bad water smell removal for a copper boiler

[azertyuiop]

I have a problem with our office rain water recuperation and underground storage. That water gets used for various office consumers (office toilets , cleaning , warm water generation) , to massively reduce city water consumption in our office building. I have emptied the three 15 000 liter tanks , let them be cleaned , and waited a week to get it sufficiently refilled with rain water. The really bad smell hasn't got away , the water looks clean , but after refilling a couple of buckets , the stench is still apparent , altough the filter in the water entry stays clean. We have lots of birds in the vincinity , their disposals in the gutter , flowing into the tanks may be the source of contamination.

Is there a product or method to get rid of that smell , other than a carbon filter system in the feeding line? That water also gets injected in a boiler with copper heating circuit , so decontamination with chlore or similar commercially available products is probably not an option (corrosion).

Any bright engineer available with a simple solution?

 

[BobPE]

just what does the water smell like? that would help a lot...since if it smelled like gasoline, we could probably tell you what to do....but I am assuming its some other kinda smell....enlighten us if you could....

What is your roof collection system material? How about the reservoir tanks, what is their material of construction. What did they look like before and after cleaning.

BobPE

 

[azertyuiop]

it smells like bird dropings decomposting on the bottom of the buried concrete tanks , or something rotting away. The walls looked beige/greenish slurred before being highpressure waterjet cleaned and returned to their original grey color. However , there must be somehow small remains in the pipe system leading to the office waterfilter , but the water is now perfectly clean , which indicate that the contamination level now must be very small.

The roof collection system is fairly simple : PVC ducting leading straight to the buried tanks , with metal roster on inlet of the ducting openings to avoid foliage to be taken with , but too coarse to stop bird dropings or smaller parts being spooled with the rain water.

I am basically looking for an simple and easy commercial alternative to the chlore used in swimming pools , because I assume that chlore will eat up the copper coil of our office water boiler system.

I prefer to regularly drop a small amount of a known active staying decontaminant that is humanfriendly and copper friendly , than to have to wrestle with the installation of a coal filter battery and regular regeneration. I have more than enough work to fill up my days there , and look for a simple quick fix to that nasty problem.

Must be a solution to this universal problem , with all those offices built in the world , no ?

 

[BobPE]

the smell is very important to us since we are not there with you. it tells us a story of your system. By rotting, do you mean rotten egg? or is it earthy/musty, or fishy?

Chlorine in smaller doses will not hurt your copper. You may try dosing it with liquid laundry bleach to see if that reduces your smell. I dont have my books here at home, but I will figure out a dose for you tomorrow. The bleach is sodium hypochlorite and is worth a try. If it does work, you can design a simple feed system and may just have to dose the tank every now and then, probably not continuously. I am in the states here and we dont have a lot of those cistern systems around. We do recycle gray water and we do use chlorine in the recycle to control growth of organisms.

I am thinking its a bacteriological film growth on your tanks that pressure washing is not taking away. The next time you clean your tanks, spray straight bleach on the tank walls to kill whats growing on them after you pressure wash. This with a little chlorine should keep your system smelling a lot better....

Do tell us what the smell smells like, that is important to us....

BobPE

 

[azertyuiop]

BobPE , many thanks for your very helpfull insights and tips. The smell is like rotten eggs , or better : like bird waste decomposting in the tank and the pipe feeding system to the office. Certainly not earthy/mushy or fishy.

In europe , it is common practice to install big cisterns to capture office rainwater , given the steep prices for city water and the taxes on ground water extraction. Our governements are 'predatory' on those water issues.

I am interested to know what the chlore concentrations are that I should apply , if there are no other chemical solutions. I am not a chemist , but know that too high chlore concentrations can burn human skin.

 

[azertyuiop]

BoBPE
I paid today a visit to the local drugstore , with a sample of the bad smelling cistern water. They informed me that the smell is typical for algae grow in water , and that this phenomenon occurs at higher water temperatures containing feeding material (bird droppings in my case). It's now a warm summer here , the drugman gave me 50gr of chloramine powder to disolve in each 10 000 liter tank , to weed out this algae grow through the whole storage and distribution system.

I hope that the problem will be solved now.

 

[BobPE]

is the water used for consumption? If not try 2 to 5 liters of bleach from the grocery store in each tank. It is tough to determine the exact dosage since I know nothing about your water quality so I am hesitant to tell you more. The chloramine wont do the trick in your case. Chloramine is not as strong a disinfectant in that form as the chlorine is bound to amonia.

Pay a visit to a local water engineer in your area, they will be able to help you determine a program to keep the smell away....

Let us know how you make out...

BobPE

 

[azertyuiop]

I think the bad smell problem is solved by the mixing of Chloramine in the rain water cisterns. The chloramine worked in the cistern for 24h , being mixed around in each tank by means of a submerged pump. I purged today the main water circuits and cleaned again the water filter , the smell is now gone.

I the bad smell comes back , I will again put 50gr of chloramine into each 10 000 liter cistern to get rid of that problem.