Effects of tall fescue biochar on the adsorption and desorption of atrazine in different types of soil

Effects of tall fescue biochar on the adsorption behavior of desethyl-atrazine in different types of soil

“…The difference of adsorption capacity between pritine soil and BC soil for DEA was partly attributed to the difference of surface micropore structure between them. Based on the authors' previous study (Li et al 2020), the SEM analysis demonstrated a developed pore structure and a clear reticulation formation of the tall fescue biochar. Therefore, the DEA molecule filled into the micropores on the surface of soils and BC soils may be a main mechanism during the adsorption reaction.…”

“…After sampling, the soil was dried, homogenized, and screened to remove plant tissue. The basic physicochemical properties of the three types of soil are described in the authors' previous study (Li et al 2020). The organic matter content decreased in the following order: black soil > brown soil > red soil.…”

“…This may be because the biochar has a developed pore structure and huge specific surface area. In comparison with the pristine soil, biochar contains denser adsorption domains and active adsorption sites on its surface (Li et al 2020), whereas the active adsorption sites on the surface of pristine soil become gradually saturated after 180 min of the adsorption process. However, a large number of unoccupied low-energy active adsorption sites remain on the surface of BC soil due to the application of biochar; these can be used for DEA adsorption in the slow adsorption stage.…”

“…The tall fescue biochar was ground, sifted through 80-mesh screens, and sealed in a dry container for subsequent analysis. The characterization of tall fescue biochar methods were shown in the authors' previous study (Li et al 2020). Briefly, the surface structure of the biochar was analyzed by a scanning electron microscope (SEM, QUANTA Q400, USA).…”

“…This may also be because of the large number of active DEA adsorption sites in the biochar, which enhance surface adsorption and pore filling of DEA in the biochar-soil system, thereby increasing the DEA adsorption capacity of soil. Due to the abundant surface functional groups and high degree of aromatization of the tall fescue biochar (Li et al 2020), the aromatic functional groups of biochar can be used as electron donors or acceptors to trigger electron donor-receptor (EDA) reactions with aromatic compounds, which improves the adsorption of DEA. Zhang et al (2013) suggested that biochar exerted an obvious adsorption effect on most pesticides with an aromatic ring structure, such as simazine and atrazine.…”