MySQL Load Data Infile (CSV) : replace/remove vertical tabs

When using LOAD DATA INFILE to load a csv file with CHARACTER SET latin1 (table also encoded as latin1) all vertical tabs are displayed as '□'. Neither replacing 'u000b' nor '\v' worked.

LOAD DATA INFILE 'database.csv'
INTO table taxa
CHARACTER SET latin1
FIELDS TERMINATED BY ';'
OPTIONALLY ENCLOSED BY '"' 
LINES TERMINATED BY '\r\n'
(columns1...@column6...column19)
SET @column6 = REPLACE(@column6, '\u000b', '\t')

When I convert the table to UTF8 and import that with 'UTF8' specified, I get an error stating "Invalid utf8 character string:..." in the first field where a \v is coming up.

Notepad++ shows me a 'VT', so I know it's a vertical tab with escape char '\v'. Replacing it with Excel(where it shows up as '□') or NotePad did not work so far.

Printing it to the frontend of my WebApp shows:

'u000b' for \v` 
'u001d' for a Group Seperator`

Question: How to remove these little f*** - Could be even done before importing them, but I couldn'T manage that either.