I would recommend you ...
Published by Tom Truong, Senior engineer
I would recommend you research about BACF (bioreactor activated carbon filter). Its also depend on how quality of waste water after treatment.
Have ever heard about one step filter. I also attached link for your reference.
https://www.witteveenbos.com/projects/improved-water-treatment-1-stepr-filter/
For more information, you can reach me at email: tan.truong@witteveenbos.com.