Zebra Mussel Control

[gazepdapi]

We have a cooling water system at one of our compressor stations that use cooling water from a local pond (that contains zebra mussels) to cool down natural gas discharge from compressors through heat exchangers. We are having issues with the mussels plugging off the exchangers and having to clean them often. I was wondering if there are any other solutions out there than just power washing the exchangers. Maybe some kind of filters or separator that can be installed upstream of the coolers? I've looked around in the forum but found very little information.

Any help would be appreciated.
Thank You

 

[QualityTime]

Chlorinate the cooling water using chlorine gas starting from the intake pipe. You can use sodium hypochorite but you will get calcium carbonate precipitation and your intake will scale right up in a very very short period of time. There are ways around this issue but it is more complicated but proven. I have done it

 

[bimr]

The veliger stage of zebra mussels is the near microscopic free-floating stage and is the most difficult stage to identify because of their small size. A filtration system would have to use a 40 micron filter to screen out the spawn larvae.

Zebra mussels are dormant when the water temperature is below 50 degrees Farenheit, so a system would operate only when conditions would trigger the mussels to become active.

Chemical treatment is considered to be more attractive. There are several chemicals that are attractive. See the reference.

http://www.che.cemr.wvu.edu/publications/projects/prod_design/zebra_mussels.pdf

 

[QualityTime]

Bimr,I would suggest that this paper was written by the manufacturers of Zephiran chloride. Municpal water treatment plants use chlorine all of the time and that is where all my experience is in. Cheapest solution there is. THM's are only an issue if the DRINKING water is colored. Even then there are allowable limits. If you are not using the water for drinking there is no issue. Also if you are worried about contaminating the source water after it has gone through the cooling system just dechlorinate the used water. Trust me on this one. The last water treatment plant I built, located just outside of the Toronto, had a 1.5 mile long 84" intake and drew water from the 55-60 ft depth of water in Lake Ontario. It has been in operation since 2000. Annual diving inspections have confirmed there are zebra mussels on the outside of the intake but it is a clean as a whistle inside the intake pipe. The solution I used was innovative and never done before. It combined knowledge of chemistry, sulphuric acid and sodium hypochlorite. I mentioned it in passing on this site.

 

[bimr]

Your post seems to off topic to the query, but I will answer it.

I don't believe that chlorine gas is the preferred method for control of zebra mussels as you suggest.

Personnel exposure concerns, insurance requirements, community safety issues and regulations have caused the majority of utilities to eliminate chlorine gas in ton cylinders and replace the gas with sodium hypochlorite bleach even though bleach is roughly 3 times the cost.

The ability of the Alkylbenzyldimethylammonium chlorides to control zebra mussels using only short exposures gives rise to a number of advantages over chlorine. These include:
[ul]
[li]Less chemicals released to the environment.[/li]
[li]Product concentrations can be monitored and verified during the entire application.[/li]
[li]Permanent installation of tankage, dikes, and feed equipment is generally not required.[/li]
[li]Reduced impact on entrained plankton.[/li]
[li]Costs are lower since far less chemical is required.[/li]
[/ul]

http://www.gewater.com/pdf/tp494.pdf

In general, I prefer to reference sources of factual information rather than just throwing out opinions. The reader is capable of reviewing the information and developing their own conclusions.

I am just a messenger. If you disagree with the papers, I suggest you contact the University of West Virginia and/or GE. I doubt that either of these organizations are selling Alkylbenzyldimethylammonium chlorides.