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A biocomposite sorbent composed of sugar beet pulp and pomelo peel was utilized for the biosorption of uranium (VI) from the aqueous solution. Parameters such as solution pH, biocomposite amount, contact time, temperature and initial concentration of U(VI) ions on the adsorption performance of biocomposite sorbent was studied. The equilibrium data fitted best to the Langmuir’s isotherm model (qe, max = 79.36 mg g–1). Obtained thermodynamic and kinetic parameters demonstrated that the biosorption process is spontaneous, exothermic, and fitted best to the pseudo-second order. The desorption study revealed that uranium recovery by 0.1 M NaHCO3 was 99.24% in the first cycle for used biocomposite.

The order of magnitude of increased growth, multiplication rate, and decreased sporulation of Bacillus subtilis after exposure to nanotesla magnetic fields (MFs) relative to control samples were observed experimentally. Earth’s total magnetic field intensity was reduced from 47.9 +– 0.4 mT to cover the range from 97.5 +– 1.7 nT to 1115 +– 158 nT in eight subsequent experiments by using three pairs of Helmholtz coils combined with Mu-metal shielding. The growth, multiplication rate, sporulation, and potassium content were measured in the probe and control containing B. subtilis cultures after 24 h of exposure to nanotesla and Earth’s magnetic fields, respectively. The observed effect is discussed with regard to its possible repercussions on Earth’s living species during geomagnetic reversals that occurred when the magnetic field was much weaker than the field that exists today. In addition, effects on future manned voyages into deep space, an environment with reduced magnetic field intensity, are considered.

Purpose: Measurement of carbon in cores of undisturbed sediments may provide valuable information on historical trends in sea primary production and carbonate precipitation which can be related to climate changes. Since core sediments are usually subjected to a different analysis, it is important to preserve the sample. Anon-destructive technique for carbon measurement in sedimentsbased on Fast Neutron Activation Analysis (FNAA) has been developed, which might replace the Loss-on-Ignition (LOI) as a conventional method for carbon analysis. Materials and methods: Method was tested on sediment samples collected from the Western Black Sea at depths up to 22 m. A surface sample and a corecut in centimeter intervals were freeze-dried. Samples weighing between 60 and 300 g were irradiated with the portable neutron generator. Gamma rays from 12C(n, n'γ)12C nuclear reaction were collected between 2000 and 4000 s by LaBr3:Ce detector. Standards for direct comparison and construction of the calibration line were prepared as mixtures of different amounts of quartz sand and graphite powder. FNAA results for total carbon (TC) were verified by LOIat 1000°C.LOIat 450°C and treatment with 1 M HCl were used to separate inorganic carbon (IC) and organic carbon(OC), respectively, followed by the FNAA measurements. Results and discussion: Climate effects on physical and biological marine processes are evident as historical changes in carbon flux to sediments. Carbon in sediments is found in the form of the OC produced byphotosynthetic organisms and as IC produced by calcifying organismsand precipitated as calcite. The FNAA is usually applied to samples weighing more than 1 kg. The method was optimized to reduce the minimum weight of the sample to 60 g, after subsequent adaptation of the set-up geometry.Carbon content measured in cores and surface sediment was between 2.8 and 6.1 wt%. OC constituted up to 84% of TC measured in the core.FNAA measurements were in good agreement with LOI analysis. Conclusions: The results have shown that FNAA can be used for the non-destructive determination of carbon in sediments in samples weighing ≥ 60g.FNAA is non-destructive, robust and fast in comparison to conventional methods for carbon determination such as LOI.The disadvantage is a relatively high MDL of 1%.