Behaviour of Nitrogen Soluble Forms in Natural Water in the Presence of Anionic and Cationic Surfactants and Mineral Substrates

Abstract

The redox processes, organic substances accumulation, chemical equilibria and adsorption of organic substances on the substrate surface function of natural water compositions and substrate granule sizes have been investigated. Laboratory simulations have been carried out for the Nistru and Isnovat river waters. The natural water models containing laurylsulphate (LS) as anionic surfactant (SAS An) and cetyltrimethylammonium (CTMA) as cationic surfactant (SAS Ct), separately and in a body, as well as the substrates Al(OH)3, Al2O3, CaCO3, H2SiO3, light fraction (clayey) of diatomite and expanded clay powder have been studied. The timely distribution of the soluble nitrogen species containing NH4+, NO2- and NO3- in the samples of natural waters has been analyzed. It has been found that LS diminishes the redox processes braking due to the partial fixation of toxic organic matter. Similar, but more pronounced enhancement impact on oxidation of nitrite ions as a result of fixation and sedimentation of organic components has been found in the case of the calcium carbonate powder. Also, CaCO3 produces a better SAS Ct separation/inactivation of organic part in the presence of both anionic and cationic SASs. A water self-purification processes effectiveness in polluted river waters decreases in the CaCO3, Al(OH)3, Al2O3, H2SiO3, light fraction (clayey) of diatomite, expanded clay powder substrate series.

Influence of organic ammonium derivatives on the equilibria between NH4+, NO2− and NO3− ions in the Nistru River water

“…The study of the behavior of stable nitrogen forms (NH 4 + , NO 2 − , NO 3 − ) in natural water basins is crucial in discovering new insights regarding the environmental matrix 17 , 22 . The investigation of the dynamics of these nitrogen species concentrations in laboratory models for a large number of river and lake waters leads to the conclusion that changes in their concentrations can serve as sensitive indicators of the composition and concentration of the organic matter and its transformations in this environment 27 – 29 , 34 – 36 . The ammonium and its environmental amine derivatives are physiological products released through a wide range of bacterial catalytic systems 3 , 9 – 16 , 18 , 19 , 21 as well as through natural redox processes.…”