Evaluating Biochar Impact on Topramezone Adsorption Behavior on Soil under No-Tillage and Rotary Tillage Treatments: Isotherms and Kinetics

• Published in: International journal of environmental research and public health Vol. 16; no. 24; p. 5034
• Main Authors: Uwamungu, Jean Yves, Nartey, Obemah David, Uwimpaye, Fasilate, Dong, Wenxu, Hu, Chunsheng
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 10.12.2019; MDPI
• Subjects: Adsorption; Adsorptivity; Bioavailability; Biomass; Calcium chloride; Charcoal; Charcoal - chemistry; Contamination; Corn; Dissolved organic matter; Entrainment; Fourier transforms; Groundwater; Groundwater pollution; Herbicides; Kinetics; Leaching; Microorganisms; Pesticides; Physics; Plants (botany); Pyrazoles - chemistry; Raw materials; Retention; Shaking; Soil - chemistry; Soil contamination; Soil temperature; Soils; Straw; Surface water; Thermodynamics; China; adsorption; isotherm; biochar; kinetics; topramezone; tillage
• ISSN: 1660-4601; 1661-7827; 1660-4601
• DOI: 10.3390/ijerph16245034

The evaluation of biochar application on the adsorption behavior of topramezone on soil under no-tillage (NT) and rotary tillage treatments (RT) has been assessed. Fourier Transform Infra-Red Spectrometry (FTIR), scanning electron microscopy (SEM), and Brunauer-Emmett-Teller) (BET) were used for the biochar characterization. Batch experiments were carried out in a laboratory to assess the adsorption of topramezone on soil through equilibrium and kinetic modeling under biochar addition. The clay content has been found to be higher under NT (18.24 ± 0.01) than under RT (15.91 ± 0.02). The total organic carbon was higher under NT. The topramezone adsorption equilibrium reached after 8 and 12 h, for NT and RT, respectively. The kinetic and thermodynamic analyses showed the adsorption under both treatments matched with pseudo-second-order kinetic and Langmuir models, respectively. After biochar addition, the pesticide adsorption capacity (40 < 25 < 15 °C) increased with decreasing temperature suggesting an exothermic adsorption process while negative values of Gibbs free energy (ΔG); -1848.07 and -366.531 J mol ; for the soil under NT and RT at 25 °C, respectively, indicated spontaneous adsorption. Negative entropy values (ΔS); -21.92 and -78.296 J mol K , for NT and RT, respectively, explained a decreased randomness process. The enthalpy was higher ( < 0.05) under RT (-23,274.6 J mol ) than under NT (-1313.73 J mol ). Conclusively, it was shown that the topramezone adsorption capacity was higher under NT, and biochar addition increased more pesticide adsorption under NT than under RT.