为了探讨碳氮比(ρ(C)/ρ(N))在反硝化过程中对于亚氮积累的影响,采用乙酸钠为碳源,在序批式实验中,通过控制进水碳氮比来研究反硝化包埋颗粒在反应过程中亚硝态氮积累的现象.实验结果表明:在反应过程中,不同的碳氮比条件下均出现亚硝态氮积累现象,且亚硝态氮积累率都表现出先升高后降低的趋势.其中,碳源充足(碳氮比为4.0~6.0)时,亚硝态氮积累率在30 min时达到最大,随后逐渐降低,反应结束时在碳氮比为4.0条件下仍有亚氮积累;当碳源不足(碳氮比为2.0~3.0)时,亚硝态氮的积累率在120 min达到最大,而后基本维持不变,说明可以通过控制碳氮比和反应时间来获得稳定的亚硝态氮积累.硝态氮和亚硝态氮的还原速率随着碳氮比的增加而逐步升高,而亚硝态氮的最大积累率与积累速率随着碳氮比的增加先升高后降低,在碳氮比为4.0时亚硝态氮的积累率和积累速率均达到最大,分别为40.8%和24.46 mg/(L·h),说明碳氮比对亚硝态氮的积累有显著影响.%In order to investigate the influence of nitrite accumulation during denitrification process, the nitrite accumulation in immobilized denitrification granules was studied in a lab-scale sequencing batch reactor ( SBR) , in which acetic sodium was used as the carbon source to control the influent ρ( C)/ρ( N) rate. The results showed that the nitrite accumulation significantly occurred during denitrification process under different ρ( C )/ρ( N ) rate and the trend shows that it first increased, then decreased. Furthermore, the maximum nitrite accumulation occurred at 30 min when ρ( C)/ρ( N) =4 -6, then decreased slightly, and the nitrite accumulation only occurred at ρ( C )/ρ( N ) ratio 4 at the end of reaction;owing to lack of carbon source (ρ?/ρ(N) =2-3) in SBR, nitrite accumulation reached the highest level at 120 min and then kept stable. This phenomenon indicated that the stable nitrite accumulation was maintained by controlling ρ( C)/ρ( N) and the reaction time. The reduction velocity of nitrate and nitrite increased slightly followed by the ρ( C)/ρ( N) increasing, but the accumulation rate and accumulation velocity of nitrite increased firstly and then decreased. When the ρ?/ρ(N) = 4, the largest nitrite accumulation rate and velocity were 40. 8% and 24. 46 mg/( L·h ) respectively. It indicated that the nitrite accumulation was affected by the ρ( C)/ρ( N) obviously.
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