How to treat waste water with high TDS?

[Abderrahmen bouchhima]

Dear ALL

I am currently working on a project dealing with constructing/provideing a waster treatement plant with a capacity of 1500 m3/day.

The water is comming from an "oilfiled" ( treated through a 3 phase separator then the oily water is passed through an API seprator then the client disposed in 3 evaporation pounds).

Our scope is to treat the water from the evaporation pounds. the water quality is as follow

I started to design the WWTP as follow:

Screen+ DAF, then combiened MBBR and MBR treatment, then chlorine injection.

As I started the requests for qutation, most suppliers stated that the biological treatment won't survive the high TDS.

So i kinldy ask if any one can help me to choose the right treatment?

Thank you in advanced.

 

[bimr]

The only process suitable is mechanical evaporation.

Link

 

[Abderrahmen bouchhima]

thx for your reply

The mechanical evaporation will heat-up the waste water until it evaporates leaving the the higher boiling contaminants behind.
But that would only surves to reduce the TDS. Where does this treatment stand? will it be after the primary treatment ?

 

[EdStainless]

If you evaporate then you just have solid waste.
Do they want any water back or just to get rid of it?
People use a long list of treatments, carbon filters, precipitation/filtration, membrane separation, partial evap (discharge clean side and keep small volume at higher concentration).
In general to treat water like this requires multiple steps focused on various constituents.
Hire an engineering firm.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, consulting work welcomed

 

[bimr]

A mechanical evaporator is used to concentrate the liquid to a brine.

Then a crystallizer is used to dewater the brine.

Link

Contact the manufacturer to see if any pretreatment is required.

 

[pierreick]

hi,

MVR is a good option but this technology required high maintenance (time and cost). Spare parts are needed (compressor part).Metallurgy of the equipment could be a killer ,what about Cl- & So4-- ?
Definitely a coarse treatment is required before evaporation (coagulation treatment ).

Note : instead of evaporation (MEE or MVR) some companies offer process where freezing is considered ( less energy consumption) .

Good luck
Pierre

 

[bimr]

Yes, freeze desalination has been proposed for desalination. I have never seen this process commercialized in the wastewater treatment market. Even if it was possible to used freeze desalination, one would still be left with the residual wastewater after the process, so it is not a complete solution.

 

[pierreick]

Hi,
@bimr ,
Three years ago I got a proposal from Europe (the Netherlands) to remove high So42- content from Waste water ! Of course the package included freezing process, water removal (ice) and waste disposal .
My view only.
Pierre

 

[bimr]

How was the concentrated residual brine stream addressed? If that waste stream was successfully handled, you would have something.

 

[pierreick]

Hi,
@bimr,
Ammonium sulfate sold to a fertilizer company nearby .
Pierre

 

[doomster]

You need a thorough analysis of your TSS. When you determine what are those then maybe you can apply simple precipitation then followed by filtration of WW.

 

[bimr]

If the salts are predominately calcium sulfate, then yes there is a possibility of precipitation. However, the resulting wastewater after precipitation will still be brackish.

The wastewater probably consists of sodium chloride and precipitation will not help.