Long term Evaluation of the Effect of Salinity on Organic Removal and Ammonium Oxidation in a down-flow Hanging Sponge Reactor

The effect of salinity on organic removal and ammonium oxidation in a down-flow hanging sponge reactor was investigated by conducting a long-term continuous experiment over a period of 800 days. The DHS reactor, constructed by connecting three identical units, was fed with artificial wastewater containing 500 mg-N/L of ammonium nitrogen and 1400 mg- COD/L of phenol. Salinity of the influent was controlled by the addition of 8.0 to 25 g-Cl-/L of NaCl. The DHS reactor was operated at a hydraulic retention time of 12 h in a temperature controlled room at 25oC. No significant inhibition of organic removal and ammonium oxidation was observed at salinities of up to 20 g-Cl-/L, at which levels ammonium oxidation and COD removal both exceeded 90%, respectively. However, at a salinity of 25 g-Cl-/L, organic removal and ammonium oxidation were both severely inhibited. In addition, the ratio of effluent nitrite nitrogen to influent ammonium nitrogen increased from 3.4% at salinities of 8.0 g-Cl-/L to 33% at salinities of 20 g-Cl-/L.

通过为期800天的长期连续实验，研究了盐度对下向流悬挂式海绵（DHS）反应器中有机物去除和氨氧化的影响。该DHS反应器由三个相同的单元连接而成，以含500毫克氮/升铵态氮和1400毫克化学需氧量/升苯酚的人工废水为进水。通过添加8.0 - 25克氯离子/升的氯化钠来控制进水的盐度。DHS反应器在25℃的恒温室内，以12小时的水力停留时间运行。在盐度高达20克氯离子/升时，未观察到对有机物去除和氨氧化有明显抑制，在此盐度下，氨氧化和化学需氧量去除率均分别超过90%。然而，在盐度为25克氯离子/升时，有机物去除和氨氧化均受到严重抑制。此外，出水亚硝酸盐氮与进水铵态氮的比值从盐度为8.0克氯离子/升时的3.4%增加到盐度为20克氯离子/升时的33%。