Contribution of ion-exchange transformation of the adsorbed complex of atmospheric aerosols to the formation of seawater salt composition

Data on the total exchange capacity and composition of the adsorbed complex of terrigenous aerosols generated in arid and semiarid regions of the earth were summarized. It was calculated that as a result of change in composition of the adsorbed complex of aerosols occurring during their interaction with seawater, 2.64–4.86 million tons/year of dissolved Ca2+ are additionally enters into the ocean and 2.45–4.51, 0.73–1.34, and 0.08–0.14 million tons/year of dissolved Na+, K+, and Mg2+, respectively, are removed.

Adsorption–desorption of ethanol on sulfonated resin catalysts for ethyl-tert-butyl ether synthesis

Ethanol adsorption on sulfonic resins of different morphological types, such as gel, macroporous sulfonic resin, mixed sample (1:1 mixture of gel-type sulfonic resin with aerosil) and sulfonic resin loaded on wide-porous mineral carrier was studied using the methods of quasi-equilibrium thermal desorption and quartz crystal microbalance. It has been observed that the faster ethanol adsorption proceeds on the macroporous sulfonic resin and the slower ethanol adsorption on the gel-type one. It is due to different swelling ability. It was found that the transfer of the ethanol molecules through the gel phase of sulfonic resin proceeds by means of the adsorption–desorption mechanism. The ratio of ethanol adsorption on sulfonic resin is one molecule per one acid site. During the ethanol adsorption on the gel and mixed sulfonic resin, one type of adsorbed complex is formed, whereas on the macroporous and loaded samples two adsorbed complexes with different energies are formed. This is probably because of the different localization of the acid sulfonic groups.

Trace and selective determination of cobalt(II) in water and salt samples using cathodic adsorptive stripping voltammetry in the presence of pyrogallol red

A sensitive and selective procedure is presented for voltammetric determination of cobalt. The procedure involves an adsorptive accumulation of cobalt pyrogallol red (PGR) complex on stationary mercury drop electrode, followed by cathodic stripping voltammetry measurement of reduction current of adsorbed complex at -1.17 V (vs. Ag/AgCl). The optimum conditions for determination of cobalt include pH 11.0, 35 ?M pyrogallol red, an accumulation potential of -0.9 V (vs. Ag/AgCl) and scan rate 80 mVs-1. The peak current is proportional to the concentration of cobalt over the concentration range of 5.0 to 280 ng mL-1 with a detection limit of 1 ng mL-1 with an accumulation time of 140 s. The method was applied for the determination of cobalt in analytical grade NaCl and water samples.

Adsorption Wave of Vanadium Complex with 2,3–Dihydroxybenzaldehyde

The polarographic behavior of the complex formed by V(V) and 2,3–dihydroxybenzaldehyde (2,3–DHBA) in the solution containing acetate buffer (pH 5,2) has been investigated. By means of a.c. polarography, chronovoltammetry and other techniques, it has been shown that the electrode process is complicated by the adsorption of 2,3-DHBA and its vanadium complex. The kinetic and adsorption parameters of the electrode process have been determined: adsorption equilibrium constant B= 1,32⋅105 mol-1⋅dm3, the attraction constant γ = 1,2, the maximum surface concentration Гmax = 9,10⋅10-11 mol⋅ cm-2; the share of the electrode surface occupied by one particle of the adsorbed complex S = 1,81 nm2 and the free adsorption energy ΔG = - 39,1 kJ· mol-1.