Hi there vikbot,
Have you backed up the data stored on the drive? In case you haven't done that, it may be a good idea to do so as the drive can fail at any time.
I don't really think you can repair the bad sectors.
One thing you can try is to use some tool in order to write zeros on it. After that, you can retest and see whether you will get similar results.
Cheers,
D_Know_WD