碳氮比对短程反硝化过程中N_2O产生的影响  

Effect of C/N ratio on N_2O accumulation and reduction during nitrite denitrification process

作　　者：巩有奎[1] 王淑莹[1] 王莎莎[1] 王赛[1] 

机构地区：[1]北京工业大学环境与能源工程学院,北京100022

出　　处：《化工学报》2011年第7期2049-2054,共6页CIESC Journal

基　　金：'城市水资源与水环境国家重点实验室'开放基金项目(QAK201006);北京市属高等学校人才强教计划高层次人才资助项目(PHR20090502);北京工业大学第九届科技创新基金(ykj-2011-5374)~~

摘　　要：采用体积为3 L的SBR反应器,通过投加NaNO2的方式调节反硝化初始NO-2-N为20 mg N.L-1,同时,投加0、0.05、0.1、0.2 ml乙醇调节初始碳氮比（C/N）分别为1.8、2.5、3.2、4.5,考察了不同C/N下亚硝的还原及N2O的变化情况,不同碳氮比条件下,最高N2O积累量分别为333、200、245、256μmol.L-1。随C/N增加,亚硝反硝化速率和N2O生成速率增加。内源反硝化N2O还原速率为35~45 mg N.（g MLSS）-1.h-1,外碳源反硝化N2O还原速率为172 mg N.（g MLSS）-1.h-1。短程反硝化过程中,反硝化初始阶段会产生N2O的积累,其主要原因是氧化亚氮还原酶的合成速率小于亚硝态氮还原酶的合成速率;低碳氮比条件下,亚硝态氮还原酶和氧化亚氮还原酶竞争内碳源电子供体,导致N2O的积累;高碳氮比条件下,NO-2和N2O同时被还原,不会产生N2O的大量积累。The effect of C/N ratio on kinetics of nitrite denitrification,as well as the corresponding N2O accumulation and reduction were investigated in a 3 L sequencing batch reactor.The initial 20 mg N·L-1 NO-2-N was obtained by adding NaNO2.The C/N ratios 1.8,2.5,3.2 and 4.5 were reached by adding 0,0.05,0.1,0.2 ml ethanol respectively.The highest N2O accumulation was 333、200、245 and 256 μmol·L-1 for each C/N ratio.The nitrite reduction and N2O production rate increased with the increase of C/N ratio.The reduction rate of N2O was about 35—45 mg N ·（g MLSS）-1·h-1 for using internal carbon sources as electron donor and 172 mg N·（g MLSS）-1·h-1 for using external carbon source.The accumulation of N2O at the initial of denitrification process was attributed to the imbalance between synthesis of NO-2 reductase and N2O reductase.Under lower C/N ratio,the competition of nitrite reductase and nitrous oxide reductase for electron donor resulted in accumulation of N2O.Under higher C/N ratio,the reduction of NO-2 and N2O happened simultaneously and large amount of N2O accumulation may not happen.

关 键 词：亚硝态氮反硝化 碳氮比 N2O 内碳源 

分 类 号：X703[环境科学与工程—环境工程]