How to detect unicode character while file write operation

Question

I copied and pasted the content into my text area and stored it in the database then I found Unicode characters as shown in the attached image in my database. How can I detect or replace them while creating a .ics file from this data?

When I fetch from the database and try to write a description in a file or log this data it prints something like the below.

 jedes Wetter.\r\\n\r\\nDa\r\n mit dein Rasen such

instead, It should be like

 jedes Wetter.\r\n\r\nDa\r\n mit dein Rasen such

It prints double \ before n

I am creating a .ics file from this. It breaks after jedes Wetter.