Funding Information:The authors cordially thank the Goiás State Water Utility “Saneamento de Goiás S. A.” (SANEAGO) for providing the biosolid sample and the Federal Institution of Education, Science and Technology of Goiás (IFG) for granting the reactor for Sewchar production. The authors are also grateful to Robert Strahl for his valuable help in the production of Sewchar; to Lorena C. T. Oliveria, Jan Becker and Anna Lempges for their valuable assistance in the earthworm lethality test; and to Carolina Brom Oliveira and Ana Maria Bezerra for performing the laboratory analysis. We gratefully acknowledge the funding from Friedrich–Ebert–Stiftung (Ph.D. scholarship) and the Seventh Framework Programme (FP7/2007-2013) (FP7/2007 – 2011) under grant agreement n. PIRSES-GA-2012-317714.
Funding Information:
Acknowledgements The authors cordially thank the Goiás State Water Utility ‘‘Saneamento de Goiás S. A.’’ (SANEAGO) for providing the biosolid sample and the Federal Institution of Education, Science and Technology of Goiás (IFG) for granting the reactor for Sewchar production. The authors are also grateful to Robert Strahl for his valuable help in the production of Sewchar; to Lorena C. T. Oliveria, Jan Becker and Anna Lempges for their valuable assistance in the earthworm lethality test; and to Carolina Brom Oliveira and Ana Maria Bezerra for performing the laboratory analysis. We gratefully acknowledge the funding from Friedrich–Ebert–Stiftung (Ph.D. scholarship) and the Seventh Framework Programme (FP7/2007-2013) (FP7/2007 – 2011) under grant agreement n. PIRSES-GA-2012-317714.
Publisher Copyright:
© 2017, Springer Science+Business Media B.V.
Keywords
- Ecotoxicology
- Hydrothermal carbonization
- Sewage sludge
ASJC Scopus subject areas
- Environmental Engineering
- Environmental Chemistry
- Water Science and Technology
- General Environmental Science
- Geochemistry and Petrology