Alternatives to chromate and surface pretreatment

We are a medium sized sheet metal shop looking for new approaches to pretreating both steel and aluminum before powdercoat painting. Currently we use an iron phosphate system (dip tanks), and we spend far too much time and money managing hazardous waste materials. Are there new RoHS compliant alternatives we could consider?

I do not understand: You are talking about iron-phosphating and in the header you talk about chromates.
These are different treatments. So what's the point?

To clarify, we want a RoHS pretreatment process that is effective on both steel and aluminum. We are not interested in separate processes for both. The title 'Alternatives to Chromate' was intended to filter out feedback that is not compliant with RoHS requirements.

Furthermore, if anyone has experience with Bonderite NT-1 or another 1 step organic pretreatment, please share your experiences (successes and failures). Secondly, we seek products that will potentially meet or exceed the QPL-81706 spec.

We use a spray-on iron phosphate Henkel Prep'n'Cote which has proved great for e/galv, aluminum or bright steel - we just adjust the pH up or down depending on the substrate.