technical Cost-effective Wastewater Treatment with INTEROX Hydrogen Peroxide

Solvay Chemicals
technical
P U B L I C A T I O N
Cost-effective Wastewater Treatment
with INTEROX® Hydrogen Peroxide
Introduction
Nearly every industry has a problem with toxic waste in one form or another.
With increasingly stringent regulations and the closing of landfills and deep
injection wells, INTEROX® Hydrogen Peroxide is proving itself a costeffective
solution for wastewater treatment. Beginning with its use in the 1970s for
controlling sulfides, INTEROX Hydrogen Peroxide now appears in catalyzed
and other advanced systems that detoxify a long list of organic and inorganic
pollutants.
Many chemical plants, paper mills, food processing operations, pharmaceutical
manufacturers and other industries use hydrogen peroxide onsite. With
it, they control amines, aldehydes, hydroquinones, mercaptans, phenols,
reduced sulfur compounds, chlorine, cyanides, chromium, iron, nitrous oxides
and other pollutants.
Hazardous waste treatment and disposal facilities use hydrogen peroxide
increasingly in their systems, treating pollutant concentrations that may
range from the ppb levels up to 10%. Remediation companies are increasingly
using hydrogen peroxide not only to treat ponds and lagoons, but to detoxify
soil and contaminated groundwater.
Treatment alternatives
In general, the methods used to treat industrial wastes fall into four categories,
although hydrogen peroxide treatment has enough unique features to warrant
a category or two of its own.
Phase transfer. These methods are primarily physical: absorbing a pollutant
onto activated charcoal (going from liquid to solid toxic wastes), or stripping
a liquid by volatilizing the pollutant (going from liquid to gaseous waste).
While phase transfer methods change the form of the pollutant, they don’t
eliminate it. In fact, they may exacerbate the problem.
Thermal oxidation. Incineration may be the only feasible method for low
volumes of wastewater with extremely high concentrations of pollutants. But
it has many drawbacks: obtaining permits for both atmospheric emissions
and residual solids disposal; funding the capital expense
of building a plant and getting the wastes to it; and paying
the high energy costs of continuing operation.
Biological oxidation. Proven over the years, biological
systems have been responsible for many environmental
improvements. However, as regulations expand, three
limitations arise.
• Some substances may be toxic to the organisms
intended to degrade them. Even where organisms
have been specially adapted, removal efficiencies
may vary widely with fluctuations in influent
concentrations.
• Some wastes slip through the system unchanged
they do not kill the biological organisms but they
are not degraded either. These refractory
compounds must be treated by other methods.
• In contaminated soils, aquifers and lagoon sludges,
oxygen usually cannot reach the system in high
enough concentrations for aerobic biological
treatment to work.
Chemical oxidation. In the past, chemical oxidation has
referred to specialized oxidation reactions involving elemental
chlorine, hypochlorite, chlorine dioxide or permanganate.
These methods have a number of drawbacks: they may
be specific to only a few pollutants; they may create toxic
byproducts (for example, chlorinated organics like
chloroform); or they may involve chemicals that are difficult
and dangerous to handle (like elemental chlorine).
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Costeffective Wastewater Treatment with INTEROX® Hydrogen Peroxide Page 1 of 6
INTEROX Hydrogen Peroxide. Technically a method of chemical oxidation,
new methods of using hydrogen peroxide take it beyond simple
oxidation/reduction reactions to the powerful oxidizing potential of the hydroxyl
radical. By tailoring the conditions of the reaction, hydrogen peroxide can
be made to detoxify one or more specific pollutants. And hydrogen peroxide
can attack a wide variety of toxic substances.
Combination biological/hydrogen peroxide systems. When you combine
the low operational costeffectiveness of biological systems with hydrogen
peroxide’s power in handling refractory or toxic wastes, plus its unique
ability to provide available oxygen, you open a new realm of possibilities
in wastewater management.
INTEROX Hydrogen Peroxide advantages
INTEROX Hydrogen Peroxide combines advantages not obtainable with any
other single form of chemical control.
Powerful. The oxidation potential values in Table One show how INTEROX
Hydrogen Peroxide and the hydroxyl radical stack up against other wellknown
oxidants. In the form of the hydroxyl radical, INTEROX Hydrogen Peroxide
is second only to fluorine in oxidizing power. Hydroxyl radicals can be created
in a Fenton’s system (iron catalyzed), which creates one hydroxyl radical for
every H O molecule. These radicals can also be created by ultraviolet light,
an advanced system with two advantages: first, each H O molecule forms
two hydroxyl radicals, and second, the UV light makes the compound
to be treated more reactive.
2
2
2
Versatile. INTEROX Hydrogen Peroxide can detoxify a broad
range of organic and inorganic wastes, including sulfides,
thiosulfates, sulfites, mercaptans, disulfides, phenols and
substituted phenols, chlorine, cyanides, organic amines,
aldehydes and quinones. This range continues to broaden
as other treatment methods become environmentally more
questionable or expensive.
Selective. INTEROX Hydrogen Peroxide can be made
selective by adjusting the conditions of the reaction. For
example, hydrogen peroxide normally does not react with
phenols by itself, but at a pH of 45 with ferrous iron
catalyst, phenol destruction takes place in minutes.
Toxicity reducer. Given enough hydrogen peroxide, many
organic wastes can be oxidized all the way to CO . Usually
that isn’t necessary. A relatively small amount of peroxide
can cleave organic molecules, reducing toxicity to acceptable
levels, or making the molecules more easily managed
by biological treatment systems.
2
2
Table One: Comparative Oxidation Potentials
Species
Volts
Fluorine
3.0
Hydroxyl Radical
2.8
Ozone
2.1
Hydrogen Peroxide
1.8
Potassium Permanganate
1.7
Hypochlorous Acid
1.5
Chlorine Dioxide
1.5
Chlorine
1.4
Oxygen
1.2
Safe. INTEROX Hydrogen Peroxide is easily transported to needed sites
and easy to use in aqueous solutions. When stored in original containers, the
rate of decomposition is less than one per year for commercial grades.
When properly handled, it is a safe and effective oxidant.
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Bioenhancer. One of the most useful attributes
of INTEROX Hydrogen Peroxide is its ability to provide
a ready source of dissolved oxygen, a useful feature
in many ways.
• Residual oxygen sweetens the wastewater stream
and prevents anaerobic conditions that could lead
to sulfides downstream.
• Injection of INTEROX Hydrogen Peroxide and
bacterial nutrients (nitrogen and phosphorus) into
contaminated soils and groundwaters turns the
earth itself into a biological treatment center.
• Use of INTEROX Hydrogen Peroxide with biological
organisms makes possible degradation of organics
in situations where either method alone would
be relatively ineffective.
• INTEROX Hydrogen Peroxide is an excellent method
for treating ponds and lagoons that have gone
anaerobic.
• Dosing of INTEROX Hydrogen Peroxide in the return
sludge line of an activated sludge system can
be used to control bulking of filamentous bacteria.
Unique combination treatment. As a bioenhancer, INTEROX Hydrogen Peroxide supplies oxygen that enables biological treatment to work
in unusual situations. Hydrogen peroxide can also solve two major problems that can occur with biological systems.
• Pretreatment with INTEROX Hydrogen Peroxide can degrade compounds that would be toxic to biological systems (for example, chlorinated
phenols). The breakdown products of these highly toxic compounds are much less toxic and easily removed by biological treatment. This often
proves to be far more costeffective than developing special biological organisms for difficult toxins.
• Posttreatment or “polishing” effluents from biological treatment can eliminate those refractory compounds that slip through the biological
system unchanged. Because most of the detoxification is done biologically, only small amounts of hydrogen peroxide are required.
Table Two: Summary of hydrogen peroxide chemistry: organic compounds
Organic Pollutants
pH
Theoretical Mole Ratio,
H O : Pollutant, 100% Basis
Reaction Time
Catalysts
2
2
Amines
Alkaline
1:1
Minutes to Hours
None
Aldehydes (Formaldehyde)
Alkaline
0.5:1
Minutes
None
BOD/COD, TOC
Acid
ca. 2:1 weight ratio
Minutes
Fe+2
Mercaptans, Disulfides
Alkaline
5:1
Minutes
Chelated Fe+2 or Cu+2 generally required.
Phenols,
Substituted Phenols,
Hydroquinones
Acid
94% phenol
oxidized with 2.5:1 mole
ratio; 99.9% with 6:1
mole ratio; total
destruction to CO
at 14:1 mole ratio
Minutes to Hours
Fe+2 required. Extent of phenol
destruction depends on H O
phenol ratio. Rate of oxidation
depends on Fe+2 concentration.
2
2
2
Table Three: Summary of hydrogen peroxide chemistry: inorganic compounds
Inorganic Pollutants
pH
Theoretical Weight
H O : Pollutant, 100% Basis
Reaction Time
Catalysts
2
2
Chlorine
Alkaline
0.48:1
Seconds
Catalyst not required, Reaction will
not work if ammonia is present.
Chromium
Acid
0.98:1
Minutes
None
Cyanides
(Free and WAD cyanides)
Alkaline
1.31:1
Minutes to Hours
Copper catalyst required. Metal cyanides
somewhat resistant. Iron cyanides
cannot be treated by peroxide.
Iron
Neutral
0.30:1
Minutes
None
Nitrous Oxides
Acid
0.4 1.7:1
Seconds to Minutes
None
Sulfides
Acid
Neutral
Alkaline
1.00.1
1.03:1
4.25:1
Minutes
Minutes
Minutes
Fe+2 can be used to speed reaction time.
Sulfites
All
0.43:1
Minutes
Catalyst not required.
Thiosulfates
Acid
Alkaline
0.15:1 (min)
1.21:1 (max)
Minutes
Minutes
Patented Solvay Chemicals catalyst
system can be used in alkaline
conditions to reduce mole ratio
of H O required.
2
2
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INTEROX Hydrogen Peroxide chemistry
Oxidation by INTEROX Hydrogen Peroxide involves complex reactions
influenced by a number of variables, including pH, catalysts, temperature,
peroxide dosage and reaction time. These variables control the reaction rate,
the consumption of hydrogen peroxide and the end products formed.
Because these variables are interdependent, changing one will affect them
all. Tables Two and Three summarize the salient features of hydrogen
peroxide chemistry.
The general approach to treating a waste stream is first to experiment with
samples in the laboratory. For detailed information on particular wastes and
specific guidelines for laboratory sampling, treating and testing methods,
contact Solvay Chemicals.
Typical applications
Solvay Chemicals has designed INTEROX Hydrogen Peroxide treatment
solutions for many different pollutants and pollution situations. The following
examples show some of the diversity of suitable applications.
Pretreatment of a thiosulfate stream prior to discharge. One West Coast
refinery was unable to discharge to the municipal treatment system because
of high concentrations of thiosulfate. By pretreating the stream with
INTEROX Hydrogen Peroxide and a patented Solvay Chemicals catalyst
system, the refinery now reduces thiosulfate from several hundred mg/L to less
than 50, within the municipality's pretreatment standards.
Polishing the effluent from biological treatment. A pharmaceutical manufacturer
in the Northeast was unable to treat a refractory organic compound biologically.
By exposing effluent from the biological system to a UVactivated hydrogen
peroxide system, they reduced the contaminant from more than 10 mg/L
to an undetectable level.
Supplying supplemental dissolved oxygen. A mechanical pulp mill uses an
effluent treatment system that operates in two stages, anaerobic and aerobic.
Plagued by hydrogen sulfide where the switch between systems occurs, the
mill solved the problem with a hydrogen peroxide feed system.
Oxidation of hazardous sulfides. A paper company had a problem with sulfides
in the sludges from the belt filter press. Since the filter rooms are enclosed,
hydrogen sulfide could have posed a real hazard to workers. Injection
of hydrogen peroxide into the sludge keeps the hydrogen sulfide in the air
below 1 ppm.
Removal of phenols and chromium from paint stripping waste. An aircraft
manufacturer uses a phenolicbased paint stripper as part of its routine
maintenance operation. After solids have settled out, the phenolic waste
undergoes a Fenton’s hydrogen peroxide oxidation at a pH of 5. Then the pH
is raised to 11 with lime, which precipitates chromium and reduces the color
of the effluent. This standard system handles phenols at concentrations up
to 1000 mg/L and chromium up to 100 mg/L or more.
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Removal of cyanide from goldmining effluent. Normally
this wastewater goes into a tailings pond where the ultraviolet
radiation present in natural light oxidizes the cyanide.
Many facilities are under pressure to discontinue this type
of treatment due to the potential of migratory bird kill. If UV
radiation isn’t sufficient, hydrogen peroxide is extremely
effective, because the copper naturally present in the
effluent catalyzes the reaction.
Reduction of phenols at a wood treatment plant. Creosoting
plants routinely have high concentrations of phenols in their
wastewater. A Fenton’s hydrogen peroxide system easily
brings phenols down to discharge criteria.
Treatment of sludge during a pond closure. In one case, the sludge
to be removed contained sulfides at concentrations greater than 1000
mg/L. This caused severe odor and toxicity problems in the dewatering
operation and prevented the dewatered sludge from being dumped
at a nearby landfill. Hydrogen peroxide not only solved toxicity and odor
problems, it did not contribute to the solids level of the sludge, which
was disposable.
Treatment of refinery sour water for sulfides and phenols. A Gulf Coast
refinery routinely injects its sour water into a deepwell. When sulfide
plugs the well, alternate sour water treatment becomes mandatory.
Hydrogen peroxide removes the high concentrations of hydrogen sulfide
and lowers the pH, after which the addition of a small amount of iron
catalyst causes the residual peroxide in the system to attack phenols.
Groundwater decontamination. In the Midwest, a leak from an underground
gasoline pipeline contaminated the aquifer with 30,000 gallons of gasoline.
The remediation company implemented an insitu bioreclamation project,
pumping hydrogen peroxide and bacterial nutrients into the ground. They
estimated that hydrogen peroxide reduced cleanup time from several
decades to less than three years.
Soil decontamination. A remediation company on the West Coast was
hired to clean up gasoline that had leaked into the soil from underground
storage tanks at a gasoline service station. They excavated the soil,
treated it with hydrogen peroxide, and put it back into the ground. The
entire process took less than a week.
Toxicity reduction of hazardous waste. A hazardous waste treatment,
storage and disposal facility in the Northeast operated a number
of treatment processes, but in many cases they were forced to ship
wastes offsite for commercial incineration. By installing hydrogen
peroxide treatment systems, they were able to treat a variety of industrial
wastes and discharge to the municipal sewer without costly incineration.
Quality
Solvay Chemicals strives to bring you the best in peroxygen
products, service and technology. Exceeding, not just meeting,
your expectations is the basis for our pursuit of continual
improvement.
To demonstrate our commitment, Solvay Chemicals’ Quality
Management System is registered to the ISO 9001:2000
International Quality Management System Standard. Our
registration encompasses the production and distribution
of INTEROX Hydrogen Peroxide at both of our manufacturing
facilities in Deer Park, Texas and Longview, Washington, as well
as administrative activities at our Houston headquarters.
Delivery
Solvay Chemicals ships product from two North American plant
sites and a number of strategically located distribution terminals.
We operate a fleet of high purity aluminum rail cars and stainless
steel tank trucks dedicated to INTEROX Hydrogen Peroxide
transport. We also can provide stainless steel ISO containers
to deliver, store, and dose liquid hydrogen peroxide. These
“isotainers” are ideal for environmental applications at remote
sites, and especially suitable for seasonal or shortterm needs.
In emergency situations, we can use our Quick Response
program to get isotainers of INTEROX Hydrogen Peroxide
to your site right away. For the information you need, call
1800SOLVAYC (18007658292).
Safety
When properly handled, hydrogen peroxide and peroxygen compounds
are safe, easytouse chemicals. However, as with most powerful chemicals,
improper application or handling could create hazardous conditions
or cause injuries to personnel. We strongly recommend you contact
Solvay Chemicals before experimenting with, designing, installing
or modifying an application system or using this chemical.
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Solvay Chemicals, Inc.
Administration/Sales/Marketing
3333 Richmond Avenue
Houston, Texas 77098
Telephone: 713/5256800
Fax: 713/5257805
Mailing Address:
P.O. Box 27328
Houston, Texas 77227
Customer Service:
P.O. Box 1167
Green River, Wyoming 82935
18004432785
Fax: 307/8726610
To our actual knowledge, the information contained herein is accurate as of the date of this document. However, neither Solvay Chemicals, Inc.
nor any of its affiliates makes any warranty, express or implied, or accepts any liability in connection with this information or its use. This information
is for use by technically skilled persons at their own discretion and risk and does not relate to the use of this product in combination with any other
substance or any other process. This is not a license under any patent or other proprietary right. The user alone must finally determine suitability
of any information or material for any contemplated use, the manner of use and whether any patents are infringed. This information gives typical
properties only and is not to be used for specification purposes.
Copyright 2005, Solvay Chemicals, Inc. All Rights Reserved.