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WHY DIFFUSED AERATION FAILS IN AERATION SYSTEM?

By Environ

September 4, 2014

When, Evaluating Aeration System, a total performance & cost of operation analysis is critical. The components of this analysis should include an evaluation of the initial capital cost of system installation, all operating and energy costs, & projected maintenance costs. Also included should be an analysis of how well the systems perform the four basic functions required of all Aerators:

1) Provide sufficient Oxygen Transfer to promote biological treatment.

2) Provide sufficient mixing to ensure homogeneity of mixed liquor suspended solids & to prevent solids settling.

3) Respond to varying process conditions to maximize energy efficiency.

4) Provide reliable service, without costly maintenance & downtime, and without reduction in oxygen transfer capability.

A detailed evaluation will quickly reveal that diffused aeration systems (IN INDIA) are able to perform only one basic function reasonably well. On the other hand, the NEW GENERATION of ENVIRON ENERGY EFFICIENT AERATORS accomplishes all four goals exceptionally well – Efficient Aeration , Excellent Mixing, Operational Flexibility & a Life Expectancy of 12 – 15 years with Minimal Maintenance.

Point to be Consider: Diffused Aeration System have gained popularity based on only one aspect of their performance: they provide high oxygen transfer efficiencies in CLEAN WATER. But, the waste water is not clean. A fine bubble diffused system which performs efficiently in clean water instantly becomes less efficient in waste water. Secondly, Mixing Efficiency is missing in Diffused Aeration System. Over a few months or so, the degrading of Oxygen Transfer Efficiency becomes more pronounced until, eventually, the Diffusers Porous Membranes will need to be cleaned manually. This is an undesirable & time consuming maintenance operation ( THE INDUSTRIES – ETP / MUNICIPAL CORPN.- STP / CETP / EXPERTS / PLANT OPERATORS / ENVIRONMENTAL ENGINEERS / TURNKEY EXECUTORS WHO HAVE FACED SUCH PROBLEMS WILL AGREE WITH THIS )

Surface Aerators, unlike diffusers, never foul, & will provide the same High Oxygen Transfer Rate along with Efficient Mixing with minimum & economical running & also saving in Energy over the life of the equipment.

Secondly, in Diffused Aeration System, as the Blower blows hot air, the temperature of the effluent rises by 50 to 80 due to which the Oxygen Transfer Efficiency reduces. While in ENVIRON ENERGY EFFICIENT AERATORS, due to efficient mixing the temperature of the effluent reduces by 100 to 200 (DEPENDING ON AMBIENT TEMP.)& hence Oxygen Transfer Efficiency increases.

The distribution of AIR is also not equal in Diffused Aeration System. While, the air is equally distributed in all the 4 corners of the Aeration Tank without settlement of sludge by ENVIRON ENERGY EFFICIENT AERATORS.

Spares, like Diffusers, Maintenance of Blowers is costly & Time consuming & specialized mechanic is required. In Environ Energy Efficient Aerators the additional features are provided, due to which Maintenance is very low (almost nil) & less time consuming. Only Gearbox is to be maintained which can be maintained by maintenance department.

Noise level of the blowers is more. Secondly, stand by Blowers is required. Noise level is low in our Aerators

In Foreign countries Aeration System having more depth of Aeration Tank, they use this system but they place the Diffusers at a very short distance (about 220mm, while in India the Diffusers are placed at about 1 mtr. – 1.5mtrs Or even more distance due to which sludge is settled between two diffusers & the results are not achieved), but if the Diffusers are placed at a short distance as placed in foreign countries, the POWER REQUIRED WILL BE MORE THAN 3 – 3.5 TIMES THAN THE POWER REQUIRED IN MECHANICAL AERATION SYSTEM. Secondly, If the system is installed as per the recommendation of the manufacturers of foreign countries then the Installation, Operational & Maintenance cost will also increase.

Secondly, the main reason of using Diffused Aeration System in foreign countries, the ambient temperature is TOO LOW due to which the Oxygen Transfer Efficiency increases, but the whole thing is reverse for INDIA.