Zupancic Gregor D, Ros Milenko
National Institute of Chemistry, Hajdrihova 19, Ljubljana, Slovenia.
Bioresour Technol. 2008 Jan;99(1):100-9. doi: 10.1016/j.biortech.2006.11.054. Epub 2007 Jan 23.
The degradability of excess activated sludge from a wastewater treatment plant was studied. The objective was establishing the degree of degradation using either air or pure oxygen at different temperatures. Sludge treated with pure oxygen was degraded at temperatures from 22 degrees C to 50 degrees C while samples treated with air were degraded between 32 degrees C and 65 degrees C. Using air, sludge is efficiently degraded at 37 degrees C and at 50-55 degrees C. With oxygen, sludge was most effectively degraded at 38 degrees C or at 25-30 degrees C. Two-stage anaerobic-aerobic processes were studied. The first anaerobic stage was always operated for 5 days HRT, and the second stage involved aeration with pure oxygen and an HRT between 5 and 10 days. Under these conditions, there is 53.5% VSS removal and 55.4% COD degradation at 15 days HRT - 5 days anaerobic, 10 days aerobic. Sludge digested with pure oxygen at 25 degrees C in a batch reactor converted 48% of sludge total Kjeldahl nitrogen to nitrate. Addition of an aerobic stage with pure oxygen aeration to the anaerobic digestion enhances ammonium nitrogen removal. In a two-stage anaerobic-aerobic sludge digestion process within 8 days HRT of the aerobic stage, the removal of ammonium nitrogen was 85%.
对一家污水处理厂剩余活性污泥的可降解性进行了研究。目的是确定在不同温度下使用空气或纯氧时的降解程度。用纯氧处理的污泥在22摄氏度至50摄氏度的温度下被降解，而用空气处理的样品在32摄氏度至65摄氏度之间被降解。使用空气时，污泥在37摄氏度以及50 - 55摄氏度时能有效降解。使用氧气时，污泥在38摄氏度或25 - 30摄氏度时降解效果最佳。研究了两级厌氧 - 好氧工艺。第一级厌氧阶段的水力停留时间（HRT）始终为5天，第二阶段包括用纯氧曝气，HRT在5至10天之间。在这些条件下，当HRT为15天（5天厌氧，10天好氧）时，挥发性悬浮固体（VSS）去除率为53.5%，化学需氧量（COD）降解率为55.4%。在25摄氏度的间歇式反应器中用纯氧消化的污泥将48%的污泥总凯氏氮转化为硝酸盐。在厌氧消化过程中添加一个纯氧曝气的好氧阶段可提高铵氮去除率。在好氧阶段水力停留时间为8天的两级厌氧 - 好氧污泥消化过程中，铵氮去除率为85%。
