Biofiltration compared to chemical scrubbing for odor control

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Biofiltration compared to chemical scrubbing for odor control
Definition of concepts and background information
Due to high levels of industrialization, food processing has increased and this means that the environment is being affected by the odors emitted from the plants of processing (Hedley 2002, p.99). Processing plants are near residential areas so that they can get workforce from the neighborhood and this means that the odor coming from the industries must be dealt with to avoid adverse effects to the people, plants and animals. These reactions are hastened by processes such as heating, smoking or drying of foods. Due to the effect of these odors to the environment, methods have been set to test the odors emitted.
Various technologies have been established to control odors from industries. The only best method for managing odorous compounds is by getting rid of the formation of the odor hence eliminating the necessity for processing the air further. This is a challenge to many industries because they can not control all their odors. Many odors released in the process of manufacturing are not a threat to the health of the public but are a nuisance and hence are to be regulated by the local government (Engen 1991, p.211).
What is biofiltration?
Biofiltration is a technology whereby vapor like organic contaminants in a stream of air are passed through a bed of permeable support media where they divide into a water film that is thin in the media and are hence degraded by microorganisms. It is a natural process occurring in the soil which has been adopted for commercial purposes. Bio filters have micro-organisms which break down VOCs and tarnish inorganic gases and mists into non-malodorous substances which are harmless e.g. water and carbon dioxide. Sullivan (2000, p.134) argued that some forms of bacteria may be initiated into the filter and most favorable conditions are provided to ensure that the specific compounds are degraded. Biofiltration uses living material to biologically degrade pollutants in processing plants.
What is chemical scrubbing?
Chemical scrubbing involves technologies of using chemicals that react with volatile compounds. This is the most efficient method of treating odors as it can treat large volumes of air at a time. This method is widely used in the United States in many industries because it is well established, well known and is reliable. Chemical scrubbing has high costs of operation compared to the other methods. It also requires that hazardous chemicals be on site. Odors being emitted by water bodies can be controlled by adding a solution of chlorine dioxide directly to the fluid that is odoriferous (Vidas 2000, p.83).
However, exposure to unpleasant odors leads to physiological stress that may be a trigger factor to many problems e.g. nausea, emotional disturbance, loss of appetite and headache (Frazer 2000, p.24).Odors are sensory responses to the chemicals in the air we inhale. Individual should expect remedies from unexpected odors that interfere with their concentration, reduces their productivity in their areas of work, evoke symptoms and make them dislike the particular environment. Studies have shown that it is crucial to establish exposure limits to make sure the workers are safe and healthy.
Comparing the suitability and costs of biofiltration and chemical scrubbing
Biofiltration is cheaper than use of chemicals in odor control. Biofiltration and chemical scrubbing have low operating costs but they differ in the costs of materials in that the costs of materials for biofiltration is low compared to those of chemical scrubbing. The maintenance costs of chemical scrubbing are high. In addition, biofilters do not pollute the environment unlike in chemical scrubbing which leads to pollution of the environment. This is because there are no secondary pollutants produced. However, Sullivan (2001, p.111) alleges that odor control intentions must be put into consideration before a method of control is chosen.
Biofiltration is more suitable than chemical scrubbing and that is the reason why it is widely used by many industries. It is used in industries dealing with animal and food products, pharmaceuticals, manufacturing plants of wood products, paint and application of coatings and manufacturing and finally in treatment facilities of waste water. It helps in treating sewage water to be used for domestic purposes and also for agriculture (Laws 2000, p.77). When compared to chemical scrubbing on the amount of area needed to design a biofilter, it seems to be the one requiring a large area and this is one of its drawbacks in installation.
Another challenge of biofiltration is that proper moisture has to be maintained throughout the whole system and this means that it requires a lot of supervision. However, biofiltration is more suitable as it is very simple to construct a biofilter and operate hence it is seen to be cost effective compared to chemical scrubbing. Biofiltration reduces the rate of pollution released by manufacturing plants and the fumes emitted are 98% clean. One disadvantage of biofiltration is that it can not control some compounds which are organic and which have low degradation rates.
In addition, biofiltration is suitable in treating waste water. It uses natural microorganisms which are present in the surface water to improve water quality. This biological method improves the quality of water by reducing diseases which are water borne, turbidity and color present in surface water. On the other hand, biofiltration poses a risk to the fertility of the soil as it kills the microorganisms which make the soil rich hence making the soil incapable of producing high yields. On the other hand, when biofiltration is applied in aquaculture, it risks the life of the aquatic species (Laws 2000, 8p.7).
However, using chemical scrubbing to control odors from water bodies means that the life of water animals will be in danger and the water will not be fit for domestic use (Vidas 2000, p.75). When the water is consumed by animals and human beings, it leads to infections due to contamination. There is also the risk of pollution which arises when chemical method is used due to the gases emitted. However, the workers at these controlling plants are mainly affected by the odors before they are minimized.
Thermal oxidation compared to chemical stabilization and containment of hazardous wastes
Definition of terms
Hazardous wastes are those types of wastes which are a threat to the health of the general public (Kummer 1995, p.108). They may exist in liquid, gaseous or even solid states. However, hazardous wastes can not be disposed off like most of the other wastes. There are various characteristics of hazardous wastes which makes them more of a risk to human beings and the environment. One is that they are ignitable. This means that they can lead to fires in certain conditions and they are combustible e.g. oils. They are corrosive. They can corrode metal containers e.g. storage tanks and drums e.g. battery acid. They are reactive. They can lead to explosions when they are heated. Hazardous wastes acts as a threat to environment in general.
Thermal oxidation has an added advantage over other methods of treating hazardous wastes in that all pollutants are destroyed rather than being captured. This method can destroy 100% of the volatile organic control. In thermal oxidation, the heat of product formation is less than of the reactants. To start this reaction, an amount of energy is required. If amount of energy emitted in product formation is more than the amount needed in initiating the reaction, the reaction will maintain itself without adding more energy. If a catalyst is used, the reaction is the same except that the energy needed to activate the reaction is now lowered. According to scientists, thermal oxidation has been found to be an efficient and a safe method for disposing off hazardous wastes (Macalady 1998, p.213).
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