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在中温(35℃)条件下,考察了土霉素(OTC)对剩余污泥厌氧消化的短期和长期影响。在短期影响实验中,采用间歇实验装置研究了OTC浓度为5、50和500 mg/L时对累计甲烷产气量的影响。结果表明,50 mg/L的OTC短期暴露下中温厌氧消化污泥的产甲烷活性会受到急性抑制,但经过141 h的驯化后系统能够恢复产气,表明中温厌氧污泥经过驯化后,可处理含高浓度OTC的剩余污泥。采用完全混合反应器进行了为期230 d的OTC长期影响实验,反应器进泥中OTC浓度从0 mg/L逐步提高为40、200和1 000 mg/L,通过定期监测产气量、甲烷含量和挥发性脂肪酸等指标来表征反应器的运行状况。当OTC浓度≤200 mg/L时系统产气量和气体中甲烷含量稳定并且消化液中挥发性脂肪酸未出现累积,表明厌氧系统未受到影响。但在OTC浓度为1 000 mg/L时运行43 d(2个污泥停留时间)后,污泥中发酵产酸细菌类群代谢活性受到抑制,导致系统产气量下降。上述结果表明,经过驯化,中温厌氧消化系统可处理OTC浓度≤200 mg/L的剩余污泥。
The effects of oxytetracycline (OTC) on the anaerobic digestion of excess sludge were investigated at medium temperature (35 ℃). In a short-term impact experiment, the impact of cumulative OTC concentrations on methane production at 5, 50 and 500 mg / L OTC was studied using a batch experimental setup. The results showed that 50 mg / L OTC short-term exposure to moderate temperature anaerobic digestion sludge methanogenic activity will be acutely inhibited, but after 141 h of domestication system to restore gas production, indicating that the intermediate temperature anaerobic sludge after domestication, Can handle excess sludge with high concentration of OTC. A 230-hour OTC long-term effect experiment was carried out using a fully mixed reactor. The OTC concentration in the reactor was gradually increased from 0 mg / L to 40,200 and 1 000 mg / L. The gas production, methane content and Volatile fatty acids and other indicators to characterize the reactor operating conditions. When the OTC concentration is less than or equal to 200 mg / L, the system gas production and the methane content in the gas are stable and no accumulation of volatile fatty acids in the digestion solution occurs, indicating that the anaerobic system is unaffected. However, when the OTC concentration was 1 000 mg / L, the metabolic activity of the bacteria producing bacteria in the fermentation was inhibited after 43 days (2 sludge residence time), resulting in the decrease of gas production. The above results show that after domestication, the mesophilic anaerobic digestion system can treat excess sludge with OTC concentration ≤ 200 mg / L.