R.O. reject water reclaim project

Too start off with, I also use a 1 1/2 inch float vlave instead of a Dema valve. It works just as well and you don't have to install the transformer or use the Dema valve of course. You can get one a a full line plumbing supply house. I'm recycling the RO waste water to the rinse water on the automatic. Took a pickup truck tank and put it up higher than the holding tank on the auto. Then got two dema valves and a float switch. And about 20 feet of 1 1/2 PVC.

The plastic holding tank is what farmers buy around the Midwest to put in the back of their trucks to haul water to stock animals. If you try to buy a large plastic tank from any other place you will pay much more. It has a 2" fitting on the bottom.

Just take the water you are sending to the drain now and run it to the tank. Also you need to connect another hose to the side of the tank for overflow, in case it should overfill. Come out with large pipe because this is gravity flow so you need to oversize it to get volume. Put a ball valve on so you can work on anything down stream.

The PVC is cheap and easy to work with so if you make a mistake just cut it off and try again. I used the largest dema solenold valve I could get my hands on which was 1", but bigger is better. This item will get expensive fast if you go big. The reason I didn't go with a mechanical float valve is that they need more pressure behind them to shut off completely. So if you were to use that kind of valve it would always leak.

Then just elbow it down into the tank about 4 or 5 inches off the bottom. This now give you a base or a platform to mount your float valve. I did use two different kinds of float valves, just experimenting with it now to see which one works best, if you look at the pictures you can see the two different ones. One is mounted on the side of the tank and has a wire going down inside the tank with two little black weights. The other is a sump type float that is easier to mount but the down side to this type is that the water has to drop down further for it to switch on. The only adjustment on this is how long the cable is from where you mount it to the side of the pipe going down in the tank. See picture This is what is called throw. The longer the cable from the pipe the higher and lower the water gets in the tank, vise versa if you make the cable shorter. but I have found that the very shortest I can set this is still not as much control as I'd like.

As far as getting into the wiring its all 24 volts because your working around water. Just run one side of the 24 volts (it doesn't matter which common or hot) to one of the wires on the solenoid valve. the other wire (from the transformer) goes to one of the wires on the float switch, the other wire on the float switch goes to the remaining wire on the solenoid valve. to complete the circuit. Hope this is not too overly simplistic of an explanation.

Did some fine tuning because it overflowed twice. Its got to be set up just right. So far I'm using all of the RO waste water.

When the bottom basters come on, the fresh water valve doesn't even come on. This should lower the water bill.

This is for two automatics.

So far I have $120 in the tank which is a 210 gal,
$45 each in two dema valves,
$20 in 1 1/2 PVC pipe,
$8 for elbows,
$34 each for two float switches to turn on the dema valves,
$24 for a 24 volt transformer to power the valves,
$7 each for two 1 1/2 plastic ball valves.

Here is the float valve. I know these pictures are not very good but I had to copy them from an already small picture.

These are a little more clear. This is a link to more pictures of my washes. http://ghaddock.photosite.com/Album1/ The write up in the magazine PC&D was misleading. I don't use a pressurized system to reclaim. I use the waste water from the RO that is pressurized to fill the tank that is above my bathroom ceiling. Then gravity draws the water back down to the holding tanks for the automatics. The lady didn't let me proof the article. She didn't really understand what I'm doing. They are always in a hurry to meet deadlines and screwed the information up. I've had many people email about this. I'll try to get to everyone as time lets me. Thanks.

great topic, very informative

Here is my version at my newest conveyor operation. 500g tank to capture ro reject, a float with relay/solenoid and fresh water backup. Submersible pump supplies line pressure with small bladder tank attached to line. This feeds water to all my mixing stations. You'll see a pvc down spout for city input with an air gap. That's what the local "mixing coordinator" require me to do even tho we have a backflow preventer. He said he didn't care what kind of water I put in their sewer but he was very concerned about any of my waters mixing with the cities'.

With reclaim I'm at 17g per wash. Which costs me 10c a vehicle for water & sewage. I also have a shallow well for irrigation and backflushing the reclaim.

pic

We are similar to Jimmy B's but we use a 5000 gallon storage tank for our RO and a matching 5000 gallon for our reject aka chemical feed. We use over sized tanks for eventual equipment failure, which gives us 1 or 2 days time to repair. that is we use 5 - 6 gallons per car, and can last 1000 cars till we are out.
The cost of the tanks were minimal, the space was difficult.

Jimmy

Guys,

We tried the R.O reject water at many of our location for a year. We made the mistake of running the water thru our cat 310 pump for hp soap and ps after 16 months we started replacing heads, valves and seals. After everything was said and done we had 80 thousand in parts and labor Now that’s money down the Drain!! Good Luck!!

Mike

I know ro water tries to re-minerize itself thus making it corrosive(that's why it cleans glass so well). But I didn't think the reject would be corrosive. What caused the problems Mike?

All of mine is going thru flojets.

PJ,

When you think about what you remove from the street water, You end up with 700-750ppm (in our area) of solids and it sand blasted our pump too the point where they had to be repaired. We noticed the trend after about 16 months! And as you know we have about 264 s/s bays and when we have a problem. WE HAVE A PROBLEM also we tend to find problem sooner than most operators that only have a few stores. Just Because of the large volume of customers.

Mike

Abrasion...that makes sense thanks for the info. Live and learn sometimes...My city-fresh water is only 60-80 tds so I don't think it's reject would be bad on a high pressure pump. Heck, we metered my reclaim and it was only 330 ppm.

Mike, we knew we were going to use reclaim water, so installed warner pumps. They supposedly can handle high TDS reclaim water. We use our reject water exclusively for low pressure chemical make up (soap, polish foam etc.), and the problems here are minimal, (cleaning out screens etc). Well worth the hundreds of $ we would spend on throwing away 6 gallons of water per car.

jimmy

My TDS is running around 350 ppm. I don't know why yours is so high. Another thing, we are talking reject water, not RO water. Which is no more acidic than your tap water. I think you had some other problem and thought it was the reject RO water. If I were guessing, I would say you were causing the reject water to cavitate on the inlet side of the pump. Thats what it sounds like to me. I've been running my setup for years with no problems what so ever.

OldTimer,

Yes I understand R.O reject Water. Since we have have stopped we replace parts maybe monthly. also cavition would be noticed right away.

Mike, sorry you had so much trouble with your set up. I have not experienced anything like that. It's saved me a lot on my water bill.

Old-timer,

Some of us are just Lucky! I think Jimmy hit the nail on the head. The Warner pumps seem to hold up better with reject water. We never used the reject water in our I.B.A . Today we send it the reclaim unit on our tunnels with Warner pumps. And as of today no problems. One of our Customer used the reject water on there truck washes with cat 3535-3540 with the same issues.

Mike

I've been capturing my RO reject water for almost 4 years now. The reject water dumps dirrectly into the omni double wagner station, then overflows into the single wagner omni pump then out of that overflow down to the floor and through the equipment room wall into the reclaim pit were it then travels into the tanks. All of it is recaptured.

Then wagner pumps and unloader have been working for 4 years without any problem. Only replacing presure gagues evey 1-2 years.

I wish my pressure gauges would last 1 to 2 years. I guess vibration kills even oil filled gauges.