Ozone Iron and Manganese Water Treatment Approach

While iron (Fe) and manganese (Mn) don’t pose health problems, water contaminated by these species can stain water fixtures and clothing that is washed with this water.  A typical treatment process involves oxidation, which makes the metals insoluble, followed by filtration.

In general, Fe is fairly easily oxidized by oxygen or chlorine.  Mn is more difficult to oxidize, but can still be oxidized by chlorine at the proper pH levels.  For both Fe and Mn there are conditions involving pH or Fe/Mn complexes with organics that make removal less efficient.  In these cases ozone can be an effective oxidizing agent that is not as sensitive to pH and organics.

Another issue with the use of chlorine based compounds such as bleach is the potential to form trihalomethanes (THM) from organics in water.  Control of THM has become a public health issue and the EPA regulates these compounds in water to less than 100 ppb.  Some public water systems have switched to ozone from chlorine due to this issue.

Application of ozone for iron and manganese removal depends on a variety of factors.  The following discussion provides some base line information on the conditions and amounts of ozone required.  Pilot testing will define the exact amount of ozone required and the type of ozone generator equipment required.

Ozone oxidizes iron from Fe (II) to Fe (III).  Fe (III) hydrolyzes to Fe (OH)3 which precipitates to a solid form which can be filtered.  The oxidation reaction requires 0.43 mg of ozone per mg of Fe (II).  Excess ozone can be used without negative effect.  Typically, a dose of 0.50 mg/l is used.  Note that we are referring to the transferred dose of ozone since there is some loss of ozone in the dissolution process.  Fe oxidizes in the pH range of 6-9.

In general, when organic materials are present in water, more ozone may be required than the amount shown above since ozone will also oxidize these materials.  The nature of the precipitate will depend on temperature and water chemistry.

Ozone oxidizes Mn (II) to MnO2 (Mn IV) which is insoluble and can be filtered out of the water.  The oxidation reaction requires 0.88 mg of ozone per mg of Mn (II).  Excess ozone beyond this ratio will form soluble Mn (VII), permanganate, turning the water pink.  If oxidizable organic material is present in the water and there is sufficient contact time, permanganate will be reduced back to MnO2 (Mn (IV)).  Manganese oxidation is most effective around a pH of 8. 

Ozone generator output can be controlled via an ORP monitor automatically.  This prevent over or under dosing of ozone into the water. It is important to note that at start-up ozone might strip deposits of iron and manganese in the treatment plant.  During the break in period, therefore, iron and manganese may remain high until these deposits are removed. 

To learn more about ozone in drinking water treatment visit:

http://www.spartanwatertreatment.com/iron-and-manganese-removal.html

Iron and Manganese

Trihalomethanes

Post is part of the efforts of the Water Research Center and Carbon County Groundwater Guardians to education private well owners and water suppliers in our area. If you need any further information, please visit our Drinking Water Helpguide Page, Water Quality Library, or search our site. 

Baseline Testing Results Wayne County Pennsylvania

 Memo

August 18, 2012

To: Wayne County, Manchester Township, PA 18436

From: Brian Oram, PG

B.F. Environmental Consultants Inc.

15 Hillcrest Drive

Dallas, PA 18612

Sample Information- Sample # 1 (Well)
Wayne County, Manchester Township

Site: 

Drilled Well- no data

Purge Time –12/16/2010 at 12:15 am

Estimated – 

Lab Number – XX-XXXX-20101216-PST - Test America / Tetra Tech

Parameter	Result	Standard	Comment
Ethylene Glycol	0.76 mg/L	< 0.3 to 14 mg/L R	Detection Limit Issue
Ethane	< 0.00049 mg/L	no standard	OK
Ethene	< 0.00052 mg/L	no standard	OK
Methane	< 0.00022 mg/L	< 7 mg/L	OK
Propane	< 0.010 mg/L	no standard	OK
Surfactants (MBAS)	< 0.013 mg/L	< 0.5 mg/L	OK
T. Kjeldahl Nitrogen	< 0.15 mg/L	no standard	OK
Radium 226	0.15 pCi/L	< 5 pCi/L	OK
Radium 228	0.06 pCi/L	< 5 pCi/L	OK
Gross Alpha	1.46 pCi/L	< 15 pCi/L	OK
Gross Beta	0.72 pCi/L	< 4 pCi/L	OK

Parameter	Result	Standard	Comment
Thorium	< 0.002 mg/L	see gross alpha	OK
Uranium	0.0011mg/L	< 0.030 mg/L	OK
Thallium	< 0.010 mg/L	< 0.002 mg/L	Detection Limit Issue
Silver	< 0.005 mg/L	< 0.05 to 0.10 mg/L	OK
Aluminum	< 0.200 mg/L	< 0.05 to < 0.2 mg/L	OK
Arsenic	< 0.010 mg/L	< 0.010 mg/L	OK
Barium	< 0.200 mg/L	< 2 mg/L	OK
Beryllium	< 0.004 mg/L	< 0.004 mg/L	OK
Boron	< 0.200 mg/L	< 0.6 mg/L R	OK
Calcium	28.4 mg/L	no standard	OK
Cadmium	< 0.005 mg/L	< 0.005 mg/L	OK
Cobalt	< 0.050 mg/L	< 0.011 mg/L R	OK
Chromium	< 0.005 mg/L	< 0.1 mg/L	OK
Copper	0.0713 mg/L	< 1 mg/L	OK
Potassium	0.660 mg/L	no standard	OK
Lithium	< 0.050 mg/L	< 0.7 mg/L R	OK
Magnesium	3.99 mg/L	no standard	OK
Manganese	0.0012 mg/L	< 0.05 mg/L	OK
Mercury	< 0.0002 mg/L	< 0.002 mg/L	OK
Molybdenum	< 0.040 mg/L	< 0.040 mg/L R	OK
Sodium	4.56 mg/L	no standard	OK
Nickel	< 0.040 mg/L	< 0.1 mg/L	OK
Lead	< 0.003 mg/L	< 0.005 mg/L	OK
Selenium	< 0.005 mg/L	< 0.05 mg/L	OK
Strontium	0.319 mg/L	< 4 mg/L R	OK
Zinc	0.0047 mg/L	< 5 mg/L	OK
Iron, T	< 0.100 mg/L	< 0.3 mg/L	OK
Iron, D	< 0.100 mg/L	< 0.3 mg/L	OK

Parameter	Result	Standard	Comment
pH	7.4	6.5 - 8.5	OK
Acidity	< 5 mg/L	no standard	OK
Ammonia Nitrogen	0.17 mg/L	no standard	OK
Bromide	< 0.20 mg/L	no standard	OK
Chloride	6 mg/L	< 250 mg/L	OK
Hardness, T	84 mg CaCO3/L	no standard	OK
Nitrate-Nitrite	0.17 mg/L	< 10 mg/L	OK
Oil and Grease	< 4.8 mg/L	no standard	OK
Conductance	230 uS/cm	no standard	OK
Sulfate	6.7 mg/L	< 250 mg/L	OK
T. Alkalinity	80.3 mg/L	no standard	OK
T. Dissolved Solids	111	< 500 mg/L	OK
Ratio TDS/ Conductivity	0.48	*****	OK
Total Rec. Phenolics	< 0.010 mg/L	no standard	OK
T. Suspended Solids	< 4 mg/L	no standard	OK

Parameter	Result	Standard	Comment
Benzene	< 0.005 mg/L	< 0.005 mg/L	OK
Ethylbenzene	< 0.005 mg/L	< 0.700 mg/L	OK
Toluene	< 0.005 mg/L	< 1.0 mg/L	OK
T. Xylenes	< 0.015 mg/L	< 10 mg/L	OK
alpha-BHC	< 0.000048 mg/L	no standard	OK
beta-BHC	< 0.000048 mg/L	no standard	OK
delta-BHC	< 0.000048 mg/L	no standard	OK
Lindane	< 0.000048 mg/L	< 0.0002 mg/L	OK
Heptachlor	< 0.000048 mg/L	< 0.0004 mg/L	OK
Aldrin	< 0.000048 mg/L	no standard	OK
Heptachlor epoxide	< 0.000048 mg/L	< 0.0002 mg/L	OK
Endosulfan I	< 0.000048 mg/L	no standard	OK
Dieldrin	< 0.000048 mg/L	no standard	OK
4, 4' DDE	< 0.000048 mg/L	no standard	OK
Endrin	< 0.000048 mg/L	< 0.002 mg/L	OK
Endrin Ketone	< 0.000048 mg/L	no standard	OK
Endrin Aldephyde	< 0.000048 mg/L	no standard	OK
Endosulfan II	< 0.000048 mg/L	no standard	OK
4,4'-DDD	< 0.000048 mg/L	no standard	OK
Endosulfan sulfate	< 0.000048 mg/L	no standard	OK
4,4'-DDT	< 0.000048 mg/L	no standard	OK
Methoxychlor	< 0.000048 mg/L	< 0.040 mg/L	OK
alpha Chlordane	< 0.000095 mg/L	no standard	OK
gamma Chlordane	< 0.000048 mg/L	no standard	OK
Toxaphene	< 0.0038 mg/L	< 0.003 mg/L	OK
2,4-D	< 0.0038 mg/L	< 0.070 mg/L	OK
Dalapon	< 0.0048mg/L	< 0.2 mg/L	OK
2,4-DB	< 0.0038 mg/L	no standard	OK
Dicamba	< 0.0019 mg/L	no standard	OK
Dichlorprop	< 0.0038 mg/L	no standard	OK
Dinoseb	< 0.00086 mg/L	< 0.007 mg/L	OK
MCPA	< 0.380 mg/L	no standard	OK
MCPP	< 0.380 mg/L	no standard	OK
Pentachlorophenol	< 0.00048 mg/L	< 0.001 mg/L	OK
Silvex	< 0.00095 mg/L	< 0.050 mg/L	OK
2,4,5-T	< 0.00095 mg/L	no standard	OK

The following are my general comments:

1. Based on the available data, I do not see any specific problems or concerns.

2. It would have been advisable to test for more of the regulated and unregulated volatile organics and MTBE.  They only tested for BTEX (Bold).

3. It would have been good if the arsenic was tested to a lower detection limit.

4. The letter R- means it was a recommended standard – not regulated.

5. Ethylene glycol – the method did not have a detection limit that is below the lowest standard for a state in the United States.  There is no Federal Drinking Water Standard. The same comment applies to Cobalt.

6. Thallium – the detection limit was not below the limit for the Safe Drinking Water Act.

Recommend retesting.

Thanks for supporting the Citizens Groundwater Database - Submit your data today - get a free evaluation and help your community.

I would like to personally thank Sylcosan Inc. Manchester Wayne County PA and a proud member of the NWPOA for releasing data to the Citizens Database.

Thanks for Helping to Track Change in Pennsylvania

Mr. Brian Oram, PG
Water-Research Center – Free Information on Water Quality

http://www.water-research.net

Questions – 570-335-1947

Please Participate in Our Private Well Survey at:

http://www.surveymonkey.com/s/NMG6RQ3

If you would like a free booklet on Private Well Water Quality, go to:

http://www.bfenvironmental.com/pdfs/Waterbooklet070610.pdf

Looking to Support this Effort - We could use the help !