摘要：

AbstractSulfonamides (SAs) are one of the most frequently used antibiotics in the veterinary industry, showing high mobility in soils. Objectives of this research were to determine the sorption, distribution coefficients and involvement of different ionic forms of sulfamethazine (SMZ), a representative SAs, and to evaluate the transport of SMZ in biochar treated soils. Biochars were produced from an invasive plant, burcucumber (Sicyos angulatus L.), under slow pyrolysis conditions at peak temperatures of 300 °C (biochar-300) and 700 °C (biochar-700), respectively. The abilities of the biochars to retain SMZ in loamy sand and sandy loam soils were examined under different pHs and SMZ loadings. Soil column experiments were performed with and without biochars addition. Results showed that biochar-700 had a high degree of SMZ retention, with resultant decreased pH in both soils. Modeled effective sorption coefficients (KD,eff) values indicated that the observed high SMZ retention at pH 3 could be attributed to the π-π electron donor–acceptor interaction and electrostatic cation exchange, whereas at pH 5 and 7, cation exchange was the main mechanisms responsible. There was no temporal retardation of SMZ in biochar treated soil as compared to the untreated soil. However, biochar-700 treatment achieved up to 89% and 82% increase in the SMZ retention in sandy loam and loamy sand soils, respectively. The overall results demonstrated that burcucumber biochar produced at higher temperature was effective in reducing the mobility of SMZ in the studied soils.Article Outline1. Introduction2. Material and methods2.1. Soil samples, biochar and chemicals2.2. Soil and biochar characterization2.3. Batch sorption experiments and TCLP extraction2.4. Determination of solid-water distribution coefficients of ionic SMZ species2.5. Data modeling2.6. Soil column experiments3. Results and discussion3.1. Soil properties3.2. Characteristics of biochars3.3. Effects of pH on SMZ sorption and speciation3.4. Partition coefficients and isotherms3.5. Transport potential3.6. TCLP extraction data4. ConclusionsAcknowledgmentsReferences

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