Different water sources have several water pollutants. If the water has the smell of rotten eggs, it has a specific metallic taste and a yellowish tint, then most likely we talk about the well water. In our previous blog posts we have discussed the well water problems such as water hardness and increased iron content, today we will talk more about the hydrogen sulfide.
Where does the hydrogen sulfide come from in the well water?
This compound is very unstable. When the hydrogen sulfide comes into contact with oxygen, safe compounds without smell or taste are formed. Thereby this gas likes the water because it has little air.
The source of the hydrogen sulfide in well water is the water’s contact with sulfur ores that are underground and contain sulfides. These rocks can be found at almost any depth, however, the greater the depth, the less chance of finding hydrogen sulfide. Hydrogen sulfide is less common near surface water or in wells where sulfate-reducing bacteria reduce sulfate hexavalent sulfur compounds to sulfites (divalent sulfur compounds).
The problem with hydrogen sulfide is also common for swamp water and the water covered with algae and silt. If the water from the filter smells like hydrogen sulfide, probably it is time to replace the filter cartridge and disinfect the system.
The hydrogen sulfide removal from the water
In addition to the unpleasant smell of the water contaminated with hydrogen sulfide, the presence of dissolved hydrogen sulfide in the water also causes several other problems, such as a decrease in the efficiency of the water purification from iron and manganese.
The easiest method of purifying the water from H2S is to settle the water in a container outdoors. It oxidizes when interacting with oxygen. However, this method is not suitable for treating large amounts of the water.
Two stages of the water treatment are mainly used in industrial processes:
- aeration (blowing small air bubbles through the water tank);
- filter cleaning with special materials.
In the case of domestic water purification the introduction of aeration is problematic. That is why the filter cleaning with catalytic materials are used.
The most popular catalytic materials are:
- Activated Centaur carbon: they are bituminous coals that have undergone activation in order to act as a catalyst for conversion of the hydrogen sulphide into sulphur without losing their adsorption properties;
- KDF-85: chemically pure copper and zinc alloy pellets. The feature of this material is that it is recommended to combined it with activated carbon as organic impurities tend to clog the load layer and reduce its efficiency.
How is the water purified from hydrogen sulfide?
Most often the filters containing Centaur material are used to remove the hydrogen sulfide from the water. Since the hydrogen sulfide is usually not the only water problem to be solved (in the case of H2S increased water hardness as well as iron and manganese content are also observed), therefore the purification of domestic water includes several stages:
- cleaning from the large mechanical impurities using BB10 or BB20 cartridge filters;
- water softening or purification from iron, manganese and hardness salts;
- catalytic filter for hydrogen sulfide removal.
In domestic conditions it is possible to use two design solutions:
- classic column filled with the filtering material.
- BB20’s main filter with a replaceable filter element filled with catalytic carbon inside.
Is it possible to drink the water with hydrogen sulfide?
The first hydrogen sulphide water medical facility was opened in Galicia, Spain in 1578 where various diseases were treated. Nowadays, the hydrogen sulfide water is mainly used to treat cardiovascular diseases, nerve and bone-joint diseases.
In general, the hydrogen sulfide water is considered medicinal and there is no notable contradiction to this fact in the public sources. However, it is important to remember that drinking water with hydrogen sulfide are used as part of the healing process for the treatment of specific diseases, which is a limited period of time.
Read also: Water softening and de-ironing , Iron .
