环境条件对土壤中磺胺间甲氧嘧啶降解的影响

Effect of environmental condition on the degradation of sulfamonomethoxine in soil

通过在实验室模拟不同的环境条件,研究常用兽药抗生素——磺胺间甲氧嘧啶(SMM)在土壤中的降解动态及其影响因素(如微生物和光照、土壤含水量、药物起始浓度等)。结果表明,SMM在土壤中的降解遵循一级反应动力学方程。SMM在土壤中的降解主要是光降解和化学降解,微生物降解只占较小比例;土壤含水量的增加明显加快了SMM的降解速率,因而可以通过降低土壤中SMM残留浓度或提高土壤含水量等方法加速SMM的降解,以降低其对环境土壤和水体的风险;SMM的降解速率随土壤中SMM起始浓度增加而降低,表明土壤中降解微生物对SMM的浓度敏感。

Sulfamonomethoxine （SMM） was a veterinary antibiotic, the residue was widely found in soil environment. Series of experiments were performed on SMM contaminated soil samples in a lab scale to determine the effects of initial SMM concentration, different moistures, microorganism and sunshine on SMM degradation. The re- sults showed that degradation of SMM in soils followed the first-order kinetic equation. SMM degradation in soil was mainly caused by illumination and chemical function, while the presence of microorganisms in soil enhanced SMM degradation. SMM degradation rate increased with decreasing initial SMM concentration, which indicated that microorganism was sensitive to SMM concentration. High soil moisture was benefit for SMM degradation. Consequently, increasing soil moisture and decreasing the initial SMM concentration might be good solutions to accelerate the degradation and reduce the environment risk of antibiotics residues.