设施条件下添加有机肥对土壤中土霉素消减作用

在设施条件下,通过在含有不同浓度(43.62、1638.78和10936.38μg/kg)土霉素的土壤中添加不同比例(5%、10%)有机肥,研究有机肥对土霉素消减的影响及其影响因素,并运用准一级动力学模型对土霉素消减动态的拟合。结果表明,在低污染处理组和高污染处理组28 d后土霉素消减进入平稳期,低污染处理组添加5%和10%有机肥后,消减率提高了17.71%和16.03%,半衰期缩短了9.02和9.50 d;高污染处理组添加5%和10%有机肥后,消减率提高了19.83%和17.93%,半衰期缩短了12.28和13.38 d。主成分分析对土壤理化性质与土霉素消减动态的分析结果表明土壤有机质、总氮及p H值与添加有机肥的比例呈较高的正相关性,土霉素的消减率与有机肥添加比例成一定的正相关性。与对照土壤比较,添加有机肥可促进土壤中土霉素的消减,并随土霉素初始浓度的增大作用更为明显,但有机肥添加比例对土霉素消减的促进作用没有显著差异。

Influence of organic fertilizer on degradation of oxytetracycline in soil in greenhouse experiment

Antibiotics in soil were known for its adverse effect on the growth and development of plants and potential risk to the health of animals and human through the food chain.Therefore, efficient methods to control and remediate the pollution of antibiotics in soil are urgently needed. . Organic fertilizer which could change the basic soil physicochemical properties and microbial activities which may have an effect on the degradation of antibiotics in soil. In the present study, the effect of organic fertilizer on the degradation of oxytetracycline was explored. The experiment follow an orthogonal experiment design, consisting of three different soils, were spiked three concentrations (43.62μg?kg-1, 1638.78μg?kg-1, and 10936.38μg?kg-1) of oxytetracycline and two levels (5% and 10%) of organic fertilizer. After mixing thoroughly, 5 kg of soils for each? replicates or treatments was incubated under optimal temperature and light conditions. The moisture of soil were adjusted weekly?Samples were collected at 0, 7, 14, 21, 28, 35, and 42 days after the setting up of the experiment. The concentration of oxytetracycline in soil measured by UPLC-MS/MS and the degradation dynamics the half-life values (DT50) was calculated according to the Pseudo-first-order kinetics model. and . Results showed that the degradation of oxytetracycline kept a stable period after 28 days for both high and low concentration groups. In the soil spiked with low concentration of oxytetracycline, application of 5% and 10% organic fertilizer increased 17.71% and 16.03% of degradation rate, consequently the half-life was reduced by 9.02 days and 9.50 days, respectively. In the soil spiked with high concentration of oxytetracycline, the degradation rate was increased to 19.83% and 17.93% when applied 5% and 10% organic fertilizer to soil, and the half-life was reduced by 12.28 days and 13.38 days, respectively. Pearson Correlation Analysis was performed on soil properties and on oxytetracycline degradation dynamics. Results revealed a highly positive correlation between levels of organic fertilizer and soil organic matter, total nitrogen, and pH values. A certain positive correlation was also observed between levels of organic fertilizer and the degradation rate of oxytetracycline. Comparing to the control soil, the application of organic fertilizer accelerated the degradation of oxytetracycline. Such effect was enhanced as the initial concentration of oxytetracycline in soil increased. However, different levels of organic fertilizer have no significant effects on the degradation of oxytetracycline.