Why anode attracts Anions if anode is positively charged and anions are negatively charged
I did a search for you and found this page 

http://electronics.stackexchange.com/questions/29992/why-is-the-anode-positive-if-anions-are-negative


here is the answer by a member named clabacchio :


  In the diode, and specifically in the so-called depletion region, there is diffusion of carriers (electrons and holes) from one region to the other. Since the Anode is positively doped, it will attract electrons from the cathode, and this will cause the formation of Anions in its side of the depletion region.