If the Bible is still usable, I recommend giving it away to a needy person or to a charity that can make use of it. You could also give it to a library along with other books you no longer need. Many libraries keep the donated books that they can use and sell the rest at used-book sales to raise funds for the library.
If the Bible isn’t usable, and if it has been blessed by a priest, it can be buried. If the Bible hasn’t been blessed, it may be disposed of as you would any unusable book. If you like, you might wrap it in paper or cloth to avoid giving scandal to any who might see it in the trash or inadvertantly dig it up.
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