Problem – Sulfur or Hydrogen Sulfide
Symptoms: Sulfur produces that distinct "rotten egg" odor and sulfate-reducing bacteria produce a slime and can promote the growth of other bacteria, such as iron bacteria. The slime can clog wells, plumbing, and irrigation systems. Bacterial slime may be white, grey, black, or reddish brown if associated with iron bacteria. Hydrogen sulfide gas in water can cause black stains on silverware and plumbing fixtures. It can also corrode pipes and other metal components of the water distribution system.
Causes:Hydrogen sulfide gas can result from a number of different sources. It can occur naturally in groundwater. It can be produced by certain "sulfur bacteria" in the groundwater, in the well, or in the water distribution system.
Health Concerns:Sulfur in wells does not cause health problems, but can have the following unpleasant and possibly expensive effects: horrible odors, corrision of plumbing an appliances, black stains and sulfur reducing bacteria problems.
Action Level: Any level of sulfur is undesirable.
When treating for Sulfur or Hydrogen Sulfide in your water, it is imperative that a good analysis of the water be performed. Not just for sulfur, but for a number of other contaminants, including hardness, pH, manganese, sulfur, TDS and others. The inter-relationships of the different contaminats will help in chosing the best technology to solve your problem.
With a Detailed Laboratory Analysis, Green Water will be able to confidently recommend the appropriate treatment.
Sulfur is considered a secondary or aesthetic contaminant. The present recommended limit for sulfur in water, 0.3 mg/l (ppm), is based on taste and appearance rather than on any detrimental health effect. Private water supplies are not subject to the rules, but the guidelines can be used to evaluate water quality.
Sulfur in wells does not cause health problems, but can have the following unpleasant and possibly expensive effects:
There are many ways by which sulfur can be removed from the water and most operate on the principal of oxidizing the sulfur (oxidation) to convert it from a gas to a solid or undissolved state. Once in the solid state, sulfur can be filtered.
A backwashing filter, is the most widely used system for removing sulfur. The most common reasons for filter failure are a lack of flow in backwash or a lack of frequency of regenerations. Filtration using various means of oxidation is the most common method of sulfur removal. Depending on the media selected, other common processes such as ozone, aeration, chlorine or peroxide injection may be used to boost the oxidizing properties of the water being treated
The pH of the water plays an important role in how quickly sulfur in gas form converts to a solid state. The higher the pH, the faster sulfur will convert to the solid state that can then be filtered. This is good in all equipment selections with the exception of a water softener where the oxidized sulfur plugs the exchange sites and fouls the resin. When using an sulfur filter at a pH above 6.5 is an absolute necessicity, and in reality a pH above 7.0 is what is really needed. A pH of 8.0 to 8.5 greatly enhances the chance of a successful application.
If it is necessary to increase the pH level, chemical feed of sodium carbonate or soda ash is preferred over a filter filled with calcium carbonate or magnesium oxide, as the filter method may foul quickly. Low pH levels when using filters are the chief reason for unsatisfactory results.
Most Popular Media
What follows is a partial list of medias used in sulfur filtration. We do not attempt to address all medias, especially ones which are dubious in design or outdated.
Birm has the ability to remove sulfur and manganese and has no effect on hydrogen sulfide. Like manganese dioxide, birm also uses dissolved oxygen as a catalyst and may require some type of pre-oxidation in cases where the dissolved oxygen content is too low to affect a maximum sulfur removal result. Birm is .1 percent manganese dioxide and is fairly leightweight, which allows for proper backwashing. Green Water does not sell a Birm Filter as there are simply better methods which are more predictable and effective for removing sulfur. At .1 percent manganese dioxide, it simply is not sustainable.
Greensand is one of the oldest but proven oxidation technologies. Potassium permanganate, itself an oxidizer, is used to regenerate the greensand. Potassium permanganate produces manganese dioxide on the surface of the mineral and, once the water comes in contact with it, any sulfur is immediately oxidized. The sulfur can be filtered and then cleaned away in the backwash cycle. Greensand is also effective with low levels of H2S or hydrogen sulfide and manganese. Again, GREEN WATER chooses not to recommend a Greensand system and dislikes the use of potassium permanganate.
Manganese Dioxide - Filox
Manganese dioxide, often callex Filox or Pyrolox, is a naturally mined ore with the ability to remove sulfur, manganese and hydrogen sulfide. The hydrogen sulfide capability exceeds that of either greensand or Birm and requires no chemicals to regenerate. It does, however, require adequate amounts of dissolved oxygen in the water as a catalyst. If the dissolved oxygen level is not sufficient it may require some type of pre-oxidation to achieve its maximum ability, such as injection of chlorine with a chemical feed pump.
Ultimately, the above methods of sulfur removal are less than satisfactory in most cases.
Other Sulfur Removal Methods
Using 5 percent to 10 percent chlorine as an oxidizer is also widely used. Chlorination requires a contact tank which should have a 20 minute supply of water at peak flow. For instance, if the peak flow is 10 gallons per minute, then a 200 gallon contact tank would be needed. Many chlorination systems are undersized in respect to the contact tank, and meet with mixed results. After the injection of the chlorine and flow into the contact tank, a backwashing carbon filter is utilized to remove the precipitated sulfur and chlorine residual. Chlorine works well as a disinfectant, but is not a good oxidizer and can only remove a small amount of sulfur. At Green Water, we do not recommend chlorination for the removal of sulfur.
Ozone is a powerful oxidizer and when used properly can be effective on large amounts of sulfur. Similar to aeration, ozone is injected into water via a contact vessel as a pre-treatment to filtration. A properly sized Ozone Generator and proper system design is the key to success. Due to ozone’s expense it is usually applied on sulfur levels higher than normal filtration is known to handle effectively. Each system is custom designed for the application. Ozone is typically three or four times the cost of other methods but has a very minimal operating cost. If you are considering the use of ozone, please call us or e-mail us at firstname.lastname@example.org
Hydrogen Peroxide - OXYgREEN Systems
The use of hydrogen peroxide in water treatment for the eradication of sulfur, and manganese is Best Suitable. It can truly be called an Eradicator because it TOTALLY removes sulfur, iron, and manganese. Properly sized, an OXYgREEN Hydrogen Peroxide System is THE MOST EFFECTIVE METHOD for removing sulfur, iron, rust, hydrogen sulfide and manganese and the rotten-egg odor from your water supply. Hydrogen Peroxide is not a hazardous chemical - to the contrary, hydrogen peroxide or H2O2, is composed of the elements of water: Hydrogen and Oxygen. There is nothing foreign or chemical added to the water supply. Unlike chlorine, hydrogen peroxide requires no contact time and the reaction or oxidation of sulfur, iron, rust, manganese and hydrogen sulfide is immediate. The OXYgREEN Hydrogen Peroxide System is the answer to practically any sulfur, iron, rust, hydrogen sulfide and manganese problem. With hydrogen peroxide or H2O2 as it is called, you can always predict for a certainity that it will always work, even with excessive amounts of sulfur (or iron).