in this study chitosan hydrogel beads with porosity ~ 0.86 and diameter ~ 20.07 mm were prepared from 85 % deacetylated chitosan for removal of cd2+ ions from aqueous solutions.  chitosan powder was dissolved into dilute acetic acid as solvent and formed into spherical beads using a phase inversion technique. the effect of temperature, initial concentration of cd2+ ions, and the period of agita...

The potential of water hyacinth ash for phenol adsorption from aqueous solution was studied. Batch kinetic and isotherm studies were carried out under varying experimental conditions of contact time, phenol concentration, adsorbent dosage and pH. The adsorption of phenol decreased with increasing pH. The Freundlich and Langmuir adsorption models were used for the mathematical description of ads...

The effective removal of dyes from aqueous wastewaters is among the most important issues formany industrialized countries. Removal of Congo Red (CR) dye from aqueous solutions was studiedusing nickel oxide nanoparticles. The operating variables studied were initial pH of solution,adsorbents dosage, temperature and contact time. The morphological information of nickel oxidenanoparticles were ch...

the modified surface of typha latifolia l. root (mstl), as an alternative economical adsorbent, wasused for the removal of ni (ii) and cd(ii) ions from aqueous solutions. the effect of initial ph, initialconcentration of metal ion, and contact time was investigated in a batch system at room temperature.the kinetics data could be fitted well by pseudo-second-order model with correlation coeffici...

Background and purpose:The presence of dyes in wastewaters may cause serious problems for the environment because of their high toxicity to aquatic organisms and unfavorable aesthetical impact. In the present study, multi-walled carbon nanotubes (MWCNTs) were used for removal of anionic dyes Direct Blue 106 (DB106) and Acid Green 25 (AG25), from water samples. Materials and Methods:MWCNTs were ...

In this work the kinetic data demanded for kinetic modeling were obtained in temperatures 350, 400, 450 and 500 oC by conducting experimentations on a Fe-Cr nanocatalyst prepared from a novel method and a commercial Fe-Cr-Cu one. The collected data were subjected to kinetic modeling by using two models derived from redox and associative mechanisms as well as an empirical one. The coefficients o...

Contamination of water resources with toxic elements is one of the challenges of thetoday's world. In this research, application of Goethite nanoparticles in removingcontamination of arsenic and mercury from synthetic wastewater in a batch mode isinvestigated. For this purpose, the effect of different factors including pH, adsorbent dosage,contac...

The contribution of variable grain sizes to uranium adsorption/desorption was studied using a sediment from the US DOE Hanford site. The sediment was wet sieved into four size fractions: coarse sand (1-2 mm), medium sand (0.2-1 mm), fine sand (0.053-0.2 mm), and clay/silt fraction (<0.053 mm). For each size fraction and their composite (sediment), batch and flow-cell experiments were performed ...

classical xerogels are robust, inexpensive and nontoxic materials with low-ordered nanoporous structures. in water streams where the ph is higher than the point of zero charge, the surface of classical xerogels such as tetraethoxy orthosilan (teos) xerogel is negatively charged. it was assumed that a xerogel can work as a strong adsorbent for metal ions without further modification. therefore, ...