yii - translation issue in php -

i have done needed translation. issue word not getting translated properly,

l’équipe 

is not getting translated properly, instead of getting l?équipe question mark dont understand how.

this how code written.

$body = mb_convert_encoding(yii::t('site', tk::getstringbetween($data->body, "{body}", "{/body}")), 'iso-8859-15', 'utf-8'); // avoid é becomes é 

it looks 'qelasy' dictionary stored in proper utf-8 encoding.

try not convert encoding.