Understanding the interactions between natural organic matter (NOM) and zero-valent iron nanoparticles (nano-Fe0) and magnetite nanoparticles (nano-Fe3O4) is essential for evaluating their performance in pollutant remediation, as well as determining their fate and transport in the environment. Batch experiments were performed to investigate the sorption/desorption behaviors of humic acid (HA) o...

A series of Fe3O4 supported on mesoporous FDU-12 silica systems were prepared by the hydrothermal conditions. The surface properties of the functionalized catalyst were analyzed by a series of characterization techniques like FTIR, XRD, N2 adsorption–desorption and TEM. XRD and adsorption–desorption analysis shows that the mesostructure of FDU silica remains intact after Fe3O4 modifications, wh...

Purpose The aim of this study was to assess phosphorusretention (Pret) capacities via P adsorption (Pads) and desorption (Pdes) by sediments collected from six different sources associated with various origins, physical, and chemical characteristics. Materials and methods Sediment samples were collected in the State of Florida, the USA, from estuary, marine, wetland, canal, river, and lake, res...

this paper presents a systematic study of the surface chemistry, porous texture and adsorptive characteristics of prepared new activated carbon using persian mesquite grain. several techniques and methodologies such as, proximate analysis, n2 adsorption–desorption isotherms, scanning electron microscope (sem), fourier transform infrared spectroscopy(ft-ir), x-ray diffraction (xrd), x-ray photoe...

poly urea-formaldehyde was synthesized simply and rapidly from urea and formaldehyde by condensation polymerization and studied for the sorption of trace acid blue from aqueous solution. the optimum ph value for sorption of the acid blue was 4. experimental results showed that the sorption capacity of poly urea-formaldehyde for acid blue was determined. the synthetic polymer can be reused for 5...

We quantify the adsorption and desorption of a monoclonal immunoglobulin-G antibody, rituxamab (RmAb), on silica capillary surfaces using electrospray-differential mobility analysis (ES-DMA). We first develop a theory to calculate coverages and desorption rate constants from the ES-DMA data for proteins adsorbing on glass capillaries used to electrospray protein solutions. This model is then us...

The ‘‘mesopore protection hypothesis’’ [Chem. Geol. 114 (1994) 347; Geochim. Cosmochim. Acta 58 (1994) 1271] proposes that organic matter (OM) may be protected from enzymatic degradation by sequestration within mineral mesopores (2–50 nm diameter). This hypothesis is a leading, though controversial, theory in explaining both the preservation of some extremely labile OM compounds and observed co...

the aim of the present work is to prepare an adsorption package to simulate adsorption / desorption operation for both single and multi-component systems in an isothermal condition by different mechanisms such as; local adsorption theory and mass transfer resistance (rigorous and approximated methods). different mass transfer resistance mechanisms of pore, solid and bidispersed diffusion, toget...

This study was conducted to elucidate the dynamic aspects of the adsorption-desorption of borate ions on edge surfaces of 2:1 clay minerals. A pressure-jump relaxation method was used to evaluate the elementary processes involved in the adsorption-desorption of borate ions by pyrophyllite in aqueous media at pH 9 and ionic strength of 0.01 (NaNOj). This clay was selected because of the small de...

The interaction of methanol with a clean <I 10) ruthenium surface has been studied using temperature programmed desorption methods. Methanol dissociates upon adsorption at 300 K and yields Ha(g) and chemisorbed CO as the domiwt products. Randomization of evolved hydrogen was shown to occur during methanol adsorption and also upon subsequent thermal desorption using isotopically labeled methanol...