Looks like the only thing that
might be a problem is that the ZD encoder is an "active-high" device (uses 5v to trigger the input port), but most modern electronics are "active-low" devices. (use ground to trigger the input port)
The Sparkfun version of the sensor
here apears to work with active-high devices.
As long as a touch (e.g., from a finger) is detected, the AT42QT1010 keeps the output line high. Otherwise, the line is kept low.
The Adafruit version of the sensor
here also appears to work with active-high devices.
When a capacitive load is detected (e.g. a person touches the sensor-pad area) the red LED lights up and the output pin goes high.
Just to be sure, can you post a link to the sensors you're using? (Bonus points for including a datasheet link.

)
If your sensors are active-low, there are several threads like
this one discussing how to use a solid state relay between an active-low coin recognzer and an active-high ZD encoder.
Scott