Study on the separation of surface-active agents in the aquatic environment
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Дата
2025
Автори
Науковий керівник
Назва журналу
Номер ISSN
Назва тому
Видавець
КПІ ім. Ігоря Сікорського
Анотація
Laboratory simulations with surfactant-polluted water from the Dniester and Prut rivers initiated with NH₄⁺ ions
demonstrated an acceleration of the conversion to nitrates, approximately four to seven times faster than in reference
samples, when granulated granite or expanded clay was applied. In contrast, CaCO₃ particles caused a visible
inhibition for the same samples, while in the water of the Isnovat River, characterized by a higher organic matter
content, the same procedure enhanced ammonium oxidation. UV spectral investigations were conducted using
aqueous solutions of anionic, nonionic, and cationic surfactants individually and in mixtures at various ratios (~10⁻⁵
mol/L, near the critical micelle concentration), recorded with PerkinElmer Lambda 25 and UV 2005 SELECTA
spectrophotometers. The UV spectra confirmed formation of SAA anionic–SAA cationic complexes. Cationic
surfactant activity in natural waters depends on the organic matter index, reflecting the anionic character of the sample.
Separation of cationic surfactants using CaCO₃ can be achieved by applying an excess of anionic surfactant (SAA
An/SAA Ct > 1), while expanded clay completely adsorbs cationic surfactants. The expanded clay substrate adsorbs
on its surface completely cationic AAS. The accelerated ammonium-to-nitrate conversion in the presence of expanded
clay and granite suggests catalytic effects of mineral surfaces enhancing adsorption and oxygen transfer. These results
provide insights into surfactant behavior and ammonium oxidation in natural waters.
Опис
Ключові слова
Surfactants, laboratory simulations, ammonium oxidation, separation process, organic matter, calcium carbonate, expanded clay adsorbent
Бібліографічний опис
Spataru, P. Study on the separation of surface-active agents in the aquatic environment / Petru Spataru // Чиста вода. Фундаментальні, прикладні та промислові аспекти : матеріали ІX Міжнародної науково-практичної конференції, 20-21 листопада 2025 р, м. Київ. – Київ : КПІ ім. Ігоря Сікорського, 2025. – С. 50-52. – Бібліогр.: 3 назви.