The authority, in addition to the moneys which may be received from the sale of revenue bonds and from the collection of revenues and earnings derived under this article, shall have authority to accept from any federal agency grants for or in aid of the construction of any project or for the payment of bonds and to receive and accept contributions from any source of money, property, or other things of value. Any such grants or contributions shall be held, used, and applied only for the purposes for which they may be made.