Source: JHFamalies Listserv Posted by: "" Date: Fri Jan 19, 2018 11:10 am ((PST))
I work in the library, though not in a public one, so I have some knowledge of the topic.
Book donations to the public library usually go straight on to the book sale rack and the proceeds of the sale go to supporting the library. This way your books benefit the library even if they are not included in the collection. And yes, if they are not sold the books may be sent to be pulped/recycled by the library as well. They cannot be used for collections because the library collection is developed in accordance with a specific collection development policy with materials acquired through publishers and library vendors. If you would like to learn more about the Queens Library collection policy it is available here.
If you don't mind a longer haul, other places you can try to give/sell your books are Strand and other used book stores. There a few of them in the city, though fewer with every passing year. Strand will give you cash/store credit for books in good condition that they can sell and will take less desirable items for free. They do not accept ARCs (advance reader copies).