Insights into the characteristics and toxicity of microalgal biochar-derived dissolved organic matter by spectroscopy and machine learning.

Journal: The Science of the total environment
PMID: 39566617

Abstract

Microalgal biochar has potential applications in various fields; however, there is limited research on the properties and risks of microalgal biochar-derived dissolved organic matter (MBDOM). This study examined how different pyrolysis temperatures (200 °C and 500 °C) and extraction solutions (0.1 mol/L HCl, Milli-Q water, and 0.1 mol/L NaOH) affect the characteristics and toxicity of MBDOM from three microalgae using multi-spectroscopy methods. Results showed that higher pyrolysis temperature reduced dissolved organic carbon (DOC), total nitrogen (TN), and total phosphorus (TP) but increased total potassium (TK) in the MBDOM. Alkaline solution promoted DOC and TN dissolution, while acidic solutions enhanced TP and TK release from biochar. The molecular weight, aromaticity, and fluorescent composition of MBDOM varied based on pyrolysis temperature, extraction solution, and microalgae species. MBDOM from low pyrolysis temperature and alkaline extraction exhibited significant toxicity to Photobacterium phosphoreum T. Correlation analysis and machine learning revealed that pyrolysis temperature had a greater influence on the characteristics and toxicity of MBDOM than the extraction solution. The toxicity of MBDOM was primarily associated with TN and DOC contents and also influenced by molecular weight, aromaticity, and humification. These findings are essential for optimizing microalgal biochar production and application.

Authors

  • Hongjia Li
    High Performance Computer Research Center, Institute of Computing Technology Chinese Academy of Sciences, Beijing 100190, China.
  • Yangzhi Liu
    State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products/Institute of Environment, Resource, Soil and Fertilizers, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, PR China.
  • TaoYuan
    Zhoushan Dinghai Ecological Environment Monitoring Station (Zhoushan Dinghai Ecological Environment Protection Technology Service Center), Zhoushan 316000, China.
  • Yuxue Liu
    State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Institute of Environment, Resource, Soil and Fertilizers, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China.
  • Tiejun Li
    Key Laboratory of Mariculture and Enhancement of Zhejiang Province, Marine Fishery Institute of Zhejiang Province, Zhoushan, China.
  • Jun Yan
    Department of Statistics, University of Connecticut, Storrs, CT 06269, USA.
  • Chenghu Yang
    State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Institute of Environment, Resource, Soil and Fertilizers, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China. Electronic address: yangchenghu135@126.com.

Keywords

External Resources

Popular Topics
Recent Journals