Removal of Cr(VI) from aqueous solutions under different conditions was investigated using either clay (montmorillonite) or micelle-clay complex, the last obtained by adsorbing critical micelle concentration of octadecyltrimethylammonium ions onto montmorillonite. Batch experiments showed the effects of contact time, adsorbent dosage, and pH on the removal efficiency of Cr(VI) from aqueous solu...

A nitrogen-doped magnetic graphene oxide (NMGO) was synthesized and applied as an adsorbent to remove Cu(II) and Cr(VI) ions from aqueous solutions. The individual and combined effects of various factors (A: pH, B: temperature, C: initial concentration of metal ions, D: CaCl2, and E: humic acid [HA]) on the adsorption were analyzed by a 25-1 fractional factorial design (FFD). The results from t...

background: the presence of heavy metals in the environment especially in water supplies have caused many concerns because of their toxicity and non-degradability. hexavalent chromium (cr) is one of the most toxic metals which is used in many industries, so it is essential to remove it from industrial wastewater. in this study, we made a comparison between different adsorption isotherms in the ...

One of the most important directions for environmental remediation is effective removal dyes and toxic heavy metals from water using newly fabricated nanoadsorbents. Here, magnetic Fe3O4 nanoparticles were combined with nitrogen-containing functional group polymers chitosan (CS) polypyrrole (ppy) to synthesize a nanocomposite (polypyrrole@magnetic chitosan) useful removing methyl orange (MO) he...

Low cost activated carbon, prepared from saw dust of Ziziphus jujube by chemical activation with phosphoric acid (H3PO4) was characterized and utilized for the removal of Cr (VI) ions from aqueous solutions under different conditions of solution pH, contact time, initial concentration, carbon dose and temperature. Adsorption of Cr (VI) ions was found highly pH dependent that increased with decr...

To investigate the relationship between Cr(VI) adsorption mechanisms and physio-chemical properties of biochar, ramie residues were oxygen-limited pyrolyzed under temperature varying from 300 to 600°C. Batch adsorption experiments indicated that higher pyrolysis temperature limits Cr(VI) sorption in terms of capacity and affinity due to a higher aromatic structure and fewer polar functional gro...

In the present study, the performance of chitosan coated carbon was evaluated for the removal of chromium (VI) and cadmium (II) from its aqueous solution. The chitosan coated carbon was prepared and characterized by using the various analytical tools such as FTIR, TGA, DSC and XRD. Batch adsorption experiments were performed in order to examine the effects of initial concentration, pH, and adso...

background & aims of the study: heavy metals are the most important and main pollutants because of their accumulation and high toxicity even at very low dose and cause serious hazards to ecological system as well as human health. thus, their removal has been challenged from drinking water and industrial waters with different technologies. the purpose of this work is to investigate the removal o...

Adsorption experiment from aqueous solutions containing known amount of chromium (Cr) using hybrid membrane of chitosan and silicon dioxide was explored to evaluate the efficiency of the membrane as sorbent for Cr(VI). Some variable parameters such as pH, contact time and the dosage of the membrane were optimized. Adsorption isotherms of Cr(VI) onto the hybrid membrane were measured with varyin...

Background & Aims of the Study: Heavy metals are the most important and main pollutants because of their accumulation and high toxicity even at very low dose and cause serious hazards to ecological system as well as human health. Thus, their removal has been challenged from drinking water and industrial waters with different technologies. The purpos...