How to deal with excessive iron ions in circulating water?

Some methods can be used to reduce the corrosiveness of the system. For example, increasing pH, using coating protection, increasing hardness, or adding corrosion inhibitors.

On our end, we first carry out systematic replacement; once the replacement is complete and the area is satisfactory, chemicals are applied for treatment. Subsequent regular sampling and analysis are conducted, and if corrosion or leakage occurs in any particular area, a thorough investigation is required

Iron ions in the circulating water system act as catalysts for corrosion. In operating circulating water systems, increasing the frequency of backwashing and extending the backwashing time can help reduce the level of iron ions in the system. However, increasing the waste discharge volume can also achieve this effect, but it uses more water. Or consult water treatment manufacturers for assistance. In short, there are many methods; it is recommended that you seek answers from water treatment manufacturers.

Firstly, an increase in iron ions definitely indicates corrosion in the system, and anti-corrosion measures must be taken. A relatively stable and reliable online method involves adding corrosion inhibitors and raising the pH of the water. Coating protection should be applied during shutdowns for maintenance; it seems less convenient and reliable compared to the use of chemical inhibitors. Another issue is an increase in turbidity, which may be caused by iron bacteria present in the water. The presence of these bacteria accelerates corrosion in the system, so bactericides need to be added online, and a bypass filtration system should be activated to reduce turbidity. Finally, there is the issue of draining and replacing the water

If the circulating water was functioning normally before, it is necessary to first check the condition of the system before determining a solution. If there are changes in the incoming water and the level of iron ions increases, as long as the situation remains stable, the system can still be considered normal ； If there is no increase in iron ions in the incoming water while the iron ion level continues to rise, then the problem lies either in the improper dosage of scale and corrosion inhibitors in the circulating water or in inadequate control of sterilization. The specific method depends on the circumstances. Scale formation in circulating water leads to under-scale corrosion; insufficient addition of corrosion inhibitors and an imbalance in the control of bacteria and algae in the system result in severe sludge deposition. Both under-scale corrosion and sludge deposition cause an increase in iron ions. The systematic approach is to first control the issue of rising iron ion levels, and then gradually replace the water and add supplements, in order to resolve the problem ultimately.

This post was last edited by slll611 on 2016-5-17 22:00. Feel free to contact me via private message if you need help :)

If it is caused by corrosion on the equipment, then the equipment needs to be inspected and protective measures taken; if it comes from the water itself, then the incoming water must be treated. There are many methods for this, and I think ion exchange resins are a cost-effective option.

We have a type of filter media imported from Germany that is very effective at removing iron; you might want to give it a try