Batch experiments were conducted in order to investigate the competitive interaction of arsenite (As(III)) and arsenate (As(V)) onto ferrihydrite as a function of initial pH, adsorbent dosage, concentration of coexisting ligands, and order of addition. The pH generally had a great impact on adsorption under both single ion and competitive conditions. However, the amount of As(V) in solution was...

The purification and concentration of enzymes by adsorption on charcoal, tannin, aluminum hydroxide, ion exchange resins, and so forth, has been an established practice in the laboratory. Some years before this work was done in 1949, alkali-cooked lignin was used as an adsorbent for mold and malt amylase (Wallerstein et al., 1945). In this paper is described our study of the adsorption of the a...

[1] The IMPACT global chemistry and transport model has been updated to include an aerosol dynamics module. Here it is used to simulate the dynamics of sulfate aerosol and its interaction with nonsulfate aerosol components: carbonaceous aerosol (organic matter (OM) and black carbon (BC)), dust, and sea salt. The sulfate aerosol dynamics is based on the method of modes and moments. In the curren...

We show that carbonaceous chondrite meteorites actively and selectively catalyze the formation of relevant prebiotic molecules from formamide in aqueous media. Specific catalytic behaviours are observed, depending on the origin and composition of the chondrites and on the type of water present in the system (activity: thermal > seawater > pure). We report the one-pot synthesis of all the natura...

The data reported in literature demonstrate that carbon paste electrodes (CPEs) are very suitable for a variety of applications and many works have thus been devoted in the development of new sensitive and selective electrode surfaces based on carbon paste as the electrode material of choice. The application of novel and promising carbonaceous materials, as electrode surfaces, is an issue of gr...

conserving water resources and protecting them from pollution are of high account in the natural cycle of our life. this study has tried to determine the refining potential and capacity of water hyacinth (eichhornia crassipes) in order to remove the cadmium from water, studying the influence of factors such as initial concentration of cadmium, contact time, absorbent mass, and ph. results have ...

The critical Rayleigh number for convective flow of pore water through a permeable spherical body is derived. The result affords constraints on carbonaceous chondrite planetesimal sizes and rates of heat production. If the chemical compositions of carbonaceous chondrites are taken as evidence against flow of pore water, then the present calculations suggest that the parent bodies were less than...

5-Hydroxymethylfurfural [HMF] is an important intermediate compound for fine chemicals. It is often obtained via hydrothermal treatment of biomass-derived carbohydrates, such as fructose, glucose and sucrose. This study investigates the formation of carbonaceous spheres from HMF created by dehydration of fructose under hydrothermal conditions. The carbonaceous spheres, ranging between 0.4 and 1...

As insufficient access to clean water is expected to become worse in the near future, water purification is becoming increasingly important. Membrane filtration is the most promising technologies to produce clean water from contaminated water. Although there have been many studies to prepare highly water-permeable carbon-based membranes by utilizing frictionless water flow inside the carbonaceo...