For As you are likely to have ...

For As you are likely to have As(III) to remove it you would be better to oxidise it to As(V) with ferric chloride or potassium permanganate Peroxide or Ozone should work too.  Then As(V) could be flocculated with Ferric sulphate the flock can be removed by MF. Not sure if this is feasible at household level. As to remove 2000ppm of dissolved solid NF or RO can be envisage alternative is to distil the water an condense the vapour into demineralised water add back so salt to make it drinkable. there are some hand pump RO system on the market.