Search results for " metal removal"
showing 4 items of 4 documents
Bio-char from dead Posidonia oceanica residues as adsorbent towards toxic metal ions
2018
Recently, the pyrolysis of biomass from different algal species and from the Mediterranean sea plant Posidonia oceanica have been proposed for renewable fuel production with a maximum oil yield of 54.97% at 500°C, and high heating values of 24-32 MJ kg-1[1,2]. The pyrolysis produces a large amount of bio-char and the accumulation of this byproduct may cause solid waste pollution problems. Although the composition and properties of bio-char depend on the raw material and on the carbonization process, it is on average composed of amorphous carbon with a highly functionalized surface, which makes it reactive towards inorganic and organic compounds [3]. Considering the reactivity of bio-char, t…
Kinetic and equilibrium study for cadmium and copper removal from aqueous solutions by sorption onto mixed alginate/pectin gel beads
2013
Abstract Kinetic and equilibrium studies have been carried out to evaluate Cd(II) and Cu(II) sorption from aqueous solution by calcium alginate and new synthesized hybrid calcium alginate/pectate gel beads with different alginate/pectate concentration ratios. Physical and chemical properties of the beads were characterized by different techniques (SEM, EDX, TGA). The best experimental pH conditions were selected on the basis of a study on the acid–base properties of pectin and alginate in aqueous solution and their ability to act as sequestering agents for copper(II) and cadmium(II) ions. Calcium released during the sorption process was determined in order to elucidate a possible ion exchan…
Functionalized Halloysite for enhanced removal of toxic metal ions from aqueous solutions
2018
During the last years several nanomaterials have been extensively used in the heavy metal ions removal from aqueous solutions. Among them, clay minerals have gathered particular interest owing to their unique features (e.g., high specific surface area, low toxicity and natural availability at low price). Halloysite nanotubes (Hal) are particular clay minerals with a predominantly hollow tubular structure. In this work Hal and their derivatives, Hal-NH2 and Hal-SH, were used as adsorbent materials of lead(II) and mercury(II) ions from aqueous solutions. The adsorption ability of clay nanomaterials towards toxic metal ions has been studied takeing into account important variables of the metal…
Kinetic and equilibrium study for Pd(II) removal from aqueous solution by sorption onto calcium alginate gel beads
2013
The more and more increasing use of catalytic converters to reduce the dangerous NOx and CO emission in the atmosphere by vehicle traffic produces a corresponding increase of palladium in the environment [1]. Among the so-called “platinum group Elements” (PGE), elemental palladium seems to be the most hazardous one because it can be easily and quickly oxidized to palladium(II) when put in contact with soil. The presence of palladium oxidized form is of great concern owing to its recognized toxicity towards plants, animals and humans. Therefore, as for the classical “heavy metals”, a removal of this element from the environment is needed and a subsequent recovery for its potential re-use is …