The formation of iron-sulfur-arsenic (Fe–S–As) minerals during biogeochemical processes in As contaminated aquifers remains poorly understood despite their importance to understanding release and transport such systems. In this study, X-ray absorption Mössbauer spectroscopies complemented by electron microscopy, chemical extractions were used examine vertical changes As, Fe S speciation for the...

Iron dosing for phosphorus reduction during wastewater treatment is wide practised across the globe. However, impacts of this in terms speciation discharged and secondary effects on removing or introducing other trace elements from into effluent have not been studied. Results are presented concentrations a range contaminants over 600 works, reported as mean concentration values derived 20 sampl...

A simple, rapid and sensitive solvent assisted-dispersive solid phase extraction method was developed for the extraction of iron(II) prior to its spectrophotometric determination. The Fe(II) reacted with 2,4,6-tris(2-pyridyl)-1,3,5-triazine, neutralized with sodium dodecyl sulfate and extracted onto the fine particles of benzophenone which were formed upon rapid injection of a mixture of benzop...

In this paper, we present the results of a one-pot process for converting, utilizing modified clinoptilolite catalyst. Iron, cobalt, and copper were introduced into zeolite structure as active centers. The catalyst was characterized in terms phase composition, structure, microstructure (using XRD, BET, FT-IR, DRS UV-VIS), well speciation metals. catalytic conducted at temperature 250 °C 1–5 h. ...

Fuel storage tanks are one of the main sources of water pollution as well as loss of crude oil and oil products in refineries.  In the process of utilization of these tanks, considerable amounts of hydrocarbons may find their way into the coastal water, which eventually lead to loss of valuable hydrocarbons. Oil type, climatic condition and characteristics of oil tanks are among the main variab...

the possibility of application of 4-nitrocatechol (4-nc) - tetrazolium salt - organic solventsystems for liquid-liquid extraction-spectrophotometric vanadium (iv and v) speciation wasstudied. six commercially available tetrazolium salts (2,3,5-triphenyltetrazolium chloride (ttc),3-(2-naphtyl)-2,5-diphenyltetrazolium chloride (tetrazolium violet, tv); 3-(4,5-dimethyl-2-thiazol)-2,5-diphenyltetra...

The evolutionary relationships of sand flies and Leishmania are discussed in this report, which draws distinctions between co-association, co-evolution and co-speciation (or co-cladogenesis). Examples focus on Phlebotomus vectors of Le. infantum and Le. major in the Mediterranean subregion.

Phenotypic traits may be linked to speciation in two distinct ways: character values may influence the rate of speciation or diversification in the trait may be associated with speciation events. Traits involved in signal transmission, such as the dewlap of Anolis lizards, are often involved in the speciation process. The dewlap is an important visual signal with roles in species recognition an...

Evolution of dominant frequencies in songs of Eneopterinae crickets was studied with respect to phylogeny. Two characters are optimized on the tree: the first describes the frequency resulting from the vibration of the harp (Fda), and the second is due to the vibration of other tegminal areas (Fdb). Fda was found to be relatively stable through the subfamily. Its low ancestral state is replaced...