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CNAA / Theses / 2005 / May /

Physical-chemical characteristics and processes in the systems waterparticulate material-bottom sediments from rivers Nistru and Prut


Author: Vasile Rusu
Degree:doctor habilitat of chemistry
Specialities: 02.00.04 - Physical chemistry
11.00.11 - Environmental Protection and Rational Utilization of Natural Resources
Year:2005
Scientific consultant: Tudor Lupaşcu
doctor habilitat, professor, Institute of Chemistry, Academy of Sciences of Moldova
Institution:
Scientific council:

Status

The thesis was presented on the 27 May, 2005
Approved by NCAA on the 22 September, 2005

Abstract

Adobe PDF document0.98 Mb / in romanian

Thesis

CZU 556.12+551.312+627.157:541.183.5+628.515

Adobe PDF document 3.65 Mb / in romanian
227 pages


Keywords

aquatic bottom sediments, structure, surface proprieties, physical-chemical models

Summary

The thesis includes physical-chemical research of bottom sediments having the purpose to establish their surface properties and influences of components, mineralogical particularities, characteristics of double electrical layer, sorption properties for phosphate, ionic exchange capacity, spatial dynamics of heavy metals, their chemical partitioning and mobility at sediment - water interface for rivers Prut and Nistru. Complex assessment of the influence of abiotic factors on water quality realized by means of multivariable statistical analyses was performed. Kinetics of nitrogen mineralization for rivers Nistru and Prut was researched and kinetics parameters were established.

The actual physical-chemical models are considered and their adequacy is checked for analysis of different aspects of surface properties. The models of double electrical layer (ДEL) were analyzed. The model of DEL postulating the concept of variable capacity for compact Stern layer is formulated and the applicability of criterion of minimum Gibbs energy for definition of non- Coulomb potential for specific chemical adsorption in acid-base interactions with sediments is established. The aspects of adsorption phenomena and models for phosphate adsorption, correlation of parameters of different models, including Stern model, are considered, and the contribution of electrostatic and chemical components is checked. The adequacy of kinetic models for nitrogen mineralization in aquatic systems is verified, andthe aspects of ammonification of organic nitrogen from point of view Michaelis-Menten kinetic models for homogeneous and heterogeneous enzymatic reactions are analyzed. The model of parallel-consecutive reactions is proposed, being analyzed in combination with modified Streeter-Phelps model, for complex analysis of the mechanisms of nitrification, oxidation of nitrogen mineral forms, organic matter and consumption of dissolved oxygen, for utilizing of model for physical-chemical simulations, and also in the practical purposes, for prediction of crisis ecological situations along the rivers Prut and Nistru.