土霉素对菌藻共生系统去除营养盐的影响机制探究

Study on the Effect Mechanism of Oxytetracycline on Nutrient Removal in Bacteria-Algae Symbiotic System

为明确新污染物土霉素(OTC)对藻-菌共生系统去除营养盐的影响及作用机制,通过控制进水OTC浓度,在反应温度30℃和进水有机负荷5.1~5.6 g/L的条件下,考察了OTC对藻-菌共生系统处理畜禽养殖废水的影响并揭示了相关机制。结果表明,低剂量(低于0.1 mg/L)OTC对藻-菌共生系统影响不明显,当高剂量(>0.5 mg/L)OTC显著降低了污染物及氮磷的去除效率。高剂量OTC降低了藻菌共生系统内污泥浓度,降低了污泥沉降性及叶绿素a产量但刺激了可溶性有机质的释放。高剂量OTC降低了微生物的活性,在4.0 mg/LOTC暴露组别内,比耗氧速率(SOUR)下降至26.7 mg O_(2)/(g VSS·h)。微生物学分析高剂量OTC降低了Proteobacteria和Bacteroidota门级别微生物,norank_f__Saprospiraceae属级别微生物。研究结果为藻-菌共生系统处理含抗生素废水提供了一定的数据支撑和理论依据。

To clarify the effect and mechanism of the new pollutant oxytetracycline(OTC) on the nutrient removal by algae-bacteria symbiosis system,the effect of OTC on livestock and poultry breeding wastewater treatment by algae-bacteria symbiosis system was investigated under the reaction temperature of 30 ℃,influent organic load of 5.1 g/L and 5.6 g/L by controlling influent OTC concentration.The results showed that the low dose(less than 0.1 mg/L) of OTC had no obvious effect on the algae-bacteria symbiosis system,while the high dose(> 0.5 mg/L) of OTC significantly reduced the removal efficiencies of pollutants,nitrogen and phosphorus.A high dose of OTC reduced the sludge concentration,sludge sedimentation and chlorophyll production,but stimulated the release of soluble organic matter in the algae-bacteria symbiosis system.A high dose of OTC decreased the activity of microorganisms,and the specific oxygen consumption rate(SOUR) decreased to 26.7 mg O2/(g VSS·h) in the 4.0 mg/L OTC exposure group.Microbiological analysis showed that a high dose of OTC reduced the Proteobacteria and Bacteroidota gate-grade microorganisms,while norank_f__Saprospiraceae belonged to the class microorganisms.The results provide some data support and a theoretical basis for the treatment of antibiotic-containing wastewater by an algae-bacteria symbiosis system.