污泥负荷对反硝化过程动力学和亚硝酸盐积累能力的探究

Effect of sludge loading on kinetics and nitrite accumulation capacity of denitrification process

为提高短程反硝化耦合厌氧氨氧化(PD/Anammox)工艺处理负荷,探究负荷对反硝化中氮转化途径的影响。在批次试验中探究不同污泥负荷对反硝化过程中动力学和亚硝酸盐积累能力的影响,并通过改变连续试验中的污泥负荷,共同探究其对短程反硝化过程的影响。在批次试验中,随着污泥负荷增高,NO_(2)^(-)-N及NO_(3)^(-)-N的反应速率都降低,但NO_(2)^(-)-N积累能力增强,亚硝酸盐积累率(NAR)最高达72.47%;在低污泥负荷下反应加快,同时也促进了NO_(2)^(-)-N还原速率,NAR降低至56.46%。在连续试验中,通过缩短HRT增大污泥负荷,反应器短程反硝化能力提升,NAR从26.86%提升至45.62%,污泥活性增加,反硝化活性试验中NAR达90.24%。污泥颗粒化结构明显,粒径和胞外聚合物含量增加。短期批次和长期连续试验结果表明,提升污泥负荷是提高反硝化过程中短程反硝化能力的有效策略。

To enhance the treatment capacity of partial denitrification coupled with Anammox(PD/Anammox)process,the impact of loading on nitrogen conversion pathway during denitrification process was investigated.Batch experiments were conducted to explore the effects of different sludge loadings on kinetics and nitrite accumulation capacity during denitrification.Additionally,by altering the sludge loadings in long-term continuous experiments,the influence of it on partial denitrification process was verified.In batch experiments,higher loadings resulted in lower reaction rates of NO_(2)^(-)-N and NO_(3)^(-)-N and higher NO_(2)^(-)-N accumulation capacity,with the nitrite accumulation rate(NAR)reaching a maximum of 72.47%.Under lower sludge loading,the reactions were accelerated,the NO_(2)^(-)-N reduction rate was increased and the NAR was reduced to 56.46%.In continuous experiments,increasing the sludge loading by shortening HRT improved the reactor′s partial denitrification capacity,rose the NAR from 26.86%to 45.62%,the sludge activity was increased,and in the denitrification activity test,the NAR reached 90.24%.The sludge exhibited a more granular structure,with increased particle size and extracellular polymeric substance content.The results of the short-term batch and long-term continuous experiments showed that,increasing sludge loading is an effective strategy to enhance the partial denitrification capacity during the denitrification process.