GUO Pi-jian

【Abstract】Since anammox can simultaneously remove ammonia and nitrite nitrogen，And low cost，have been researched by many scholars，Its high ammonia wastewater treatment has great application value. However， high concentrations of organic carbon on anaerobic ammonium oxidation significantly inhibited. How to achieve anaerobic ammonium oxidation and denitrification coupling， is now a focus of research in the training process， anammox bacteria and denitrifying bacteria on pH， organic matter with different requirements， this paper summarizes the anammox and denitrification startup method and pH， organic matter on anaerobic ammonia oxidation and denitrification coupling and explore control strategies for anaerobic ammonium oxidation and denitrification coupling recommendations.

【Key words】Anammox； Denitrification ； Organic matter； pH

0 Introduction

Delft University in the Netherlands proposed a new biological nitrogen removal technology named anammox， refers to the microorganisms under anaerobic conditions that direct electron acceptor electron donor that the redox reaction product was N2[1-2]. And compared to conventional nitrification and denitrification， denitrification， high efficiency， low energy consumption and costs， eliminating the need for additional organic electron donor， efficient use of oxygen， oxygen consumption decreased Alcaligenes zero， reducing the and the required chemical reagents， reduce operating costs， while also reduce secondary pollution， and low sludge production has great advantages. The reaction is now considered the most simple and most economical ways things denitrification， but organics in wastewater anammox bacteria will produce a strong inhibition [3]， and anaerobic ammonia oxidation in the removal of ammonia and nitrite nitrate will also produce up to 90% of the nitrogen can be removed so simple anammox process， denitrification results are unsatisfactory.

In recent years， many studies have found that anammox bacteria and denitrifying bacteria can coexist in a reactor， a certain coupling， which for organic wastewater treatment provides a new way of thinking， this article focuses on the recent anammox and denitrification summarize the research progress and prospects.

1 Anammox and denitrification coupling reaction start up

Anaerobic ammonium oxidation and denitrification coupling reaction is to study the coupling reaction starting basic conditions. Currently， there are two commonly used starting method： one to 1：1.32 ratio of ammonia and nitrite nitrogen and water distribution starts anammox reaction， the reaction starts successfully after adding organic matter in the water， after acclimation， to achieve the anaerobic ammonium oxidation and denitrification are coupled. Second， the direct use has been launched successfully anammox reactor Sludge anammox and denitrification are coupled.

As can be seen， the two methods are not fundamentally different， are the first to start the anammox reaction， it is because the era of anammox bacteria cycle is long， very sensitive to environmental conditions， so you need to start the anaerobic ammonium the oxidation reaction to achieve the coupling between the two. [4]

2 Organic matter on anammox and denitrification coupling effects

Lv Yong tao， etc.[9]studies have shown that organic carbon source environment ANAMMOX stable operation， and more than autotrophic TN removal system has increased， denitrifying bacteria and anaerobic ammonium oxidizing bacteria result of joint action； when the COD value of 50mg / L， the total nitrogen removal rate， with an average of 96.59%.

Liu Jin ling and other studies have shown that low concentrations of glucose（0. 5mmol·L-1） under the conditions of anaerobic ammonia oxidation and denitrification coexist ANAMMOX priority； high concentration of glucose （≥ 1mmol·L-1） under the conditions denitrification as the main reaction. sulfate reduction occurred in the anaerobic ammonium oxidation and denitrification after.

3 Effect of pH on anaerobic ammonium oxidation and denitrification coupling effects.

pH on anaerobic ammonium oxidation and denitrification coupling has important implications. anammox bacteria growth optimum pH range of 6.7 to 8.3 [6]， the growth of denitrifying bacteria suitable pH 6 to 9 [7].

Hu Yong has other [8] for organic carbon under anaerobic ammonia oxidation optimum value of the study found that in the presence of organic carbon under anaerobic ammonia oxidation reaction can be carried out between the initial value of 6.02 to 9.00， and the optimum value of 8.00 ， then COD， NH4 +-N and NO2-- N removal rate were 84%， 69.9% and 99%， COD， NH4+-N and NO2-- N removal have reached the ideal state. pH value is too low （less than 5.06） or too high （above 9.00）， denitrification and anaerobic ammonia oxidation reactions were stopped for.

Tian Wen ting[10] and other studies when the pH is controlled at 7.0 to 8.5， the basic anammox bacteria is not affected when the pH controlled at 7.0 to 8.0， denitrifying bacteria has been less affected； optimum of 7.5； when pH 8.5 when denitrifying bacteria was strongly inhibited.

4 Conclusion

In recent years， many scholars anammox and denitrification coupling has been studied， the paper starts methods and their impact pH and organic matter to do a certain generalization. An anaerobic ammonium oxidation and denitrification coupled relatively slow start， you need to realize anammox start. Second， in the presence of organic matter， when low concentrations can promote anaerobic ammonium oxidation， so that both achieve maximum removal efficiency， and the high concentration of anaerobic ammonia oxidation inhibition， denitrification strengthened. Third， the anammox bacteria and denitrifying bacteria have their own suitable pH value， to find the optimum coupling reaction pH.