The difference between brown salt and white salt
Brine organic purification decides what colour your product comes out. OROX separates the refractory organics by membrane first and oxidizes only what remains, which removes 50 to 80% of them instead of 10 to 50%.
What is brine organic purification?
Brine organic purification is the stage that takes the refractory organics out of high-salinity brine before anything is crystallized.
OROX does it with a strategy of separation first, oxidation second. A membrane removes the high-molecular-weight organics, and targeted oxidation is applied only to what survives that step.
It is the technical foundation of the whole zero liquid discharge train. Everything downstream, purification and crystallization alike, depends on how clean the brine arrives.
Destroying what you could have removed
Ozone charges you for every molecule it breaks. A membrane charges you almost nothing to take the same molecule out.
The conventional approach to organics in brine is oxidation, applied to everything in the stream. It works, up to a point. The molecules that matter most, the high-molecular-weight refractory ones, are also the hardest to oxidize, so the dose climbs and the removal still stalls between 10 and 50%.
So OROX inverts the order. Separate the refractory fraction out, concentrate it into a small side stream, and then oxidize the much easier remainder. Removal rises to 50 to 80%, the ozone bill falls, and the crystals come out white.
Separation first, oxidation second
High-recovery brine enters an organic separation system, which intercepts and concentrates the refractory organics into a separate stream. The purified brine then passes to oxidation, where a much smaller dose finishes the job.
The separated organic concentrate does not go back into the loop. Depending on the site, it is consumed internally, routed to the biological sludge system, or dried with the mixed salt.
Against 10 to 50% for ozone applied directly to the same brine, and achieved with less ozone rather than more.
That gap is the reason OROX is described as the technical foundation of the ZLD train rather than one more unit in it.
You can see it in the crystal
Process arguments are easy to make and hard to check. This one is not. Salt crystallized from untreated brine is brown, because the organics crystallize alongside the sodium chloride. The same brine after OROX crystallizes white.
That colour is not cosmetic. A brown salt goes to hazardous landfill as a cost. A white salt meets a national standard and goes to a buyer as revenue. The specifications are on our zero liquid discharge page.
Three things that move together
Better oxidation, less oxidant
Intercepting and concentrating the refractory organics raises the effectiveness of the ozonation that follows, and lowers the dose it needs. Both at once, because they are the same effect.
More stable salt quality
Crystal quality stops depending on how the brine happened to look that week. The variable that used to move it has been taken out of the loop.
A better cost structure
Membrane separation is capital; oxidant is a permanent operating line. Shifting work from the second to the first is what changes the lifecycle number, not the equipment price.
OROX sits between high-recovery brine concentration and selective crystallization, and it is engineered with both. That is the whole argument for buying a train rather than a unit.
Frequently asked questions
What is brine organic purification?
It is the stage that removes the refractory organics from high-salinity brine before the brine is crystallized. Those organics are what stain the salt and what force a plant to burn oxidant. Removing them, rather than destroying them all, is the cheapest route to a clean crystal.
Why separate before oxidizing?
Because oxidation is expensive and separation is not. Ozone destroys a molecule by breaking it apart, and it charges for every one. A membrane removes the same molecule for a fraction of the energy. Applying oxidant only to what is left is a better cost structure and a more stable process.
How much better is it than ozone alone?
Ozone applied directly to the brine removes 10 to 50% of the refractory organics. Membrane separation followed by targeted oxidation removes 50 to 80% on the same feed, while using less ozone to do it.
What happens to the organic concentrate?
It is a small, concentrated stream. Depending on the site it is consumed internally, routed to the biological sludge system, or sent to the mixed-salt drying unit. It leaves the loop instead of circulating in it.
Does it change the salt?
Visibly. Salt crystallized from unpurified brine comes out brown, because the organics crystallize with it. The same brine after OROX crystallizes white. A brown salt is a hazardous waste; a white salt is a product with a specification.
Where does it sit in a ZLD train?
Between brine concentration and crystallization. HiBARS concentrates the brine, OROX purifies it, and SERECS separates and crystallizes the salts. Reverse the last two and the crystals are stained no matter how good the crystallizer is.
Send us your brine COD
Start here
If your crystallizer is producing a salt you cannot sell, the answer is upstream. Send the brine analysis and we will tell you how much of that COD is separable.
Useful to include
- Brine flow and TDS
- COD, and how much of it is refractory
- Current oxidant type and dose rate
- The salt you are producing today and its colour
- Whether a crystallizer already exists on site
Contact us directly
- info@jing-yu.com
- Phone
- +86 21 6593 0816
- Office hours
- Monday to Friday, 9:00 to 18:00 Shanghai time (GMT+8)