Article pubs.acs.org/jchemeduc
A Multidisciplinary Science Summer Camp for Students with Emphasis on Environmental and Analytical Chemistry Gunnar Schwarz,†,# Wolfgang Frenzel,‡ Wolfgang M. Richter,§ Lothar Taü scher,∥ and Georg Kubsch*,† †
Department of Chemistry, Humboldt-Universitaet zu Berlin, 12489 Berlin, Germany Technische Universitaet Berlin, 10623 Berlin, Germany § Bonito e.V., Fichtenweg 8, 21709 Himmelpforten, Germany ∥ Institut für Angewandte Gewässerökologie GmbH, 14554 Seddiner See, Germany ‡
S Supporting Information *
ABSTRACT: This paper presents the course of events of a five-day summer camp on environmental chemistry with high emphasis on chemical analysis. The annual camp was optional and open for students of all disciplines and levels. The duration of the summer camp was five and a half days in the Feldberg Lake District in northeast Germany (federal state of MecklenburgWestern Pomerania). The participants took part in the continuation of the examination of the lakes in the region, which leads back more than 50 years. They gained hands-on experience in environmental characterization of various lakes and classification by determining chemical, physical, and biological parameters such as phytoplankton, zooplankton, and macrophytes. Short lectures are presented by professionals covering a theoretical background of limnology, environmental chemistry, a variety of analytical methods, freshwater biology, and the specifics of the region. The camp in its present form was established in 1995, and about 20 students took part in the camp per year. Camp development, considerations regarding employed analytical methods, balance of theory, and other implications are discussed. KEYWORDS: General Public, Second-Year Undergraduate, Upper-Division Undergraduate, Analytical Chemistry, Environmental Chemistry, Hands-On Learning/Manipulatives, Applications of Chemistry, Instrumental Methods
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INTRODUCTION Environmental aspects have been integrated into chemistry curricula to introduce chemical concepts, increase learning motivation and trigger awareness of environmental problems.1−8 As with other application-oriented education in analytical chemistry, this puts aside the method-by-method approach toward education framed in specific and relevant contexts.9 The concept of science camps is often adapted for younger learners, but they can also be of distinct advantage for students at colleges and universities. Topics can be addressed in much more detail outside of the usual learning environment, because of the densely structured but informal setting10−14 and the combination of fruitful theoretical instruction with hands-on experiences.15−17 A blend of environmental topics with the science camp concept seems to be of particular benefit. Recently, this Journal published a paper by Tomasik et al.,18 in which the authors described an environmental research-based lab course in analytical chemistry as a camp for undergraduate students. While the work of Tomasik et al. was in some ways restricted in order to fit the study regulations for a mandatory course, the camp presented here was able to engage a multidisciplinary approach and give more emphasis toward the complex framework of the determined chemical parameters. © XXXX American Chemical Society and Division of Chemical Education, Inc.
In the 1950s the nonprofessional skin-diver association Bonito, which was named after the German term for Euthymus pelamys and based in the former German Democratic Republic (GDR, better known as East Germany), started to survey the lakes in the Feldberg Lake District. During their dive sessions, they observed drastic changes of the water quality. Despite the political framework, they proceeded successfully with extensive investigations using simple and improvised methods and instrumentation. After the political turns in Germany in 1989, the research was set on a more academic basis with scientists of the chemistry department of Humboldt-Universität. Finally, in 1995, an annual camp for students during the summer break was implemented. During the first years, the camp addressed environmental analysis more generally and included analyses of air, soil, and water. Later it was refined, focusing on fresh water lakes and assessing their water quality, and methods were changed accordingly. Participants could therefore contribute to the long-term and ongoing investigations of the lakes and study the outcome of several measures to improve the environmental quality. The summer camp was operated by several institutions under the direction of the Department of Chemistry at the Humboldt-
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DOI: 10.1021/acs.jchemed.5b00211 J. Chem. Educ. XXXX, XXX, XXX−XXX
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Universität zu Berlin. It was open to all students of all universities and colleges independent of the field of study. The considerable program consisted of lectures that gave introductions and overviews of the particular issues and hands-on activities, including on-site sampling, sample preparation and chemical analysis using various methods. Additionally, several other lectures about connected issues, a guided hiking tour and biological investigations completed the program.
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CAMP DESCRIPTION
Aim and Multidisciplinary Concept
As a foremost aim, participants gained insights into the modes of operation of diverse analytical methods in the context of environmental chemistry and fresh water lakes. The central analytical component was the determination of the water quality of the lakes. During the camp, the participants determined multiple physical and chemical parameters by performing sampling, sample preparation, measurements, and data evaluation. They finished by evaluating and documenting the water quality of the investigated lakes based on their findings. Thereby, hands-on experience as well as understanding and assessing the underlying analytical process were of importance. Furthermore, in order to emphasize the causalities and impacts of parameters, substantial credit was given to the related fields of limnology, geography, lake and fresh water biology, and nature conservation. Therefore, participants acquired additional awareness of the complex interplay of conditions and parameters in such ecosystems and estimated the environmental status of the lakes. The Feldberg Lake District
There were several reasons for choosing the Feldberg Lake District (in the federal state of Mecklenburg-Western Pomerania) for this camp. The end-moraine landscape was shaped by the ice age, and between slightly rolling fields, meadows, and woods lie many lakes of different size, depth, and water quality (Figure 1). For four of the lakes, there were reliable boats available for sampling, and the nature park offered guided hiking tours. Instructors and participants could be accommodated and supplied at reasonable prices next to one of the most natural lakes of the region, where also rooms for establishing a temporary field lab and rooms for lectures could be established. The course was based on the activities of the Bonito association and clearly benefited from data and experience gathered over many decades. During the 1970s and -80s the water quality decreased rapidly in most of the lakes due to a typical eutrophication processes caused by nutrient inflow from wastewater and overfertilization of nearby agricultural areas. The eutrophication has been stopped, and the lakes are recovering at different speeds. Therefore, lakes of different environmental status could be analyzed within short distances from the camp site.
Figure 1. (Top left) The holiday complex serving as the campsite next to the Lake Krüselin, reproduced with kind permission from Brennke & Menzke GbR. (Top right) View of the Lake Krüselin. (Bottom) Detail of the Feldberg Lake District, the camp side at the Krüseliner Mühle,and investigated lakes are indicated (A, Lake Krüselin; B, Schmaler Luzin; C, Lake Scharteisen; D, Feldberger Haussee), reproduced with kind permission from the Landesamt für innere Verwaltung Mecklenburg-Vorpommern.
ACTIVITIES In a holiday complex next to the Lake Krüselin, where instructors and participants were accommodated, a provisional field laboratory, which also included a room for lectures and meetings, was established prior the start of the camp. The brief lectures of about 1 h every morning provided fundamental background on topics addressed during the camp (Table 1). The hands-on activities, especially chemical analyses, were performed in groups of 2−4 participants. Each group was
assigned to one of the lakes, and was responsible for performing all tasks for the assigned lake, including sampling, sample preparation, and analyses. Furthermore, the groups prepared short summaries of their results and presented them to the other groups at the end of the camp. Beside chemical analysis, a hiking tour offered further insights toward landscape development, flora and fauna and nature conservation. Two special lectures, one by coauthor W. M. Richter related the cultural history of the Feldberg Lake district
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DOI: 10.1021/acs.jchemed.5b00211 J. Chem. Educ. XXXX, XXX, XXX−XXX
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Table 1. Program Schedule: Outside Activities (Blue), Lab Activities (Orange), Lectures (Green), and Other Activities (White)
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with the work of the Bonito association and presented concepts, past measures, and results of lake renovation in the region. To give participants the opportunity to become more familiar with microscopy during the week, plankton was also sampled on the first day of the camp, and on the last day, camp activity focused on freshwater biology. After an introduction to the subject matter by a lecture, the lakes were again investigated from this point of view, especially regarding the lake flora. Plankton samples with microalgae and zooplankton were examined and classified by optical microscopic inspection. The macrophytes (stoneworts, water plants) are good indicators of the water quality.
RESULTS AND DISCUSSION
All of the lakes examined were dimictic and still in the summer stagnation phase during the investigations. This was one of the first characteristics encountered by the participants during the sampling on the first day (Figure 2). Because the camp took place at the end of the stagnation phase, nutrient concentrations were different from layer to layer (Table 2). Lakes Krüselin and Feldberger Haussee
The results from Lake Krüselin and Feldberger Haussee are presented here briefly. It has to be pointed out that the investigations are only snapshots of complex systems and were gained under “field conditions”. Data interpretation should take this into account, and information gathered must be handled carefully. However, even under these circumstances, reliable results could be obtained, and the results (Table 2 and Table S2 in Supporting Information) are in agreement with overall observations. Lake Krüselin is one of a few lakes in the region that is still in its original conditions. Beside rainwater from the surroundings, only the inflow from nearby Lake Dreetz, which is in good condition as well, and which is filtered through gravel, contributes to the water body. There is also drainage from the lake and the water body is exchanged within only one and a half years. This effectively counteracts an enrichment of nutrients. Hence, only a low concentration of nutrients was recorded in Lake Krüselin, which had a high Secchi depth of more than 5 m, sometimes up to 10 m. High stocks of macrophytes, 12 species of stoneworts, Charales, one species of yellow green algae, Xanthophyceae, one species of mosses, Bryophyta, and 21 species of water plants, Spermatophyta were found and identified.19−21 Lake Krüselin could be classified as mesothrophic. Together with the adjacent lime swamp, Lake Krüselin has been a nature reservoir since 1975. Already classified eutrophic in 191422 and 1924,23−25 the Feldberger Haussee is now one of the most nutrient-rich lakes in the region,22 caused by the wastewater of the city of Feldberg and a dairy farm nearby, which has also affected other lakes nearby with direct connections. Although the wastewater has not been directed into the lake since 1978, restoration is still a problem. In 2011 the sediment was covered with aluminum chloride to prevent dissolution of phosphates. Recent analysis data obtained from the camp indicated that the phosphate concentrations are now ten times lower than in previous years.
Chemical and Physical Analysis
As the camp had a high emphasis on methods of analytical chemistry utilized in environmental sciences, these dominated the overall practical workload of the participants, while the connectivity to other parameters was always addressed. While instructors helped, guided, and oversaw the entire subject, participants carried out the different processes and kept written records themselves as much as possible. The sampling for chemical analysis was carried out on the first day of the camp. This took place at the deepest points of the lakes using several rowing boats. The water transparency (Secchi depth) and temperature and oxygen depth profiles were recorded directly at the site. From every temperature layer a water sample was taken, and the hydrogen sulfide content was determined also right at the site by titration. Additionally, sediments were sampled. At the campsite, basis parameters such as pH and conductivity were determined immediately. The samples were processed according to the methods’ demands, including filtration, UV digestion, drying, and extraction of sediments, and analyzed during the following days. Table 2 gives an overview of the chemical parameters investigated and analytical methods employed. The basic analytical equipment included ion chromatography, gas chromatography, automated and manual titrations, flame atomic absorption spectrometry, voltammetry, and photometry. More details can be found in the Supporting Information. Sometimes, when available, additional methods were applied, e.g., flow injection analysis with photometric detection for ammonium, nitrate, and phosphate determination. C
DOI: 10.1021/acs.jchemed.5b00211 J. Chem. Educ. XXXX, XXX, XXX−XXX
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Table 2. Results of Chemical Analysis for Two Lakes Feldberger Haussee Conditions at 10:45:a Continuous Rain; Water Transparency: 1.80 m Method and Analyte
Unit
Ion Chromatography Chloride mg/L Nitrite mg/L Nitrate mg/L o-Phosphate mg/L Sulfate mg/L Photometry Ammonium mg/L o-Phosphate mg/L Atom Absorption Spectroscopy Calcium mg/L Magnesium mg/L Total Hardness °dH Titration Total Hardness °dH Carbonate Hardness mmol/L Voltammetry (UV Digest) Lead μg/L Cadmium μg/L Other Parameters pH Redox potential mV Hydrogen sulfide mg/L BOD3b mg/L CODc (KMnO4) mg/L CODc (O2) mg/L Methane (GC)d mg/L Sediment Analyses Dry Substance % Photometry Phosphate mg/kg (DS)e Atom Absorption Spectroscopy Calcium mg/kg (DS)e Magnesium mg/kg (DS)e Iron mg/kg (DS)e Voltammetry (UV Digest) Cadmium mg/kg (DS)e Lead mg/kg (DS)e
Surface: 0.2 m
Thermocline: 6 m
Lake Krüselin Conditions at 10:15:a Rain; Water Transparency: 6.1 m
Lake Bottom: 11 m
Surface: 0.2 m
Thermocline: 11.5 m
Lake Bottom: 15 m
26.4 NDf 0.01 NDf 33.0
26.6 NDf 0.01 NDf 32.8
27.5 NDf 0.04 0.22 12.8
17.0 NDf 0.05 NDf 30.2
17.3 NDf 0.05 NDf 29.5
19.1 NDf 0.08 NDf 27.3
NDf NDf
NDf NDf
7.65 0.28
0.04 NDf
NDf 0.02
0.13 NDf
35.8 7.8 6.8
42.8 8.5 7.9
66.5 8.2 11.2
43.3 7.0 7.6
42.8 7.0 7.6
53.8 6.5 8.9
7.2 2.2
9.0 2.4
g 4.2
7.2 2.0
7.4 2.0
9.7 2.8
6.0 NDf
6.1 NDf
1.6 NDf
3.0 NDf
7.2 NDf
2.1 NDf
7.7 85 NDf 0.7 37.67 9.53 g
7.2 47 6 g 48.04 12.15 g
6.7 −337 10 g 75.22 19.03 16.4
7.4 266 g 0.5 23.84 6.03 g
7.3 254 g g 20.86 5.28 g
7.1 2.80 4 g 21.17 5.36 0.2
10.5
10.9
5216
1200
134830 1270 7523
211340 1890 4460
NDf 19.5
1.3 64.6
a Sampling took place on September 16, 2013. bBOD3: Biochemical oxygen demand. cCOD: Chemical oxygen demand (determined by titration with KMnO4 or O2 sensor). dGC: Gas chromatography. eDS: Dry substance. fND: Not determined (
