Following are the three methods which are employed for the purpose of aeration in activated sludge process: 1. Diffused Air Aeration 2. Mechanical Aeration 3. Combined Diffused Air and Mechanical Aeration. Method # 1. Diffused Air Aeration: In the diffused air aeration method compressed air is introduced into the mixture of sewage and returned activated sludge (or mixed liquor) in [...]
Various systems of mechanical aeration have been developed to achieve the required Agitation, most of which are patented. Some of these systems of mechanical aeration which are commonly used are as indicated below: 1. Hartley System or Birmingham Bio-Flocculation System 2. Haworth System or Sheffield Aeration System 3. Link-Belt System 4. Kessener System 5. Simplex System. 1. Hartley System or [...]
The various types of activated sludge processes are listed below: 1. Conventional Activated Sludge Process 2. Tapered Aeration Process 3. Step Aeration Process 4. Contact Stabilization Process 5. Complete Mix Process 6. Modified Aeration Process 7. Extended Aeration Process. The characteristics and design parameters for these processes are given in Table 13.3. These processes are described in details below: Type [...]
In this article we will discuss about:- 1. Introduction to Activated Sludge Process 2. Oxygen Requirements and Transfer 3. Secondary Settling 4. Advantages and Disadvantages of Activated Sludge Process. Introduction to Activated Sludge Process: The activated sludge process was developed in England in 1914 by Ardern and Lockett and was so named because it involved the production of an activated [...]
The following are the various types of activated sludge process: 1. Tapered Aeration 2. Step Aeration 3. High Rate Treatment or Modified Aeration 4. Two Stage Aeration 5. Activated Aeration 6. Reaeration 7. Contact Stabilization 8. Complete Mix 9. Extended Aeration Method. Type # 1. Tapered Aeration: This is also called controlled aeration. If samples are collected at various points [...]
In this essay we will discuss about:- 1. Meaning of Activated Sludge 2. The Activated Sludge Process 3. Variables 4. Capacity of Aeration Tank and Detention Period 5. Return Activated Sludge 6. Advantages and Disadvantages 7. Operation of Activated Sludge Plant. Essay # 1. Meaning of Activated Sludge: When sewage is passed or trickles through a grit bed, the sewage [...]
Aeration units are the main units of the activated sludge process, the main aims of which are to supply oxygen to the sewage; to keep the return sludge aerobic and to mix up the return sludge with sewage thoroughly. All the aeration units can be broadly classified as follows: 1. Diffuser Air Units 2. Mechanical Aeration Units 3. Combined Mechanical [...]