Is the money spent by the husband from his funds deposited in banks, which have been commingled with usurious interest, considered unlawful, knowing that he was previously unaware of the prohibition of interest and his wife was also unaware of it until recently?

The husband must withdraw the deposit from the usurious bank immediately. As for the interest generated from it, he must dispose of it by spending it on general Muslim welfare or distributing it to the poor and needy. It is not permissible for him to keep it for himself. If the wife knows that the money she is receiving is usurious interest, it is not permissible for her to take it. However, if the husband's money is mixed, there is no objection to dealing with it. The wife should explain the Islamic ruling on usurious interest to her husband.