This is difficult for an 'Anglo' speaker of English to answer, because the specific use of leave and general canons of politeness and formality in Indian English are different from US and British practise.
But to acknowledge a fact means to "confirm" that it is true, so you should not use acknowledge unless you are requesting a specific action from the recipient, such as an email response or a formal notice.
It appears that you are writing only to inform the recipient of your absence; if that is the case, then you should say something like "please be aware" or (more formally) "please be advised". But the previous sentence has already informed the recipient that you won't be in, so unless your "leave" has some further consequence for your recipient this last sentence is superfluous.
It may be, however, that you are writing to request the recipient to take some specific action required by your absence, such as formally granting you "leave" or posting the fact that you are taking a day's leave to official records. If that is the case, then your final sentence should address that specific action.
And if you are in fact requesting a response stating that the recipient has received your message or that the necessary action has been taken, you may write Please acknowledge X; but since that word is often used when speaking of admitting a fact reluctantly, you might do better to write Please confirm X.