HYDROGEN PEROXIDE/OZONE FOR MUNICIPAL WATER SUPPLIES?

 Reprinted from the ECHO Newsletter

Published by:

ECH2O2 Inc.

P.O. Box 126

Delano, MN 55328

The information in this newsletter is for research and educational 

purposes only. It is not intended to be used for diagnostic or 

prescriptive purposes. 

SPRING 1992                                          VOLUME IV, NUMBER IV 

HYDROGEN PEROXIDE/OZONE FOR MUNICIPAL WATER SUPPLIES? 

If what the media is saying is true about chlorine destroying the ozone 

layer, then it is urgent that attention should be given to one of the 

largest uses of chlorine, and that is municipal water supplies. Some 

limited experimental studies are being done in the U. S. on the use of 

hydrogen peroxide and/or ozone as a disinfectant for municipal water 

supplies. These two substances are widely used in Europe. As an 

example, 3000 cities in Europe use ozone to disinfect their municipal 

water supplies. Paris is one of the cities that has used ozone for 

many years. Los Angeles, California recently installed an ozonator in 

their water system. Let's take a look at some of the studies that have 

been or are being conducted.

H2S WATER TREATED WITH H2O2 

Mohan V. Thampi authored the article "Water Treatment Controlled By 

H2S Levels", appearing in the May, I991 issue of WATER/Engineering & 

Management. Thampi says that "More than 90 percent of the drinking 

water supply in Florida is derived from groundwater aquifers. In 

Central Florida water wells 500 to 1000 feet deep tap the Floridian 

aquifer. This raw groundwater is of excellent quality, with all 

contaminant levels, except for dissolved H2S (aq)." Hydrogen sulfide 

(H2S) is generally stripped out of the water by cascade tray aeration 

or mechanical forced-draft aeration. Then it is stored in elevated 

tanks and chlorinated prior to distribution. Population growth and 

widely varying water demands have resulted in current processes not 

being as efficient as they once were. During high demand periods, 

there is less stripping of H2S, use of higher quantities of chlorine, 

turbidity (cloudiness) and this results in poor water quality as to 

taste and odor. Thampi goes on to say "To find a quick and cost 

effective solution to the turbidity and chlorine residual problem, a 

pilot test was conducted using NaOH (sodium hydroxide) and H2O2 

(hydrogen peroxide) chemicals at the 10 million gal./day Econ Water 

Plant in Orange County." Finding the correct H2O2 dosage proved 

difficult initially. "It was found the turbidity occured despite 

(the) addition of H2O2 and most of this H2O2 was leaving the tank 

unreacted. Chlorine demand was unusually low. This meant there was 

another H2S oxidizing reaction taking place." "Inspection of the 

insides of the tanks showed high clusters of colloidal sulfur adhering 

to the tank walls. Thus, it was deduced that the oxygen dissolving 

during the aeration was continuing to react with the H2S in the tank

the tank because of favorable equilibrium conditions. When excess H2O2 

was added to overcome the air oxidation, only then would the H2O2 

oxidation with H2S proceed. So during startups, it took about 2 days 

for the H2O2 reaction with H2S to establish its own reaction 

conditions in the tank.

         OXIDATION  TREATMENT OF WELLS FOR TWO EASTERN CITIES 

The March, 1991 issue of Public Works contained an 

article by Dyksen et al about the experimental use of ozone and 

hydrogen peroxide for the clean up of two contaminated wells. One of 

the wells is located in New Jersey and the other at Spring Valley, New 

York. A grant of $66,000 was awarded by American Water Works Research 

Foundation of Denver to the Ridgewood Water Department. Expertise and 

financial resources are also being provided by Malcolm Pirnie, Inc. of 

Paramus, New Jersey, for a total project cost of $115,600. "The 

project's overall objective is to develop a practical and cost 

effective means of applying the ozone/ H2O2 treatment system for use 

at individual public water supply wells. A pilot test unit will be 

designed to inject, dissolve and contact the oxidants in a pressurized 

line, simulating conditions in a well pump discharge line." 

Dyksen et al reported the importance of controlling organic 

contaminants in groundwater.  This can be done by protecting 

groundwater resources and/or by reclaiming groundwater that has been 

affected.  Chlorinated hydrocarbon solvents and gasoline- related 

contaminants have been detected in groundwater supply systems.

Precautions have been taken at some wells affected by organic 

chemicals with such techniques as packed tower air stripping and 

granular activated carbon systems but there are limitations with each 

process. There is potential for air contamination around packed towers 

since organic substances are transferred from water to air. With 

activated carbon there is a need to replace the carbon on a frequent 

basis and a concern about using it where radon occurs, ". . . because 

of the potential buildup of radioactive materials in the GAC bed." 

Methods considered were several Advanced Oxidation Processes (AOP's) 

because they ". . . have the potential for removing organics from 

drinking water including ozone, chlorine, chlorine dioxide, 

permanganate, and hydrogen peroxide." Ultraviolet light alone or in 

combination with other oxidants was also considered. In the end, ozone 

and hydrogen peroxide were chosen as having the most potential. 

Advantages of an in-line treatment of ozone/hydrogen peroxide are the 

fast destruction of many organic chemicals, adaptability for plant 

applications, cost-effectiveness and lack of toxic air emissions. 

Reports should be out soon on these tests. 

COMPARISON STUDIES OF PEROXIDE AND OZONE

 

An article by David W. Ferguson et al appeared in the April I990 issue 

of the AWWA Journal and is entitled "Controlling Taste and Odor 

Compounds, Disinfection By products and Microorganisms." It describes 

the third of a five phase pilot project being conducted by the 

Metropolitan Water District of Southern California, ". . . in 

evaluating the hydrogen peroxide ozone (PEROXONE) advanced oxidation 

process----(followed by secondary disinfection with chloramines) for 

removal of taste and odor compounds, control of disinfection by-

products (DPM's), and inactivation of microorganisms." The water being 

treated is from the California State Water Project and the Colorado-

River. 

At the pilot plant facility, ozone is bubbled through four glass ozone 

contactors. Just prior to this, the raw water can be treated with 

hydrogen peroxide by means of a metering pump or in-line static mixer. 

The water depth is maintained at 16 feet and water treatment times 

varied up to 12 minutes, as do the levels of oxidation treatments. The 

article contains some plant schematics, numerous tables and charts 

describing the experiments and their effects on contaminants, effect 

of contact time, oxidation residuals, etc. Further studies will be 

conducted through the mid-1990's as the five phase process continues. 

Thus far, the study concludes that PEROXONE is significantly more 

effective than is ozone alone in oxidizing taste and odor compounds. 

As reported in a previous newsletter, a pilot plant was being designed 

". . . to cleanse San Fernando Valley water-supply wells of industrial 

solvents." This was reported in the March 25, 1988 issue of the Los 

Angeles Times. Hydrogen peroxide and ozone were selected over 

alternative processes because they remove contaminants from the water 

without creating hazardous waste problems. The initial design cost for 

the plant at North Hollywood was $423,200, the cost of the plant that 

was to be uilt to range from $500,000 to $1.5 million. The plant was 

designed to break down trace chemicals including TCE and PCE. Wells 

eventually to be treated are in Los Angeles, Burbank, Glendale and in 

the Crescenta Valley County Water District. "More than 2 dozen wells 

have been shut down because of pollution."