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The basic process to reduce the phosphate ions in aquatic environments is to move the phosphorus circulation processes on the water–sediment phase boundary towards depositing it in the solid phase through chemical precipitation or adsorption. Modern technologies for removal of phosphorus can be based on cheap and environmentally friendly natural polysaccharides modified with multivalent metals. In this study alginate/goethite hydrogel composite has been investigated for phosphate uptake from aqueous solutions. The composite was produced by a cross-linking reaction between sodium alginate and calcium chloride in six configurations of suspensions, which differed in goethite content. In all cases, spherical and durable capsules of alginate/goethite composite were produced. In laboratory tests, mechanical stability of the capsules at various temperatures and the coexisting ions of lake water were tested. Chemical composition of the aquatic environment had a strong influence on their mechanical stability. Static batch adsorption of phosphate studies were carried out for two adsorbents: goethite and alginate/goethite composite. The goethite gelation resulted in almost double growth of sorption capacity in the case of adsorption from deionized water and, on average, a 50% growth in adsorption from the environmental water compared to raw goethite. The alginate/goethite adsorbent removed phosphate in a wide pH spectrum—from 4 to 10. Results suggest that the proposed adsorbent has potential for the removal of phosphate from contaminated water.

CO(2) reduction and CO adsorption on noble metals (Pt, Rh, Pd) and their alloys (Pt-Rh, Pd-Pt, Pd-Rh, Pd-Pt-Rh) prepared as thin rough deposits have been studied by chronoamperometry (CA), cyclic voltammetry (CV) and the electrochemical quartz crystal microbalance (EQCM). The influence of alloy surface composition on the values of surface coverage, eps (electron per site) and potential of the oxidation of CO(2) reduction and CO adsorption products is shown. The oxidation of the adsorbate on Pt-Rh alloys proceeds more easily (at lower potentials) than on pure metals. On the other hand, in the case of Pd-Pt and Pd-Rh alloys the adsorbate oxidation is more difficult and requires higher potentials than on Pt or Rh. The analysis of the EQCM signal is presented for the case of adsorption and oxidation of carbon oxide adsorption products on the electrodes studied. The comparison of adsorption parameters and the EQCM response obtained for platinum group metals and alloys leads to the conclusion that reduced CO(2) cannot be totally identified with adsorbed CO.

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Results of the last 10 years of our investigations on the use of reticulated vitreous carbon (RVC Ò ) in various types of cells show that this kind of porous conductive glassy carbon can be successfully used as a matrix for active mass and as a current collector in many primary and secondary batteries. This paper focuses mainly on the use of RVC Ò modified with metals like Pt, Rh, Pd, Ni, Pb and their oxides in construction of the following types of cells: (1) zinc-carbon primary and secondary batteries, (2) rechargeable cell systems with NiOOH cathode, (3) electrochemical capacitors with Pd and Pd-Rh alloys, and (4) lead acid battery. The most important improvement in performance has been achieved with lead-acid and zinccarbon batteries. Especially for the modified zinc-carbon battery, which has been constructed in the popular AA format, manufactured on a small (laboratory) scale, and tested according to the IEC norms as a battery for commercial use, the capacity has been higher by ca. 20% compared with the batteries available on the market. Also, results obtained for thin layers of Pd and their alloys deposited on RVC Ò are promising in terms of the application of these kinds of electrodes in electrochemical capacitors. The pseudocapacitance of a Pd-Rh/RVC Ò composition may reach 540 F g -1 .