Industrial Ecology and the Geoenvironment - Sustainable Practices in Geoenvironmental Engineering - page 116

goods or products serve the individual consumer directly. An example of this from the
diagram shown in Figure 4.2 is the production of metal consumer goods. Most reports
on these industries are satisied with the distinction between upstream and downstream
types, and in general, these would be suficient to encompass all the activities engaged
in the exploitation and use of the products obtained from mining. However, the nature
of the impacts on the geoenvironment can be vastly different depending upon whether
it is a midstream industry that produces or prepares parts for use by other downstream
industries or a downstream industry that concentrates on consumer production goods.
For example, the impacts from contaminants that ind their way into the geoenvironment
from the metal fabrication and processing midstream industries can be more signiicant
than in the production and assembly of their counterpart downstream industries.
Metallurgical industries cover a vast variety of processes depending on the inal product
issuing from the industry in question. The common practice of classifying these indus-
tries into three kinds of industries in relation to the material source used in the process
and product produced, allows one to conveniently group the kinds of interaction of these
industries with the geoenvironment. The midstream-downstream industries represented
in the top right-hand corner drawing (Figure 4.2b), for example, are intensive users of
energy. The foundries produce smoke stack emissions that are sources of (a) acid rain gen-
eration and (b) land environment contamination when noxious airborne particulates ind
their way onto the solid land environment. The use of wet scrubbers and/or dry collectors
can reduce harmful discharge of noxious gases and airborne particulates. Some of the
discharges for foundries producing steel and aluminum include the various heavy metals
such as lead, zinc, manganese, chromium, arsenic, iron, nickel, and copper. For many other
industries, in addition to the heavy metals, we will have a variety of organic chemicals
included in the hazardous air pollutants (HAPs). A listing of many of these can be found
at http://www.epa.gov/ttn/atw/188pols.html (USEPA 2013).
4.4.1.1 Metal Fabrication and Processing
Typical metal fabrication and processing midstream-downstream industries are those
that produce value-added metals and metal goods. The types of metals include iron, alu-
minum, copper, lead, zinc, gold, tungsten, tin, silver, cadmium, etc., and are produced
in a variety of forms. These serve as downstream products or as resource material for
other downstream industries. Some of the downstream industries in this present category
include (a) metals inishing industries, e.g., electroplating, anodizing, and coatings and
(b) industries and assembly plants utilizing metals for production of goods, e.g., manufac-
ture of automobiles, planes, trains, ships, ovens, refrigerators, and tin cans, to name a few.
Interactions between downstream industries and the geoenvironment are primarily in
respect to energy resources needed to satisfy the energy requirements of the industries,
and the handling and disposal of the waste discharges, including the inadvertent spills
and overlows during processing, manufacture, and production. The demands for energy
in downstream industries, especially those in the category of material preparation and
inishing, are of considerable concern in the overall strategy to reach the sustainability
indicators that deine the sustainability goals in the energy resource ield. The next chapter
discusses many of these concerns and strategies. Increased eficiency in manufacturing
and production technology can alleviate some of the demands on energy use in these
kinds of industries.
The metal inishing industries use a signiicantly large proportion of toxic chemicals
in their various processes to produce, for example, corrosion resistance, wear resistance,