Oleg G. Vorobyev, Andrey V. Shamshin

St.Petersburg State Marine Technical University

Processes of transfer of mass-energy and information in a GTS are subject to the same general regularities as those in artificially created physico-chemical systems (PCS). In that case, a natural subsystem of a GTS can be analysed as a chemical reactor with distributed parameters and within which are occurring processes directed towards the neutralisation of a technogenic loading of mass and energy. The classical definition of a PCS was given by Academician V. Kafarov - "An m-phased, n-componented continuum, distributed in space and variable over time. Given the presence of a source or a discharge, at every point within a homogeneous medium and at phase boundaries there occurs a transfer of matter and energy. The system is complicated by the combination of phenomena of different kinds (hydromechanical, chemical, thermal, diffusional etc.) and by its linear, non-linear, concentrated and dispersed parameters" (Kafarov 1982). On the basis of this definition we can classify PCSs of different hierarchical levels by the character of their interaction with the natural environment and the degree of transformation of natural materials, energy and information. Such a classification is presented in Table 3.

The first two levels of the classification, the "Technological Apparatus" (TA) and the "Technological Line" (TL), are seen as "technical PCSs" processing natural materials or the products of their artificial transformation. The three remaing higher-order PCSs are geotechnic systems (GTSs).

The hierarchy of physico-chemical systems (PCSs). Let us examine the distinguishing features of GTSs at levels 3 to 5. The intensity of the processes within a GTS is governed by the specific nature of the technological processes. The territory of a GTS which is a third-level GTS can be divided into an impact zone of immediate effect and a zone of indirect influence. The impact zone is that in which the industrial enterprises are actually located and therefore subject to powerful and purposeful transformation. In this zone are concentrated the matter and energy directly involved in the technological processes. The impact zone can itself be subdivided into three subzones, the active subzone, the subzone of weakened activity and the peripheral subzone. In the active subzone, in technological apparatuses and technological lines, occur processes reworking natural resources in extreme conditions with intense loadings (pressure, temperature, concentration) and here originate the maximum technogenic burdens for the environment. The form these burdens take depends on the degree of openness of the technical systems, that is, on the intensity of mass-energy exchange with the surrounding environment. In the subzone of weakened activity are located stores of raw materials, finished products, reagents etc. This subzone is distinguished by a high concentration of matter involved in the technological processes, by heightened pressure, normal temperatures and a greater degree of openness than the active subzone has. The peripheral subzone also contains storage facilities, tanks etc for waste products, providing high concentrations of matter at normal pressures and temperatures. The burden on the surrounding environment is here relatively great because migration of matter from the storage sources takes place in conditions where the environment has been transformed, the landscape surface often disturbed or displaced, with damaged soil and vegetation cover and with changes in the dynamics of subsurface waters. Technical systems in this subzone are virtually open, with some partial limitations in localised storage depots, waterproof coverings etc.

The zone of indirect influence is represented by a natural landscape with heightened concentrations of those materials involved in the technological processes. This zone manifests in the highest degree the action of natural self-purifying environmental mechanisms, depending on geographical conditions, the magnitude of technological pressure and the ecologically permissible maxima for such burdens.

The accumulation in the natural environment of technologically generated products has necessitated the development of intensive methods to defend that environment and a review not only of tactical procedures but also of the strategy of environmental protection, to favour optimisation of PCS structure and its connecting flows of mutual exchange at all hierarchical levels.

Any PCS generates, in the course of its activity, an information-saturated, non-stationary mass-energy field significantly exceeding at every point within it the background values of the corresponding components in the environment around. In a number of cases, with the movement from one level of the system to another (TA, TL, IP-SE, IN-SE, TPC), we observe the superimposition of such fields, leading to the formation of local critical zones with anomalously high concentrations of materials contained in industrial waste. The elaboration of principles of optimisation of a PCS must take account of this development.

An objective criteria for assessment of GTS processes offers exergy (Yantovski 1988). It is exergy method of thermodynamic analysis that allow to estimate both energy conversation processes and damage to surrounding environment. Also, different sorts of waste can be directly compared in exergetic terms.

Exergy method can be applied for the analysis of thermal, chemical and other plants, technological chains of processes, the life cycle of a product or a whole country (Wall 1998, Gong 1999, Stepanov 1990). Combined with ecological and ecomomic theories, exergy can be used for ecologo-economic optimisation in a system (Vorobyev 1997, 1998 and Jorgensen S. 1981).

Let’s use of exergetic theory for GTS analysis. We can define technogenic load into time t by the help of exergy indexes per square or volume of environment:

; (1)

where E_W is chemical exergy of waste from industrial object, F and V are accordingly square and volume of surrounding environment.

Environmental response on pollution can be defined by the indicator, which describes change of chemical composition of environment. This indicator is defined by the difference of entropy per volume of environment:

, (2)

Use of thermodynamic approach for calculation of indexes of technogenic load (i) and indicator of environmental quality (j) according to the above mentioned formulas, allows:

• to estimate a level of the ecological risk of the substance and energy transformation processes. It gives an opportunity of the choice of the alternative variant in conformity with concrete regional conditions;
• to assess a degree of the rationality and efficacy of the natural resources use;
• to estimate a value of permissible regional load on environment;
• to definite the priorities of the production waste, its sources and priorities of the infestation in environmental protection activity;
• to create a rational system of the ecological management of industry;
• to perform calculations in the same units - Joules.

Experience of application of that method has showed its reliability, flexibility and prospect.

So we consider, that exergy indexes and indicators have high information content and its foundation on the rigorous thermodynamic calculations both the technogenic core and natural elements of ecosystem.

1. Kafarov V.V. 1982. Principles of creation of chemical industry without waste. Moscow: Nauka (in Russian).
2. Yantovsky E. I. 1988. Flows of energy and exergy. Science, Moscow. (in Russian).
3. Wall G., Yantovsky E., Lindquist L. and Tryggstad J. A zero emission combustionpower plant for enhanced oil recovery. Energy , Vol. 20, No. 8, pp. 823-828.
4. Gong M. 1999. On exergy as an ecological indicator. M. Sc. thesis, Department of Physical Resorce Theory, Goteborg University.
5. Stepanov V. S. 1990. Chemical energy and exergy of substances. Science, Novosibirsk. (in Russian).
6. Vorobyev O.G., Zotov L.L., Shishevilov D.V. 1997. Ecological estimation of industrial production life-cicle. Ecologikal Chemistri, 6(3),pp.196-203 (in Russian).
7. Jorgensen S. and Mejer H. 1981. Application of exergy in ecological models. Liege: CEBEDOC, pp. 587-590.
8. Frumin, G. 1998. Estimation of water objects conditions and ecological norm. St. Petersburg (in Russian).