兽药金霉素在畜禽粪便上的吸附特征研究

通过振荡平衡吸附试验,研究了兽药金霉素在鸡粪和猪粪上的吸持特征并对其吸附机制和影响因素进行探讨.结果表明,金霉素能被畜禽粪便强烈吸附,吸附过程属于快速吸附,吸附等温线呈非线性,能用Freundlich模型很好地描述;雨水很难解吸被粪便吸附的金霉素,存在解吸迟滞现象,用甲醇、3 mol/L NaCl和3 mol/L MgCl2 3种溶液仅分别解吸出了18.3%～20.4%、18.7%～19.4%和55.7%～57.6%被粪便吸附的金霉素.金霉素在畜禽粪便上的吸附受pH和离子强度影响,随pH值和离子强度增大吸附量减少,二价钙离子体系比一价钠离子体系对吸附的影响大.表明有机质吸附和阳离子交换可能是金霉素在畜禽粪便上主要的吸附机制.

Sorption Characteristics of Veterinary Antibiotics Chlortetracycline on Manure

The sorption characteristics of high-use tetracycline veterinary antibiotics-chlortetracycline (CTC) on pig manure and chicken manure were investigated in laboratory according to the OECD guideline 106. The results showed that CTC was strongly and rapidly adsorbed to the two manures and Freundlich model could describe preferably the CTC nonlinear sorption isotherms. The adsorbed CTC was difficult to be desorbed by rain with desorption H of 1.522 for pig manure and 1.329 for chicken manure, respectively. Only 18.3%-20.4%, 18.7%-19.4% and 55.7%-57.6% adsorbed CTC were desorbed by methanol, 3 mol/L NaCl and 3 mol/L MgCl2. The sorption of CTC on manure were affected by solution pH and ionic strength, the amount of adsorbed CTC on manure decreased with an increase of pH value and ionic strength, and greater sorption effect in the Ca systems than the Na systems was observed. These results suggest that organic matter and cation exchange mainly contribute to the sorption of CTC on manure.