Reuse Lagoon Water for Cooling Tower Water?

[ChE51]

I am currently working on a project to reuse the stormwater collected in a lagoon onsite. My first idea was to reuse it as tote-cleaning water but many water quality & operations issues have come up. Since the cooling tower water is treated already for bugs could the answer to my problem be reusing the lagoon water as cooling tower makeup water? Does anyone have any thoughts/experience/concerns?

Cheers
CHE51

 

[DeltaCascade]

Stormwater is often an suitable source of make-up for cooling towers. It can be of similar quality to river make-up water. It MAY even contain relatively "clean" water from undergound firewater system leaks, etc (wondered where all that water MAY be coming from when it isnt raining?). You MAY want to filter it to remove suspended solids. You will need to analyze it to see it's suitability... calcium, TSS, turbidity, silica, TSS, sulfphates, ammonia, COD, etc ... Beyond the scope here to define what cooling towers can tolerate (eg up to 1200 ppm Ca as CaCO3 is possible, 6000 to 10000 conductivity, etc), and it depends on your blowdown rates or cooling water to overall make-up water concentration ratios. Perhaps talk with your cooling water treatment vendor and work with them on the potential for a water re-use project!
Regarding bugs (microbiological activity), chlorinating the water as far upstream as possible should take care of that ... and good control in your recirculating cooling water. Of course, if the storm pond make-up water has lots of "bug food" in it (ammonia nitrogen, COD etc), it may require treatment or it may not be suitable for adding to cooling tower makeup.
Good luck.

 

[ChE51]

Thanks Delta, I was already planning to filter for TSS and the other parameters you mentioned are fairly low. I just wasnt sure if the addition of alot more bugs would be a big concern. Hopefully I'll find somewhere to use this lagoon water soon. I cant remember if you were involved in one of my last threads but I was first designing a system to reuse this water for tote cleaning but the bugs are a big issue since they could contaminate products. I was going to heat the water for residence time of 10-15mins to kill these bugs but I have since learned that certain bugs can withstand these conditions. Do you perhaps have any innovative solutions that you have heard of/read of where this type of water has been reused?...One interesting suggestion I read was to reuse it as "garden water" to water the plant lawn and garden (havent explored it - only would work in spring/summer).......regardless thanks for you help

 

[DeltaCascade]

Regarding TSS, cooling water shouldnt have more than about 50 ppm in my opinion. Based on cooling water cycles times make-up ppm, you could have 200 ppm in cooling water (ie: 20 ppm in make-up), but your sidestream filter must keep it below about 50 ppm in cooling water...
Regarding "bugs" .. I guess you have to define the water quality that you want, define the water quality that you have, and see if a treatment to make the two meet is suitable and ecnonomical. It depends what you need
... you could possibly use nano-filtration to remove bugs (if the filter doesnt get plugged with TSS, or scale etc or need pretreatment), or just chlorinate it well .. etc .. it
If using it for cleaning totes, perhaps the rinse water could still go to cooling tower after it has done its tote cleaning ... unless it creates water high in other undesirable contaminants ...
Use as cooling tower make-up may be best bet?
Cheers & Good luck//