ThioguardŽ
The challenge of maintaining
a human friendly environment is with us every day. Clean air, pure
food and water, and sanitary wastewater treatment ... they are all
part of our quality of life, all part of our complex ecosystem. Unfortunately
they are also too often under attack. And sometimes, steps we take
to bolster one part of the ecosystem can have a negative effect on
another sector.
That condition is certainly true for our nation's wastewater. During the
last 25 years, regulatory changes which were designed to help make sure
some parts of the environment were protected, have resulted in a deterioration
of municipal wastewater. These changes have fundamentally altered the physical,
chemical, and biological properties of wastewater, making it more hazardous
than ever before.
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As the chart illustrates,
(dissolved sulfide vs. total metals) the significant reduction
in total metals concentration, for example, has led to dramatic
increase in dissolved sulfides, and thus in the corrosive properties
of wastewater. The out come has been to subject municipal sewer
systems to an even higher level of corrosion.
The implications are clear, in 2000 the Environmental Protection Agency
(EPA) estimated that municipal sewers are failing six times faster than
their rehabilitation rate. What's more, the EPA predicts that by 2016,
over 50% of the United States' 600,000 miles of sewer lines will be in
poor, very poor, or inoperable condition.
In addition, pretreatment, pretreatment, longer retention times, and
the higher strength of today's wastewater all contribute not only to
corrosion, but sewer and plant odor, FOG (fats, oils, and grease) treatment
plant upsets, and an increased overall cost of wastewater treatment.
But there is an answer to this dilemma ......
ThioguardŽ
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