Water Filtration Systems

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Howdy.

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Sup.

Hey there.

Hello.

Greeting and salutations.

Did the moderators really ask you not to say 'hi'?

I think it depends on how often you plan to service the systems....the bigger the filter, the less maintenance required....the smaller and cheaper the filter, the more service required....it's a trade off....and you say the supply is 1500 ppm, but no target figure on the low end....I'm assuming this system is exposed to the open air, this is going to add particulate as well, in any system circulating all or part of the water...I might be old fashioned but I prefer to follow the manufacturers recommendation on cleaning and servicing the equipment, less chance of a liability issue....

Filtration will not do much to reduce TDS unless the filter is effective at removing particles less than 2 micrometers.

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I think you are going to have to flush water, whether using exchange resin or RO or something els. possibly unless using disposable media. However, there should be improvements in reduced deposits and a reduction in waste water as compared to continual dillution/drain.

Are you using sacrificial anodes in the pans? If not, you might want to try doing so as it does help.

A good quality RO unit would be the best solution as far as purifying the water is concerned but it will also be somewhat costly.

It will have a minimum of blow down to carry the solids away however you may have to install a holding tank to offset the loss in throughput flow.

3 gallons per hour is less than the large residential reverse osmosis systems. There are 100 gallon per day systems with several filtration stages and RO selling for less than $200.

some threads are never worth considering. I offer no solutions

Replies.

Solar eagle,

300-500 ppm tds acceptable range, Bon aire's only recommendation is to wash cooler with water ( presumably same water as supply water ) Champion says use wire brush ( you can image what wire brush does to a painted surface ) / after warranty expires ( 1 year ) no more liability issues.

Truth - compromise,

Because of drought and water runoff restrictions, I may need to look at ro again, the ideal would be to reduce or eliminate bleed off.

Shock,

Anodes last about 2 months @ 90% dissolve - metal body cooler, 3 months plastic body cooler, sodium in water eats them & no change in scale build up, holding tank- I think you mean a plastic bucket and then there is the training of clients to empty bucket into foliage regularly.

Fredski,

You must know something, your house is only about 75 miles from mine, maybe you think about it and come back later.

I would go with the RO system....but if it's a wise decision to filter the water at all, I'll leave that up to you...

http://www.homedepot.com/p/EcoPure-Reverse-Osmosis-Water-Filtration-System-ECOP309/204338168

If the water is for a residential abode I see no way to clean it up other than to install a water softener and/or a RO unit to treat all water used inside the home and to service the cooler(s).

There is a myriad of water treatment companies that offer free water analysis to determine what is needed to clean the water up. Have you contacted any in the area?

This is a two part response.

Who pays for the water?

Who pays for the filters and chànges them?

Who pays for the replacement coolers and installation?

Swamp coolers may soon be outlawed in CA.

Here in Arizona we have plenty of water. Our golf courses use more water than anywhere else in the USA.

Not to bash SE, but RO is, I believe, misunderstood as a filtration medium.

The referenced RO system's, "Maximum daily production rate is 18.46 gal. per day".

There are NO actual performance specifications quoted. Replacement filters are $47.00 USD each.

To use RO in an evap cooler, you need a re-circulation system to pump the water through the filter. That pump needs to supply a minimum feed water pressure of 40 psi. Maybe I'm wrong and 18 GPD makeup water is sufficient.

Just sayin'.

Well my understanding is that this is to be a recirculating system...that means the water supplied on a daily basis would be the evaporation rate, plus any splash out etc....The posted link was for example only, not a recommendation on sizing or brand or source....

From prior knowledge of swamp coolers the supply water is from the drinking water supply of the home. The EPA considers anything over 500 ppm contaminated. If the water does have disolved solids that high. I would be addressing it to the customer as a health issue. Have them install whole house filtration for their own heath reasons. Your problem solved as long as they maintain it.

Whole-house filtration, indeed any form of filtration in any size or form, cannot reduce TDS on its own; other processes are need in addition to filtration.

The point is water that has 1500 ppm may not be fit to drink. That informing the customer to prevent their own health issues that may arrise from it. Would be the right thing to do. If the customer takes the steps to correct it What ever necessary. Then it would also take care of the issues in the swap cooler.

I had that in the original message, Mildred. Line 1, I think.

Replies (2)

Shock,

I am currently working with a distributor of purified water in my area ( direct to public sales ), he offered to be my supplier for stand alone evap cooler & whole house systems, I do the leg work, I.e. , I love a challenge, the more obstacles that are put up, the more persistent I become.

Lyn,

You pay for the water, you pay for the filter ( actually I pay for the filter, then I charge you what I pay for the filter, then I charge you to maintain your system, in other words you save money by paying for labor only, this saves you the money needed for stroke play on your local golf course, you pay for replacement cooler then pay me to install it, Can you cite source of outlaw issue ? ( you have my email- the same one on my business card) Who exactly is your water provider, I can contact them to get an analysis sheet.

Pwslack,

I agree with your summation, although I would like to invalidate your invalidity, I can't afford services of process engineer, can you provide resource on student level process engineers working in this area I may contact for opinions ?

Ozzb, true statements.

Crabtree, one question, who exactly is Mildred ? Enquiring minds want to know.

Tony

Tony,

The buildings in question belong to a friend of mine.

City of Mesa supplies the water.

He lives in Ca. and I just look at things for him and hire people to do the work.

His problem is that he is paying the water bill so the tenants have no incentive to conserve water.

For my trouble, he sends me bottles of VERY expensive tequila. Like Don Julio Real', Partida Elegante and right now I'm working on a bottle of Gran Patrón Piedra Tequila Extra Añejo. These all cost over $300.00 a bottle.

Could solar distillation be used? Could the evaporated water be reclaimed?

Cripes its hot in here, I'm sweating like a swamp.

Of course it can. They harvest fog in the Himalayas. But that doesn't necessarily make the water "potable", I.e. fit for drinking.

Why would you have to use it for drinking water? I don't drink water, fish fornicate in it.

This makes water portable:

That would only make it pail-atable.

To make it potable, something more kettle-like is needed; something used to make tea or stew....either that or perhaps some cannabis, or potassium hydroxide, or maybe just a little knob with which to adjust resistance.

So, this "knob" you speak of, would that be a potabiometer, or just a knob that gets harder to turn?

Perhaps you could pre-precipitate in a low flow reservoir. Something along the line of adding limewater, and a volitile base, like ammonia, to raise pH and cause precipitation. Allow the precipitation a low flow area, and perhaps cheap disposible media on which to settle. A filter could be used to remove anything that precipitated that didn't settle.

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For the systems that continually dillute/flush, depending on the materials involved, lowering pH to discourage precipitation might be something to consider.

Tony, I considered getting the calcium out of the water at my rental properties. I wanted to do it for the pipes and the scale on the fixtures and swamp cooler pads. Three of my properties have the big box type coolers and at one I installed a Durango. Every year, I install a set of those blue high efficiency pads and by mid summer they are caked with scale. I do have a run off line on one of the coolers (it's built into the water pump) and I don't see a difference in the pads compared to the coolers without the run off.

The Durango has a run off line and its like you said, it's about 3 gals per hour. The cost of the pad is high, so I'd rather waste some water vs change the pad. It's also not as easy to change the pad vs the big box type cooler.

Here are things I considered when I made my decision to leave everything alone. If you run the water through a softener, you've added sodium to your client's tap water. Not good for high blood pressure types. Some cities have a ban on softeners due to chloride levels in the rivers, so it may not be an option. Also, water softener need to recharge the exchange tank and water is used in the process. RO systems also need water to flush the membrane, so you'll be wasting water. Also, RO systems need pre filters and the RO membrane needs to be changed, which adds maintenance and material costs.

My recommendation is to pipe the run off water from the swamp cooler into a small tank, then use it for watering the landscaping. It'll have a slightly higher calcium concentration, but it shouldn't hurt anything. That's what I wound up doing.

RO is the answer. If you have Calcium salts, convert them to Sodium salts, by putting a Softner before RO.

My first question is, what is the raw water source? Is this a surface water source or a water well source? Other than testing for the TDS constituents, has the water been tested for other contaminants in accordance to your State Dept. of Health regulations? Has the water been tested for the presence of Coliform bacteria, aka Bach-T Count, as well?

The USEPA Secondary Regulations advise a Maximum Contamination Level (MCL) of 500mg/liter (500 parts per million (ppm)) for TDS. Numerous water supplies exceed this level. When TDS levels exceed 1000mg/L, it is generally considered unfit for human consumption. A high level of TDS is an indicator of potential concerns, and warrants further investigation. Most often, high levels of TDS are caused by the presence of Iron, Magnesium, Potassium, Chlorides, Sodium, etc.. These ions have little or no short-term effects, but toxic ions, such as lead, arsenic, cadmium, nitrate, others may also be dissolved in the water may pose significant short-term and long-term health risks.

There are several TDS removal methods available, but none are close to being perfect. There are always trade-offs. The better technologies available are RO, Distillation, DI Deionization (as a polishing filter after RO), and Microfiltration. Following most of these treatment methods, you may have to provide Oxygenation injection, otherwise the water may taste flat, but that's a palpable concern rather than a health concern.

If your raw water source is a surface water, or if it's a well water source having a Coliform Count >1.0, then be prepared to include disinfection unit processes following the RO (etc) unit, be it chlorination, ozone, UV or a combination thereof.

Here's a good source from Canada regarding the discussion of TDS in potable drinking water:

http://www.hc-sc.gc.ca/ewh-semt/pubs/water-eau/tds-mdt/index-eng.php

If you employ RO technology, I would highly recommend also employing a high quality Water Softener as a pretreatment "roughing" unit to help knock down the dissolved mineral concentrations or if you have high levels of dissolved Iron and Magnesium install a Manganese Green Sand filter with Chlorine and Potassium Permanganate injection. There's no way around eliminating backwash water for any of the treatment technologies. Also, RO is incredibly energy intense, so expect high electric consumption and bills. You're Clients will love you for that afterwards. NOT!

Replies (3)

Research & other things I have been doing:

I went to city of hemet to inquire about water quality and the level of TDS range and averages, as soon as I can I will go to the water agency that serves Valle vista, I live in Valle vista, an unincorporated area of riverside county. Valle vista is served by Lake Hemet water district ( the water does not come directly from lake hemet, but from wells I presume are fed by underground aquifers that flow from the San Jacinto mountains. The city of Hemet is supplied by wells located around the city and gets additional make up water supplied by MWD ( Metropolitan water district), MWD has their own wells too.

The engineer and technician told me hemet uses a loop system with water tanks and pressure pumps to support the system. Water samples are drawn every 7 days and sent to an outside contractor for testing ( my thought was Babcock labs but they wouldn't confirm that ) purposes. My observations are ( note: wells are a secure site and only authorized personnel can draw or test at locations) rudimentary, if the system is a loop, then how does one and more areas have consistently higher levels of TDS than other areas ? ( I couldn't get a difinitive/ spell check/ answer to that question) .

According to their analysis, 2012-2014, showing average and range ( indications based on total number of wells tested but does not indicate average or range based on specific locations)

Chloride-272/44-530, iron-102/0-120, manganese-20/0-23, specific conductance-1410/770-2100, sulfate-160/110-260, TDS-879/480-1300

The vendor in hemet who is providing with materials and equipment to build/create a water filter system tests the water at their location everyday - before and after purification, their numbers indicate TDS averages between 1200-1700 before and 10-15 after. Their system uses a combination of filters including coconut shell Gac, RO, and DI resin.

I will try different combinations of filters and equipment to see what I come up with.

Tony

Annual water quality reports for municipal water is required by the EPA. The specifics of analysis for many of these reports can be found on line.

Here is one place to look:

http://ofmpub.epa.gov

Also interesting, it looks like hemet and valle vista are recipients of wholesale water from Riverside which has been noted for water quality violations. Not sure if they have to do water quality reports on water received from other reporting municipalities or not.

'....if the system is a loop, then how does one and more areas have consistently higher levels of TDS than other areas ?...'

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Sounds like it isn't well mixed. Likely demand is such that certain wells/sources predominantly supply certain areas, even though everything is interconnected.

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Less likely, but wouldn't be surprising, the samples might consistently be taken/handled in a different way dependent on the sampling location.

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Perhaps the walls of the supply pipe are adding corrosion products to the supply water in certain areas, or there might be potential difference that causes solids to build up on the pipe walls, lowering TDS locally.

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Sorry, still nothing difinitive.

Sorry, left something out.

The vendor also uses UV.

We can't use water softener in this area.

That's nonsense. Total dissolved solids are already dissolved. You've been had.

Have you asked ''your average customer service person'' to connect you to their engineering people ?...

I would suggest that RO is not the answer in this case.

For the RO unit to operate, there will be bypass water that is probably greater volume than your current "dump to waste" from the evaporator and you will still need to provide additional energy (cost) to run that unit and then the RO membranes need to be serviced, cleaned with costly chemical processes blah...blah blah.

If they are dissolved, then study the chemistry to make the precipitate and run that with a solids removal process before entry to the cooler. Simpler maintenance, reliability no worse than current system, cost effective, energy effective.

Good luck

Without looking at all the comments, I am suspecting the hexametaphosphate "scum" may not be scale, rather a biofilm supported in part by the hexametaphosphate. Collect some of the solid residue from the flushing and have it looked at through a microscope to see what kind of critters might be there. If there is an effulgence, then adding an occasional bleach pulse as an alternate to the hexametaphosphate to the flush may facilitate the process. You may find that this approach may let the suspend the solid mass sufficiently that it would be a wash through not requiring bleeding.

Simplest solution: Use a mixed bed ion exchange resin in the feed line. It will replace all positive and negative ions with Na+ and Cl- , leaving you with a dilute solution of NaCl which is much more soluble than Ca and Mg carbonates. You will still need a small bleed-off to limit the TDS in the swamp cooler. The ion exchange resin can be regenerated by running a strong sodium chloride solution through it. Alternatively, chuck it away and sell your customers a new one periodically.

On second thoughts (from an ex-water treatment chemist): A mixed-bed acid & alkaline deionization resin would be better. The cations are replaced by H⁺ and the anions by OH^-, thus ultimately replacing all the ions with H₂O. No more TDS left at all. Possibly some colloidal silica and ferric oxide, which are not dissolved, will be left behind. May not be a problem, but can be removed by ultrafiltration. Good luck!

It's good to see that you're dealing directly with the local jurisdictions, etc.

Also, maybe contacting the local American Water Works Association (AWWA) can also shed some light on the issue(s)?

Try bingle-ing ''ca-nv-awwa.org''

Also, FYI, AWWA is conducting a program entitled ''International Symposium: Biological Treatment'' on drinking water, in Long Beach, CA, on Jan. 27-28, 2016 with sessions on:

- ''Biofiltration Applications in Reuse''

- ''Biofiltration Applications in Drinking Water'', and

- ''Biofiltration for Inorganic Contaminate Removal''

Seems Like it would be a good opportunity to connect with consultants who are currently working directly in water treatment...

By the way, the AWWA has recently published an updated version of ''M53'', which is their manual on Microfiltration...