季节性温差变化对非控温PN-Anammox工艺稳定脱氮的影响

Effect of seasonal temperature difference on stable nitrogen removal of non-temperature controlled PN-Anammox process

采用具有自回流的分区式部分亚硝化(PN)和厌氧氨氧化(Anammox)耦合工艺,利用季节性温度的变化,研究了逐步降温对耦合工艺整体脱氮效能及各区域氮素转化能力的影响.结果表明,当温度由35℃降低到25℃时,因厌氧区Anammox的氮去除速率由18 kg·m^-3·d^-1下降到9 kg·m^-3·d^-1,导致耦合工艺的整体氮去除速率大幅度下降,由1 kg·m^-3·d^-1下降到0.5 kg·m^-3·d^-1.当温度降低到20℃时,联合工艺的脱氮速率下降趋势趋于缓慢,但好氧区的NO-2-N生成速率开始明显下降,由0.9 kg·m^-3·d^-1下降到0.2 kg·m^-3·d^-1.同时,亚硝化菌(AOB)的优势生长被打破,硝化菌(NOB)开始大量增长,出水NO-3-N浓度迅速增大.运用Arrhenius公式对联合工艺总氮去除速率及各个区域氮转化速率与温度的关系进行非线性拟合,发现厌氧区Anammox的氮去除速率的温度特征系数比好氧区NO-2生成速率的温度特征系数大,表明温度对PN-Anammox工艺的Anammox的效能影响更大.

The effect of gradual cooling on the nitrogen removal rate of each area in partial nitrification-anaerobic ammonia oxidation(PN-Anammox)process reactor was studied by using a series of partial nitrification and Anammox process with recycling device with the seasons change.The results showed that,when temperature reduced to 25℃,the total nitrogen removal rate dropped from 1 kg·m^-3·d^-1 down to 0.5 kg·m^-3·d^-1 in combined process due to nitrogen removal rate declined obviously from 18 kg·m^-3·d^-1 down to 9 kg·m^-3·d^-1 in anaerobic zone,When the temperature reduced to 19℃,and nitrite produce rate begin to declined obviously from 0.9 kg·m^-3·d^-1 to 0.2 kg·m^-3·d^-1 in aerobic zone,the total nitrogen removal rate declined a bit.At this point,the NO-3-N concentration in effluent increased quickly,shows that the advantage of AOB growth was broken,while NOB started to grow a lot.The temperature coefficient of Arrhenius law for nitrogen removal rate in anaerobic zone was higher than aerobic zone,shows that temperature has more influence on Anammox process.