硫化物对亚硝化污泥的活性抑制研究

Study on the inhibition of sulfide on activated sludge activity for nitritation

污水厂进水或厌氧单元出水中的硫化物会对污水处理工艺的硝化反应过程产生潜在抑制作用,认识和调控硫化物对活性污泥生化反应过程的影响对污水厂工艺的发展具有重要意义.亚硝化过程对于保障污水工艺氮的去除至关重要,本研究以硫化物对亚硝化过程的影响为研究对象,探讨相关影响过程的特征和发生机制.同时,选择不同典型浓度范围的硫化物和不同存在状态对亚硝化过程的影响开展研究.结果表明,硫化物浓度由10 mg·L^(-1)提高到30 mg·L^(-1),氨氧化抑制率由16.3%提高到40%,但随着硫化物浓度进一步升高,氨氧化抑制率上升并不明显.进一步通过硫化物对羟胺氧化反应的影响实验发现,硫化物导致羟胺氧化速率下降要大于氨氧化阶段.同时系统内硫化物耗尽后,氨氧化反应和羟胺氧化反应均不能完全恢复.铁盐作为常见的硫化物去除剂,铁盐加入后并未能够有效消除硫化物对亚硝化过程的抑制.

Understanding the impact of sulfide on the biochemical reaction of activated sludge for nitritation is great significance in wastewater treatment plants. This study systematically investigated the inhibition effect of sulfide on ammonia oxidation activity of activated sludge. The ammonia oxidation activity gradually decreased from 16.3% to 40% with the sulfide concentration increasing from 10 mg·L^-1 to 30 mg·L^-1,and maintained at this level despite that the sulfide concentration kept increasing. By the experiment of hydroxylamine oxidation rate,we found that sulfide inhibition effect on the hydroxylamine oxidation was bigger than ammonia oxidation. Afterwards,sulfide was aerobically depleted in the aqueous solution system. However,the ammonia and hydroxylamine oxidation activity could not both be recovered. Further experiment indicated that the ammonia oxidation activity could also not be recovered by adding ferrous chloride,which has been previously considered as a useful chemical for eliminating sulfide inhibition.