Probing the toxicity of hydrothermal carbonised wastes on soil biota: Effect of reaction temperature and feedstock
Files
(Published version)
Date
2024
Authors
Luutu, H.
Rose, M.T.
McIntosh, S.
Van Zwieten, L.
Rose, T.J.
Editors
Advisors
Journal Title
Journal ISSN
Volume Title
Type:
Journal article
Citation
Chemosphere, 2024; 369:143857-1-143857-10
Statement of Responsibility
Henry Luutu, Michael T. Rose, Shane McIntosh, Lukas Van Zwieten, Terry J. Rose
Conference Name
Abstract
Hydrothermal carbonised wastes (hydrochars) can have toxic effects on soil biota, but factors influencing toxin formation in hydrochar, and subsequent toxicity to soil organisms, have not been elucidated. This study investigated the toxicity of hydrochars on soil biota, with a focus on earthworm (Eisenia fetida) avoidance, microbial metabolic quotient (qCO2) and microbial activities. Two reaction temperatures (200 ◦C and 260 ◦C) and different feedstocks (biosolids, chicken manure and rice straw) were used. Hydrochars produced at 260 ◦C were highly toxic to earthworms, causing earthworm avoidance of >84 %. Hydrochar from chicken manure and rice straw produced at 200 ◦C also caused significant avoidance (76–84 %), although with chicken manure, high salt (Na) concentration was the underlying factor rather than toxic organic compounds. In contrast, biosolids hydrochar produced at 200 ◦C showed no negative effect on earthworms. Further examination of biosolids hydrochar (260 ◦C) following extraction with water, methanol, acetone-hexane, or sequentially, indicated that toxins causing earthworm avoidance were both polar and non-polar organic compounds, as well as soluble salts. Despite increased qCO2 suggesting microbial stress, hydrochars generally increased phospholipid fatty acids (bacteria and fungi), soil respiration, enzyme activities and N mineralisation. Findings reveal that while higher temper ature hydrochars are highly toxic to earthworms, they do not adversely affect overall soil microbial health
School/Discipline
Dissertation Note
Provenance
Description
Access Status
Rights
© 2024 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license ( http://creativecommons.org/licenses/by/4.0/ ).