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Air pollution is dangerous. Concerns about global air pollution levels are increased. People feel the pressure for growing air pollution. Enviro news explore the day to day methods available to modern industries to help minimize air pollution using practicable system.
Pollution control is the process of reducing or eliminating the release of pollutants (contaminants, usually human-made) into the environment. It is regulated by various environmental agencies that establish limits for the discharge of pollutants into the air, water, and land. A wide variety of devices and systems have been developed to control air and water pollution and solid wastes.
Volatile Organic Compounds (VOCs)
One of the major causes of both indoor and outdoor air pollution are volatile organic compound (VOGs) . VOCs are found within a wide range of consumer products, including solvent-based paints, printing inks and petrol products. Due to the proven contribution of VOCs to air pollution (and ultimately smog) VOC control regulations are enforced around the world to protect the environment against them.Water pollutio
WATTER POLLUTION
Methods of controlling water pollution fall into three general categories: physical, chemical, and biological. For example, one form of water pollution consists of suspended solids such as fine dirt and dead organisms. These materials can be removed from water by simply allowing the water to sit quietly for a period of time, thereby allowing the pollutants to settle out, or by passing the water through a filter. (The solid pollutants are then trapped in the filter.)
Chemical reactions can be used to remove pollutants from water. For example, the addition of alum (potassium aluminum sulfate) and lime (calcium hydroxide) to water results in the formation of a thick, sticky precipitate. When the precipitate begins to settle out, it traps and carries with it solid particles, dead bacteria, and other components of polluted water.
Biological agents can also be used to remove pollutants from water. Aerobic bacteria (those that need oxygen to survive) and anaerobic bacteria (those that do not require oxygen) attack certain chemicals in polluted water and convert them to a harmless form.
Activated Carbon
Activated carbon is a popular air pollution control method. One of the most common forms of carbon treatment in air pollution control is carbon adsorption. This method sees the use of dry chemical scrubbing media such as carbon filters for the adsorption of fumes from the air.
The Big Problem: CO2 Emissions
One of the challenges associated with catalytic oxidizers is the necessary operation speed to catch the unburnt hydrocarbons before they leave the exhaust pipe. Standards of catalytic oxidizers are increasing each year, although carbon dioxide emissions still pose a problem. It is not possible to oxidize CO2 emissions into anything less harmful to the environment.
We’ve all seen Gas flares (or flare stacks) burning off unwanted substances and releasing them into the environment. Gas flares burn excess and flammable gases and liquids from plant equipment in an elevated chimney.
Examples of gas flare usage include chemical plants, landfills and oil rigs. Their most common purpose is to protect against unplanned over-pressuring of the plant equipment. The gases we see leaving the chimneys are released automatically whenever any piece of plant equipment becomes over-pressurised. The released substances are burned as they exit the flare stacks.
One of the world’s largest gas flaring sites (and a major source of concern for environmentalists) is the Niger Delta, which sees more natural gas flaring during crude oil production than any other country. llutants
Solid pollutants
Solid pollutants consist of garbage, sewage sludge, paper, plastics, and many other forms of waste materials. One method of dealing with solid pollutants is simply to bury them in dumps or landfills. Another approach is to compost them, a process in which microorganisms turn certain types of pollutants into useful fertilizers. Finally, solid pollutants can also be incinerated (burned).
Air Pollution vs Noise Pollution
Efforts have been made to reduce the impact of gas flares on air pollution levels. The injection of steam into the flame can serve to reduce the amount of black smoke released during gas flaring, although one problem with this is an increased level of noise during the burning which can lead to complaints from those living within earshot. Some environmentalists argue that this is an easy choice to make in light of the urgency to lower air pollution levels.
Acid Gas Control - SO2
Several systems for dry scrubbing are available, including Spray Dryer Absorbers (SPAs) and Dry Sorbent Injectors (DSIs). Usually known as spray dryers, SPAs remove the presence of acid gases from the environment through absorption in the dryer.
Wet or Dry Scrubbers?
DSIs are mainly used in medical waste applications and involve the injection of an alkaline into a gas stream. This causes a reaction to create solid salts which can then be removed. The ability of DSIs to reduce air pollution is limited in the less advanced systems.
Dry scrubbers are ideal for air pollution reduction applications in which the lowest level of water involvement is vital. They are particularly suited to the removal of aerosol mist, metal finishing and battery wet and dry charging.
Whilst dry scrubber methods do not rely on saturation of the gas stream, wet scrubber air pollution control methods see contact between the stream of polluted gas and a scrubbing liquid. The gas is stripped of its pollutants as it is pushed through the liquid.
Advantages associated with wet scrubbers in air pollution control applications include their capacity to withstand high temperatures and moisture levels, they necessitate a smaller operating space due to compact equipment and they have the ability to neutralize corrosive gases. Applications of wet scrubbers include exhaust cleaning, the treatment of industrial process gas streams and the incineration of medical waste.
Drawbacks of this method include corrosion and the requirement of treatment on the spent liquid. Worth noting, is the fact that the disposal of the water must be handled according to the current wastewater regulations, which can be time consuming. Additionally, the need for high pressure during operation makes the powering of wet scrubbers costly for businesses
Inspection of the various VOC control solutions available demonstrates that whilst there are plenty of options, none of them are flawless. Advice on the best VOC control solution for the individual business can be gained by contacting suppliers with the working knowledge of air pollution reduction technology to help you make the right choice - both for your business and the environment.
A global attempt to taking on pollution
While artificial chemicals have improved the quality of life around the world, they have also posed a threat to the health of people and wildlife. In late 2000, in an effort to control the effect of toxic global pollutants, the United Nations Environment Program organized a meeting to draft a treaty to restrict the production and use of twelve persistent organic pollutants (POPs), especially those used as pesticides. The twelve toxic chemicals cited, which environmentalists have called the "dirty dozen," include eight pesticides (aldrin, chlordane, DDT, dieldrin, endrin, heptachlor, mirex, and toxaphene), two types of industrial chemicals (hexachlorobenzene and polychlorinated biphenyls or PCBs), and two types of industrial byproducts (dioxins and furans). These toxic pollutants were chosen not because they are the most dangerous, but because they are the most widely studied. Since it is still widely used in Africa to control malaria, DDT was given a special exemption: it can be used in those countries until replacement chemicals or strategies can be developed and put into place. One hundred and twenty-two nations (including the United States) agreed to the treaty. Before it can take effect, however, at least fifty of those nations must also ratify it.
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