Hydrothermal carbonization and pyrolysis of sewage sludge: Plant growth effects of hydrochar and biochar
Wastewater treatment plants generate biosolids with high moisture content that can be transformed via hydrothermal carbonization (HTC) into hydrochar for agronomic application. This study compares the effects of fresh and washed hydrochar (HTC at 230 ◦C, 45 min) and biochar (pyrolysis at 650 ◦C, 1 h...
| Autores: | , , , , , |
|---|---|
| Tipo de recurso: | artículo |
| Fecha de publicación: | 2025 |
| País: | España |
| Institución: | Universidad Autónoma de Madrid |
| Repositorio: | Biblos-e Archivo. Repositorio Institucional de la UAM |
| Idioma: | inglés |
| OAI Identifier: | oai:repositorio.uam.es:10486/737860 |
| Acceso en línea: | https://hdl.handle.net/10486/737860 https://dx.doi.org/10.1016/j.biombioe.2025.108424 |
| Access Level: | acceso abierto |
| Palabra clave: | Waste valorization Thermochemical treatment Soil amendment Tomato Quinoa Informática |
| Sumario: | Wastewater treatment plants generate biosolids with high moisture content that can be transformed via hydrothermal carbonization (HTC) into hydrochar for agronomic application. This study compares the effects of fresh and washed hydrochar (HTC at 230 ◦C, 45 min) and biochar (pyrolysis at 650 ◦C, 1 h) produced from sewage sludge on seed germination and early plant development. Tomato (Solanum lycopersicum L.) and quinoa (Chenopodium quinoa Willd.) seeds were sown in marginal soil amended with 1 %, 3 %, and 5 % (w/w) of each char. The high inorganic content of sewage sludge resulted in hydrochars with significant ash content, rich in nutrients (Ca, Fe, Mg, P), but also in potentially toxic elements (Cr, Cu, Pb), whereas biochar showed lower concentrations of As, Cd, and Ni, and higher levels of B, K, Mg, Na and Mn, along with changes in pH and electrical conductivity. Fresh hydrochar significantly inhibited tomato seed germination (75–90 %), biomass (75–100 %) and shoot height or leaf area (50–100 %) depending on application rate. Hydrochar washing reduced phytotoxic compounds, resulting in plant performance comparable to the control. Quinoa, generally more stresstolerant, showed no significant differences in seed germination and growth, although dry biomass decreased with fresh hydrochar. Biochar enhanced seed germination and plant biomass. Lipid peroxidation increased with the lowest amendment rate of fresh hydrochar and biochar, despite no transcriptional changes of stress-related genes being detected. Overall, this study supports the use of washed hydrochar to improve tomato plant performance, although the effects of char amendments may vary depending on the plant species |
|---|