What I try is to remove this parameter from the URL "/ Sports% 20-% 20Arte" and then make a selection in the BD
$busqueda = str_replace('%20'," ",$busqueda);
but until now I only keep this: Sports-Art and I want to achieve something like this: Sports - Art
In addition to your example that works correctly and considering that you are using URLs you can use urldecode
string urldecode ( string $str )
Decode any cipher type% ## in the given string. The symbols ('+') are decoded as the space character.
echo urldecode ('http://localhost/mercadito/categoria/index/Deportes%20-%20Arte');
Print the space you need
http://localhost/mercadito/categoria/index/Deportes - Arte