Sustainability in the Undergraduate Chemistry Curriculum - ACS

Chapter 9

Sustainability in the Undergraduate Chemistry Curriculum Downloaded by COLUMBIA UNIV on July 30, 2012 | http://pubs.acs.org Publication Date (Web): December 23, 2011 | doi: 10.1021/bk-2011-1087.ch009

Jeremiah K. N. Mbindyo* Department of Chemistry, Millersville University, P.O. Box 1002, Millersville, PA 17551-0302 *E-mail: [email protected]

Since late 1980’s, there has been a major emphasis on sustainability in all sectors of society. Education has been recognized as a major tool for fostering the ideals of sustainability. Possible approaches for integrating sustainability in the chemistry curriculum are discussed.

Introduction In order to understand the need for an emphasis of sustainability in the chemistry curriculum, it is helpful to look at the historical roots of the term. The World Commission on Environment and Development (WCED) is generally credited with popularizing the term sustainable development. The commission, which was established in 1983 to examine the link between development and the environment was chaired by Gro Brundtland. It was established in response to concerns that development was depleting planetary resources and creating new environmental problems while at the same time poverty, which the development was supposed to alleviate, was on the increase. In 1987, the commission produced a report titled “Our common future” (1). Prior to the report, population growth was seen as the source of many environmental problems around the world. However, the commission asserted that uncontrolled exploitation of resources was the most significant threat to the planet. Indeed, they observed that the population problem was more an effect of unsustainable uses of resources rather than its cause. The commission defined sustainable development as one in which humanity meets the needs of the present without compromising the ability of future generations to meet their own needs. This has come to be the commonly used definition of sustainability. In addition, the report observed that there © 2011 American Chemical Society In Sustainability in the Chemistry Curriculum; Middlecamp, C., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 2011.

Downloaded by COLUMBIA UNIV on July 30, 2012 | http://pubs.acs.org Publication Date (Web): December 23, 2011 | doi: 10.1021/bk-2011-1087.ch009

is a limit to how much the biosphere can absorb the effects of development. However, this limit is not absolute, but defined by the state of technology. Social re-organization and management of technology can preserve the environment while realizing the economic growth needed for its exploitation. Subsequent conferences on sustainable development have emphasized the crucial role of education. In 2002, the United Nations declared 2005-2014 as the decade of Education for Sustainable Development (2). The goal is “to integrate the principles, values, and practices of sustainable development into all aspects of education and learning, in order to address the social, economic, cultural and environmental problems of the 21st century”.

Chemistry and Sustainability Chemistry as a science is central to many fields of human endeavor. For example, the agricultural sector requires chemical products such as fertilizers, pesticides and food preservatives, while the pharmaceutical industry uses chemical products in the design and manufacture of drugs. For a long time, the chemical industry gave little or no consideration to the effects of chemical products on the environment. The goal of many of industries was simply to maximize profits. However, in recent years, there has been a paradigm shift. It is now recognized that successful enterprises should not only maximize profits, but also score highly on environmental and societal returns. This constitutes the so called triple bottom line. One of the ways in which the chemical industry has responded to concerns about the effect of chemical products on the environment is through the practice of green chemistry. This is defined as the design of chemical products and processes that reduce or eliminate the use and generation of hazardous substances (3). The guiding philosophy of green chemistry is to reduce or eliminate waste, minimize hazards, and lower energy requirements of chemical production processes. Chemical enterprises can improve their sustainability by applying the principles of green chemistry. However, the concept of sustainable chemistry is much broader than the practice of green chemistry. Sustainable chemistry also embraces the issue of positive returns to society. This distinction between green chemistry and sustainable chemistry can be illustrated by considering the use of corn based ethanol as an additive to gasoline. Ethanol is more environmentally friendly than methyl tert-butyl ether (MTBE) or other fossil fuel based octane boosters. Since ethanol is an oxygenate, ethanol blended gasoline burns more efficiently and emits less volatile organic compounds (VOCs) compared to gasoline containing MTBE as an octane booster. Furthermore, the use of corn, a renewable feedstock, and yeast, a biocatalyst to produce ethanol is consistent with the principles of green chemistry. Ethanol blended gasoline also competes favorably in price compared to gasoline blended with other octane boosters. There are however some limitations to the use of corn based ethanol as an additive to gasoline that impact the sustainability of the process. The use of corn as feedstock in ethanol production leads to higher prices of the produce due to increased demand. This increase in price hurts the poor who may not be able 92 In Sustainability in the Chemistry Curriculum; Middlecamp, C., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 2011.

to afford corn yet it is a common staple food around the world. In addition, using arable land to support fuel production when a large population in the world is going hungry can not be viewed positively from a social benefits perspective. Thus, while production of ethanol from corn for blending with gasoline demonstrates sound principles of green chemistry and is profitable, it may not be sustainable due to limitations on societal returns.


Engaging Students on Sustainability Issues Most college students have some knowledge about current environmental concerns. Concepts like carbon footprint, climate change, renewable energy, recycling and living green are not new to them. This knowledge can be useful in the classroom for teaching sustainability. However, there is an accompanying risk. If technologies are presented as sustainable or green when they are not, students may not have the scientific background needed to critically evaluate such claims. Thus, an attuned curriculum can be a tool to correct misinformation and provide the knowledge, skills and critical application necessary to challenge incorrect assertions (4). Students can influence decision making through participation in interest groups, civic activities and conversations with those within their sphere of influence. Students are also consumers. If equipped with the correct information, they can make personal choices that are supportive of good environmental practices. For example, they can choose to purchase products that are manufactured in an environmentally responsible manner.

Integrating Sustainability in the Curriculum Approaches that can be used to integrate sustainability in the undergraduate curriculum will vary depending on the level of the courses. Quite often, there is little room to incorporate a new chapter on a topic such as sustainability in existing courses. However, discussions related to sustainability can be woven into many content areas so as to provide enrichment without replacing core content. One of the motivations for the practice of sustainable chemistry is to prevent environmental problems. It seems logical therefore, that discussion of sustainable chemistry should be preceded with creating understanding of the environmental problems that need to be solved or that can result from non sustainable practices. Thus, introducing a discussion of environmental issues in any content area provides a good starting point for incorporating sustainability in the curriculum. At the upper division level, special topics courses that address environmental and sustainability issues are more appealing. Examples of these two approaches will now be discussed.

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Introducing Sustainability in Introductory and Lower Division Courses The first example demonstrates application of this approach in lower level laboratory courses. A review of several commercial laboratory manuals and published experiments reveals a strong emphasis on safety of experimental procedures and handling of hazardous chemicals, but limited or no mention of the environmental aspects of generated waste. In one laboratory experiment that involves qualitative analysis of inorganic ions for example, students are directed to empty waste into a beaker during experiments then transfer it into designated containers at the end of the laboratory period. The waste generated in the experiment contains species such as Cu2+, Hg2+, Sn4+, Bi3+, Pb2+, Ni2+and CrO42-. Other experiments generate waste containing complexing agents such as EDTA and o-phenathroline, and reducing agents such as Na2S2O3. It should be possible to add a brief discussion on the fate of properly and improperly disposed waste during the pre-lab period without sacrificing much class time. The instructor can point out that if poured down the sink, this waste would end up in a waste water treatment plant that is not equipped to remove these chemical species. The chemicals may then be released into surface or ground water, providing a pathway to human consumption and harm to health. A discussion of the fate of the collected waste can cover treatment options such as precipitation and the recovery of metals by electrolysis. Additional discussion can include waste minimization and microscale experiments, getting the message closer to the principles of sustainability. Cann and Dickneider give excellent examples of using laboratory experiments to introduce green chemistry concepts in organic chemistry courses (5). In synthesis reactions, achieving a high percent yield (Y) is always a desirable goal. However, in green chemistry, an important measure of how environmentally friendly reactions are is the % atom economy (AE), defined as the mass of desired product as a percent of the total mass of all the starting materials. Cann and colleagues combine these two measures to arrive at a new metric, the percent efficiency (RE) defined as:

Students learn that a high percent yield is not the only important consideration and that reactions with high reaction efficiency would be more environmentally friendly. To incorporate the concept successfully, it is necessary to teach about atom economy first. A third example demonstrates how a topic that seems unrelated to sustainability can be linked to the issue by incorporating environmental aspects. Many general chemistry textbooks have problems on calculating volume or mass of a liquid using density as a conversion factor. Students are asked to calculate the volume of a liquid given the mass and density, or to calculate mass given density and volume. Additional manipulations involve converting units from metric to English systems of measurement. Conversions involving mercury are popular since it is a liquid at room temperature and it has unusually high density. 94 In Sustainability in the Chemistry Curriculum; Middlecamp, C., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 2011.

Mentioning the environmental problems related to mercury using the example of mercury thermometers and their replacement with alcohol thermometers can get students thinking about broader issues that are relevant to sustainability.


Upper Division Topic Courses In order to fully equip chemistry students with the knowledge needed to authoritatively discuss sustainability, it is important to offer at least one course that delves into environmental and sustainability issues in depth. Indeed, given the current emphasis on sustainability, it is almost imperative that all chemistry students should take such a course. Similar sentiments have been expressed by the ACS Committee on Environmental Improvement (6). I now discuss incorporation of sustainability in two special topics courses that I have taught. Students in both courses are usually chemistry, biology, industrial health and hygiene or earth science majors. The first course, Environmental Chemistry I, is populated mostly by juniors but some sophomores and seniors also take the class. Students in the second course, Environmental Chemistry II, are usually a mix of seniors and juniors and will have taken the first course. One portion of the first course deals with traditional environmental chemistry topics such as toxic heavy metals and water treatment, toxic organics (pesticides, dioxins, furans and PCBs), air pollution and atmospheric processes (stratospheric ozone, ground level air pollution) and, energy sources and greenhouse effect (global warming and renewable energy). These topics provide an important background about environmental issues. Students are also given assignments to research on sustainable chemistry practices and make presentations to the class. In one approach, students are assigned case study topics. Examples include supercritical CO2, GM crops, recyclable carpeting, pressure-treated wood, replacement of CFCs, ionic liquids, antiscalant and dispersing agent, recyclable carpeting, biodegradable polymers, biodiesel, and targeted insecticide delivery. These topics are outlined in the course textbook (7) but students are required to do additional research. A second approach that has been used is to ask students to pick an issue of interest to them which they then present to the class as an opener prior to the bigger presentation. This takes no more than 2-3 minutes. They are required to have one graphic that will depict the issue and possible solutions. Short video clips from the web are allowed. Examples of topics have included compact fluorescent lights, green roofing, bottled water, water from sewage, biodegradable chelating agents, lead paint replacements, disposable diapers, green toothbrush, chlorine free bleaching, green shower curtains, phytoremediation, biosand water filters and lifestraw water purifier. There is always an amazing variety of topics. Students seem very interested in the presentations. In another type of assignment, students are asked to explore environmental and sustainability issues from around the world and identify how they can personally get involved. They are required to give a geographical and cultural context to the issue. This includes displaying a map of the region and highlighting interesting cultural, historical or other facts. The exercise promotes 95 In Sustainability in the Chemistry Curriculum; Middlecamp, C., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 2011.


an appreciation of the global aspects of environmental problems and that environmental problems transcend geographical barriers. Topics have included fate of electronic-waste, recycling of graphite in dry cell batteries, impact of river damming, cyanide fishing, coal mining and clean coal technology. The laboratory portion of the course covers topics such as water quality analysis (hardness, alkalinity, dissolved oxygen, chromium, nitrate and phosphorous) some instrumental techniques (GC-MS, AAS, UV-Vis) and box model analysis of waste accumulation in lakes. Experiments that relate directly to sustainability include microemulsions as green solvents, analysis of sunscreens at the microscale and synthesis of biodiesel (8–10). Additional topics on sustainability such as industrial ecology, green chemistry, hazardous waste minimization, regulation and treatment are discussed in the second course. More information about the content covered in that course can be found in the main textbook used in the class (11).

Conclusion Despite a crowded curriculum, there are some ways to include sustainability in the chemistry curriculum. A desirable outcome is practical application of the knowledge and skills acquired. Thus, students should be able to make sustainability an important consideration in decisions they make in their professional roles in the future. Since sustainability transcends all disciplines and economic sectors, what they learn should serve them well in their chosen careers.

References Our Common Future: The World Commission on Environment and Development; Brundtland, G., Ed.; Oxford University Press: New York, 1987. 2. Education for Sustainable Development URL, http://www.unesco.org/en/ esd/. 3. Anastas, P. T.; Warner, J. C. Green Chemistry Theory and Practice; Oxford University Press: New York, 1998. 4. Colins, T. Science (Washington, DC) 2001, 291, 48–49. 5. Cann, M. C.; Dickneider, T. A. J. Chem. Educ. 2004, 81, 977–980. 6. Pence, L. E. J. Chem. Educ. 2008, 85, 1608. 7. Baird, C.; Cann, M. Environmental Chemistry, 4th ed.; WH Freeman: New York, 2009. 8. Katz, C. A.; Calzola, Z. J.; Mbindyo, J. K. N. J. Chem. Educ. 2008, 85, 263–265. 9. Mbindyo, J. K. N.; Brown, A. K. J. Chem. Educ. 2010, 87, 1388. 10. Meyer, S. A.; Morgenstem, M. A. Chem. Educ. 2005, 10, 130–132. 11. Manahan, S. Environmental Chemistry, 9th ed.; CRC Press: New York, 2010. 1.

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Sustainability in the Undergraduate Chemistry Curriculum - ACS

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