污泥返混对自热高温好氧消化效果的影响研究

Effect of sludge backflow on autothermal thermophilic aerobic digestion process

研究了污泥返混对自热高温好氧消化(ATAD)效果的影响。通过对二沉池污泥稳定化效果的考察,研究了间歇式ATAD过程中有机物、氮、磷等的变化情况。结果表明,有10%(质量分数)的消化污泥返混时,在消化15d时污泥挥发固体(VS)去除率达到38.5%;而无消化污泥返混时,污泥VS的去除率仅为33.4%;在消化21d后,前者和后者的VS去除率分别为40.1%和39.9%,均达到污泥稳定化的要求。研究发现,两个反应器污泥ATAD过程中溶解性COD(SCOD)、氨氮含量均呈现消化初期快速上升、消化中期在一定范围内波动、消化后期下降的趋势;TP、TN含量呈现出消化初期快速上升,消化中后期在一定范围内波动的趋势。

The effect of sludge backflow on sludge autothermal thermophilic aerobic digestion （ATAD） process was investigated through batch experiments. The variation of volatile solids （VS）, pH,ORP and SCOD as well as the transformation of nitrogen, phosphorus during ATAD process was monitored to study the stabilization efficiency of sludge. It was showed that VS removal rate reached to 38.5% after 15 days of digestion with 10% backflow of diges- ted sludge. However,the VS removal rate was only 33.4% when there was no sludge backflow. The VS removal rate increased to 40.1% and 39.9 % respectively after 21 days of digestion,the digested sludge all achieves the standard of sludge stabilization. During the ATAD process with and without sludge backflow,the soluble chemical oxidation de- mand （SCOD） and ammonia nitrogen （NH4＋-N） increased rapidly at the beginning of digestion,kept in stable at the middle stage, and decline progressively at the end of digestion. For total phosphorus and total nitrogen, they remained stable after the sharply rise at the beginning of digestion.