蚯蚓过腹处理对污泥中四环素降解及大量营养元素赋存的影响

针对污泥中大量抗生素残留对环境的威胁和污泥资源化利用的瓶颈等问题，采用微宇宙实验手段研究了蚯蚓过腹处理污泥过程中四环素的降解特征和污泥蚓粪中大量营养元素的赋存特征。结果表明，污泥中的四环素降解率与处理时间呈正相关关系；室温静置32 d后，污泥中9%~11%的四环素发生降解。蚯蚓过腹处理下，污泥中四环素浓度与四环素降解率呈负相关关系，随着污泥中四环素浓度的增加，四环素降解率逐渐降低，蚯蚓过腹处理32 d后，污泥中四环素的降解率提升了45%~64%。蚯蚓过腹形成的污泥蚓粪中总氮和有机质含量显著减低，而铵态氮、硝态氮、速效磷、速效钾和总钾含量以及pH和电导率均显著升高；随着污泥中四环素浓度的增加，污泥蚓粪中总氮和氨氮含量以及pH和电导率呈显著降低趋势；污泥蚓粪中铵态氮和硝态氮含量、pH和电导率与四环素降解率均呈正相关关系。蚯蚓过腹处理能够显著提升污泥中四环素的降解率及污泥蚓粪中速效氮磷钾的含量。

Effect of earthworm swallowing on the tetracycline degradation and accumulation of macro-mineral element in sewage sludge

In order to solve the environmental pollution problem that caused by large amount of residual antibiotics in the sludge and sludge resource utilization, the laboratory-controlled sludge microcosms was used to study the effect of earthworm swallowing on the tetracycline degradation and accumulation of macro-mineral element in sewage sludge. The results showed that the degradation rate of tetracycline in sludge was positively correlated with treatment time. After 32 days static treatment (no adding earthworms to sludge) at indoor temperature, only 9%~11% tetracycline was degraded. Under the earthworms digestion treatment (adding earthworms to sludge), the tetracycline concentration was negatively correlated with its degradation rate. With the increase of the concentration of tetracycline in sludge, its degradation rate decreased. The degradation rate of tetracycline under the earthworm digestion treatment increased by 45%~64%. The total nitrogen and organic matter content in the vermicompost significantly decreased, while the ammonium nitrogen, nitrate nitrogen, available phosphorus, available potassium and total potassium content, pH and EC significantly increased. With the increase of tetracycline concentration in sludge, the total nitrogen and ammonia nitrogen content, pH and EC significantly decreased. The ammonium nitrogen, nitrate nitrogen, pH and EC value in the vermicompost were positively correlated with the degradation rate of tetracycline. In summary, the treatment of adding earthworms to sludge can significantly improve the degradation rate of tetracycline in sludge and the available nutrients in vermicompost.