THIS REVIEW SUMMARIZES SOME RECENT EXPERIMENTS WITH ICE NANOPARTICLES (LARGE WATER CLUSTERS) IN MOLECULAR BEAMS AND OUTLINES THEIR ATMOSPHERIC RELEVANCE: (1) Investigation of mixed water-nitric acid particles by means of the electron ionization and sodium doping combined with photoionization revealed the prominent role of HNO3 molecule as the condensation nuclei. (2) The uptake of atmospheric molecules by water ice nanoparticles has been studied, and the pickup cross sections for some molecules exceed significantly the geometrical sizes of the ice nanoparticles. (3) Photodissociation of hydrogen halides on water ice particles has been shown to proceed via excitation of acidically dissociated ion pair and subsequent biradical generation and H3O dissociation. The photodissociation of CF2Cl2 molecules in clusters is also mentioned. Possible atmospheric consequences of all these results are briefly discussed.

• Klíčová slova
• aerosols, atmospheric chemistry, molecular beams, molecular dynamics, photochemistry, photodissociation, water clusters,
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

BACKGROUND, AIM AND SCOPE: To predict the fate of persistent organic pollutants in the environment, several aspects have to be considered carefully: their basic physical and chemical properties, distribution, transport within and among compartments, biotic and abiotic transformation processes, as well as effects on living organisms including humans. Laboratory simulation of the processes that control the chemical behavior of organic compounds in the environment is often desirable for deeper understanding, as well as for determination of basic characteristics required for successful environmental modeling. However, laboratory exercises targeted on the simulations of environmental processes are very rare. MATERIALS AND METHODS: Practical training was designed as a supplement to the course of Environmental Chemistry. The whole course consists of seven experiments in a logical sequence-partition coefficient (n-octanol-water), Henry's Law Constant, soil sorption, volatilization from soil, bioaccumulation, photochemical degradation and microbial degradation. The objective is to gain knowledge of the principal physical processes, by which chemicals move, concentrate and dissipate, as well as of the principal routes of biotic and abiotic degradation. RESULTS: New practical course reflecting current topics and approaches of environmental chemistry was introduced to M.S. students at Masaryk University in 2004. Detailed description of the course including experimental techniques is provided in this article. DISCUSSION: Lab course employs basic techniques for the study of environmental processes to strengthen links between the theory taught in the lectures of Environmental Chemistry, laboratory simulations, and processes in the real word. CONCLUSIONS: A significant effort towards developing this laboratory exercise was devoted with the goal of providing a context for teaching both fundamental theories and environmental techniques, strengthening the link between the theory and processes in the real world, providing a scientific background for understanding the environmental problems, challenging the students with the experience of simulating the physical, chemical, and biological processes that control contaminant fate and transport in the environment, showing the students importance of the interdisciplinary approach and giving the students a taste of the excitement and challenge of the research in real conditions. RECOMMENDATIONS AND PERSPECTIVES: The laboratory course was taught with a great success, and it became a part of recommended study plans for M.S. students in Environmental Chemistry and Ecotoxicology. Suggested experiments proved to be suitable for simulation of biotic and abiotic transformations, bioaccumulation, as well as distribution and transport processes in a student laboratory with good reproducibility and accuracy. The response of the students was very positive.

• MeSH
• ekologie výchova   MeSH
• kurikulum MeSH
• látky znečišťující životní prostředí chemie   toxicita   MeSH
• univerzity MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Česká republika MeSH
• Názvy látek
• látky znečišťující životní prostředí MeSH