80 Organic waste recycling: technology and management
The first alternative which employs a recovering machine gives higher
production quantity per cost than the second alternative. Therefore based on the
financial feasibility, the recovering machine should be selected.
Technology changes
Technology changes are oriented toward process and equipment modifications
to reduce waste, primarily in a production setting. Technology changes include
the following:
- changes in the production process;
- equipment, layout, or piping changes;
- use of automation; and
- changes in process operating conditions, such as flow rate,
temperatures, pressures, and residence times.
Example: Technology changes
The U.S. DA-Magnuson Infrared Antipollution Peeling Process uses infrared
energy at 900°C (1,650°F) to condition the surfaces of potatoes treated with
strong sodium hydroxide solutions (refer to Figures 2.2 and 2.3). The peel can
then be removed mechanically by soft rubber scrubbing rolls rather than by
water as is done in conventional caustic peeling. A final spray rinse using low
volumes of water removes residual peel fragments and excess sodium
hydroxide. Direct comparison of this process with conventional peeling has
demonstrated that the strength of the waste discharged has been reduced by 40
percent (Jones 1973).
Input material changes
Input material changes accomplish waste minimization by reducing or
eliminating the pollutant materials that enter the production process. Also,
changes in input material can be made to avoid the generation of pollutant
wastes within the production processes. Input material changes include: (i)
material purification; and (ii) material substitution.
Product changes
Product changes are performed by the manufacturer of a product with the intent
of reducing waste resulting from a product’s use. Product changes include:
- product substitution;
- product conservation; and
- changes in product composition.