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FORTELIUS, Carola1, AKERMAN, Marja-Leena2 & LAINE, Olli3
Evitech, Leiritie 1, 01 600 Vantaa, Finland
1carola.fortelius@evitech.fi
2marjaleena.akerman@evitech.fi
3olli.laine@evitech.fi
Abstract: A project based laboratory course for studying the purification of polluted soil from different points of views has been developed at the Espoo-Vantaa Institute of Technology. The aim of the course is to train the students for a broader problem solution approach but also to integrate analytical chemistry and microbiology with process engineering. The course was implemented with second year BSc students, who already have basic skills in microbiology and process engineering and a good knowledge in chemistry. The results from the course were very encouraging.
Keywords: integrated, laboratory, project, purification,soil
Environmental technology is integrated in several degree programs at the Espoo-Vantaa Institute of Technology. This fact made a good basis for carrying out an experiment with a new type of laboratory training. In the programs of Biotechnology, Chemistry and Process Engineering was a new course implemented as an integrated laboratory project course, jointly between the three programs. The theme of the course this year was soil purification, focusing on degradation of poly aromatic hydrocarbons (PAH) in soil.
The pollution of soil and water with crude oil and petroleum products is an increasing environmental problem. Many of these contaminants are polyaromatic hydrocarbons and have toxic and carcinogenic properties. Some microorganisms are capable of degrading and/or utilizing PAHs. Programs for treatment of PAH polluted soil usually consist of both a biotechnical and a process engineering part [Park et al. 1990]. One of the educational goals for the course was, that the students would realize the problems connected with soil treatment and be able to use the knowledge they already have or attained during the course, for solving some of the problems.
The course is optional for students in the fields of biotechnology, process engineering and environmental science. The minimum entry requirements for admission to the course are passes in the subjects Microbiology and Analytical Chemistry at first level. The topics varies from year to year but a main subject is given at the beginning of the course. It is implemented as a project course, focusing on a practical biotechnical or environmental problem. The course is a three ECTS, which means 80 working hours per student. It consists of laboratory work in microbiology, chemistry and process engineering, a written project plan and a final report.
The integrated laboratory studies of soil purification was implemented as a project course with several independent projects running in parallel. Each project was carried out by a group of four to six students. The projects had some features in common, i.e. all projects consisted of a microbiological part, a chemical and an process engineering part. Each group had still its own problem framing and the subjects for the essential part varied. The titles of the subjects are mentioned in table 1.
Table 1. Main subjects for the literature surveys in the final reports.
| group "C-tytöt" | Composting of PAH contaminated soil |
| group "Reuma" | Qualitative detection of PAH with TCL |
| group "Ankka" | Qualitative detection of PAH with HPLC |
| group "Raemae" | Bioreactors for studying soil remediation |
| group "Arsch" | Qualitative detection of oil with FTIR |
| group "Meri" | Microbiology of bioremediation |
| group "Everest" | Biological succession during purification of PAH contaminated soil |
The practical work was performed in three different laboratories and were supervised by the technical staff. This enabled independent work possibilities for the students and still supported them by technical and educational means.
The course was planned for fourth year students but the timetable for their last year was very busy and the interest among second year students was much larger. When the course started it was occupied by second year students that had previously finished their practicals in microbiology and wanted to learn more in this field.
After two weeks of practical laboratory work the students had formed an idea of what the project required in time and skills. Based on their own experience and the advice they got from the teachers each group prepared its own timetable, a project plan and decided what the final goal for the project would be. This meant that all the seven groups advanced at their own pace and also reached different final results.
All seven groups started their projects by screening for potential microorganisms. Two different media were mainly used for isolation, one complex medium [Alef 1995] and one poor medium. The poor medium consisted of tap water and a some non-carcinogenic PAH-compounds as the only carbon source. In a few weeks all groups had succeeded to isolate between four and twenty different microorganisms. Among the isolates there were representatives of gram positive and negative bacteria, actinomycetes, yeasts and moulds. The isolated microorganisms were purified and identified as far as it was possible, and then further tested for their degrading properties. Methods described by Bagy et al. [1992] and Bogardt and Hemmingsen [1992] were used for testing.
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The samples were also analysed chemically. Since at least one the samples originated from a gasoline station, the initial oil content was analysed with FTIR and HPLC methods. When the pure microbe cultures were tested for their degrading properties according to the method of Bagy et al. [1992], the tests were analysed with a HPLC method described by Makela and Pyy [1995].
The results from the tests showed that some of the isolated microorganisms had the ability to degrade PAH-compounds.
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Based on the results from the chemical tests six strains were chosen for testing in a bench scale process. Each group of students was given the task of choosing a laboratory scale reactor for soil purification from the literature or developing an own one. Because of problems with the timetables the task was only fulfilled by one of the groups. The reactor chosen was a 'closed box'-type, with sensors for measuring temperature, moisture, pH and carbondioxid in the gas phase. The results from this part has not been reported at the moment of writing.
The students were asked in a questionnaire about their opinions. When they compared the ordinary laboratory courses with the project course they thought that the positive qualities with the project course were that they felt they learned more because they were motivated. The laboratory results from one part of the project interacted with the results from another part so it was important to do all parts of the work carefully to be able go on with the project. The students also thought they learned to work more independently and still practice team work. On the other hand team work was annoying when some of the group members did not carry their responsibility for the project. Some of the groups had problems with their timetables, and looking for information caused problems for some of the students.
A common opinion was that the possibility to use already learned skills and apply theoretical knowledge made the laboratory work more satisfying. Another motivating factor was that the problem was actual and a practical application of environmental protection. The final response from the students was very positive and they strongly recommended its use in other disciplines, too.
The starting point for the experiment with an integrated laboratory course was to try a new way of teaching to raise the learning level of the students. From the student's point of view this meant training in practical skills as well as independent working, which includes taking the responsibility for the own project and practising problem analysis and problem solving.
Since the groups set up their own objectives for the course and prepared their own project plans and timetables, the results must be examined in the light of these initial facts. The ability to estimate the amount of available time and plan the practical work varied. The groups that made the most realistic timetables and plans were those that finally got the best results. In the final evaluation the members of these groups showed that they also had learned a lot during the course. On the other hand the members in one group declared at the end of the course, that none of them had a clear picture of what they had tried to do and why. Still they thought that the material was sufficient and that they had got enough supervision.
It seems like the student's personal motivation and commitment have even stronger influence on the learning process in this kind of courses than in ordinary laboratory teaching. If the student's interest can be awakened at the beginning of the course the results at the end are probably also very good. These kind of projects are convenient as optional courses at the second half of the studies when the student already has skills in basic disciplines. The combination of several disciplines for solving a common problem showed up to be a interesting approach. Motivation can be increased further by giving the students a possibility to suggest their own subjects for the projects.
The authors thank the Environmental Agency of the city of Helsinki for giving the permission of sampling, Katarina Helander for technical assistance in the laboratories, and Mikko Makela for helping with the electronical shaping of this manuscript.
ALEF, K. Microbiological characterization of contaminated soils. Methods in Applied Soil Microbiology and Biochemistry: Academic Press, London, 1995. pp. 503-505. ISBN 0-12-513840-7.
BAGY, M., SHOREIT, A. & HEMIDA, S. Naphtalene-antracene-utilizing microorganisms. J.Basic Microbiol. 32: 299-308 (1992)
BOGARDT, A. & HEMMINGSEN, B. Enumeration of phenanthrene-degrading bacteria by an overlayer technique and its use in evaluation of petrolium-contaminated sites. Appl. Environ. Microbiol. 58: 2579-2582 (1992)
MAKELA, M. & PYY, L. Effect of temperature on retention time reproducibility and on the use of programmable fluorescence detection of fifteen polycyclic aromatic hydrocarbons. J. Chromatogr. A 699: 49-57 (1995)
PARK, K., SIMS, R., DUPONT, R., DOUCETTE, W. & MATTHEWS, J. Fate of PAH compounds in two soil types: influence of volatilization, abiotic loss and biological activity. Environ. Toxicol. Chem. 9: 187-195 (1990)