Editorial :
This article introduces practical examples of
undergraduate-level chemistry-based environmental science lectures and seminars
by Prof. Akitsu. Sustainable and ecological issues are closely related to
chemical problems, but there are also features that make each item complicated.
We will take a structure that links problems and solutions such as the current
status of environmental pollution, changes in fossil fuels, merits and demerits
of power generation methods, conversion to renewable energy, new fire safety
problems, and examples of further environmental pollution. Furthermore, blind
solutions cannot address the "trade-off" relationship with a wide
field of view, e.g., social scientific issues (cost, safety, and convenience,
etc.). In this report, we describe an example where "system thinking"
is desired for environmental problems that cannot be solved in a straight line. The
motivation of this case report environmental problems are a collection
of various chemical phenomena [1]. However, when solving ecological issues, it
is required to optimize not only the specific optimization (solution) but the
whole. In recent years, there has been a growing movement to incorporate system
thinking into chemical
education
(primarily environmental chemistry). The composition of the problem is that the
issue is intertwined in a sophisticated manner, so that one solution can cause
a new challenge, and that there are disadvantages in terms of social security
even if there are scientific and technological advantages, etc. It is one of
the areas that can be said to be a good target for system thinking [2]. One
of the authors (Prof. Akitsu) gave a lecture on chemistry based on environmental science for three years
[3]. Handle various ecological topics (e.g., life cycle assessment, nuclear
power, rare metals, etc.). After that, for a small number of chemical students
at a seminar, we have been continuing classes for two years to make them think
about a solution to the problem where the problems mentioned above contradict
each other. In
this article, we introduce the main contents of the lecture (taking complex
issues in a chained fashion and considering the “trade-off relationship”, Scheme 1). Scheme 1: Concept of
trade-off relationship in environmental chemistry. A
solution to an environmental problem we will pick up from the lecture and
explain various issues related to the global environment, which is in a
trade-off relationship that causes new disadvantages when trying to overcome
the obstacles. Herein we depict the chain of issues discussed in the
“Environmental Science” lectures. Each item contains Current status, Merits (if
any), Demerits (more than two reasons from a different field) to be overcome. Atmospheric
water environment, material circulation S, N, C Energy
is economically disadvantageous and does not spread, and safety has created new
problems. Chemistry of oxides [4] and vibrational modes for infrared
(greenhouse effect of CO2) is associated with this problem. With the
industrial
revolution,
fossil fuels are conventionally used as an energy source for making machines
work. The development of the industry has enriched life. However,
CO2 is generated, causing global warming, acid rain, and air
pollution. Therefore, it is necessary to develop renewable energy that does not
use fossil fuels such as coal and oil. However, renewable energy is
economically disadvantageous and does not spread, and safety has created new
problems. Energy
conversion (coal and oil) Chemistry
of oxides and acid-base reactions [4] (and surface chemistry of foam) may be
associated with this problem. Air and water pollution can be prevented
if there are no harmful components (NOx, SOx) in the gas
burning fossil fuel. From coal to oil, oil desulfurization technology can be
the solution. The ability to do work is energy. The energy that humans can
theoretically use is free energy. If the free energy is negative, the reaction
proceeds spontaneously. Human beings are mutually converting and using human
power in carrying out social life. Energy,
particularly fossil fuel thermal energy, can be converted into various energy.
Power plants convert thermal energy into electrical energy. Electrical energy is used in
multiple ways. The
use of carbon-neutral bioethanol and biodiesel fuels instead of
conventional petroleum fuels has been promoted because of the emission of CO2
by combustion. No emission methods should be required. However, since oil is
flammable, it is difficult to digest it once a fire occurs. Furthermore, when
mixed with petroleum, it will defoam the fire extinguisher because of its
hydrophobicity and hydrophilicity, which may be a problem with safety [5]. Chemistry
of radio reactions of actinoides4 may be associated with this problem. Nuclear
power generation is used as an alternative to thermal power generation that
emits carbon dioxide. Heat is released when a large mass nuclide splits into a
small mass nuclide. It is a power generation method in which water is heated by
the heat to generate power. Nuclear
power generation uses energy from fission. Therefore, it is different from thermal power generation and does not
emit CO2 and gases that cause air pollution during power generation.
From these points of view, it can be said that it is an environmentally
friendly energy source. However,
the fuel for nuclear power is radioactive. Therefore, safety management and
appropriate risk assessment must be conducted. Once an accident occurs, it will
cause massive damage like Fukushima and Chernobyl. It can be said that it is
environmentally friendly in that it does not emit carbon dioxide in this way,
but it must also take into consideration the danger of radiation. Chemistry
of hydrogen, oxygen, acid-base reaction and
electrochemistry (of course materials such as catalytic metals and polymers as
electrolytes) may be associated with this problem [4]. A fuel cell is a cell
that generates electricity using hydrogen as a fuel. The energy from the
reaction of burning oxygen and hydrogen is taken out.It can be said that it is
an environmentally friendly power generation method because only water is
discharged as a product. There
are problems with hydrogen safety and the way it is generated. Even if compared
with other fuels, since the combustion range is as full as 4% to 75%, it can be
said that storage and transportation are difficult because it is a flammable
gas. Also, when generating electricity with a fuel cell, carbon dioxide is not
emitted. Currently, steam reforming, which is a standard method of hydrogen
production, emits CO+H2O → CO2+H2, and carbon
dioxide. In this context, solar cells may be proper as renewable energy generation. Chemistry
of solid semiconductor, photo-induced electron transfer, and sensitizer
(organic dyes and metal complexes) may be associated with this problem [4].
Solar cells are attracting attention in place of fossil fuels that place a
burden on the environment. The light energy of the sun can be used to obtain
current by the light power effect. There are commonly used silicon-based solar
cells and types and dye-sensitized solar cells at the research
stage. Solar
cells are environmentally friendly energy sources because they do not emit CO2
or air pollutants. Furthermore, since power can be generated where sunlight
strikes, it is possible to shorten the distance between the power plant and the
consuming place as in the conventional type and it can be said that energy loss
is small. In
order to use solar cells, it is necessary to have a large site and a store in
rainy weather. For the first time at India Cochin International Airport [6], it
succeeded in supplying all the electricity with sunlight. However, in order to
operate the airport stably, more than 46000 solar panels are installed. Also,
we purchase electricity at night or when it rains. Thus, it is difficult for
solar power generation to supply power at this time stably. Also, safety
management at the time of the fire of solar cells is also required. Photovoltaic cells generate
electricity both during the fire and while receiving sunlight. This makes it difficult
to extinguish the fire [7]. Environmental
hormones and flame retardants Chemistry
of polymer combustion, halogen compound [8] and biochemistry may be associated
with this problem. We need a way to ensure the security described above. One
way is to raise the flame retardancy. It is to increase the flame retardancy of
the material itself and to make it hard to burn. Specifically, a flame
retardant is added. A halogen type flame retardant is mentioned as
1 type of flame retardant. When a halide is added, the radical trapping effect
stabilizes the active OH radical. However,
environmental
pollution
due to flame retardants has been reported. Mainly, soil contamination in the
pasture around the Great Lakes of the United States is severe. Flame retardants
released into the air, contaminate the soil and are absorbed by plants. Dairy
cows consume contaminated grass and are contaminated with baby milk. In other
words, human beings are damaged by bioconcentration. Also, the environmental
impact of flame retardants was pointed out, and the use was restricted. After
that, new flame retardants were developed and repeated [9]. Atmospheric
water environment (again)… Environmental
pollution problems are repeated for different substances and elements in this
way. It
can be said that conventional chemical education alone, which tends to be a
problem, is not enough to solve such problems in terms of both environmental
problems and safety/harmfulness without leaving such problems. There is the
great hope for its use in system thinking, which is a methodology that combines
various theories and principles throughout and harmonizes. However,
environmental problems range widely, and the relationship between victims and
perpetrators is complicated. In particular, it is difficult to solve with mere
science and technology alone, and it is necessary to take into consideration
the relationship between science and technology and society, such as the
economy and politics. In other words, it is required to look around and
optimize the whole society. For that purpose, it is also necessary to change
chemical education with the times. In the past, education was given
independently in each field, such as organic chemistry, inorganic analysis chemistry, physical
chemistry, biochemistry, and the like. Indeed, this approach can be used to
deal with pollution problems. From now on, in order to aim for the solution of
complicated environmental problems, it is essential to make the education to
connect the fields which acquire knowledge to be able to return chemistry to
actual social problems across fields. 1.
Whitesides
GM. Reinventing Chemistry (2015) Angew Chem Int Ed 54: 3196-3209. https://doi.org/10.1002/anie.201410884 2.
Matlin
SA, Mehta G, Hopf H and Krief A. One-World Chemistry and Systems Thinking
(2016) Nat Chem 8: 393-396. https://doi.org/10.1038/nchem.2498 3.
Akitsu
T. Environmental Science: Society, Nature, and Technology (2018) Pan Stanford
Publishing, Singapore 180. http://dx.doi.org/10.1201/9780429468230 4.
Weller
M, Overton T, Rourke J and Armstrong F. Inorganic Chemistry (2010) 6thedition,
Oxford university press, UK. 5.
Wakisaka
T, Morita M and Akitsu T. Metal containing surfactants of fire extinguishing
compositions for bioethanol blended gasoline, Petroleum Engineering II:
Petrochemical of Chemical Technology Series (2015) Studium Press LLC, USA 321-336. 6.
http://cial.aero/Pressroom/newsdetails.aspx?news_id=360 7.
Akitsu
T and Mizuno K. Trade-off in fire-retardant solar cell materials and
environmental issues (2018) Edelweiss Chem Sci J 1:1-1. http://dx.doi.org/10.33805/2641-7383.101 8.
Housecroft
C and Sharpe AG. Inorganic Chemistry (2012) 4th edition, Pearson, UK
1256. 9.
Venier
M, Salamova A and Hites RA. Halogenated flame retardants in the Great Lakes
environment (2015) Chem Res, 48.7: 1853-1861. https://doi.org/10.1021/acs.accounts.5b00180 Takashiro
Akitsu, Professor, Department of Chemistry, Faculty of Science, Tokyo
University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo 162-8601, Japan,
E-mail: akitsu2@rs.tus.ac.jp
Mizuno K and
Akitsu T. Environmental chemistry lectures based on system thinking for
university students (2019) Edelweiss Chem Sci J 2: 14-16 Undergraduate/General, Environment chemistry, System
thinking, Environment scienceEnvironmental Chemistry Lectures Based on System Thinking for University Students
Kenta Mizuno and Takashiro Akitsu
Abstract
Full-Text
Introduction
Chain
Structures of Various Problems
Nuclear
power
Fuel
cell
Solar
cell
Conclusion
References
Citation
Keywords
