A decorated FDNY firefighter wants to get his job back after he resigned over a failed drug test — a lapse he blamed on emotional issues stemming from 9/11.

Glen Merkitch, who started his career with the Bravest in 2000, filed an appeal in Brooklyn Supreme Court after Fire Commissioner Daniel Nigro denied his bid to be reinstated in June.

In his petition, Merkitch, 43, says Nigro has “explicit and sole authority” to reinstate him — similar to what he did when he gave Joseph Cassano, son of former Fire Commissioner Salvatore Cassano, his EMT job back in September.

The younger Cassano had resigned over racially charged tweets that were uncovered by The Post.

A random drug test showed Merkitch had cocaine in his system in August 2011 but he insisted it was an “isolated” incident triggered by a visit from a son of a friend who died in the terror attacks.