Unit 17

1. Unit 17 Activated Sludge Processes 活性污泥法

2. 回流 进水 出水 初沉沉淀 好氧生物处理 消毒 二次沉淀 预处理 剩余污泥 污泥浓缩和脱水 Schematic diagram of conventional wastewater treatment

3. Activated sludge processes； 1)conventional activated sludge process 传统活性污泥法 2)extended aeration process延时曝气法 3)contact stabilization 接触稳定法（吸附-再生法） 4)high-rate modified aeration高负荷法 5)oxygen-activated sludge纯氧曝气活性污泥法 6)step aeration（ 阶段曝气）分段进水活性污泥法 etc.

4. The mixture is referred to as mixed liquor. • 混合物被称作混合液。

5. Some of the organic material is synthesized into new cells or used to support growth of existing cells; the surplus is comprised of waste and excess sludge. 有机物质一些被（微生物）合成新细胞或者由于已有细胞的生长；余下的部分为（没被分解）的废物和剩余污泥。

6. The clarifier overflow proceeds to disinfection and final discharge or to supplemental treatment, if needed. • 沉淀池的溢流进入消毒和最终排放，必要时，还应由追加处理（来达到排放标准的要求）

7. The MLSS represents the quality of microorganisms performing treatment in the aeration basin. • MLSS表示曝气池中起处理作用的微生物的量。

8. volumetric loading 容积负荷 ABV—— aeration basin volume 曝气池体积 CML 曝气池悬浮固体浓度 CRS 回流污泥中悬浮固体浓度 Y 微生物产率系数 D 微生物衰减系数

9. A primary advantage of this system is its relatively low initial cost • 传统活性污泥法工艺的主要优点是相对低的基建投资。

10. The basic principle of the extended aeration process is to retain the mixed liquor in the aeration basin long enough so that the production rate of new cells is the same as the decay rate of existing cells. • 延时曝气的基本原理是使混合液在曝气池内停留时间足够长，这样可使新生细胞的产率与已有细胞的衰减速率相等。

11. The premise of the contact stabilization process is that colloidal and insoluble BOD is removed rapidly by biological sorption, synthesis, and flocculation during a relatively short contact time. 接触稳定法的前提是胶体和溶解状态的BOD通过生物吸附、合成和絮凝作用在相对短的接触时间内可被快速去除。

12. The return sludge goes to a reaeration (stabilization) basin where the flocculated and absorbed BOD is stabilized before discharge to the contact basin. • 回流污泥进入一个再生池，其中被絮凝和吸附的BOD在污泥排入到接触池前得以再生（稳定）。