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A variety of new and emerging technologies can neutralize and, in some cases, even destroy the hazardous
characteristics of industrial waste. One new encouraging technology is known as supercritical water oxidation. The process is simple but expensive. Water is heated and pressurized and mixed
with organic compounds, which dissolve. Later, oxygen gas is added to the mix, and harmful substances are burned away. What's left is harmless. This gigantic pressure cooker, unfortunately,
is very expensive. Less expensive processes may become available; for example, a team at the University of Texas at Austin has developed a working water oxidizer.*
Other technologies currently being used in the Texas market include:
- Oxidation. Either humid air or a chemical
process is used to remove organic constituents from a water-based hazardous waste stream.
- Bioremediation. This process uses
microorganisms bred to have an appetite for hydrocarbons to "eat" oil spills or even heavy metals.*
- Carbon adsorption. This is a process in which toxic substances adhere to a specially treated carbon surface.
- Gas absorption. Toxic gas is compressed under pressure and vented into an absorbing or reactive unit.
- Dechlorination. This process chemically
replaces chlorine with hydrogen or hydroxide ions, leaving chlorinated substances nontoxic.
- Neutralization. This process either makes
an acid substance less so by adding alkaline substances, or makes a basic substance more acidic by adding acid.
- Oxidation. This process adds oxygen through
the application of "wet" air or chemicals to substances such as sulfurs, phenols, or cyanides, rendering them nonhazardous.
- Precipitation. This process separates
solids from a liquid waste through the use of chemicals so that the solid portion can be managed more safely.
- Vitrification. This term refers to any
process that uses electricity to encase products in glass. For example, electrical currents can be introduced into contaminated soils at such high voltages that the soil vitrifies, or
"turns to glass." Other similar systems that chemically or physically reduce the mobility of hazardous constituents include both micro and macro-encapsulation as well as
stabilization, either through the use of cement or pozzolanic substances.
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