Most likely severe shock from the replanting.
Could you tell us (1) what city you are in and (2) how long ago you did the replant and (3) what potting mix/soil you used in the new pots.
Unless they are a specifically grown mini-orange for patio growth, you are probably not going to ever get any decent fruit off them unless they are planted in the ground.
That said, citrus still make nice potted plants provided they are well-grown, for that mediterranean look, the smell of the crushed leaves and the occasional flush of scented flowers.
Potting up was probably needed but I'd say you have just given your plants a bit too much of a jolt and they are having trouble recovering. Dropping leaves is a classic defensive mechanism and not necessarily a sign of imminent death.
If you removed a lot of soil from the roots to rid them of the ant problem, then they may have suffered some damage in the process.
Then they went from a dry and sterile soil into, presumably, one fresh with added nutrients, water saver crystals and all, and watered.
That alone may have set them back a little but adding the chelates might have been a final straw.
The oen on the right I see is right by a swimming pool so it potentially either gets splashed with chlorine or salt water, and is also in a baking hot position on pavers and with sun reflected off the water.
I suggest you move them immediately, to a spot where they get semi-shade for a few weeks. Personally I would prune them back by about 1/3 as those drying leaves are not going to recover and you should aim to create a better shape for a nice bushy tree once they start to make new leaves.
The ant problem might not be entirely gone - please check if there was a secondary cause/attractant like scale or mealy bug. Also it's worth using some ant dust round the trunk if you see any activity on the surface. Keep the pots off the ground while you move them so ants don't immediately re-invade.
The one on the right also needs a bit more soil added as there are roots exposed at ground level, and generally, a mulch would be beneficial (a bark type, not right up to the trunks) in any case for pots in such a potentially hot position.

I agree with everything Alisonoz has said above, I'd just like to add that the best place for citrus is in the ground - natural earth. I suggest that's what you do if you have the space: dig holes twice the size of the pots, add some compost if you can to the soil you put back in after you plant and water in well. Incidentally, I read a very good article from horticulturist Jason Hodges in his 'Love your Garden' column in the (Sydney) Sun Herald on page 44 today on this very subject - citrus in the home garden. Well worth reading for all citrus growers. If you can't get the paper you should be able to bring it up via 'Google'.
Regards
B.