猪粪堆肥过程中金霉素去除及重金属形态变化

Removal of Chlortetracycline and Morphological Changes in Heavy Metals in Swine Manure Using the Composting Process

抗生素和重金属的广泛使用导致了畜禽粪便中抗生素和重金属的大量残留,堆肥工艺不但可降解残留的抗生素,也能固化重金属.本文以养殖场猪粪为对象,利用中试好氧堆肥反应装置,研究不同金霉素浓度时的猪粪堆肥特性及去除情况[0mg·kg^(-1)(CK)、10 mg·kg^(-1)(T1)和50 mg·kg^(-1)(T2)],同时开展堆肥过程重金属形态变化的研究.结果表明,堆肥结束后,CK组金霉素没有检出,T1和T2组抗生素降解率分别达到96.31%和97.32%,金霉素降解过程符合一级动力学模型.堆肥可以使重金属固化,Cu、Zn元素的生物可利用态(可交换态、可还原态)逐渐转化为生物毒性低的可氧化态与残渣态,Cu、Zn明显钝化.相关性分析表明金霉素的去除与生物可利用态Cu、Zn呈现显著的正相关性.

The widespread use of antibiotics and heavy metals in livestock farms results in large residues of antibiotics and heavy metals in the livestock manure. Composting technology can biodegrade residual antibiotics and solidify heavy metals. A pilot composting reactor was used to analyze the characteristics of chlortetracycline（ CTC） removal at different antibiotic concentrations [0 mg·kg^-1（ CK）,10 mg·kg^-1（ T1）,and 50 mg·kg^-1（ T2） ]. Moreover,the morphological changes in heavy metals during the composting process were analyzed. After composting,no chlortetracycline was detected in the CK group and the antibiotics degradation rates of T1 and T2 groups reached 96. 31% and 97. 32%,respectively. The chlortetracycline degradation fits the pseudo-first-order kinetics model. Heavy metals can be solidified during the composting; thus,the bioavailable state of Cu and Zn（ exchangeable state,reducible state） changed into the oxidation state and residues with apparent passivation formed. The correlation analysis showed that the removal of CTC showed strong positive correlations with the biological available Cu and Zn.