利用活性污泥快速富集污水碳源的试验研究

Quickly Enrichment of Carbon in Wastewater by Activated Sludge

通过小试研究了活性污泥对城市污水中有机物的吸附特征,分析了富碳污泥在静置沉降过程中对有机物的释放过程.结果表明,活性污泥能够快速吸附污水中的碳源,约10 min左右即可完成对不溶性有机物的吸附,对溶解性有机物的吸附过程较慢(约30 min).富碳污泥在进行静置泥水分离过程中,存在有机物释放过程,在30～100 min的静沉时间段,TCOD的释放量约为11.44 mg.g-1;60～150 min的静沉时间段,SCOD的释放量约为6.24 mg.g-1.同时,以小试结果为依据,建立了一套中试活性污泥富碳系统,研究了连续运行模式下,活性污泥对污水碳源和氮磷的吸附效果,以及富碳活性污泥的沉降特性.结果表明,通过活性污泥的吸附作用,COD、TN和TP的平均去除率可以分别达到60%、10%和75%,富碳污泥SVI为34.2mL.g-1.本研究结果的应用不但可以有效地回收污水中的碳源,还可以减轻后续处理负荷,起到稳定进水水质的作用,有利于降低废水C/N值,提高后续的硝化处理效果.

Pilot tests were carried out to investigate the absorption characteristics of the carbon source in urban wastewater by activated sludge and to analyze the carbon release from the carbon absorbed activated sludge in the settling process.The results indicated that carbon in wastewater could be quickly enriched by activated sludge.The absorption process of indissolvable organic matter could be finished as shortly as less than 10 min,while the absorption process of the dissolved organic matter was relatively slow and should consume up about 30 min.Moreover,carbon release was observed in the settling process of enriched sludge.In the period of 30-100 min,the release amount of total COD（TCOD） was 11.44 mg·g-1,while in the period of 60-150 min,the release amount of dissolved COD（SCOD） was 6.24 mg·g-1.Furthermore,based on the results of the bench-scale tests,a pilot-scale plant was built to investigate the absorption of carbon,nitrogen and phosphorus by activated sludge and the settleability of enriched sludge.The results indicated that under continuously operation mode,60% of COD,75% of TP and 10% of TN in the wastewater could be removed by the absorption of activated sludge,and the enriched sludge with SVI of 34.2 mL·g-1 presented good settleability.Carbon enrichment by activated sludge could not only reclaim the carbon source in wastewater,but also reduce the loading of organic matter and give low C/N for the following nitrification unit and improving the nitrification efficiency.