为了考察活性污泥系统对环境pH值变化的响应,采用四个小试SBR反应器进行平行试验,研究了在不同原水pH值和不同瞬时混合后pH值条件下,系统污水处理效果以及污泥沉降性的变化.结果表明,由于许多生化反应(硝化、反硝化、放磷等)都消耗或产生碱度,以及水溶液中普遍存在的离子电离平衡,使活性污泥系统对环境pH值的变化具有很好的调节作用.pH值与硝化过程关系密切,当系统pH值在7.2～8.2时,增加DO质量浓度可显著地升高硝化反应速率.当pH值＜7.0时,硝化过程受到严重抑制,增加DO质量浓度的方法对提高硝化速率不再有效.另外,当pH值在7～8时,活性污泥放磷量和吸磷量都随着pH值的升高而升高,但是当pH值进一步升高时,变化不再明显.活性污泥沉降性对pH值变化不敏感,试验期间差异不大.不同的是酸性条件下污泥沉后上清液较浑浊,而碱性条件下的污泥沉后上清液较清澈.%In order to investigate the responses of activated sludge system to pH variation, 4 lab - scale sequencing batch reactors ( SBR) were used to study the variations of wastewater treatment performance and sludge settle ability under different pH raw wastewaters and different pH after impulsive mixing conditions in parallel. The results showed that, because many biochemical reactions can produce or consume alkalinity, and there existed a lot of ionization equilibriums in aqueous solution, the activated sludge system had an excellent accommodation on pH variations. The relationship between pH and nitrification was close. When pH was in the range of 7.2 ～8.2, nitrification rate could increase significantly by rising DO concentration. When pH was lower than 7.0, nitrification process was inhibited seriously, and rising DO concentration would not increase nitrification rate any more. In addition, when pH was in the range of 7 ～ 8, the amounts of phosphorus released and uptaken both increase with pH increament. When pH increased further, the increasing extent was not significant. Sludge settle ability was not sensitive with pH variation, and it did not show any obvious difference during entire experimental period. The supernatant after sedimentation under acidity condition was turbid, while it was clear under basicity condition.
展开▼
