modifying M-smectites (where M is an exchangeable cation) with long-chain cationic surfactants or with quaternary ammonium cations are potential candidates for serving as sorbents of different organic compounds, as thickeners in paints, greases, oil
rather than adsorbate diffusion into the internal sorption sites. A possible external phenomenon to conform to this picture may be a surface enhancement associated with a highly energetic heterogeneous sorbent surface [ 27 ]. At low dye concentration, the
An overview of the adsorption characteristics of 3-cyanopropylsiloxane-bonded silica gel as a specific, moderately polar sorbent which can be used for separation of different classes of organic and inorganic substances in both normal- and reversed-phase chromatography is presented. The most important separation mechanisms that govern the retention on this sorbent are underlined. In addition, some recently published applications of 3-cyanopropylsiloxane-bonded silica gel as a sorbent in thin-layer chromatography are listed.
cartridges, such as OASIS HLB [ 7 ] or StrataX [ 21 ], is time-consuming and expensive. Here, dispersive SPE was utilized with sorbents to purify the samples in a more efficient and cost-effective process.
Previous reports have suggested that PSA
Adsorption of Cr(VI) by two tannin sorbents is evaluated using radiotracers. Evaluation of the sorption process shows that
the Cr(VI)-tannin molecule binding is the principal responsible for chromium adsorption. High sorption capacities were registered
for both sorbents at pH 2. ForEucaliptus Saligna Sm sorbent (ETS) sorption capacity is 0.92±0.03 mmol/g and forLysiloma latisiliqua sorbent (LTS) is 3.8±0.3 mmol/g. Influence of different ions present in water is examined. High sorption capacity is reported
for LTS in sea and tap water samples. It represents 90–94% of adsorption in distillated water.
Adsorption of mercury(II) and methylmercury by two tannin sorbents was investigated using radiotracers. High sorption capacities
for mercury are registered for both sorbents at pH 7. ForEucaliptus Saligna Sm sorbent (ETS) the maximum sorption capacity was 1.2±0.2 mmol/g and forLysiloma latisiliqua sorbent (LTS) was 8.5±0.2 mmol/g. Methylmercury adsorption maximum was recorded at pH 4 and in buffered solutions at pH2.
This species can be recovered in the presence of mercury(II). Influence of different ions present in water was examined. High
recoveries were reported for ETS in tap water samples but a decrease of uptake is observed for seawater.
A sorption-desorption-regeneration cycle composed of sorption of cesium on the sorbent in reduced state from strong nitric acid medium in the presence of an inhibitor such as hydrazinium salt, desorption of cesium by converting the spent sorbent into an oxidized state with a strong nitric acid eluent containing nitrous acid, and regeneration of the sorbent with a reducing agent such as hydrazinium salt was found to be possible with practically no loss of the sorbents when insoluble hexacyanoferrates of copper were used as redox type of ion exchangers.
A chelating sorbent obtained by immobilization of thionalide on the macroporous resin Bio Beads SM-7 was used for speciation of antimony(III) and (V) in natural waters. Antimony(III) was separated from Sb(V) by sorption on a column with the sorbent at pH 5. Antimony(V) in the effluent was reduced to Sb(III) and preconcentrated by sorption on the sorbent from 0.5M HCl solution. Both the separated species were determined directly on the sorbent by neutron activation analysis.
Apricot stone shells were carbonized under certain chemical and thermal conditions to produce sorbents having a quantitative affinity to retain some radioactive nuclei. The sorbent shows a thermal stability upto 500 °C. The diffraction patterns clarify that the sorbent is mainly amorphous in structure. Carbon in these shells was elementally analyzed and the data reveal a predominant content of acidic surface centers with hydrophilic properties. The isoelectric point (pHPZC) was determined and found to be 4.2 implying the acidic nature of the sorbent surface. The sorption of Cs+, Co2+ and Eu3+ on the prepared sorbent was studied from aqueous solution under different variables and the sorption capacity had values from 0.23-1.15 meq/g.
Organoclay-based nanocomposites obtained by modifying Na-smectites with long chain surfactants are potential candidates for serving as sorbents of different organic molecules, as thickeners in paints, greases, oil