The Pennsylvania State University, Department of Ecosystem Science and Management, 116 ASI Building, University Park, PA, 16802, USA.
US Arid Land Research Center, USDA-ARS, 21881 North Cardon Lane, Maricopa, AZ, 85138, USA.
Chemosphere. 2022 Feb;289:133038. doi: 10.1016/j.chemosphere.2021.133038. Epub 2021 Nov 24.
Due to rises in antibiotic resistance, fate and transport of antibiotics in soil systems requires greater understanding to determine potential risks to human and animal health. Adsorption coefficients (K and K) are standard measures for determining sorption capacity and partitioning behavior of organic contaminants in solid matrices. Frequently, sorption studies use higher antibiotic concentrations (mg L) and larger spiked water volume to mass of soil (>5:1), which may not reflect sorption behaviors of antibiotics at low concentrations (ng L - μg L) in natural soils. The aim of this study was to determine sorption and desorption behaviors of four antibiotics commonly found in soils due to wastewater reuse using parameters replicating typical soil conditions. Concentrations (μg L) of sulfamethoxazole (SMX), trimethoprim (TMP), lincomycin (LIN) and ofloxacin (OFL) were equilibrated with four soil types at a 2:1 ratio of spiked water volume to mass of soil, which better represents field conditions. Log K and log K value ranges in this study were 1.88-1.95 and 3.2-4.7 for TMP, 0.43-1.4 and 2.7-3.2 for SMX, and 0.65-1.4 and 2.0-4.1 for LIN, respectively. Ofloxacin adsorbed tightly to soil particles, and adsorption coefficients could not be calculated. Sorption values were higher than previous studies that used similar soil types but had higher ratios of spiking solution to mass of soil (>5:1). Overall, OFL and TMP are expected to strongly interact with soil particles and be less mobile, while SMX and LIN are expected to be more mobile due to weaker sorption interactions.
由于抗生素耐药性的增加，土壤系统中抗生素的归趋和迁移需要更深入的了解，以确定其对人类和动物健康的潜在风险。吸附系数（K 和 K）是衡量有机污染物在固相中吸附能力和分配行为的标准方法。通常，吸附研究使用较高的抗生素浓度（mg/L）和较大的加标水体积与土壤质量比（>5:1），这可能无法反映出抗生素在自然土壤中低浓度（ng/L-μg/L）时的吸附行为。本研究的目的是使用典型土壤条件下的参数，确定由于废水再利用而在土壤中常见的四种抗生素的吸附和解吸行为。磺胺甲恶唑（SMX）、甲氧苄啶（TMP）、林可霉素（LIN）和氧氟沙星（OFL）的浓度（μg/L）与四种土壤类型在 2:1 的加标水体积与土壤质量比下达到平衡，这更能代表实际情况。本研究中 TMP 的 log K 和 log K 值范围为 1.88-1.95 和 3.2-4.7，SMX 为 0.43-1.4 和 2.7-3.2，LIN 为 0.65-1.4 和 2.0-4.1。氧氟沙星与土壤颗粒紧密吸附，吸附系数无法计算。吸附值高于先前使用类似土壤类型但加标溶液与土壤质量比更高（>5:1）的研究。总体而言，OFL 和 TMP 预计与土壤颗粒强烈相互作用，迁移性较低，而 SMX 和 LIN 由于吸附相互作用较弱，预计迁移性较高。
