It seems like your database configurations defined in database.php under Config folder is incorrect. Here encoding should be utf8 as well.
public $default = array(
'datasource' => 'Database/Mysql',
'persistent' => false,
'host' => 'localhost',
'login' => 'root',
'password' => '************',
'database' => 'projectimpossible',
'prefix' => '',
'encoding' => 'utf8',
);
Thanks