Dimethyl arsenate removal from an effluent wastewater stream

[Nimit_shah]

Hi,

Does anyone here have any experience in treating Dimethyl arsenate from an effluent stream? Concentration: ~ 1000 - 1500 ppb, has a bunch of other heavy metals as well. Like is there an effective (in terms of kinetics) way to first reduce and then demethylate MAs(V) to As(III) (reducing agents, bacteria?) ?
Then, perhaps it could be oxidized to As(V) and later precipitated with FeCl2.

Or would a CASP/MBR system work for this effluent stream ?

Any thoughts?


Thank you in advance for your help.

 

[georgeverghese]

For the heavy metals, have you considered liquid liquid extraction with an organo phosphorus derivative - the chemistry wizards at Cytec Industries, USA may be able to help with the Cyanex 200 / 300 / 900 series extraction solvents. Literature I have indicates these solvents work at pH<6 or so, but they may have others that work at pH=7.

 

[georgeverghese]

A more conventional route may be cationic - anionic exchange resins which are selective for these heavy metals and arsenate.

 

[moltenmetal]

Forget about liquid/liquid extraction for tiny concentrations like this. Arsenic removal from drinking water is well studied and there is plenty of literature for you to review.