Energetic oxygen precipitation is one possible explanation for the auroral molecular hydrogen emissions observed by the Voyager ultraviolet spectrometer. These ions deposit their energy in the Jovian thermosphere by means of ionization, dissociation, excitation, and heating processes. The photochemistry of both the neutral gas and the ionosphere is altered by the influx of atomic oxygen. The au...

Heavy metal pollution has become one of the most serious environmental problems today. The treatment of heavy metals is of special concern due to their recalcitrance and persistence in the environment. In recent years, various methods for heavy metal removal from wastewater have been extensively studied. This paper reviews the current methods that have been used to treat heavy metal wastewater ...

The removal of ammonium (NH(4)(+)) and phosphate (PO(4)(3-)) from supernatant of anaerobic digestion by magnesium ammonium phosphate (MAP) formation was studied. To be able to find out the loss of NH(4)(+) by its transformation to NH(3), rates of NH(4)(+) removal by aeration and by MAP formation combined with aeration were compared. NH(4)(+) removal by aeration was found to be insignificant. Th...

in this study chemical method of dissolution-precipitation was applied to produce amorphous silica nanoparticles from rice straw ash (rsa), the waste material of rice cultivation. the morphology, particle size, structure and area of specific surface of synthesized amorphous silica nanoparticles were evaluated using transmission electron microscopy (tem), x-ray diffraction analysis (xrd) and bet...

The mixing precipitation of CaCO3 in natural waters was theoretically studied by the methods of chemical equilibrium calculation. Results show that mixing precipitation of CaCO3 can be produced by mixing between two unsaturated water samples with respect to CaCO3, two oversaturated water samples, an unsaturated water sample and an oversaturated water sample. Mixing precipitation can be classifi...

Effluents from recirculating aquaculture systems (RAS) contain high concentrations of nitrogen and phosphorous wastes and thus often require proper treatment to prevent potential detrimental impacts on receiving water bodies. The purpose of this study was to evaluate the feasibility of membrane filtration coupled with chemical precipitation as a pretreatment step with emphasis on phosphorus rem...

Two-dimensional dendritic growth due to solute precipitation was simulated using a phase-field model reported earlier [Z. Xu and P. Meakin, J. Chem. Phys. 129, 014705 (2008)]. It was shown that diffusion-limited precipitation due to the chemical reaction at the solid-liquid interface has similarities with diffusion-limited aggregation (DLA). The diffusion-limited precipitation is attained by se...