反应时间和碳磷比对单级好氧除磷的影响

Impacts of Reaction Time and C to P Ratio on Single Aerobic Phosphorus Removal System

为了研究单级好氧除磷工艺的影响因素,采用序批式间歇反应器(SBR),通过设定不同的反应时间和进水碳磷比(质量比),考察了单级好氧过程中PO_4^(3-)-P浓度、聚-β-羟基丁酸盐(PHB)以及DO、ORP等参数的变化.结果表明,在DO浓度低于0.6 mg/L的单级好氧系统中,存在着稳定的生物除磷现象.进水末期污泥中的PHB含量与放磷量近似成正比,且适当地缩短反应时间有助于强化除磷效果.碳磷比与除磷的关系比较复杂,当PO_4^(3-)-P浓度恒定时,增加碳磷比可显著强化放磷和吸磷过程;当碳源浓度恒定时,增加碳磷比对强化除磷的作用有限.ORP的变化趋势能够清楚地指示除磷的过程,当ORP小于-150 mV时,系统会发生显著的磷释放.在低溶解氧环境下,传质受限产生的厌氧微环境是发生单级好氧生物除磷的重要原因.

In order to investigate the impact factors of single aerobic phosphorus removal process,sequencing batch reactor（ SBR） was applied. Through altering reaction time and influent C/P,variations of PO4^3--P concentration,poly-β-hydroxybutyrate（ PHB）,parameters such as DO and ORP were investigated. The results showed that,when DO was below 0. 6 mg·L^-1,stable biological phosphorus removal was existed in single aerobic system. The sludge PHB content at the end of feeding period was in proportion to the released phosphorus content,and decrease reaction time properly was helpful to enhance the phosphorus removal effect. The relation between C to P ratio and phosphorus removal was complex,when PO4^3--P concentration was constant,increase C to P ratio could enhance the processes of phosphorus release and uptake significantly; when carbon source concentration was constant,the effect of increase C to P ratio was limited. The variation tendency of ORP could distinctly indicate the phosphorus removal progress,when ORP was below-150 m V,significantly phosphorus release would happen. Under low DO condition,the micro-anaerobic environment caused by mass transfer resistance was the key reason for the take place of single biological phosphorus removal.