in order to prevent damaging charset while usnig Zend_Dom_Query please see the hack below. It happens that you experience wrong characters even if the document is UTF-8 and you specified this encoding when you creted your Zend_Dom_Query instance. The problem is in Zend_Dom_Query::queryXpath() method on line
$domDoc->loadHTML($document);
If your html has meta tag written like this: it might have garbage in latter dom queries in output. To fix that there is a dirty hack mentioned here :https://ru.php.net/manual/en/domdocument.loadhtml.php#95251. To fix you can change the mentioned above line to:
$domDoc->loadHTML('' .$document);
Assuming you’re running 1.11 ZF version where encodings had been introduced in the component. Otherwise you should either download the latest component version or set the encoding yourself.