温度对好氧颗粒污泥脱氮性能及颗粒稳定性的影响

以乙酸钠与葡萄糖混合基质为碳源,采用间歇式气升内循环反应器(SBAR),以颗粒解体后含有大量丝状菌的污泥为接种污泥,考察了颗粒污泥反应器的启动及温度对好氧颗粒污泥脱氮性能与颗粒稳定性的影响.结果表明,在温度为20℃时,成功实现了颗粒污泥反应器的启动,形成的颗粒结构致密,表面光滑;污泥容积指数(SVI)为70mL/g,平均粒径为3.2mm,平均湿密度为1.029g/mL.当温度直接升高到26℃时,出水NH4+-N由10.6mg/L降为0.2mg/L,同时出现了出水亚硝酸盐的积累,积累率达到93.9%.但是,在温度升高后的47d中,由于胞外多聚物(EPS)中蛋白质与多糖比值的降低,导致颗粒表面的电负性的增加,最终使得颗粒逐渐解体.

Effect of temperature on performance of ammonia nitrogen removal with aerobic granular sludge and granule stability

The experiment was carried out in a sequencing batch airlift reactor (SBAR) using mixture of sodium acetate and glucose as carbon source. Start-up of the aerobic granular reactor and effect of temperature on the removal characteristics of ammonia nitrogen and granule stability were investigated. Aerobic granule with compacted structure and smooth surface could be obtained at 20℃ using the disintegrated granules as inoculated sludge. The average diameter, density and SVI of the obtained granules were 3.2mm, 1.029g/mL and 70mL/g, respectively. When temperature directly increased from 20℃ to 26℃, the ammonia concentration in effluent was reduced from 10.6 to 0.2mg/L. At the same time, nitrite accumulation in effluent was observed with a nitrite accumulation ratio (NO₂^--N/NO_x^--N) of 93.9%. However, granules disintegrated gradually due to the decreased ratio of protein to polysaccharide in extracellular polymeric substance (EPS) during the following 47d tests.