Persistence and environmental implication of pharmaceuticals in agricultural soil is determined depending on adsorption, bioavailability and toxicity. This study aims to assess adsorption/partitioning behaviour of diclofenac (DCF) and its impact on microbial activity in four agricultural soils, differing in pH, organic carbon content, and cation exchange capacity. Results from batch studies suggests that soil/water partition coefficients of DCF are essentially nonlinear, i.e. depends on drug amount (p = 0.001), and positively correlated with soil organic carbon (p = 0.008). The adsorption data can effectively be modelled using Freundlich isotherm (regression coefficients between 0.84 and 0.90). In soil incubation studies, DCF could not be detected after 6 days of spiking (20 µg/g) in all soil types, including abiotic control. This suggests an interplay of combined biotic/abiotic process in DCF removal. Though microbial activity (based on tetrazolium reduction) declined with incubation time, but was not correlated with DCF exposure, particularly in soils rich in organic carbon.

药物在农业土壤中的持久性和对环境的影响取决于吸附，生物利用度和毒性。这项研究旨在评估双氯芬酸（DCF）的吸附/分配行为及其对四种农业土壤中pH，有机碳含量和阳离子交换能力不同的微生物活性的影响。批处理研究的结果表明，DCF的土壤/水分配系数基本上是非线性的，即取决于药物量（p  = 0.001），并且与土壤有机碳呈正相关（p = 0.008）。吸附数据可以使用Freundlich等温线有效建模（回归系数在0.84和0.90之间）。在土壤培养研究中，加标6天（20 µg / g）后，在所有土壤类型中都未检测到DCF，包括非生物对照。这表明生物/非生物结合过程在DCF去除中的相互作用。虽然微生物活性（基于四唑鎓还原）随孵育时间降低，但与DCF暴露无关，特别是在富含有机碳的土壤中。