Solved! Go to Solution.
The MERGE() Function (https://docs.trifacta.com/display/PE/Merge+Function), in conjunction with the Set Transform (https://docs.trifacta.com/display/PE/Set+Transform), should accomplish this.
It would look something like this:
Transformation: Set
Columns: Your_column
Formula: MERGE([your_column, 'your_string'], 'optional_delimiter')
It's important to remember that the values you would like to concatenate are listed inside an array. The optional delimiter allows you to separate the original values of your column, and the string you are concatenating to it, with a dash, underscore, etc.
sweet, this helps with one of the other things I was trying to do too!