Upon what grounds could a divorce be procured under the code?

The quote below should assist you with the above post.

Once wedded, the husband and the wife were free to separate at will and without constraint, save as the authority of the husband's parents over him—not relaxed upon his marriage—might restrain him. Marriage, therefore, was treated as a contract which was at all times mutual, binding only as the parties continued to consent that it should bind. Either party could with a word dissolve it.

http://www.sacred-texts.com/cfu/eoc/eoc09.htm