Can I submit the same article, which is written in two different languages, to two different journals simultaneously? I have written an article in Persian and then translated it into English. Is it possible to send them to two different journals (one in Iran and the other one in Belgium)?
Yes, this is a problem. You should not submit the same work to more than one journal at a time. This applies regardless of language - merely being in a different language does not make the actual work unique.

Further, consider some practical considerations - a simultaneous submission means that you'll have to go through peer-review for both papers and (assuming you don't get caught and summarily rejected) presumably have to make some changes. What if the changes don't align? Now you don't have two translations of the same paper, but two subtly different papers in two languages.

If you're genuinely interested in making your paper more accessible, either post a translation online, or wait until one paper is accepted and then approach a journal in the other language about posting a translation.