introduction industrialization and urbanization of societies have caused many environmental problems. therefore, environmental protection has recently become highly important. water resources are particularly of high risk of pollution from industrial waste disposal to river, surface, and ground water, and also from discharge of water to municipal waste water collection systems. these effluents ...

the contamination of water by toxic heavy metals is a world-wide environmental problem. discharges containing cadmium, in particular, are strictly controlled due to the highly toxic nature of this element and its tendency to accumulate in the tissues of living organisms. low concentration (below 5 mg`/l) of cadmium is difficult to treat economically using chemical precipitation methodologies. i...

we evaluated the effect of fe/alumina catalyst contained different cadmium contents and two synthesis temperatures on producing carbon nanotubes by chemical vapor deposition of methane as a feedstock.  x-ray powder diffraction (xrd), n2 adsorption-desorption, scanning electron microscopy (sem), transmission electron microscopy (tem), raman spectroscopy and thermogravimetry analysis (tga) were u...

The sorption of cadmium (Cd) and lead (Pb) by calcium alginate beads (CAB) from aqueous solutions in batch systems was investigated. The kinetic and thermodynamic parameters, as well as the sorption capacities of CAB in each system at different temperatures, were evaluated. The rate of sorption for both metals was rapid in the first 10 minutes and reached a maximum in 50 minutes. Sorption kinet...

Abstract Adsorption is an important phenomenon widely used for the removal of contaminants. Several drinking water contaminants such as arsenic and fluoride, vanadium chromium, nickel, cadmium cobalt are found to coexist in nature multi-component mixtures water. Hence, modeling adsorption isotherms designing treatment systems has gained importance recently. However, review studies competitive l...

this study reports the removal of cadmium from wastewater in batch mode, using two carbonaceous adsorbents viz. sunflower head carbon (shc) and sunflower stem carbon (ssc) prepared from waste biomass of sunflower. the adsorbents were characterized by fourier transform infrared spectroscopy (ft-ir), scanning electron microscopy (sem) and energy dispersive x-ray analysis (edx). the results of bat...

cadmium (cd) concentration in soil solution and its bioavailability is controlled by sorption-desorption reactions. the objective of this research was to compare cd adsorption behavior in six calcareous and four acid soils. soil samples were equilibrated with 0.01 m ca(no3)2 containing 25 to 3200 mg cd l−1. results showed that the tendency for adsorption was high at low cd concentrations (0-400...

this article presents the method of extraction-preconcentration of lead, cadmium, and nickel ions from food samples using the ghezeljeh montmorillonite nanoclay (geleh-sar-shoor) as a new native adsorbent in batch single component systems. the extraction-preconcentration of heavy metals were carried out by applying the solid phase extraction (spe) method followed by atomic absorption spectrosco...

The study investigated the preparation and characterization of biochars from water hyacinth at 300°C to 700°C for cadmium (Cd) removal from aqueous solutions. The adsorption process was dominated by oxygen-containing functional groups with irregular surfaces via esterification reactions. Furthermore, the mineral components in the biochars also contributed to Cd absorption through precipitation....