how will we seprate a mixtue of O-nitrophenol and p-nitrophenol ?

Mixture of o-nitrophenol and p-nitrophenol can be separated on the basis of their volatility as ortho-nitrophenol is steam volatile and p-nitrophenol is not. Kindly refer to the following link for details. 
https://www.meritnation.com/ask-answer/question/while-separating-a-mixture-of-ortho-and-para-nitrophenols-b/alcohols-phenols-and-ethers/6327436