两类抗生素对EBPR系统的短期生物抑制作用实验研究

基于强化生物除磷(EBPR)系统,从除磷过程、挥发性脂肪酸(VFA)的消耗过程、聚羟基脂肪酸酯(PHAs)的合成与消耗过程、胞外聚合物(EPS)的总量变化过程及比呼吸速率(SOUR)的变化过程等多个角度出发,系统地研究了高浓度(10 mg·L~(-1))红霉素和土霉素对EBPR系统的短期冲击作用.结果表明,高浓度(10 mg·L~(-1))红霉素和土霉素在24 h之内均能对除磷过程产生明显的抑制作用,除磷效率分别下降至63.3%和61.2%.抗生素对VFA的消耗过程并无明显作用,而对PHAs的厌氧合成和好氧消耗过程影响较为显著.同时,高浓度(10 mg·L~(-1))抗生素对EPS中蛋白质(PN)合成量的抑制率在26.7%以上.SOUR变化过程的分析结果表明,抗生素对EBPR系统中微生物的呼吸作用抑制显著,在高浓度(10 mg·L~(-1))抗生素反应器中抑制率在16.0%以上.对比分析结果表明,相同浓度的土霉素比红霉素对EBPR系统的抑制更为显著,且EBPR系统的好氧过程比厌氧过程更容易受到抑制.

Short-term effects of two antibiotics on the performance of enhanced biological phosphorus removal system

The performances of enhanced biological phosphorus removal (EBPR) systems in terms of the variations of phosphorus-removal (P-removal) efficiency, volatile fatty acid (VFA) concentration, polyhydroxyalkanoates (PHAs) content, extracellular polymeric substance (EPS) concentration and special oxygen utilization rate (SOUR) after exposure to erythromycin and oxytetracycline for 24 h were evaluated in this research. The P-removal efficiency decreased to 63.3% and 61.2% under the effect of erythromycin (10 mg·L^-1) and oxytetracycline (10 mg·L^-1) for 24 h, respectively. In the process of VFA consumption, no obvious inhibitory effects were detected. However, serious negative effects were detected in the process of PHAs production and consumption. Meanwhile, the PN in EPS declined by 26.7% at least after exposure to antibiotics with high concentration (10 mg·L^-1). According to the SOUR analysis, high concentrations (10 mg·L^-1) of antibiotics seriously inhibit the oxygen utilization process (decline by 16.0% at least). Results of contrastive analysis show that oxytetracycline had more serious negative effects than erythromycin on the performance of EBPR system, and the processes in aerobic stage were inhibited more grievously than those in anaerobic stage in the EBPR system.