Title: Unit 14 Learning Module
Course: SAT 170 Introductory Biotechnology > Section: SAT 170 Introductory Biotechnology

Unit 14 Learning Module

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Biotechnology in the Fields of Forensics and Environmental Science
Environmental science is a multidisciplinary field which encompasses concepts of many other fields including ecology, biology, chemistry, geology, and geography, among others. Much of the focus of environmental science is studying the living and physical components of the environment, especially towards the goal of identifying and solving environmental problems. The two main branches of environmental science include environmental studies and environmental engineering. Environmental studies typically focus on the social, political and ethical factors that influence the relationship that we humans have with the environment, while environmental engineering examines the impacts of technological developments on our natural resources. Environmental engineers rely heavily on the techniques of biotechnology to find solutions to improve air, water and food quality as well as to remediate pollution sites. We have discussed many of the methods and techniques used by environmental engineers in previous units; including bioremediation, green manufacturing technologies, and the use of biofuels. We will further explore these and other topics in this unit.

In order to better understand the role of biotechnology in environmental science, we will take a closer look at the problems facing environmental scientists. In response to wide-spread pollution and the recognition that natural resources are limited, an increasing amount of attention has been paid to the impact that humans have on the planet. To evaluate the key factors of human impacts, researchers often use what is known as the IPAT equation, which is written as I = P x A x T where I stands for impact, P stands for population, A stands for Affluence, and T represents technology. The premise for this calculation is primarily that humans are consumers and, the more humans there are, the more materials they will consume. Thus, the size of the human population will directly impact the environment. Additionally, it is known that there is a distinction in the rate of consumption of individuals in well-developed countries when compared to those of less-developed countries. This is the A, or affluence factor. The affluence of a nation is often measured as GDP per capita. GDP stands for gross domestic product and represents everything that a countries economy produces in a year. The GDP per capita is calculated by dividing that GDP by the number of people living in that country; thus, the GDP per capita represents the output of a countries economy per individual. The higher the GDP per capita, the more prosperous the country. Individuals with more money are likely to spend more on goods, and thus tend to consume more than those individuals with less money. The last component to the IPAT equation and the factor that we will focus on is the technology. By improving methods for the production, transportation, distribution and disposing of goods, the impact associated with technology can be significantly reduced. This is where biotechnology can have profound effects on reducing the impacts that humans have on the environment.

In unit 12, we talked extensively about green manufacturing technologies including bioproduction, the use of biomass for feedstock and biofuels, and the production of more biodegradable products. All of these are examples of the overlap that exists between industrial biotechnology and the use of biotechnology in environmental science. Additionally in unit 11, we discussed the production of biopharmaceuticals and the use of nanotechnology which can have huge impacts on the environment as it reduces the chemical processing necessary for the production and delivery of therapeutic compounds. In unit 10, we explored the applications of biotechnology in agriculture, which focused on improving agricultural methods to increase the food supply while reducing the impacts of that production on the environment. From these examples, we can see that by using biotechnology in a variety of different fields, we have the potential to reduce the impacts that humans may have on their environment. This is related to a concept known as sustainable development (SD). SD is a set of methods for human development that take into consideration that the Earth is a system and the things that we do can impact that system. It also considers that as a system, the things that we do in one part of the system can impact another part of the system (e.g. pollution from North America can affect air quality in Asia) and the things we do today can impact the future of the system. SD aims to meet our current needs while preserving the environment, and many believe that the tools offered through biotechnology can help us to do that.

You may recall from unit 9 that bioremediation is defined as the use of living organisms, usually microorganisms, to remove pollutants from the environment. We discussed in that unit various types of bioremediation including the use of microbes to clean-up oil spills as well as the role of plants and fungal organisms in phytoremediation and mycoremediation, respectively. We also discussed in situ bioremediation which occurs when microbes are already present in the area where they will bioremediate. In situ bioremediation will often require additional nutrients or environmental conditions to stimulate the growth of these organisms in a technique known as biostimulation. Biostimulation can be performed using injection wells that can insert the necessary nutrients into a particular area.
Shown here is the national data on GDP per capita for the various countries throughout the world.

Biostimulation adds necessary nutrients and modifications of environmental conditions to increase the growth of bioremediators. Biostimulation wells pump nutrients into substrates and subsurfaces.

Biofiltration is another form of technology which relies on microorganisms to remove pollution from the environment. Biofiltration methods are used to degrade pollutants as they are generated from a process to avoid having these pollutants introduced into the environment. Biofiltration techniques are commonly used in wastewater management, aquaculture and to remove pollutants from the air. Biofilters that are designed to remove air pollutants contain films of microorganisms that are immobilized onto different parts of the filter. The incoming gas is humidified so that when the air passes through the filter, the pollutants can be metabolized by those microorganisms. The microorganisms are converting pollutants to nonharmful products through a process known as oxidation. For this reason, this method of treatment is sometimes referred to as biooxidation.

Bioscrubbers are also used for the removal of air pollutants. The design of a bioscrubber is slightly different than that of a biofilter. A scrubbing liquid which consists of microorganisms and water is circulated through a bioscrubber reactor and as gases are pumped into the bioscrubber the pollutants are removed by the microorganisms. The gases leaving the bioscrubber are clean of air pollutants.

Another technique relies on a biotrickling filter, which is sometimes referred to as a percolating filter because it often contains a fixed bed of media such as rock, gravel or peat moss through which materials can percolate. Other biotrickling filters consist of media such as plastic rings and open pore foam. The media serves as a place for the growth of biofilms which will contain the microorganisms that are responsible for removing the pollutants. Biotrickling filters are also commonly used for the treatment of wastewater. As wastewater applied to the media, one or more layers of biofilms form as microorganisms accumulate. These microorganisms serve the purpose of removing many of the compounds polluting the wastewater.

The overall schematic of a biotrickling filter is shown in this diagram. Notice the layer of media which is required for the growth of biofilms of microorganisms. | Plastic media such as those shown here are popular choices in the construction of biofilters. | Porous fragments of ceramic shown here are also common forms of media found in biotrickling filters as they provide a significant amount of surface area for the growth of microorganisms.

Bioswales are an important component of sustainable landscapes as they have the ability to filter out many contaminants of runoff water before that water enters our waterways.

Surface runoff water represents another potential source of pollution that can be addressed using living organisms. For this reason, bioswales are commonly utilized. Storm water represents that which reaches the Earth’s surface as rain or snow. A certain portion of this storm water can be absorbed into the ground. The rest of that storm water creates what is known as surface runoff. This surface runoff will either enter the waterways of will first be channeled into storm sewers before entering the water ways, thus it is important that any pollutants present in this surface runoff are removed. This is where bioswales come in. Bioswales are systems that create a slightly sloped landscape for water to pass through. These bioswales contain native vegetation and rubble which aids in the filtration of pollutants from the water as it passes through the bioswale to the waterways. Bioswales can be incorporated as landscape elements to replace storm sewer systems. The use of bioswales is considered to be a sustainable landscape practice because of their ability to remove pollutants and the fact that they rely on native vegetation which is already suited to grow in a particular environment.