Thank you all for your replies.It was fairly obvious what was causing the problem ,the disconcerting element was that the faulty ADC was producing corrupt data and this was affecting so many other systems. We had a page of seemingly unrelated ecam and had to paste the pieces together to confirm our initial thoughts on what the root cause was.
When the ecam recognizances that the ADC has failed the procedure is to select the alternate ADC.Performing this action based on the indications we had did not stop all the related failures produced by the erroneous data.,possibly because the Ecam had not recognized the failure and it failed to do so until after engine shutdown.