Throughout writing the reflection on my teaching practices, I try to find out the advantages and the limitations of green chemistry approaches in my teaching laboratory. I agree that “reflection is an intrinsically good and desirable aspect of professional development” (Bain, Ballantyne, Mills, and Lester, 2002, p.10). Applying the green chemistry approaches is a part of my journey as a learner and an educator. Reflection on three of the cognitive interests of Habermas
(technical, practical and emancipatory) as described by Grundy (1987, p.10), I realized that most of my teaching practices are shaped by technical interest. This story remains me on the other reflection when I try to start applying green chemistry approaches.
One day, my students have practical work on determination of iron in water. It is common that the percentage of Iron the water at my university is higher than the health standard. Therefore, the practicum of Iron determination is important to control the water quality. However, since the first time, I just follow the practicum procedures which already set up by the department. I never realize or evaluate the procedures within my teaching until my student come to ask the questions. He asked me “Why do we add 25 mL of acid sulphate solution, (he showed me the practicum book), is it right?” This “why” question seems to be a simple question, I also could answer “yes, just follow the procedures”, but it caused me to think, “Acid sulphate uses for avoiding hydrolysis and creates reaction environment, if we add 10 mL, the reaction remains continue. So, why should we add 25mL?” I looked at the practicum book, “Why do I never think about the quantities?” I realized that the quantity of the solutions that they use is more than necessary. In the silent, I think but I neither do nor know what I should do. The book is already published. If I want to change it, I have to do experiments to prove my ideas in experimental methods were precise .Should I trap again in the standardization of procedures? Should I just silent, even I know the better way?
I now use that story as my critical reflection on the technical interest. I did not mind about my students’ understanding for I just required them to finish the experiments. They had to do the experiments using exactly the same procedures and quantities as stated in the practicum book. According to Grundy (1987, p.12), the technical interest focuses on controlling students and academic achievement. In addition, I tended to finish the experiments and used the “wonderful uncontestable assessment” card without an apprehension of my students’ understanding. I just stayed in the laboratory and observed my students’ experiments. I manipulated and controlled the teaching environment (Stable & Nord, 1985, p.15) through systematic experimental procedures and assessments. I never asked their understanding of the concepts because of the many experiments to finish in a limited time. The focus was finishing too many experiments within a short time. I did not realize that my target of finishing those chemistry experiments predisposed me to teach chemistry with meaningless experiences. I neglected the value of the educational process and the way of my students’ understanding (Henderson, 2004, p.50) to give them the worth value of knowledge.
Furthermore, there are 12 principles of green chemistry which are 1) prevention atom, 2) economy, 3) less hazardous chemical syntheses, 4) designing safer chemicals, 5) safer solvents and auxiliaries, 6) design for energy efficiency, 7) use of renewable feedstocks, 8) reduce derivatives, 9) catalysis, 10) design for degradation, 11) real-time analysis for pollution prevention, 12) inherently safer chemistry for accident prevention. These 12 principles guide me to apply several strategies in my laboratory such as small quantity of chemical substances, substitution of dangerous chemical substances, and recycling the waste which concern on effectiveness of teaching laboratory, environment friendly, and students’ safety. However, I realized that all the strategies that I apply only focus on how the practicum becomes effective and how it becomes environmental friendly. I never think that how it could influence my students’ perception on the environmental problems. Moreover, encouraging them to be aware and active participation in the sustainability will be challenging for my pedagogical practices. Throughout the exploring research studies on green chemistry, I found that most research studies focus on how to create the procedures of chemistry process which involves with green chemistry approaches. But, the research on green chemistry in education is less explored, especially the ideas on students’ empowerment on sustainability education. As a beginning teacher, I realized my limitation on knowledge and practical experiences. Therefore, this writing process will help me much to be a professional teacher. Moreover, these are several strategies which I apply in my laboratory which is guided by green chemistry approaches:
The less Quantity and Less Dangerous of Chemical Substances
My critical reflections taught me that I could make the improvements. Compared to the school system and university, a lecturer has more room to change the methods or material as long as the objectives are achieved. For example, I changed the procedures of analytical chemistry practicum by green chemistry approaches. I applied small quantity of chemical substances and substitution of dangerous chemical substances. Those are elements of a green chemistry approach, which are reducing the quantity of dangerous chemical substances (Lancaster, 2002). I remember my bad experience in organic laboratory 4 years ago. If we had used a small quantity, that accident might not have happened. The toxic gas that I inhaled can be the result of the excess quantity of dangerous chemical substances. Although I realized that, there was also a safety issue which related to the laboratory condition.
I start to apply green chemistry approach by changing the practicum procedures. In the laboratory my students did the experiment while I also tried to do the experiment but I used the least quantity of chemical substances. Sometimes, the reactions did not take place and I gave up. I only had two semesters to finish my experiments. I proved my methods by using the methods for students in another group who also did analytical chemistry practicum. Some of my methods worked but others failed. The weakness is the apparatus; we do not have small-scale laboratory equipment. Therefore, sometimes, it was difficult to analyze the small amount of product of reactions using large volume equipment. At the end, before I went to Australia, I already changed to some new methods. Now, the methods are applied in the Analytical Chemistry.
Moreover, I realize that I don’t want trap into the measurement. But, I try to find out the procedures within the new methods are valid and applicable to be applied in Analytical Chemistry practicum. Moreover, throughout, analysis of the students’ practicum report, I found that the results both using the green chemistry approaches and without using green chemistry approaches is almost similar. The factors which might be influenced the results is the skills of students and the equipment. Furthermore, I applied the different methods on “Determination of Iron” which apply green chemistry approaches and without green chemistry approaches. The procedure with Green Chemistry approaches not only provides the effective process of practical work, but also using the less quantitity and types of chemical substances. However, I realize that the procedure of Iron determination without green chemistry approaches is to teach student how to work with the Fe(III) sample. Therefore, the students have to understand the concept beyond the procedure.
Furthermore, the other problem that I found in analytical chemistry practicum was safety. Analytical chemistry laboratory was not appropriate for 30 students which are crowded. Sometimes, it was very difficult for me to observe all of my students’ activities. It was also difficult for me to inhale the fresh air. In addition, most of chemical substances used in analytical chemistry laboratory are dangerous. Therefore, it was very important for me to be concern about students’ safety. One day, one of my students did not use the gas mask. So, I asked him “Why are you not using the gas mask?” He said, “I forgot to bring it.” I strongly advised him “You should have one, either borrow it from your friends or go out of this laboratory.” It was just too difficult religiously for me to discipline my students in the laboratory. However, I had to educate my students to observe safety measures, since they will become chemistry teachers who are responsible for their students’ safety in the laboratory. I would remember then my accident. I did not want it happening with my students. Laboratory safety Laboratory’s size is too small for 30 students. I tried to minimize the interaction between my students and the dangerous chemical substances. I substituted some dangerous solution with others. For example, to determine concentration of Iodium, we can use Arsenic Oxide, but it is very toxic. Therefore, I changed it to Iron. Sometimes, if I could not change the substances, I chose another method which would not use the dangerous chemical. I had many ideas to change, but my knowledge about those reactions was very limited. Thus, experiences like this taught me that using small quantities of chemicals, small-scale equipment, reducing the waste, and recycling are the concepts of “green chemistry”.
The Waste Problems
I was also concerned with the waste from my laboratory within the environmental issues. My students used to throw the waste directly to the washbasin. It was too dangerous because the concentrated solution will have negative effects on the environment. I remember the time when I saw the houses around my university and I put it into story which stimulates to think critically on my role.
Where is the Waste?
I am looking at the window at the third floor of science laboratory. My eyes focus on the houses around my university. The houses are not in good condition because of most of the people who live there come from low income family. The waste are everywhere, the dirty water stagnant around the houses, the air are polluted and bad smell. My eyes move around the one place which they called it public toilet. It is common that there are some public toilets which are used by the people around the place which are inappropriate condition. Looking back to the laboratory room where my students work on the practicum. Then, I think of the wastes that are produced by my laboratory. It might be pass the place where the people live there. I know that there are some places for the laboratory waste, but because of the high cost of waste management, sometimes the waste treatment is inappropriate. As the result, the liquid waste could be adsorbed by the soil which is groundwater resources. Then, the water is used by those people. Oh my God, how could it happen? May be I just the little effects now, but how about 5, 10 or 15 years later? What should I do then?
Again, the reflection encourages me to do the improvement. I decided to apply the new rule. They had to dilute it first before throwing it to the washbasin. The other strategy that I used was using sand. I put the container with sand inside it. My students had to throw the waste there. It was better than throwing them into the washbasin that was connected to the water channel. In addition, I thought about the recycle process of using chemical solution, such as silver nitrate that is used as a titrant. That solution can be recycled as a silver precipitation. However, at that time, it was very difficult for me for rechecking the experimental methods and recycling at the same time. I realize that the strategies that I applied are very simple, but as a beginning teacher, I just think that I have to do something, not only as an educator who has responsibility to shape my students, but also as a human who has social responsibility to the society. Therefore, I am really hope that my journey at SMEC could be the powerful provision for me to be an critical and reflective educator.