Thursday, November 5, 2009

Aeration Tank

Aeration tank is the major of the wastewater treatment structure. Treatment of wastewater using aeration equipment also called secondary treatment. Design of aeration tank absolutely refer to incoming load to the tank.

Aeration tank refers to several design for the activated sludge treatment type. A few secondary treatment tank are listed as below:
  1. Extended aeration
  2. Oxidation ditch
  3. Batch reactor
For extended aeration tank, there are a few mutation where the process actually holding same concept such as:
  1. Loyal extended aeration (LEA) - the word "loyal" refers to the designers or the manufacturer of the tank and the tank made from fibers.
  2. Hi-Kleen - Normally known as a package plant where the whole structure from equilization tank, aeration tank and clarifier were ready made (fabricate in factory) from fiber or any suitable material.
The manufacturer are significantly using the same procedure in designing the treatment process, whereby the name normally to show to market about their company.

For batch reactor, few mutation of how the treatment stage are arrange prior completion of wastewater treatment process. Batch reactor means, a bulk/volume of wastewater be treated in the same tank. Batch reactor doesn't need clarifier during sedimentation stage. There are significant stage in the batch reactor includes:
  1. Aeration stage
  2. Settling/Sediment stage
  3. Decanting/remove clean water stage
Best arrangement from the stage means reduction of expenditure during STP development/construction. On the other side, the operator will also need extra expertise in order to adapt this situation. The criticality scoring will increase as the situation will increase risk of releasing failed FE to the natural receivers. A few type of arrangement will also produce a few names such as:
  1. IDEA - Intermittent Decanting Extended Aeration - become more popular in recent years.
  2. IDEAL - Intermittent Decanting Extended Aerated Lagoon.
  3. SBR - Sequencing Batch Reactor -most popular arragement in Malaysia because of the capabilty of existing designers and STP operator. (more easy than other 'batch' treatment process)