Can I use Zend_Log to handle PHP errors?

you can use set_error_handler to catch PHP errors and use Zend_Log to log them as you please.

The only problem with this function it won't catch all PHP errors, it is not possible to catch errors like syntax errors ....

An other method is to play with the register_shutdown_function function

like this:

error_reporting(E_ALL);
    ini_set('display_errors', 0);

    function shutdown(){
        $isError = false;
        if ($error = error_get_last()){
            switch($error['type']){
                case E_ERROR:
                case E_CORE_ERROR:
                case E_COMPILE_ERROR:
                case E_USER_ERROR:
                    $isError = true;
                    break;
            }
        }

        if ($isError){
            echo "Script execution halted ({$error['message']})";
        } else {
            echo "Script completed";
        }
    }

    register_shutdown_function('shutdown');

It's worth to be noted then even by combining both methods it won't catch all errors, like syntaxes errors .... But you could see that kind of error using a normal browser.