短程反硝化处理酸性含氮废水及N_(2)O释放特性

Nitrous oxide emission indenitrification using nitrite as electron acceptor for treating acidic nitrogenous wastewater

短程反硝化处理酸性含氮废水具有节约碳源并降低剩余污泥量的优点。研究在SBR系统中通过升高进水NO^(-)_(2)浓度并降低进水pH的方式成功实现了NO^(-)_(2)型反硝化的启动和稳定运行,并研究了长期酸性条件下N_(2)O的释放特性和微生物群落的变化。结果表明,pH由6.5降至5.0时,NO^(-)_(2)还原速率反而略有升高,达10.88 mg/(h·g)VSS,N_(2)O产生率由2.07%升至7.17%,但总体保持在较低水平。处理酸性废水系统中,unclassified_k_norank_d_Bacteria和Thauera属成为优势反硝化菌,它们对N_(2)O的减量释放起到重要作用。

Using nitrite denitrification to treat acidic wastewater has the advantages of saving carbon sources and reducing the amount of excess sludge.The start-up and stable operation of denitrification using nitrite as the electron acceptor were successfully achieved by increasing the influent NO~-_(2) concentration and reducing the influent pH in a laboratory-scale SBR,and N_(2O) emission in single cycle and change of community was also investigated under long-term acidic conditions.The results showed that when the pH decreased from 6.5 to 5.0,the reduction rate of NO~-_(2) slightly increased to 10.88 mg/(h·g) VSS,and the N_(2O) production rate remained a low level from 2.07% to 7.17%.In the acidic wastewater treatment system,unclassified_ k_ norrank_ d_ Bacillus and Thauera became dominant denitrifying bacteria and they played an important role in reducing N_(2O) emission.