BIO-OXIDATION - A TECHNOLOGY FOR SUSTAINABLE

Bioscrubber Advantages:

• save the cost of installing a humidification process
• smaller footprint than other bioreactors
• Because pH control and nutrient feed can be automated, it requires less attention than other bioreactors.
• Process is ideal for emissions that produce acids upon treatment.
• Bioscrubber can treat emissions containing particulate matter.

Media

• Media selection is critical in biofilter design. Media must provide a suitable environment for microbial growth and maintain a high porosity to allow air to flow easily. Critical properties of media material include (1) porosity, (2) moisture holding capacity, (3) nutrient content and (4) slow decomposition.
• Inoculum
• Operating conditions

Bio scrubber

consists of two reactors:-

• The first part is an absorption tower, where pollutants are absorbed by a liquid phase.
• second reactor, which is a kind of activated sludge unit, where microorganisms growing in suspended flocks in the water degrade the pollutants.
• The effluent of this unit is re-circulated

Bioscrubber Disadvantages:

• more expensive
• Over feeding can cause excessivebiomass growth, which can plug the bioscrubber.
• Operating cost can be higher
• Needs expensive and complex feeding and neutralizing systems.
• To control biomass growth, toxic and dangerous compounds must be inventoried and handled.

bio-scrubber

Bio oxidation

Bio-oxidation is a biological air pollution control technology that utilizes bacteria & fungi to biologically absorb and digest vapour phase VOCs and odorous compounds

Bio reaction

BIOTRICKLING FILTER

Bio-reaction is simply the use of microbes to consume pollutants from a contaminated air stream. Almost any substance, with the help of microbes, will decompose(decay) given the proper environment

• similar to a biofilter.
• pollutants are also transferred from the gas phase to a biofilm that grows on a packing material.
• packing materials are made of chemically inert materials, such as plastic rings.
• nutrients are not available in these materials.

Factors affecting bio-reaction

Acidity:

Temparature:

A blast of hot air can totally kill a biomass faster than any other accident , When emissions from a process are too hot, operators often pass hot emissions through a humidifier that cools gases down by evaporative cooling

Most bioreactors perform best when the bed pH is near 7, or neutral. Some pollutants form acids when they decompose Production of acids over time will lower pH and will eventually destroy microbes. If a process emits pollutants that produce acids, a plan must be developed to neutralize these acids

Thank you

Moisture:

Microbes and Feeding:

The second most critical variable is bed moisture. Microbes need moisture to survive and moisture creates the bio-film that removes (absorbs) pollutants from an air stream so that they can be assimilated by microbes. Low moisture problems can be corrected by passing emissions through a humidifier.

bio-reaction tests to determine which microbe strains perform best on a particular mix of pollutants. They can then inoculate the bed media with those strains and start up with the "right" microbes in place. . Pollutants provide the main source of food and energy, but microbes also require macronutrients to sustain life. Decay of an organic bed media can provide most macronutrients. However, if a bed is deficient in certain nutrients, microbes will cease to grow and could begin to die.

Air pollution

Conclusion

Air pollution is the introduction of chemicals,particulate matter, or biological materials that cause harm or discomfort to humans or other living organisms, or damages the natural environment into the atmosphere

• Like many other control technologies, bioreaction works in many cases, but not all. The trick is knowing when it will work and when it won't
• If emissions are very concentrated or extremely toxic, they are probably not suitable for bioreaction.
• Yes, bioreaction is a viable, low cost option in some circumstances, for the facilities that have emissions that qualify for this technology.

Air pollutants

Effects of air pollution

Suspended particulate matter

Sulphur oxides (SOx)

Nitrogen oxides (NOx)

Carbon monoxide (CO)

Hydrocarbons (HC)

Hydrogen sulphide H2S

Lead

chronic bronchitis,

lung cancer,

dermatitis due to irritants and carcinogens in smoke and other Respiratory disease

BIO-OXIDATION - A TECHNOLOGY FOR SUSTAINABLE POLLUTION CONTROL

Dharani prasad v

4GM10bt006

Dept of biotechnology

GMIT davangere

Reference

Bio-filter Disadvantages

1.Jim Boswell; Michael Foggia.,” Bio-Oxidation an Engineered Treatment Of Industrial Air Streams” Met-Pro Environmental Air Solutions;2005

2. Boswell, J., “Biofilter Applications in the Coatings Industry,” Journal of the Paint and Coatings Industry, XVII (7), pp. 78-83 (July 2001).

3. Emission of green house gases in the united states:1987-11992,doe?/eia report 0573,us government printing offices, washington, dc, October, 1994.

4. Air pollution control engineering , de nevers n., swcond edition 2000, Mc Graw hill, new York.

Bio reactor Techniques

• Large land requirement for traditional design.
• No continuous internal liquid flow in which to adjust bed pH or to add nutrients.
• Traditional design does not have a covered top
• Bed replacement can take 2 to 6 weeks,

depending on bed size.

• Bio-filtration
• bio scrubber
• Bioremediation

Bio-filtration

• Use moist solid media
• Driving force is solubility in water and biodegradability
• High treatment performance is associated with low molecular weight and high water solubility

Filter media is for providing:-

• large surface area
• Energy source and nutrients to the microorganism.
• Stable structural matrix to allow the gas stream to pass through

Bio filter Advantages:

• Very moderate initial capital costs
• Low operating costs
• Large energy savings over other technology
• Generates non-hazardous by-products
• Treatment to handle wide range of VOCs
• Consortium of microorganisms, once well developed can handle moderate fluctuations in input gas content

• Utilization of Natural Materials and Microorganisms Growing in a Media Bed to Destroy Organic Compounds and Remove Air Toxics from an Air Stream

• Addition of Biomass Support Media (Wood or other packing) improves bio-filter performance through reduced pressure drop and improved air flow and contaminant distribution.