https://www.learnreligions.com/disposal-of-quran-2004546

Not a link to a Quran quote, but it mentions the 3 main ways Islamic teachings state to dispose of old/broken Qurans.

1.burying 2.placing in flowing water 3.burning

Also a fun fact, these only pertain to The Quran in Arabic. Any other language is not considered to be literally Allah’s words and does not have to be discarded in those ways.