Reclaiming Clean Energy from Wastewater
As the Earth becomes more developed many changes in the environment are becoming apparent. These changes are unexpected and often faced with opposition from skeptics. One of these problems is global warming. Global warming is caused by the release of greenhouse gases into the atmosphere. Greenhouse gases are produced on a large scale by combustion of fossil fuels. A major contributor to greenhouse emissions is the combustion of coal, oil, and gas in power plants. Many options to fossil fuels as a source of energy have been suggested, but with increasing energy demands our society is reluctant to risk a change. Alternatives such as wind energy, nuclear power, and fuel cells have all been suggested, but all have draw backs and limitations. The focus of this paper is expanding fuel cell production of clean energy. The problem with fuel cells is that they require hydrogen to produce energy, and currently hydrogen is produced by hydrolysis of water with dirty energy. Dirty energy refers to energy that creates dangerous byproducts such as greenhouse gasses and criteria pollutants. It is said that we can never extract more energy from hydrogen than is put into it. This is true only if we use conventional methods to produce hydrogen. What if we could turn to nature to find a way for us to produce hydrogen?
As it turns out nature did find a way millions of years ago. Bacterial cells evolved proteins called hydrogenases that release hydrogen gas by fermenting carbohydrates. This process releases hydrogen gas as a byproduct. Clostridium butyicum can be used to create hydrogen gas on a production level. A source for clean hydrogen for fuel cells has been found. But where to the carbohydrates come from?
Scientists at Pennsylvania State University found a creative source for these carbohydrates, sugars in municipal wastewater. Using Clostridium sp. to produce hydrogen gas from sludge could change wastewater treatment plants into local power plants. The plants would utilize the hydrogen gas in fuel cells. Clostridium sp. requires anaerobic conditions for hydrogen production. This would decrease the costs for wastewater treatment, as aerators are a very expensive component of wastewater treatment, in addition to generating clean energy. Wastewater treatment would have to shift to anaerobic processes. By changing wastewater treatment plants into power plants the burden of energy production would be shifted away from fossil fuels. Reductions in greenhouse gas and criteria pollutant emissions will have a myriad of effects that will benefit humanity.
The decrease in fossil fuel combustion will benefit humanity by reducing global warming and by improving health of individuals. According to Plan B the raise in world temperatures could lead to increased intensity and occurrence of severe storms, the raise of sea levels, and the increased occurrence of heat waves. These factors adversely affect tourism, insurance, and agriculture (Brown). The raise of sea levels even only one meter will displace millions of people. Heat waves have killed thousands of people in the last few decades. These are severe complications that arise with global warming, this alone should encourage governments to shift focus from fossil fuels to clean energy sources. This is not where the benefits of clean energy stop. The health of all humans is affected by other byproducts of combustion of fossil fuels, the criteria pollutants.
The combustion of fossil fuels releases toxic substances in addition to greenhouse gases. Nitrogen oxides, sulfur oxides, ozone, particulates, and carbon monoxide are all products of fossil fuel combustion (Moore). These criteria pollutants all adversely affect human respiratory systems increasing the occurrences of asthma, respiratory infections, and other health complications. By contributing to the reduction of fossil fuels this technology is improving human health as well as the environment.
The costs of upgrading current wastewater treatment plants to clean power plants may seem expensive especially if the costs are given to local governments. In order to assess the price of upgrading treatment plants the benefits to local citizens must be assessed as well. By decreasing greenhouse gases global warming is slowed down which will benefit humanity in an unquantifiable manner. By decreasing criteria pollutant emissions the benefits to local communities can be quantified. By looking at the occurrences of asthma, respiratory infections, and other related health complications in local populations local officials could recognize the monetary benefits of relying on clean energy rather than fossil fuels. If the government were to subsidize the cost of changing the treatment plants the way that fossil fuel power plants are subsidized then the burden would be taken from local governments. Not to mention the new power plant will generate usable energy that will eventually pay for any equipment to harness the energy.
Energy sources should be shifted from fossil fuels to clean energy sources, such as fuel cells. This is only beneficial if the source of the hydrogen, for the fuel cell, is from a clean source. The research presented in this case study outlines the technology necessary for clean hydrogen production. As concerned scientists and citizens it is our responsibility to encourage the shift from fossil fuels to clean energy sources. In the future wind energy farms, and fuel cell power plants could supply enough power for local communities. In addition to changing our energy sources we must also encourage the use of energy efficient appliances and practices in residential and commercial units. Fossil fuel combustion supplies ample energy. By replacing fossil fuel power plants with less powerful energy sources the supply of energy will be decreased. This must be offset by a decrease in demand. This must be satisfied by citizens, industry, and government regulations.
By looking to nature for solutions to hydrogen demands a potentially limitless source of hydrogen has been found. This plan is only economical if existing structures, such as wastewater treatment plants, can be used. This topic must be researched in order to increase the efficiency of hydrogen production before we can safely say this is the answer, but it is a great start.
Brown, Lester R. Plan B. W.W. Norton & Company: New York, 2003.
Moore, Gary S. Living with the Earth 2nd Ed.: Concepts in Environmental Health Science. Lewis Publishers: New York, 2002.