二价铁耦合有机碳源强化低碳源污水脱氮除磷处理

摘要

As the shortages of high cost and high sludge production of adding external carbon source for denitrification and chemical phosphorus removal in the effluent of biological system in low-carbon wastewater treatment process in China's southern cities,this research took the simulated wastewater of denitrificaton (BOD/NOx-N =2.5) as research object and Fe (Ⅱ) was dosed in semisequencing SBR anoxia reactor as coupling agent of organic carbon source in order to enhance denitrifying biological activity synergy chemical phosphorus removal efficiency.The low-carbon wastewater was fed to the SBR as influent.Fe (Ⅱ) with different kinds of organic carbon source were added to the SBR,nitrogen and phosphorus removal efficiency was investigated during the experimental period in considering pollutants removal efficiency and economic cost.FeSO4 · 7H2O plus CH3 OH were determined to be the best coupling body.Besides,the result showed that coupling body can increase 2.83％ denitrifying rate,this may be because of the iron promoting the enzyme activity of denitrifying bacteria.The optimal conditions were confirmed by orthogonal experiment,the results showed that the optimal conditions were:m(CH3OH)/m(NOx-N) =5,Fe/P =2.4、T =33 ℃ 、pH =7.The effluent(N and Pconcentration) could reach class Ⅲ of the Environmental Quality Standards for Surface Water under this condition.%针对我国南方城市低碳源污水处理过程投加外碳源脱氮、生化池后投加化学药剂除磷经济成本高、污泥量大的弱点,本研究以强化反硝化生物活性协同化学除磷为手段,以BOD/NOx-N为2.5的模拟反硝化过程污水作为研究对象,向半序批式SBR缺氧反应器中投加Fe(Ⅱ)作为有机碳源的耦合剂,在兼顾处理效果和使用经济因素方面分别对Fe(Ⅱ)和有机碳源的种类及其投加量进行了比较和筛选,确定了最佳的耦合体为FeSO4·7H2O加CH3OH.试验结果表明,耦合体的脱氮效率比单独投加CH3OH平均提高2.83％,这可能是因为铁元素促进了反硝化细菌的酶活性.进一步通过正交试验优化脱氮除磷效果,结果表明:当外加碳源CH3 OH维持m(CH3OH)/m(NOx-N)=5,Fe/P=2.4、温度控制在33℃、pH值=7为最适条件,此条件下的N、P出水可达到地表水Ⅲ类标准.