6 replies to this topic

[Dharmesh]

We are treating Seawater in Desalination Unit. We are using polyelectrolyte as a coagulants in clarifier from where water is diverted into the dual media filter and than to RO.

Polyelectrolyte 150 gms mixed with 75 lit. of water.

Problem:

Poly electrolyte solution chokes the dosing pump line frequently even though we continously agitate it.
Some times it makes crystal formation inside the tank. What is the reason for that and is there any alternative of polyelectrolyte? What is the correct procedure to make polyelectrolyte solution?

[mvancleave]

Your best bet is the vendor for your chemical. They have usually seen most of the problems out there and can usually offer a solution.

From what you describe, it sounds like your solution could be too strong (i.e. supersaturated). Try a more dilute solution and see if that helps (of course, you will have to adjust your dosing rate accordingly). I would still contact the chemical vendor and see what they have to say.

[Dharmesh]

Your best bet is the vendor for your chemical. They have usually seen most of the problems out there and can usually offer a solution.

From what you describe, it sounds like your solution could be too strong (i.e. supersaturated). Try a more dilute solution and see if that helps (of course, you will have to adjust your dosing rate accordingly). I would still contact the chemical vendor and see what they have to say.

Thanks for reply. But we are follow the procedure given by vendor only. Earlier the solution concentration was low i.e. 75 gm per 75 lit. after some trial and error by vendor he suggest to increase the concentration. The water turbidity improved but problem mentioned earlier still there. The same problem we face even with the low concentration also. Please provide some help on this.

[DRS]

Are you, by any chance, using untreated water for solution preparation?

[Dharmesh]

Are you, by any chance, using untreated water for solution preparation?

No we are using RO outlet water with less than 1 NTU Turbidity.

[mvancleave]

Hmm ... interesting problem. Can you tell us more about your chemical? What polyelectrolyte are you using? Are you sure it has not been contaminated?

[kumaqal.engr]

Respected Sir,
In my practice polyelectrolyte, megnafloc, nalfloc is added in a very little amont
in our practice we add it in a tank with agitator and and even plant air is provided for mixing,
we use almost 500 gm in 5000 litre of water. But it still create a little problem for the solution of this we give one more water line which combined the the discharge of polyelectrolyte solution, to avoid any choking in the pump. this line is also used for flushing. for polyelectrolyte batch there is no need to use ro water,