How to solve "cannot open shared object" problem while opening subprocess within apache

Question

I run a web application in apache. My application try to execute a executable written by QT.

But I always encounter "cannot open shared object libQtWebkit.so: No such file or directory" error.

I can run this executable in shell without any problem. I tried set LD_LIBRARY_PATH but still not working.

How can I set shared library path for apache to make it run this executable?

Thanks!

(Note: for more detail, my web application is written by django which run in mod_wsgi, I try to run my executable file with subprocess.Popen. This executable is written by QT 4.6.3, located on $HOME/lib/qt (not system installed QT version), I set QTDIR and LD_LIBRARAY_PATH, but not working)