What is Odor Control:

An odor is defined as a sensation resulting from the reception of a stimulus by the olfactory sensory system. Controlling odors is an important consideration for protecting the environment and our community amenity. Odors can be generated from a vast range of sources including sewage treatment processes and industrial effluents.

 

Odor Control Technologies:

Typical odor emission control applications are the removal of odor from sewage treatment plants & sewage wet waste. Odor related complaints from communities surrounding WWTPs have been increasing for many WWTPs. Here, several emission sources need odor control equipment, e.g. such as pump stations, wet wells, sludge dewatering, manholes, air valve chambers, and sludge trans-shipment operations from silo into trucks. Sewage odor consists of mainly hydrogen sulphide & H2S is dangerous to be released to the environment. Hydrogen sulphide, the gas, also contains organic sulphur components (mercaptans, hydrocarbons) and ammonia.

Odor control technologies can be grouped into three distinct categories:
1. Chemical Absorption
(acid and caustic wet scrubbing)

2. Biological Oxidation
(bio-filtration and bio-scrubbing)

3. Adsorption
(activated carbon and other adsorptive medias)

4. The Combination of above systems are usually used for Biological Oxidation & Cehmical Scrubbing

Chemical Absorption

Chemical Absorption:

Chemical scrubbers achieve odor removal by mass transfer absorption via contact of air stream with aqueous solution on random packing material in a scrubbing chamber. The liquid is typically water, adjusted to the proper pH and oxidation potential by chemicals.

Two parameters define the performance of any absorption scrubbing system. These are the efficiency of gas/liquid contact and the adequacy of a chemical within the aqueous phase to promote reaction and absorption. Corodex Industries uses a special media which increases the efficiency of the scrubber in smaller tower size.

Main features:
1. Scrubbing liquid make-up system
2. Scrubbing liquid re-circulation system
3. Scrubbing liquid discharge system
4. Scrubbing liquid system
(chemical for adjusting the pH and ORP value )
5. Ventilation system

Biological Oxidation

Biological Oxidation:

Biological oxidation is a process by which the bacteria and other types of micro-organisms consume dissolved oxygen and organic substances in wastewater, using the energy released to convert organic carbon into carbon dioxide and cellular materials.

Biological oxidation is broken into two broad categories:


1. Bio-oxidation using inorganic media
(bio-scrubbers or bio-trickling filters)
2. Bio-oxidation using organic media
(traditionally referred to as biofilters)

Main features:

1. Scrubbing liquid make-up system
2. Scrubbing liquid re-circulation system
3. Scrubbing liquid discharge system
4. Nutrient dosing system
5. pH controller system
6. Ventilation system
Odor-Control-Technologies-Biological-Oxidation

Adsorption

Adsorption:

Adsorption is a process that uses activated carbon to adsorb odorous compound into activated carbon material. This is accomplished by passing the odorous air across a bed of activated carbon, allowing the adsorptive process to occur and releasing the clean air to atmosphere.

Main features:

1. Prefiltration system (demister)
2. Ventilation system
3. Carbon mediaOdor-Control-Technologies-Adsorption

Combined Technologies

Combined Technologies:

When a situation arises, where an odor stream contains both high levels of H2S and significant level of organic sulfur compounds. In a combined systems consisting of 2 technologies become more pratical. For this particular instance, a first stage system such as a bio-scrubber or
catalytic carbon system might be used for removing the H2S. A second stage bio-filter system would then be ideal to treat the mercaptans and any remaining H2S, which at this point would be at a very low level.

Another situation that often requires a combination approach is that of odor control in sensitive areas. There are times when the odor source is quite close to facility fence line. Some odor control technologies have an odor unit level at their discharge that might not be acceptable if the neighbors are close to the fence line. For example, bio-filters have an effluent odor unit (OU) level between 200 and 400 OU. This level may represent a considerable reduction of odors prior to the bio-filter but may still be too high for the neighbors. In this case, a solution would be to add a second stage activated carbon system to further reduce the OU level to 100 or less. This odor control technique is known as polishing.