Environmental Engineering Reference
In-Depth Information
9.8 Concluding Remarks
1. The concern in this chapter is for land environment sustainability, as it pertains
to the effects of anthropogenic discharges of wastes in the land environment.
Attention has been focused on developing concepts that consider the natural
capital of land environment. The objective for sustainability has been articulated
as follows:
To ensure that each natural capital component maintains its full and uncom-
promised functioning capability without loss of growth potential.
2. For the objective to be fulilled, actions, reactions, and management techniques
require speciication of
indicators
that mark the path toward sustainability of
the natural capital. Although we recognize that absolute sustainability is not
generally attainable, one should nevertheless adopt and implement strate-
gies and technological/engineering means that point toward sustainability
objectives.
3. The irst half of this chapter examined the nature of indicators, and has distin-
guished between system status and material performance indicators. This dis-
tinction is necessary since various situations demand a proper accounting of the
relationship between the two. Figure 9.4 provides the protocols that assist in this
type of accounting.
4. Contaminants from anthropogenic activities are perhaps the largest sources and
types of geoenvironment stressors. The manner in which they are handled in
respect to land environment impact will, to a large extent, greatly dictate whether
sustainability or “near sustainability” of the land environment and/or its natu-
ral capital can be achieved. The impact of these (contaminants) and the imple-
mentation of indicators as a technique for assessment need proper consideration.
Figure 9.5 provides the sustainability goals in respect to waste discharge onto the
land environment, and the subsequent igures provide examples. To some extent,
we can learn how to prescribe the necessary indicators to achieve the objective.
Obviously, real ield situations are both site- and industry-speciic.
5. In the assessment of waste impacts, it is clear that this cannot be achieved without
an understanding of both the interactions with the subsoil system and the goals
of sustainability. Central to the various issues is the problem of gaining a proper
knowledge of the health status of the subsoil system. This requires one to be able
to predict the transport and fate of pollutants in the subsoil system. The problem
of prediction is not a simple problem that can be handled with one set of tools.
Analytical-computer modeling is perhaps the most common technique used to
provide information that allows one to predict system behavior.
6. For pollutants that can partition between the aqueous phase and the soil solids in
the subsoil system, we have well-developed advection-diffusion transport mod-
els that can address the problem. The pitfalls in implementation of such mod-
els include the availability (or lack) of appropriate and realistic input parametric
information (especially partition and distribution coeficients) and chemical reac-
tions that affect the status of the contaminants in the system.
7. The use of geochemical speciation modeling allows one to determine these reac-
tions. However, since kinetic reactions are not readily handled in some of the pres-
ent available geochemical models and since many of these models are not coupled
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