Fail-Safe RO Reject Water Recycling Suggestions?

[mjwalsh]

We are brainstorming a bit about the most "foolproof & failsafe" way of recycling RO reject water.

We still have a pristine "barely used" but older 1" three port brass diverting valve that was part of when we had to re-do our boiler system back in in the middle nineteen eighties. Putting together a control system that uses that for rerouting when needed ... the reject water to floor drain ... if the check valve port on our existing water supply piping ... does not keep up with the tank potential overflow status &/or empty status ... both would be protected by a tank float level switches.

What might we be oversimplifying &/or overlooking based on some of you who have a RO water reject recycling system that is reliable etc??? Remember ... yours truly can be a bit faint hearted & honestly would like to avoid major mistakes. Possibly contaminating potable drinking water "legal code" comes into my mind???

 

[OurTown]

What are you going to use it for? Keep in mind that the TDS may be double what your soft water coming into the RO system is.

 

[Greg Pack]

Check the TDS of your reject water. It should probably be twice what your tap water is and is soft, it should be good for a variety of things. If you have an automatic it's very simple to reuse it by dumping it into a rinse water tank. Gravity can be used to dump it into a holding tank. I like gravity because it's a constant and requires no maintenance. You could also dump i into a cold water rinse tank for a SS. In this setup you leave the normal pressurized feed for the rinse tanks in place and just adjust the floats downward. That way, when you run out of reject water the normal pressurized system takes over and supplies water to the pumps.

At one wash I have a wall mounted tank that Coleman makes. we mount it up around 8' on the wall and it simply dumps into the water wizard holding tank using a simple BOB valve and a 1" line. At a second wash I have a vertical storage tank thats about 7' high that has about a 500 gallon capacity. I dump reject in there. It gravity feeds a hydraflex pump (that is floor mounted) for the chemicals on the Istobal. In this reject tank I have a float switch attached to a sprinkler solenoid. If the water level gets too low (around 3' high) the switch closes and the solenoid opens, providing soft water to the tank so that the pump doesn't run dry.

 

[I.B. Washincars]

With your wash being SS only, it's going to be a challenge to do it in a way that won't affect the quality of the wash. If a customer rinses with your reject water and then leaves, the spotting will be off the charts, since the TDS will be so high. Maybe someone else will come up with a good way to use it, but I don't think it's a good idea for a SS. Maybe somehow in your laundromat?

 

[mjwalsh]

With your wash being SS only, it's going to be a challenge to do it in a way that won't affect the quality of the wash. If a customer rinses with your reject water and then leaves, the spotting will be off the charts, since the TDS will be so high. Maybe someone else will come up with a good way to use it, but I don't think it's a good idea for a SS. Maybe somehow in your laundromat?

I am pretty sure I can find a strategic route for the water towards the laundromat or have it only go to the slightly warmer water that goes to the tiny individual self service gravity tanks ... during when the customer chooses hi pressure soap. I have hired a couple of part timer "jack of all trades" ... the project will also take a bit of manpower. Hopefully, the "one inch ports" 3 way diverting valve that was left over from our boiler system redo nightmare is still 100% good.