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1.
A nonlinear model of the decomposition of a multicomponent contaminant is developed with allowance made for the distribution of components over their reactivity. Model application is illustrated by the analysis of published empirical data on organic matter biodegradation in water column and bottom sediments, in an activated-sludge bioreactor, and the biological absorption and enzymatic destruction of organic matter by macrophytes. Photodestruction, chemical destruction, and sedimentation are also considered. The nonlinear model is compared with a first-order reaction equation.__________Translated from Vodnye Resursy, Vol. 32, No. 3, 2005, pp. 322–336.Original Russian Text Copyright © 2005 by Dolgonosov, Gubernatorova. 相似文献
2.
A. M. Dolgonosov N. K. Kolotilina A. G. Prudkovskii 《Geochemistry International》2016,54(13):1236-1251
This paper briefly describes original developments in the theoretical and practical ion chromatography. It is demonstrated that new methods may be applied for the highly-selective analysis of complex natural objects. The determination of different species of sulfur and other ions in the condensates of fumarolic gases is considered in detail as an example. 相似文献
3.
A model is developed to describe the degradation kinetics of an organic substance with chaotic structure of macromolecules.
The model is based on the results of analysis of lignin structure and its degradation mechanisms described in previous papers
of this series. Model postulates are formulated and their chemical substantiation is given. Degradation regimes corresponding
to different molecular size distributions are studied. The decrease in organic carbon concentration at the asymptotic stage
of the process is shown to obey the power law. Theoretical results were checked against some empirical data taken from the
literature. 相似文献
4.
Analysis of paleolimnological data on a part of Lake Imandra (Kola Peninsula), polluted by wastewaters discharged from a copper-nickel plant, is used to calculate the vertical profile of toxicity of bottom sediments and determine the response of dominant species of diatomic complex to the growing toxicity. The species are aggregated by the similar responses to the load. The dependence between the population sizes of diatom groups and toxicity is established. The diatom complex is shown to change its structure twice—at the toxicity exceeding the background level by factors of 1.2 and 3.2, respectively. A model is developed to describe variations in the species composition of the community under growing toxicity; the model is shown to be applicable to the analysis of paleolimnological data. General analysis of the model is given, and typical scenarios of variation in the number of species under growing toxic load are described. 相似文献
5.
Mechanisms of enzymatic degradation of a persistent organic substance are discussed in the case of lignin. The major groups
of lignin-decomposing microorganisms and their enzymatic systems are described. The biochemical mechanisms of the action of
main lignin-decomposing enzymes are analyzed. Typical sizes of enzyme molecules are estimated. The results of analysis are
used to formulate the major regularities of lignin destruction, which are required for the construction of a kinetic model
of this process. 相似文献
6.
7.
The bacteriological indices of water quality, including coliforms, sulfite-reducing clostridia, total microbial count, coliphages, and fecal streptococci were analyzed. A model describing fluctuations in microorganism population in the aquatic environment is proposed. A stochastic differential equation was obtained and used to derive a lognormal distribution of organism population. The model was applied to describe time series of bacteriological indices of the Moskva River Water Source. Satisfactory agreement was obtained between theoretical distributions and empirical data in a wide range of index values embracing one to three orders of variations in microorganism population. A forecast procedure was developed and applied to calculate the exceedance probabilities of different levels of bacterial pollution of the water source. Time periods with higher bacterial pollution were identified. 相似文献
8.
The balance of a component contained in river water is considered taking into account its input with lateral inflow and decay
in the aquatic environment. Random changes in lateral inflow causes fluctuations in the parameters of component input and
decay. A stochastic equation of component balance is derived and used as the basis for the construction of an equation for
the probability density of component concentration. The solution of this equation shows that the probability density follows
lognormal law. This theoretical result is applicable to the analysis of time series of water salt composition components,
including pH, alkalinity, chlorides, ammonia, iron, and aluminum. The applicability of the lognormal law is proved and distribution
parameters are evaluated. The distributions of three components (pH, alkalinity, and chlorides) are found to split into two
lognormal branches, describing high and low component concentrations. In the case of pH and alkalinity, this splitting is
due to seasonal effects, while in the case of chlorides, it is caused by the difference between concentrations in the surface
runoff at the early and final stages of snow melting and rainfalls. The application of the statistical distributions for probabilistic
forecasting of extreme component concentrations is considered. The exceedance probability of standard limits of the components
is considered. The use of exceedance probability in hydrochemical standardization is demonstrated. 相似文献
9.
A model is developed to describe the degradation kinetics of an organic substance with chaotic structure of macromolecules. The model is based on the results of analysis of lignin structure and its degradation mechanisms described in previous papers of this series. Model postulates are formulated and their chemical substantiation is given. Degradation regimes corresponding to different molecular size distributions are studied. The decrease in organic carbon concentration at the asymptotic stage of the process is shown to obey the power law. Theoretical results were checked against some empirical data taken from the literature. 相似文献
10.
Daily time series of phytoplankton concentration are theoretically analyzed with the use of population dynamics equation with
fluctuations in the growth factor and environmental carrying capacity taken into account. The statistical distributions of
phytoplankton cell concentration are shown to obey different laws, depending on the season of the year: lognormal in the winter
and logarithmic in the vegetation period. The probability of extremely high concentration numbers is described by the normal
law. The verification of the obtained relationships against a body of empirical data confirmed the theoretical forecasts.
The obtained results make it possible to predict the probabilities of various phytoplankton concentration values within a
wide range, including the domain of large values, which are of greatest hazard in terms of water quality, water treatment
processes, and aquatic ecosystem well-being. 相似文献