Hi Liv The vacuum evaporators is expensive system for recovery of brine and use for small recovery system,I suggested you about EDR for recovery of brine

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Hi Liv

The vacuum evaporators is expensive system for recovery of brine and use for small recovery system,I suggested you about EDR for recovery of brine 

 

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Hi Ali,

By "EDR", are you referring to "Electrodialysis Reversal" for volume minimisation?  If so, EDR typically isn't economical for feed streams where the TDS is higher than 3,000-10,000 mg/L TDS (i.e. the upper bound at about 50% recovery producing a brackish reject stream of 20,000-25,000 mg/L TDS).  EDR does have advantages in terms of scale avoidance for non-ionic species (particularly silica). 

Above a ~10,000 mg/L TDS feed and producing a brine reject stream of 60,000-100,000 mg/L (lower bound for sodium chloride dominated solutions and upper bound for sodium carbonate/bicarbonate dominated solutions), reverse osmosis is more economical for volume minimisation, dependent on the chemistry and pretreatment. 

You might be able to increase the recovery of the EDR or RO system by instigating a precipitation or seeding step.  This can be either interstage (e.g. HiPro by Aveng Water) or in a recycle loop (e.g. GE's NTBC system, Desalitech's CCD) but these aren't yet in common use and are heavily dependent on the chemistry, which also needs to consistent (especially seeded processes).

Above 60,000-100,000 mg/L TDS feed, you'd typically have to use a thermal process (there are many forms to choose from) or consider more novel technologies (e.g. humidification-dehumidification, membrane distillation etc).

If you are referring to "Electrodialysis Metathesis" (EDM), the sophisticated cousin of EDR, the economics of resource recovery (i.e. a revenue stream) may mean that you'd go above the 10,000 mg/L limit for the feed.  This also isn't a common process.  Typically thermal crystallisation is used for resource recovery from brine streams.

Cheers,

Matt.

Dr Matthew ​Brannock ​CEng, CSci, ​MIChemE, RPEQ ​

matthew@​​​​saltwatersolutions.​com.​au  ​ ​​

www.​​​saltwatersolutions​​​​​.​com.​au   ​​

www.aqmb.net

 

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