Cooling Water Blowdown Water Usage

• Garden watering.
• Process area hose-down.
• Fire fighting reservoirs and training activities.
• Maintaining levels in navigable waterways.
• Etc.

What treatment do you give you cooling water? Why does treatment company refuse it?

If there is an RO water reject stream recovery plant at the facility it might be suitable as an additional feedwater source, though it would need analysis in the first instance and possibly pretreatment before the RO reject recovery stage. Seek advice from the RO plant supplier if this happens to be an option before introducing it to the reject recovery system.

The usual water treatment chemicals added to open recirculating evaporative cooling systems are zinc organophosphonate (scale and corrosion inhibitor) and a biocide (to prevent algae and bacteria), so perhaps it's not surprising that they don't want you to recycle it. The blowdown water will, of course, be of higher TDS than the feedwater by a factor, typically of 5-times.

Other than RO suggested by others, you might consider a "concentrator." This is like a small cooling tower and evaporates off the water from the heated solution, leaving a very concentrated sludge that can be disposed via a hazardous waste service. There are also versions that use a vacuum rather than heat and can reduce the dissolved materials to a solid. Takes energy to operate of course.

Can't think of any other solution to your solution (!) off-hand

Thanks.. our TDS is almost 7 times so .. I guess that its a matter of disposing of the water in a safe way, I like your idea of a " concentrator".. thanks

marcellus gas well drillers in my area are having a problem finding enough water for fracking. they use millions of gallons of water per well.

i hope this gives more insight on the possibilities.

My first reaction to discovering that the blowdown water is hazardous waste would be to talk to the water treatment supplier (and his competitors!) to see if there is anything available that can be (a) used later in feedwater after filtering or treating in some way, or (b) can be concentrated and not have the sludge be hazardous waste, or (c) can be held and biodegraded enough to be legally flushed to sanitary sewer. There has been much work in this field to develop less toxic chemicals and ones that either biodegrade or degrade in other ways into less toxic products.

If this has just been discovered then there is the possibly the supplier is just providing something that was spec'd years ago in a different environmental reality. I came across something similiar to this in a couple of hot water generators some years ago...the treatment chemical supplier was supplying something spec'd 20 years earlier by an engineer that was better at civil works than water chemistry. And the plant guys thought that retubing a boiler once a year was normal. The two groups never thought to talk to each other!!

Jon.

Wastage of water should be minimized by adopting reliable technology. Water treatment company needs to be requested to reexamine their treatment process. Recharging the ground by injecting this waste water if it is feasible can be considered.

If you had enough waste water and a little spare space, you could use fast growing water plants like marsh reeds or especially water hyacinth which is a weed that thrives on toxic sludge and nutrient rich solutions, followed by bamboo to remove the remainder of the TDS. In some mining residue holding ponds hyacynth is used to remove and concentrate poisonous mineral salts, then harvested, digested and the resultant methane is used to generate 'free' power to run the plant and squeeze dry incoming mulch. Surplus to sell or use as part of a CHP. The ash contains the metal oxides. This works best with salts of moderately high melting point metals like copper, which is commonly used in cooling towers to supress algal bloom.

The method has also been used with nickel, cadmium and other toxic metal salt solutions.

In integrated steel plant where I work have several cooling towers including a captive thermal power plant. Also ammonical water comes out from coal chemical plant. Only yesterday "Zero water discharge system" was commissioned which facilitates treatment and recycling of all waste water generated in the plant. It only require conviction and neccessary expenditure for large scale treatment facility.

A heat excjanger can be used to make use of the relatively cold water out of the cooling Tower to cool the make up water entring the tower and replacing the drain water. A ROI study has to be done because your investment is depending on the unit Cost of water in your city.

You might look at an on-site treatment solution that would bring your numbers down to a tolerable limit. Contech has a product called Magellan, that can be designed arojund your flow numbers and delivered on site within a short time. You should look it up to see if it would work for you. A lot of companies that pay high fines ($20k/month) for their feed to enter the regular sewer flow, are installing these and cutting thier fines completely. I do not work for Contech, but recently saw a presentation on this prioduct and was impresssed. The website is www.ContechES.com. Hope this helps.