Add to you .htaccess or in httpd.conf the following configuration line (directive):
AddDefaultCharset utf-8
Apache HTTP Server Manual:
This directive specifies a default value for the media type charset
  parameter (the name of a character encoding) to be added to a response
  if and only if the response's content-type is either text/plain or
  text/html. This should override any charset specified in the body of
  the response via a META element, though the exact behavior is often
  dependent on the user's client configuration. A setting of
  AddDefaultCharset Off disables this functionality. AddDefaultCharset
  On enables a default charset of iso-8859-1. Any other value is assumed
  to be the charset to be used, which should be one of the IANA
  registered charset values for use in MIME media types.
Don't dorget to restart your httpd server in case of editing httpd.conf.
EDIT 1:
Looking at your rewriterules, I would recommend you trying the following insted:
RewriteRule ^(.*)-(.*)/(.*).html?$ search.php?co=$1&location=$2&keyword=$3 
RewriteRule ^(.*)/(.*).html?$ search.php?co=$1&keyword=$2 
RewriteRule ^(.*)-(.*).html?$ search.php?co=$1&location=$2