Remove non-utf8 characters from string

Question

Im having a problem with removing non-utf8 characters from string, which are not displaying properly. Characters are like this 0x97 0x61 0x6C 0x6F (hex representation)

Answer 1

$string = preg_replace('~&([a-z]{1,2})(acute|cedil|circ|grave|lig|orn|ring|slash|th|tilde|uml);~i', '$1', htmlentities($string, ENT_COMPAT, 'UTF-8'));