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The long-term activity of a polymetallic ore mine in the region of Tarniţa-Suceava, Romania, has resulted in an enormous amount of waste material, collected in tailing dumps and ponds. The impact of the waste materials on the surrounding ecosystem and human health are far to be fully estimated. The deposited waste has exerted negative impact on the environment, especially on the soils that host dumps and drainage waters. Heavy metals, including arsenic also interfere with the metabolism of plants, and reduce the nutritive value of the produce. Consequently, we applied several chemical analyses and germination tests in an attempt to estimate the ability of soil to maintain the plants growing, the bioavailability, and heavy metals uptake. Copper, zinc, arsenic, and lead were the most abundant toxic elements in the studied samples. The sequential extraction revealed that up to 51% of copper was retained by amorphous and crystalline iron oxides in soil. The heavy metal concentration in river water during dry season varied from 0.13 mg/L (Fe) to 4.2 mg/L (Zn), being below the maximum contamination level for drinking water. The seeds germinated on the studied soils accumulated elevated concentrations of heavy metals thus indicating the bioavailability of soil contaminants. Arsenate decreased significantly the germination rate of wheat seeds, but phosphate has proved antagonistic. Germination tests may also be a reliable tool in the investigation of toxicity of waste materials to the environment. Decontamination methods based on salt extraction in water and some solutions are discussed as well. [ABSTRACT FROM AUTHOR]

Bacteriorhodopsin (bR) is a red-colored protein found in cell membranes of the organism Halobacterium salinarum, being considered as a light activated proton pump that transports protons across the plasma membrane. Because bacteriorhodopsin is one of the simplest ATP-producing systems known in biology, it has been the subject of intensive investigations. The bR photo-intermediates were seen in the mechanistic model considering that this protein links light energy to the translocation of protons across the bacterial membrane. However, once released outside the Halobacterium cell, the protons should return alone through the bacterial membrane via ATP synthase to produce ATP. Therefore, we reassess the electron crystallographic data used in parallel with X-ray measurements to study the post-illumination conformational changes of bR. Bacteriorhodopsin photointermediates have been defined in kinetic and spectroscopic terms as BR570, K590, L550, M412, N560, and O640. We recalculated the Förster cycle for bR and admitted that an energy quantum corresponding to the near infrared radiation could explain ATP formation and provide the most feasible molecular mechanism. Our hypothesis shows that the vectorial proton pumping mechanism is not fully correct. Protons are released due to bR excitation only as a secondary process and spread both inside and outside bacterial cells. Hence, protons cannot play an essential role in ATP production. Instead, spectral shift of 138 nm simultaneously with proton release corresponds to an energy quantum of 17.44 kcal/mol. Obviously, this energy can be used by ATP synthase to release one mole of ATP. We also revaluated different experimental data in the light of Eugen Macovschi's biostructural theory. Peter Mitchell’s hypothesis and the mechanism of action of uncoupling agents are also discussed here. Our hypothesis is consistent with experimental data and recent theories of other researchers, such as that of Paul Boyer. [ABSTRACT FROM AUTHOR]

Nutrient pollution and harmful algal blooms cause major environmental damage as well as serious human and animal health problems. Moreover, they take a toll on the economy, hurting industries and sectors that depend on clean water. High levels of nitrogen and phosphorus in water induce algae to grow faster than the lake ecosystems can handle. The increase in algae content damages the quality of lake water, food resources, and reduces the amount of oxygen needed to survive aquatic life. So-called algal blooms can severely reduce oxygen in water, leading to fish diseases and fish death. Based on analytical data (average, minimum and maximum values) obtained in each monitoring section, the surface water quality assessment has been done. Sampling was done in March, June, August and October in the three lakes situated in Neamth County, Romania (Eastern Carpathians). The trend assessment of the nitrates concentrations in surface water was also considered. The investigated indicators were: physical - temperature, chemical - pH, dissolved oxygen, total nitrogen, total phosphorus and biological numerical density, biomass and chlorophyll a. Total nitrogen and phosphorus as well as chlorophyll a were spectrophotometrically determined. The dissolved oxygen was measured with a titrimetric method using sodium thiosulfate. The evolution of phytoplankton in Red lake over time revealed a quantitative maximum of both analyzed indicators (numerical density and biomass) in October (966,500 organisms/L and 1,209 mg/L, respectively). Besides, the chlorophyll indicator also showed a peak in October (2.91 mg/L). The lowest numerical densities and biomass were reported in March in the middle lake area, both for Bâtca Doamnei and Izvoru Muntelui, as a result of increased values for total suspended matter, which was negatively correlated with the phytoplankton development. The number of algal organisms and phytoplankton biomass produced were directly proportional to temperature and phosphorus concentration, but inversely proportional to the dissolved oxygen and total mineral nitrogen. As for Izvoru Muntelui Lake, the maximum biomass of phytoplankton in August confirmed the intensification of lake eutrophication. All three lakes had stable and low total phosphorus levels. As expected, A close relationship was found between the level of dissolved oxygen and the temperature of water of the investigated lakes. [ABSTRACT FROM AUTHOR]

Heavy-metal pollution of forest soils around closed mines represents an important environmental concern and we measured the contamination level in the forest plants. The waste material generated by the now-abandoned ore-processing plant of Tarnița-Suceava, Romania, situated in the Eastern Carpathians, contain large amount of heavy metals, aluminum, and arsenic. The high risk of environmental contamination of sterile dumps is amplified by their susceptibility to airborne, hydromechanical and hydrochemical transport. In the investigated area, the topography, soil, vegetation, hydrology, fauna, microclimate and landscape were much altered or even destroyed. After careful experiments at the laboratory level, we have proposed some chemical remediation and bioremediation methods, which can be used both in Romania and abroad. This research relies thus on eco-friendly methods for heavy metals removal from contaminated forests with mining waste. First of all, we determined the high concentrations of Cu, Fe, Pb, Zn, Ba, and As, and observed that they affect much the germination of wheat seeds used here as an indicator of toxicity. Moreover, the germination of Triticum aestivum L. was even interrupted by sterile dump material, which is highly concentrated in copper and arsenic. The yeast-based decontamination of soil containing high amounts of heavy metals and arsenic, originated from a sterile dump of Tarnita-Suceava, Romania, was then studied among other bioremediation methods. However, yeast (Saccharomyces cerevisiae) succeeded to retain only partly heavy metals and arsenic from soil extracts. By our opinion, the high amounts of metalic contaminants should be first removed by chemical ways for example by precipitation at pH 12 (out of contaminated site), filtration or centrifuging and then neutralization of filtrate/supernatant to pH 6-7. Electrolysis could be also used to recover precious or harmful metals. Therefore, in this particular case the ex situ chemical decontamination with alkaline solutions in order to hinder further and continuous contamination of soil and natural waters by the waste huge deposits should be followed by some mild bioremediation procedures able to remove in due time almost all the metal ions found in great excess around the barite and copper closed mines. [ABSTRACT FROM AUTHOR]