微膨胀对好氧颗粒污泥脱氮过程中N_2O产生量的研究

N_2O Production in Nitrogen Removal by Micro-expansion of Granular Sludge

采用控制低溶解氧(DO)在SBR反应器内,研究了好氧颗粒污泥微膨胀的实现;考察了微膨胀颗粒污泥对COD和氨氮去除效能以及温室气体N2O产生量.结果表明,在低DO条件下可以获得微膨胀颗粒污泥,污泥容积指数(SVI)大都在150～250 mL.g-1之间.微膨胀颗粒污泥对COD和氨氮去除量影响不大,COD去除率从89.45%上升到90.99%;氨氮去除率从77.29%降至68.29%;硝化速率从38.95×10-3 mg.(g.min)-1降至33.46×10-3 mg.(g.min)-1.微膨胀颗粒污泥对N2O产生量影响很大,微膨胀颗粒污泥N2O产生量为2.42 mg.m-3是没有发生微膨胀颗粒污泥N2O产生量的1.26倍.微膨胀颗粒污泥N2O释放速率由3.63×10-3mg.(L.min)-1上升到4.72×10-3mg.(L.min)-1.

Controlled low dissolved oxygen（DO） in a sequencing batch reactor（SBR） was used to study the realization of microexpansion of aerobic granular sludge,and the removal efficiency of COD and NH4＋-N as well as the production of the greenhouse gas N2O by the micro-expansion of granular sludge was investigated.The results showed that under the condition of low dissolved oxygen micro-expansion of sludge could be achieved,and the sludge volume index（SVI） was mostly in the range of 150-250 mL.g-1.The micro-expansion of granular sludge did not have significant influence on the removal of COD and NH4＋-N.The COD removal rate increased from 89.45% to 90.99%,the NH4＋-N removal rate decreased from 77.29% to 68.29%,and the nitrification rate dropped from 38.95 × 10-3 mg.（g.min）-1 to 33.46 × 10-3 mg.（g.min）-1.The micro-expansion of granular sludge had a big influence on the production of N2O,and the N2O production by the micro-expanded granular sludge was 2.42 mg.m-3,which was 1.26 times of the N2O production of the granular sludge without micro-expansion.The N2O release rate in the micro-expanded granular sludge increased from 3.63 × 10-3 mg.（L.min）-1 to 4.72 × 10-3 mg.（L.min）-1.