Permeate Flux and Treatment Efficiency in an Activated Sludge Process with Submerged Membrane Separation

浸没式膜分离活性污泥法是一种高效节能的污水处理工艺。特别是单反应器膜分离系统，由于系统组成简单，并且通过间歇曝气操作反应器，可以有效地去除富营养化问题的原因物质氮，因此现在对该系统的兴趣越来越大。然而，影响该系统脱氮和渗透通量的操作因素尚未明确，本研究通过连续运行的反应器来研究曝气周期和污泥负荷对这些性能的影响。首先，研究了曝气周期的影响。反应器在四种不同的曝气周期条件下运行。结果表明，30分钟曝气和30分钟不曝气的循环在脱氮和维持渗透通量方面都是最有效的。其次，研究了污泥负荷的影响。在高容积负荷条件下，对有排泥和无排泥的运行进行了比较。结果表明，无排泥运行方式，污泥负荷随运行时间的延长而降低，在两种运行方式中均具有优势。

Activated sludge process with submerged membrane separation is a high-efficient and energy-saving wastewater treatment process. Interest has been now growing particularly in a single-reactor membrane-separation system, because the system component is simple and nitrogen, which is a cause substance of the eutrophication problem, can be efficiently removed by operating the reactor with intermittent aeration. However, operational factors influencing on nitrogen removal and the permeate flux in this system have not been clarified yet.This study was conducted to investigate the effects of aeration cycle and sludge load on these performances by continuous operation of the reactors. First, the influence of aeration cycle was investigated. Reactors were operated under four different conditions of aeration cycle. As the results, a cycle of 30 minutes aeration and 30 minutes non-aeration was most effective in both nitrogen removal and the maintenance of permeate flux. Next, the influence of sludge load was investigated. Operation with sludge drawing was compared with the operation without sludge drawing under high volumetric load conditions. It was revealed that the operation without sludge drawing, in which sludge load was decreasing with time, had the advantage in both of the performances.