Manganese Deposition

How many plants experience Mn deposition and/or stainless steel under-deposit corrosion due to Mn/Fe deposition?  

Taxonomy

• Drinking Water Security
• Chemical Treatment
• Chemical Analysis
• Solutions
• Drinking Water
• Infrastructure
• Corrosion Prevention
• Deposition

6 Answers

1. On the other hand, Manganese concentration is controlled at the entrance of the water treatment plant, by precipitation.

2. It depends on the quality of the water entering the process, now if we talk about a recirculation process in industrial services of refineries or steel mills, with an efficient treatment of antiscalant and biodispersants at an adequate pH the deposition is negligible.

3. This will teach me to read the question.  Approximately 10-20% of closed cooling and chilled systems will have issues with iron or manganese deposits.

4. I have carried out work investigating manganese deposits on stainless steel and copper.  In nearly all of the samples, bacteria were involved in both the deposition and corrosion.  Clear evidence was found of bacteria being present within the deposits and once these were introduced into fresh samples of stainless steel and copper in the presence of water, they grew and produced fresh deposits.  Stainless colonisation is slower than copper but still occurs.  I am sure that there will be exceptions, but so far the presence of manganese bacteria is the reason for deposits and corrosion.

5. I believe the answer is simple - where there is Mn in the water and either SS or Cu Alloys are present, there is deposition and subsequent under deposit corrosion.  The severity of the deposits and UDC is more about Mn concentration, oxidizing practices, treatment protocol(s), and equipment performance.

6. The answer is this:   # Zones where Mn/Fe are in the ground-water (or surface water if possible) x # of water treatment plants in each zone x unknown factor.  The unknown factor is what equipment was installed at each plant to mitigate Mn/Fe residuals, and its efficacy in removal.

   Considering that this can remain a problem in certain zones, the unknown factor may be near unity.  Considering that the problem has already been encountered in these zones, and allowing for at least some effective plans on controlling the issue, the unknown factor may be nearer 0.1.