Sorption and Dissipation of Tetracyclines in Soils and Compost

• Published in: Pedosphere 2010-12, Vol.20 (6), p.807-816
• Main Authors: LI, Ling-Ling, HUANG, Li-Dong, CHUNG, Ren-Shih, FOK, Ka-Hang, ZHANG, Yong-Song
• Format: Article
• Language: English
• Subjects: antibiotics; half-life; mobility; organic carbon; soil amendment
• ISSN: 1002-0160; 2210-5107
• DOI: 10.1016/S1002-0160(10)60071-9

Two agricultural soils were collected from Dahu and Pinchen counties and swine manure compost (SMC) from Ping-tung County in Taiwan, China to investigate the sorption and dissipation of three tetracyclines (TCs), i.e., oxytetracycline (OTC), tetracycline (TC) and chlortetracycline (CTC), in compost, soils and soil/compost mixtures with different organic carbon (OC) contents. There were seven treatments in total. TCs were most strongly adsorbed to SMC in all treatments due to the high OC content. When SMC was present in the soils, the sorption of TCs was significantly enhanced, which might be attributed to the increased OC content and CEC. The adsorption of TCs showed non-linear adsorption isotherms and fitted well to the Freundlich model. After 49 d of incubation at 25 °C in soils and soil/compost mixtures in the dark, TCs elapsed in all substrates, with the time required for 50% degradation (DT 50) between 20 and 41 d, and the time for 90% degradation (DT 90) between 68 and 137 d. Soil amended with compost enhanced the stability of TCs and reduced their mobility. The dissipation of TCs in a soil environment was slow, indicating that these compounds might be persistent in soil.