if its proper biodeisel, there is no reason why it shouldn't.There are a few caveats though, fuel lines, if made from natural rubber will deteriorate quicker, and will require replacing sooner.
fuel filter will need changing up to 3 times after switching (depending on mileage of the car) as the bio breaks down the crud and deposits in the lines/tank and can block the filter, reccomend changing after 3 tankfuls and 6 tankfuls, and 9 if its done lots of miles.
if under warrenty, manufacturers may not honor the warrenty if run on bio, check first.
If you want to run it, and are ok with the above, start with a 10% mix for a tank, if its ok, move to 20, and so on, if you show signs of misfire, go back to dino deisel, if its fine, up the % till you get to 100%
one last point, you will need to either buy an anti gelling agent, or switch to dino deisel in the winter, as bio gells up, when it does, you car will go nowhere until its warmed up.
If you look in the handbook it should tell you, it does in our Ceed one anyway, section 1 pages 4 and 5. Says you can use commercially supplied fuel containing no more than 7% biodiesel which meets EN14214. It goes on to say thatany damage caused by non approved fuels will not be covered by the warranty. There is also a caution note regarding using low sulpher diesel if the car has a dpf. You car will have a dpf and at £1000 + toreplace are you prepared to risk it save a bit of money. All commercially available diesel in this country is low sulpher thus no need to go looking.
As someone with Kia knowledge and works with Kia diesels on here said do not use in Common Rail diesels as its a heavier viscosity to normal diesel and can damage the pump. VW do not recommend it in their engines common rail or not.