A2/O系统受低C/N冲击及修复前后的微生物活性研究

利用2套A2/O工艺装置,通过在实际污水中添加铵盐的方式模拟低C/N冲击的不利情况,采取常规工艺调控措施进行修复,研究了冲击及修复前后的微生物活性变化.结果表明,A2/O系统在受到低C/N冲击之后,耗氧呼吸速率(OUR)、脱氢酶活性(DHA)、三磷酸腺苷(ATP)和聚β-羟基丁酸(PHB)4项指标迅速响应,降幅分别为81.8%,87.0%,90.5%和72.9%.提高污泥回流比和减小污泥龄都是有效的修复措施.修复期间,4项指标均呈现先快后慢的回升规律.提高污泥回流比是通过降低冲击负荷的方式实现OUR指标的基本回复,但DHA、ATP和PHB较受冲击前水平还有10%~20%不等的差距.减小污泥龄是通过逐步排出受损污泥来消除冲击的不利影响,过程中A2/O系统的处理效果不佳,但最后4项指标能够完全恢复.

Microbial physiological biochemical activities of the low C/N shock to A2/O system and its restoration

By adding ammonium into the raw wastewater to simulate the low C/N shock,two sets of lab-scale A2/O (anaerobic-anoxic-oxic) system were constructed to investigate the physiological biochemical activities of the shock and further restoration.Results showed that oxygen uptake rate (OUR), dehydrogenases activity (DHA), adenosine triphosphate (ATP) and poly-β-hydroxybutyric acid (PHB) responsed well to the shock with a drop over 81.8%、87.0%、90.5% and 72.9%,respectively.Both increasing the sludge reflux ratio (R) and reducing the sludge retention time (SRT) were effective restoration measures.After the restoration the value of R,OUR barely resumed, however, DHA、ATP and PHB still had a 10% to 20% gap left,compared to those before the shock.The reduction of SRT could gradually eliminate impacts of the shock by discharging the damaged sludge.Although the A2/O system didn’t well perform during the restoration period,all of the four physiological and biochemical activities of micro-organisms recovered fully in the end.