Effect of deuterium-depleted water on reproduction of rainbow trout

During the artificial reproduction of salmonides, the fecundity can be increased either by improving the viability of spermatozoa, or by extending the time period during which a roe micropile remains open, thus allowing its fecundation. Practically, this can be achieved by the use of some fertilising techniques suitable for fish species. Here, we show that the reproduction of rainbow trout in a 1:1 solution of deuterium-depleted water and distilled water led to a significant increase in survival of roes during their embryonic development. Moreover, the addition of glucose and fructose into the deuterium-depleted fertilising solutions led to a further increase in roe survival during embryonic development. The increase in survival is mainly explained by an increase in the motility of spermatozoa.     

Effect of temperature and particle size on the thermal desorption of PCBs from contaminated soil

Thermal desorption is widely used for remediation of soil contaminated with volatiles, such as solvents and distillates. In this study, a soil contaminated with semivolatile polychlorinated biphenyls (PCBs) was sampled at an interim storage point for waste PCB transformers and heated to temperatures from 300 to 600 °C in a flow of nitrogen to investigate the effect of temperature and particle size on thermal desorption. Two size fractions were tested: coarse soil of 420–841 μm and fine soil with particles <250 μm. A PCB removal efficiency of 98.0 % was attained after 1 h of thermal treatment at 600 °C. The residual amount of PCBs in this soil decreased with rising thermal treatment temperature while the amount transferred to the gas phase increased up to 550 °C; at 600 °C, destruction of PCBs became more obvious. At low temperature, the thermally treated soil still had a similar PCB homologue distribution as raw soil, indicating thermal desorption as a main mechanism in removal. Dechlorination and decomposition increasingly occurred at high temperature, since shifts in average chlorination level were observed, from 3.34 in the raw soil to 2.75 in soil treated at 600 °C. Fine soil particles showed higher removal efficiency and destruction efficiency than coarse particles, suggesting that desorption from coarse particles is influenced by mass transfer.     

Atmospheric chemistry of perfluorobutenes (CF3CFCFCF3 and CF3CF2CFCF2): Kinetics and mechanisms of reactions with OH radicals and chlorine atoms,IR spectra,global warming potentials,and oxidation to perfluorocarboxylic acids

Relative rate techniques were used to determine k(Cl + CF₃CFCFCF₃) = (7.27 ± 0.88) × 10^?12, k(Cl + CF₃CF₂CFCF₂) = (1.79 ± 0.41) × 10^?11, k(OH + CF₃CFCFCF₃) = (4.82 ± 1.15) × 10^?13, and k(OH + CF₃CF₂CFCF₂) = (1.94 ± 0.27) × 10^?12 cm³ molecule^?1 s^?1 in 700 Torr of air or N₂ diluent at 296 K. The chlorine atom- and OH radical-initiated oxidation of CF₃CFCFCF₃ in 700 Torr of air gives CF₃C(O)F in molar yields of 196 ± 11 and 218 ± 20%, respectively. Chlorine atom-initiated oxidation of CF₃CF₂CFCF₂ gives molar yields of 97 ± 9% CF₃CF₂C(O)F and 97 ± 9% COF₂. OH radical-initiated oxidation of CF₃CF₂CFCF₂ gives molar yields of 110 ± 15% CF₃CF₂C(O)F and 99 ± 8% COF₂. The atmospheric fate of CF₃CF₂C(O)F and CF₃C(O)F is hydrolysis to give CF₃CF₂C(O)OH and CF₃C(O)OH. The atmospheric lifetimes of CF₃CFCFCF₃ and CF₃CF₂CFCF₂ are determined by reaction with OH radicals and are approximately 24 and 6 days, respectively. The contribution of CF₃CFCFCF₃ and CF₃CF₂CFCF₂ to radiative forcing of climate change will be negligible.     

A review on thermal analyses of cyclodextrins and cyclodextrin complexes

Environmental Chemistry Letters - Cyclodextrins are valuable natural or synthetically modified cyclic oligosaccharides that are widely used for ameliorating properties of biologically active...     

Winter arsenic pollution in 10 forest ecosystems in the mountainous border regions of the Czech Republic

Environmental Science and Pollution Research - Arsenic (As) concentrations and deposition fluxes were measured in snow and rime at 10 mountain-top sites near the borders between the Czech Republic...