苯酚对厌氧氨氧化污泥脱氮效能长短期影响

通过接种厌氧氨氧化(ANAMMOX)污泥,研究了苯酚浓度对ANAMMOX污泥脱氮效能长短期影响.短期结果表明,随着苯酚浓度的增大,氮去除率快速下降.当苯酚浓度大于600 mg·L-1时,NH+4-N的去除率降低到6%以下,TN的去除率只有10%左右.长期实验结果表明,当苯酚浓度小于100 mg·L-1时,NH+4-N的去除率都能达到99%以上,说明低浓度苯酚对ANAMMOX菌有一个驯化的过程.当苯酚浓度高于400 mg·L-1时,NH+4-N的去除率只有23.59%,TN去除率只有50.3%,ANAMMOX污泥抑制明显,与短期结果相同.此时反硝化菌活性明显高于ANAMMOX菌,说明苯酚可作为有机碳源诱发体系中发生反硝化反应,最终导致反硝化菌在体系中占据主导地位.但高浓度(1 000 mg·L-1)苯酚对反硝化菌也具有抑制作用.通过拟合得到苯酚对ANAMMOX半抑制有效浓度(IC50)为71.57 mg·L-1.经过18 d的恢复后,NH+4-N去除率基本恢复,但氮素之间的转化计量式发生了改变,ρ(NH+4-N)去除/ρ(NO-2-N)去除/ρ(NO-3-N)生成为1∶0.86∶0.2.研究结果表明,将苯酚控制在合理范围内可以使反应器达到同步脱氮除酚的效果.

Short or Long Term Influence of Phenol on Nitrogen Removal Efficiency of ANAMMOX Sludge

The effects of phenol concentration on nitrogen removal efficiency in ANAMMOX sludge were studied in short or long term.The nitrogen removal rate decreased rapidly with the increase of concentration of phenol in short-term.When the phenol concentration was above 600 mg·L^-1, the removal rate of NH₄⁺-N was lower than 6% and the removal rate of TN was only about 10%.The long-term experimental results showed when the phenol concentration was below 100 mg·L^-1, the removal rate of NH₄⁺-N can reach 99%, which indicated that ANAMMOX bacteria have a process of adaptation to the low concentration of phenol.However, when the phenol concentration was above 400 mg·L^-1, the removal rate of NH₄⁺-N and TN was only 23.59% and 50.3%, the activity in sludge was significantly inhibited which was similarly to the short-term and the activity of denitrifying bacteria was significantly higher than ANAMMOX bacteria.As an organic carbon source, phenol can activated denitrification reaction and finally plays a dominant role in the system.However, the high concentration of phenol (1000mg·L^-1) also has an inhibitory effect on denitrification bacteria.Half inhibitory concentration (IC₅₀) of phenol to ANAMMOX activity was 71.57 mg·L^-1 by fitting.After 18 days' recovery, the stoichiometric ratios of nitrogen were changed, although the NH₄⁺-N was basicly removed.The ratio of removed NH₄⁺-N, reomved NO₂^--N and produced NO₃^--N was 1:0.86:0.2.Our results showed that the concentration of phenol should be controlled within a reasonable range, so that the reactor can achieve simultaneous removal of phenol and nitrogen.