间歇曝气周期对低C/N比污水生物脱氮的影响

Effect of intermittent aeration cycle on biological nitrogen removal of wastewater with low C/N ratio

研究了间歇曝气生物脱氮工艺中 ,曝气周期和污水的 C/N比对脱氮效率的影响 ,以及氧化还原电位 (ORP)变化规律。中试试验结果表明 ,TN污泥负荷为 0 .0 5 kg/(kg MLVSS· d)时 ,间歇曝气系统的硝化反应所需曝气时间与总反应时间比至少要在0 .5以上 ,一周期内搅拌时间不宜超过 1h;反硝化过程中难以找到 ORP曲线突变点 ,因此 ,在低 C/N比污水生物脱氮中 ORP难以作为工程控制参数 ;由于原水的碳氮比太低 ,TN去除率只有 3 5 %～ 40 %左右 ,为提高脱氮效率有必要投入外加碳源。

The effects of intermittent aeration cycle, inlet C/N ratio on biological nitrogen removal efficiency and variation tendency of oxidation\|reduction potential (ORP) were studied. The results showed that a half time was needed in a intermittent aeration cycle to achieve sufficient nitrification, and the agitation time should be less than one hour in a cycle. Due to too low C/N ratio in inlet wastewater, the ORP bending\|point didn't appear in denitrification period and the TN removal efficiency was lower than 40%, so in this case, ORP was couldn't apply as process control parameter and it was necessary to add external carbon to improve nitrogen removal efficiency.