A biological oxidizer is a device that uses

micro-organisms A microorganism, or microbe,, ''mikros'', "small") and ''organism'' from the el, ὀργανισμός, ''organismós'', "organism"). It is usually written as a single word but is sometimes hyphenated (''micro-organism''), especially in olde ...

to treat

wastewater Wastewater is water generated after the use of freshwater, raw water, drinking water or saline water in a variety of deliberate applications or processes. Another definition of wastewater is "Used water from any combination of domestic, industr ...

and the

volatile organic compound Volatile organic compounds (VOCs) are organic compounds that have a high vapour pressure at room temperature. High vapor pressure correlates with a low boiling point, which relates to the number of the sample's molecules in the surrounding air, a ...

s produced by commercial and industrial operations. Biological oxidation devices convert

biodegradable Biodegradation is the breakdown of organic matter by microorganisms, such as bacteria and fungi. It is generally assumed to be a natural process, which differentiates it from composting. Composting is a human-driven process in which biodegradati ...

organic compounds into

carbon dioxide Carbon dioxide (chemical formula ) is a chemical compound made up of molecules that each have one carbon atom covalently double bonded to two oxygen atoms. It is found in the gas state at room temperature. In the air, carbon dioxide is transpar ...

and

water Water (chemical formula ) is an inorganic, transparent, tasteless, odorless, and nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living organisms (in which it acts as a ...

. This is a natural occurring process which differs from traditional

chemical A chemical substance is a form of matter having constant chemical composition and characteristic properties. Some references add that chemical substance cannot be separated into its constituent elements by physical separation methods, i.e., wi ...

and

thermal A thermal column (or thermal) is a rising mass of buoyant air, a convective current in the atmosphere, that transfers heat energy vertically. Thermals are created by the uneven heating of Earth's surface from solar radiation, and are an example ...

oxidizing agents and methods. Some of the more commonly used micro-organisms are heterotrophic bacteria, which play an important role in biological degradation processes. Generally, these micro-organisms are rod shaped and

facultative {{wiktionary, facultative Facultative means "optional" or "discretionary" (antonym '' obligate''), used mainly in biology in phrases such as: * Facultative (FAC), facultative wetland (FACW), or facultative upland (FACU): wetland indicator statuses ...

. Biological oxidizers provide a stable environment which allows bacteria to naturally oxidize and stabilize a large number of organics in a more efficient manner. Some of the emissions that may be treated biologically include: *

heterocyclic compounds A heterocyclic compound or ring structure is a cyclic compound that has atoms of at least two different elements as members of its ring(s). Heterocyclic chemistry is the branch of organic chemistry dealing with the synthesis, properties, and ...

(such as

quinoline Quinoline is a heterocyclic aromatic organic compound with the chemical formula C9H7N. It is a colorless hygroscopic liquid with a strong odor. Aged samples, especially if exposed to light, become yellow and later brown. Quinoline is only sli ...

pyridine Pyridine is a basic heterocyclic organic compound with the chemical formula . It is structurally related to benzene, with one methine group replaced by a nitrogen atom. It is a highly flammable, weakly alkaline, water-miscible liquid with a d ...

); *

polyaromatic hydrocarbons A polycyclic aromatic hydrocarbon (PAH) is a class of organic compounds that is composed of multiple aromatic rings. The simplest representative is naphthalene, having two aromatic rings and the three-ring compounds anthracene and phenanthrene. P ...

(PAHs); * pharmaceutical substances; *

polychlorinated biphenyls Polychlorinated biphenyls (PCBs) are highly carcinogenic chemical compounds, formerly used in industrial and consumer products, whose production was banned in the United States by the Toxic Substances Control Act of 1976, Toxic Substances Contro ...

; *

hydrocarbons In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons are examples of group 14 hydrides. Hydrocarbons are generally colourless and hydrophobic, and their odors are usually weak or ex ...

(oil); *

benzene Benzene is an organic chemical compound with the molecular formula C6H6. The benzene molecule is composed of six carbon atoms joined in a planar ring with one hydrogen atom attached to each. Because it contains only carbon and hydrogen atoms, ...

toluene Toluene (), also known as toluol (), is a substituted aromatic hydrocarbon. It is a colorless, water-insoluble liquid with the smell associated with paint thinners. It is a mono-substituted benzene derivative, consisting of a methyl group (CH3) at ...

ethylbenzene Ethylbenzene is an organic compound with the formula . It is a highly flammable, colorless liquid with an odor similar to that of gasoline. This monocyclic aromatic hydrocarbon is important in the petrochemical industry as an reaction intermediat ...

, and

xylene In organic chemistry, xylene or xylol (; IUPAC name: dimethylbenzene) are any of three organic compounds with the formula . They are derived from the substitution of two hydrogen atoms with methyl groups in a benzene ring; which hydrogens are sub ...

(BETEX); *

methyl ethyl ketone Butanone, also known as methyl ethyl ketone (MEK), is an organic compound with the formula CH3C(O)CH2CH3. This colourless liquid ketone has a sharp, sweet odor reminiscent of acetone. It is produced industrially on a large scale, but occurs in nat ...

(MEK); * some metals. The prompt removal of a wide range of wastes and pollutants from the environment is the foremost requisite leading to minimal negative

environmental A biophysical environment is a biotic and abiotic surrounding of an organism or population, and consequently includes the factors that have an influence in their survival, development, and evolution. A biophysical environment can vary in scale f ...

impact and

sustainability Specific definitions of sustainability are difficult to agree on and have varied in the literature and over time. The concept of sustainability can be used to guide decisions at the global, national, and individual levels (e.g. sustainable livi ...

Microorganism A microorganism, or microbe,, ''mikros'', "small") and ''organism'' from the el, ὀργανισμός, ''organismós'', "organism"). It is usually written as a single word but is sometimes hyphenated (''micro-organism''), especially in olde ...

s offer excellent anabolic and catabolic adaptability to degrade and produce stabilized organic matters from contaminants.

Microbiology Microbiology () is the scientific study of microorganisms, those being unicellular (single cell), multicellular (cell colony), or acellular (lacking cells). Microbiology encompasses numerous sub-disciplines including virology, bacteriology, prot ...

is providing significant views of regulatory metabolic pathways as well as effectiveness to adaption and biological degradation in our changing environment.

Biological destruction mechanism of hazardous air pollutants

Micro-organisms are utilized in biological remediation to control industrial and commercial

vapor In physics, a vapor (American English) or vapour (British English and Canadian English; American and British English spelling differences#-our, -or, see spelling differences) is a substance in the gas phase at a temperature lower than its critic ...

effluent Effluent is wastewater from sewers or industrial outfalls that flows directly into surface waters either untreated or after being treated at a facility. The term has slightly different meanings in certain contexts, and may contain various pollut ...

s. When utilizing biological oxidation systems for the remediation emissions, the off gases or vapors are passed through a packed bed having a thin biological film at the surface. The micro-organisms are immobilized into the thin biological film, as the vapor passes over the film they become attached and are oxidized or stabilized. The biological film accomplishes the

degradation Degradation may refer to: Science * Degradation (geology), lowering of a fluvial surface by erosion * Degradation (telecommunications), of an electronic signal * Biodegradation of organic substances by living organisms * Environmental degradation ...

process, as the biological sump water is reprocessed over the biomedia it creates additional biological growth and as the film increases so does the biological oxidizers efficiency. Large surface area and footprint were once required to treat waste water vapor and industrial plant emissions, with the advent of advanced biological oxidation equipment a smaller footprint is required. The footprint will typically occupy the same space as conventional

thermal oxidizer A thermal oxidizer (also known as thermal oxidiser, or thermal incinerator) is a process unit for air pollution control in many chemical plants that decomposes hazardous gases at a high temperature and releases them into the atmosphere. Principl ...

Biological controls

Excessive formation of the biological film may lead to certain problems such as sloughing, it is an important factor to maintain optimum biological film. Maintaining the biological film is accomplished by proper moisture content. For this purpose the humidity of the air is adjusted within the reaction chamber before the vapor flows over the packing media. The biological packing media may be natural or made of synthetic

plastic Plastics are a wide range of synthetic or semi-synthetic materials that use polymers as a main ingredient. Their plasticity makes it possible for plastics to be moulded, extruded or pressed into solid objects of various shapes. This adaptab ...

. Recirculation of the water is always completed in the biological oxidation system to make the system more cost-effective.

Biochemical oxygen demand Biochemical oxygen demand (BOD) is the amount of dissolved oxygen (DO) needed (i.e. demanded) by aerobic biological organisms to break down organic material present in a given water sample at a certain temperature over a specific time period. T ...

(BOD) indirectly measures the amount of easily biodegradable organic matters thus very low values indicate direct waste water disposal. The prompt removal of a wide range of wastes and pollutants from the waste gas flow is the foremost requirement of biological oxidizers to meet regulatory permitting requirements.

Micro-organism A microorganism, or microbe,, ''mikros'', "small") and ''organism'' from the el, ὀργανισμός, ''organismós'', "organism"). It is usually written as a single word but is sometimes hyphenated (''micro-organism''), especially in olde ...

s differ in their ability to rapidly metabolize different pollutants, so the selection of the proper mix of organisms is critical.

Research Research is "creativity, creative and systematic work undertaken to increase the stock of knowledge". It involves the collection, organization and analysis of evidence to increase understanding of a topic, characterized by a particular att ...

is underway to genetically modify various organisms to improve their performance in biological oxidation.

Benefits of biological oxididation

Biological oxidation of organic matters has led to the innovation of a low cost secondary treatment of the waste water emissions and industrial air emissions. The process of

biodegradation Biodegradation is the breakdown of organic matter by microorganisms, such as bacteria and fungi. It is generally assumed to be a natural process, which differentiates it from composting. Composting is a human-driven process in which biodegrada ...

offers a very fast method which typically offers 4,000 catalytic cycles per minute. Destruction rate efficiency is generally greater than 99% on most biodegradable organics emissions. The biological oxidation technology is free from secondary emissions () with limited production. While other oxidation technologies such as

thermal oxidation In microfabrication, thermal oxidation is a way to produce a thin layer of oxide (usually silicon dioxide) on the surface of a wafer. The technique forces an oxidizing agent to diffuse into the wafer at high temperature and react with it. The rat ...

produces CO, NO₂ and CO₂.

List of manufacturers

The following manufacturers have been involved in the development, design and planning of waste gas purification systems for a wide range of industries: Global manufacture of turnkey systems. * American Fabrication and Supply, LLC

Biological destruction mechanism of hazardous air pollutants

Biological controls

Benefits of biological oxididation

List of manufacturers

See also

References

Further reading and external links