挥发性脂肪酸和氨氮对污泥厌氧消化中病原指示微生物灭活的影响

通过外源添加不同浓度挥发性脂肪酸(VFA)和氨氮,模拟研究剩余污泥固态中温(35℃)厌氧消化条件下,VFA和氨氮浓度对病原指示微生物灭活效果的影响。试验结果表明:经过VFA组持续8 d和氨氮组持续28 d的厌氧消化后,消化液中的总大肠杆菌和粪大肠杆菌的杀灭率均达到99.9%以上;且初始VFA和氨氮浓度越高,消化系统中病原指示微生物的灭活效果越好。厌氧消化结束后,高浓度VFA组和氨氮组粪大肠杆菌均在检测限以下,表明剩余污泥固态厌氧消化中产生的高浓度VFA和氨氮能够提高剩余污泥消化残渣的生物安全性。

Effect of volatile fatty acids and ammonia nitrogen concentration on pathogen indicators inactivation during sludge anaerobic digestion

The effect of volatile fatty acid （VFA） and ammonia nitrogen on pathogen indicators inactivation during excess sludge anaerobic digestion were investigated through a simulation test of adding VFA and ammonia nitrogen with different concentrations into substrate under medium temperature （35 ℃ ） condition. The results showed that, VFA and ammonia nitrogen were both important factors affecting the inactivation of pathogen indi- cators. After a 8-day anaerobic digestion with VFA addition or a 28-day anaerobic digestion with ammonia nitro- gen addition, more than 99.9% of total coliforms and fecal coliforms in digestive juice were inactivated; and the inactivation effect was improved with the increase of VFA and ammonia nitrogen concentration. At the end of the anaerobic digestion, the density of fecal coliforms in groups with high concentration VFA or ammonia nitrogen addition was under the detection limit, which indicated that, high concentration VFA and ammonia nitrogen pro- duced during the anaerobic digestion could enhance the biological safety of the excess sludge digestion residue.