Datta Tania, Liu Yanjie, Goel Ramesh
Department of Civil and Environmental Engineering, University of Utah, 122 South Central Campus Drive, Salt Lake City, UT 84112, USA.
Chemosphere. 2009 Jul;76(5):697-705. doi: 10.1016/j.chemosphere.2009.02.040. Epub 2009 May 5.
The treatment and disposal of excess sludge has been a rising challenge for wastewater treatment plants worldwide. In this study, simultaneous sludge reduction and nutrient removal was evaluated in laboratory scale sequencing batch reactors (SBRs). Two SBRs were operated alongside for a duration of 370d. One SBR was operated to achieve nutrient removal (control-SBR) at 10d solids retention time (SRT), while the other (modified-SBR) was operated to achieve nutrient removal along with sludge reduction. Sludge reduction in the modified-SBR was accomplished by subjecting the recycled biomass to feasting and fasting at sufficiently high SRT close to infinity (phase I and II) and finite SRT (phase III). The observed biomass yield in the modified-SBR was estimated to be 0.17mg TSSmg(-1) COD, representing 63% sludge reduction compared to the control-SBR. The NH(3) levels in the effluents from both SBRs always remained below detection limit. The average dissolved phosphorus removal efficiencies in the control-SBR and the modified-SBR were 87% and 84%, respectively, during phase II. However, the biomass of the modified-SBR increased during phase II. To control this, biomass wastage was initiated directly from the modified-SBR during phase III at a rate equivalent to the observed biomass accumulation rate in the system in phase II. This resulted in an overall 100d SRT for the modified-SBR system. Following this change, biomass accumulation in the modified-SBR was controlled, and a net 63% sludge reduction could be sustained along with 90% phosphorus and 100% NH3 removal. Consistent denitrification activities were also noticed in both SBRs despite the absence of any carbon source during the anoxic phase of every cycle.
剩余污泥的处理与处置一直是全球污水处理厂面临的日益严峻的挑战。在本研究中，在实验室规模的序批式反应器（SBR）中评估了同步污泥减量和营养物去除效果。两个SBR同时运行370天。一个SBR在10天的固体停留时间（SRT）下运行以实现营养物去除（对照SBR），而另一个（改良SBR）运行以实现营养物去除并同时进行污泥减量。改良SBR中的污泥减量是通过使循环生物量在足够高的接近无穷大的SRT（第一阶段和第二阶段）和有限的SRT（第三阶段）下进行“ feast and fasting”来实现的。改良SBR中观察到的生物量产率估计为0.17mg TSSmg(-1) COD，与对照SBR相比，污泥减量达63%。两个SBR出水的NH(3) 水平始终低于检测限。在第二阶段，对照SBR和改良SBR中溶解磷的平均去除效率分别为87%和84%。然而，改良SBR的生物量在第二阶段有所增加。为控制这一情况，在第三阶段直接从改良SBR中以与系统在第二阶段观察到的生物量积累速率相当的速率进行生物量排放。这使得改良SBR系统的总SRT为100天。在此变化之后，改良SBR中的生物量积累得到控制，并且可以维持63%的净污泥减量以及90%的磷去除率和100%的NH3去除率。尽管在每个周期的缺氧阶段没有任何碳源，但两个SBR中也都观察到了持续的反硝化活性。
