finding nonblank cells and reporting their addresses

Hi! New to the forum; hoping someone can help me out.

I have a pretty big worksheet (230 columns x over a thousand rows). Any given column might have 3-4 nonblank cells; the rest are blank.

What I want to do for each column is obtain the address of each nonblank cell, then grab the contents of the corresponding cell in the B column and concatenate the results.

In the attached example, I want to put the function in d2, and the expected result would be ar 001, fc 001, hw 003.

Any help is very much appreciated! :-)