I find myself agreeing with Fred Wiesler from QUA Group. They make membrane products and you can find more about the company here: http://quagroup.com/about-qua/mission-vision/
He talks about using nanotechnology to improve membrane technologies for areas that see water insecurity or scarcity. I think we’ll also see an expansion of the cloud point precipitation processes that are patented by QUA.
It always depends of the size of the plant and also the influent flow what need to be treated. membrane technology is pretty expensive and you have to find the balance in between long term operation and the initial investment budget
I run a WWTP with 3 MBR process trains designed by GE water and process technologies. Very efficient process. Yes there is the higher initial capital cost. But the plant is significantly smaller than a typical conventional plant. These types of systems are most advantageous if overall volume of influent that needs to be treated is relatively low. One major adavantage is they are indoors and your not suseptable to the issue with extreme elements. Its a question of connections in the system and available land space really.