A Dynamic Model for Simulating Atmospheric, Surface and Soil Water interactions in Hillslope of Loess Area Under Natural Conditions and Its Application

The mechanism of atmospheric, surface and soil water interactions (water transformation) in hillslope under natural conditions was analyzed, and a dynamic model was developed to simulate infiltration, overland flow and soil water movement during natural rainfall in hillslope, by bringing forward concepts such. as rainfall intensity on slope and a correction coefficient of saturated soil water content for soil surface seal. Some factors, including slope angle, slope orientation and raindrop inclination, which affect the rainfall amount on slope, were taken into account while developing the dynamic model. The effect of surface seal on infiltration and water balance under a boundary condition of the second kind was also considered. Application of the model in a field experiment showed that the model simulated precisely the infiltration, overland flow and soil water movement in hillslope under natural rainfall conditions.

Potential Renaturalisation of Lakes as An Element Building Up Water Resources： An Example of Mosina Lake, Poland

Water deficits observed in many regions of the world make it necessary to implement measures intended to improve this situation. Poland is one of the countries with the poorest water resources in Europe due to its natural conditions and human impact. As a result of land reclamation carried out over decades, many elements of its hydrographic system have been changed, and some of them, like lakes, have disappeared altogether. In the days of the socio-economic transformation and more frequent extreme events, what seems worth considering is the renaturalisation of non-existing lakes, an idea presented in this paper on a selected example.

Water chemistry controlled aggregation and photo-transformation of silver nanoparticles in environmental waters

The inevitable release of engineered silver nanoparticles（Ag NPs） into aquatic environments has drawn great concerns about its environmental toxicity and safety. Although aggregation and transformation play crucial roles in the transport and toxicity of Ag NPs, how the water chemistry of environmental waters influences the aggregation and transformation of engineered Ag NPs is still not well understood. In this study, the aggregation of polyvinylpyrrolidone（PVP） coated Ag NPs was investigated in eight typical environmental water samples（with different ionic strengths, hardness, and dissolved organic matter（DOM） concentrations） by using UV–visible spectroscopy and dynamic light scattering. Raman spectroscopy was applied to probe the interaction of DOM with the surface of Ag NPs. Further, the photo-transformation and morphology changes of Ag NPs in environmental waters were studied by UV–visible spectroscopy, inductively coupled plasma mass spectrometry, and transmission electron microscopy. The results suggested that both electrolytes（especially Ca2＋and Mg2＋） and DOM in the surface waters are key parameters for Ag NP aggregation, and sunlight could accelerate the morphology change, aggregation, and further sedimentation of Ag NPs. This water chemistry controlled aggregation and photo-transformation should have significant environmental impacts on the transport and toxicity of Ag NPs in the aquatic environments.

Is there a silver lining? Aggregation and photo-transformation of silver nanoparticles in environmental waters

The nanotechnology industry advances rapidly,and at the vanguard are the promising silver nanoparticles（Ag NPs）,which have diverse applications.These nanometer-sized particles have been shown to inhibit the ability of bacteria to produce adenosine triphosphate（ATP）,a molecule necessary for chemical energy transport in cells.The antimicrobial properties of Ag NPs（and Ag＋）make them valued antibacterial

Methodological progress in trace amounts of structural water in nominally anhydrous minerals

In the deep Earth, hydrogen mainly occurs as structural hydroxyl and molecular water in minerals and melts, constituting mobile and immobile aqueous components. Hydrous minerals contain hydrogen which occupies a specific structural position and constitutes an indispensable component of chemical formulae. On the other hand, nominally anhydrous minerals do not contain hydrogen in their chemical formulae, but can host trace amounts of water in structural position and lattice defect. The molecular water may occur in the lattice defect as fluid/melt inclusions in minerals. Even though the water content of nominally anhydrous minerals is very limited generally in the order of ppm(parts per million), they may play a significant role in influencing the physicochemical properties of mineral and rock systems. With the continuous improvement of modern instrumentations, the analytical methodology exhibits trends for higher spatial resolution, lower detection limit and integral multiple methods on the water amount and its isotopic ratio. Among these methods, Fourier transform infrared spectrometry remains the most widely used, while secondary ion mass spectrometry, continuous flow mass spectrometry, elastic recoil detection analysis and Raman spectrometry are promising. This paper provides a brief review on the methodological progress and their applications to the analysis of structural water in nominally anhydrous minerals.