If you notice a metallic taste in your drinking water, the water has a high iron content. Tap water and well water are the most common sources of water with high iron content. Therefore, knowing how to filter the iron from your water is important. Although iron has dual functions, drinking water with high iron content can have some side effects. In this article, you will learn about the side effects of iron in drinking water and several ways to remove iron from your water.
How to tell if water is high in iron?
You need to test to determine if the water has high iron content. Generally speaking, the iron content in water is low, usually less than 1 mg/L.
If you see yellow-brown, reddish-brown, or rust-like colors in the water. Or you find yellow-brown or reddish-brown stains on pipes, faucets, etc. This can indicate that the water has a high iron content. Because when water comes into contact with oxygen, it reacts to form a ferrous oxide, and you will find that the color in the water will be very obvious.
You can also judge by smell. If you smell a strong metallic smell in the water, it means that the water is very likely to have a high iron content. When you see reddish-brown sediment at the bottom of the storage tank, it is also a sign of high iron content in the water.
If you still can't easily judge by the above methods, then you can buy a professional water quality test kit, which usually has reagents and test strips. You can use it according to the instructions, and then judge whether the iron content in the water is too high by the change in color. If you want a more accurate test result, you can send the water sample to a professional water quality testing laboratory for testing.
How does iron get into drinking water?
Iron is the most abundant element in the earth's crust and the fourth largest element in the earth's crust, accounting for more than 5% of the mass of the earth's crust. Generally, there is a large amount of iron in many rock formations, which will dissolve after being soaked in rainwater. However, dissolved iron will penetrate rocks and soil. There are mainly the following ways for iron to enter drinking water:
Natural sources: If water containing dissolved iron enters groundwater, iron will enter the water supply system, such as tap water, well water, etc.
Pipeline corrosion: Many water supply pipes will corrode after long-term use, causing iron particles to enter the water supply system. This will affect the increase of iron content in water.
Additives in water treatment: In some water treatment processes, iron-containing chemicals may be added to help remove suspended particles or control algae growth. These iron compounds may sometimes remain in the water after water treatment, resulting in increased iron content.
Industrial pollution: For example, mining, steel manufacturing, etc., will discharge iron-containing wastewater. If these wastewaters are not strictly professionally treated, and then the wastewater flows into the local water source environment, it will cause the iron content of the local water quality to increase.
Iron in drinking water is usually present in two forms: soluble ferrous iron (Fe²⁺) and insoluble ferric iron (Fe³⁺). Iron itself is not harmful to human health, but high concentrations of iron can cause changes in the color, taste, and odor of water, affecting the acceptability of the water. In addition, iron may form rust deposits in pipes, affecting water flow and the efficiency of water supply systems.
What is a safe level of iron in drinking water?
According to the data from the US Environmental Protection Agency (EPA), the recommended iron content standard in water is 0.3 mg/L. This standard value mainly prevents changes in taste and color and corrosion of pipes and equipment. It does not have adverse effects on the human body.
What are the side effects?
Drinking water with a moderate amount of iron is not harmful to human health, but if the iron content in drinking water is too high, it may bring some side effects, as follows:
- As mentioned above, high iron content in water will have a metallic taste, which may make the water taste bad and affect the drinking experience.
- If you drink water with high iron content, it will cause digestive problems such as stomach pain, nausea, or constipation.
- If you use water with high iron content to bathe or wash your hair. It may cause dry and itchy skin. Hair becomes dry, brittle, and dull.
- If you use water with high iron content to wash bathroom fixtures, clothes, and dishes, it may leave brown or red stains.
- If water with high iron content passes through pipes for a long time, iron sediment and residue will accumulate, and even cause pipe blockage.
- If bacteria and iron combine, bacterial slime and rust may be produced. The risk of well water is generally higher. If your home is drinking well water, you need to test the well water regularly.
Will reverse osmosis remove iron?
Best reverse osmosis filters can filter iron from water. If your well water contains a lot of minerals, a reverse osmosis water filtration system can also filter it. If the water contains trace amounts of lead and arsenic, it can also reduce their content.
Reverse osmosis mainly uses a semipermeable membrane (RO membrane) to filter out most impurities in the water, such as heavy metals, nitrates, chlorine, fluoride, bacteria, and viruses. The pore size of the reverse osmosis membrane is 0.0001 microns, which is much smaller than the particle size of iron ions and most contaminants. It can completely retain iron ions on the other side of the membrane and only allow pure water to pass through. At the same time, the filtration effect of reverse osmosis is as high as 99%, which is very efficient.
However, if the iron content in the water is high, it may cause the RO membrane to become blocked. If this happens, it is recommended that you need to pre-treat it. You need to remove some of the iron by precipitation or oxidation to protect the life of the reverse osmosis membrane. If you don't mind damaging the reverse osmosis membrane, you can filter it directly, but you need to keep an eye on the efficiency of the RO membrane.
Many people think that if reverse osmosis filters the iron in the water, then the human body is not supplementing iron. This is not the case. You can get enough iron through diet, such as lean meat, seafood, spinach, poultry, nuts, etc.
Other ways to remove iron from water
Precipitation method
Water is exposed to air to react with iron and oxygen to produce a ferrous oxide precipitate that is insoluble in water, and then the precipitate is removed by filtration. This is the simplest method, which is generally used for pretreatment and is usually used for groundwater with a high iron content. However, this method cannot completely remove iron.
Oxidation Filters
In addition to reverse osmosis filtration, oxidation filters are ideal for removing iron from water. It can effectively remove harmful chemicals such as arsenic from well water.
Oxidation filters can also remove iron from well water. It can oxidize the iron in the water into iron oxides that are insoluble in water, and the filter media can capture the oxidized particles. This method is particularly suitable for treating water with high concentrations of ferrous iron (Fe2+) because ferrous iron turns into ferric iron (Fe3+) after oxidation, which is easier to filter out.
Oxidation filters are not only suitable for removing iron from water but also other metal impurities such as manganese. You can combine it with other filtration technologies. Oxidation filters can improve water quality and make it more suitable for drinking and daily use.
Is iron out safe for drinking water?
It is safe to drink. After the iron in the water is removed, the taste of the water will improve. If you drink water with a high iron content, there will be a metallic taste, and long-term drinking will have some side effects. Therefore, for water with a high iron content, you need to remove the iron in the water through methods such as reverse osmosis and oxidation.
However, if you want to ensure that the drinking water is clean and safe, you need to consider whether there are contaminants in the water, such as bacteria, parasites, viruses, etc. Therefore, you need to regularly test the water for contaminants. If there are contaminants in the water, you need to filter it through a reverse osmosis system, because the reverse osmosis system can remove 99.99% of the contaminants in the water.
FAQ
Does boiling water get rid of iron?
No. While boiling kills microorganisms and removes volatile substances, it does not remove iron from the water. Instead, boiling may cause the iron in the water to precipitate and create rust-like deposits, making the water look cloudy or have a metallic taste.
Can high iron in water cause skin problems?
Yes, high iron content in water can cause rough, dry, and itchy skin. It can also lead to the formation of acne and pimples. For people with sensitive skin, it may trigger an allergic reaction.
What does high iron in water do to your hair?
It can make your hair dry and brittle. Water with high iron content may cause itching on the scalp. If you use water with high iron content for a long time, your hair may lose its softness and smoothness.
Does water softener help with iron?
The effectiveness of a water softener in removing iron from water is limited, depending on the iron concentration, but it can remove calcium and magnesium ions from water, thereby reducing the hardness of the water.
Will a charcoal filter remove iron in water?
The removal effect is not significant, but charcoal filters can remove some organic compounds, volatile organic compounds, chlorine, odors, and some heavy metals.
