Identification and Classification of the Dissolved Substances from Sludge Biochar and Their Effects on the Activity of Acid Phosphomonoesterase

Sustainability, vol. 14, pp. 9749

Abstract

Soil extra-cellular enzymes are the main driving force for microbial and biochemical processes, which makes them sensitive indicators for soil health and quality. Returning large amounts of sludge or its biochar to farmland may introduce exogenous substances into soil and have a significant impact on soil enzymatic activity. This study aimed to evaluate the effects of substances dissolved from sludge biomass and its biochar added at different amounts and produced at various temperatures (200 °C, 300 °C, and 450 °C) on the activity of acid phosphomonoesterase. Results showed that the activity of acid phosphomonoesterase was significantly inhibited by these dissolved substances from biochar pyrolyzed at different temperatures, especially at high concentrations of 50 mgC L−1 and upon the exposure to DBC200. The conformation of acid phosphomonoesterase became loose and flexible after exposure to dissolved organic matter (DOM) extracted from biochar in terms of reduced α-Helix contents and increased β-Turn contents as deduced from circular dichroism spectra. According to the results of multiple linear regression, it can be concluded that the increased contents of arsenic as well as protein-like components within dissolved substances may be responsible for the inhibited enzymatic activities and the altered enzymatic conformation. Our findings provide evidence that the pyrolysis of sludge at a higher temperature would be helpful to reduce its negative impacts on the soil ecosystem.

Authors 7

1. Junyuan Zhang

   Kunming University of Science and Technology

   Affiliation as printed

   Yunnan Key Laboratory of Soil Carbon Sequestration and Pollution Control, Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China

2. Yang Liu corresponding

   Kunming University of Science and Technology

   Affiliation as printed

   Yunnan Key Laboratory of Soil Carbon Sequestration and Pollution Control, Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China

3. Bowen Li

   Kunming University of Science and Technology

   Affiliation as printed

   Yunnan Key Laboratory of Soil Carbon Sequestration and Pollution Control, Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China

4. Chunling Tan

   Kunming University of Science and Technology

   Affiliation as printed

   Yunnan Key Laboratory of Soil Carbon Sequestration and Pollution Control, Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China

5. Dandan Zhou

   Kunming University of Science and Technology

   Affiliation as printed

   Yunnan Key Laboratory of Soil Carbon Sequestration and Pollution Control, Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China

6. Martina G. Vijver Aachen Institute of Environmental Sciences (CML)

   Leiden University

   Affiliation as printed

   Institute of Environmental Sciences (CML), Leiden University, 2300 RA Leiden, The Netherlands

7. Willie J.G.M. Peijnenburg Aachen Institute of Environmental Sciences (CML)

   Leiden University · National Institute for Public Health and the Environment

   Affiliation as printed

   Institute of Environmental Sciences (CML), Leiden University, 2300 RA Leiden, The Netherlands

   National Institute of Public Health and the Environment (RIVM), Center for Safety of Substances and Products, 3720 BA Bilthoven, The Netherlands