You may find some ...
Published by Tom Eckhoff, Principal at Arrigetch Environmental Consulting LLC
You may find some information in this similar forum:
https://www.researchgate.net/post/What_low-cost_methods_are_available_to_remove_TDS_in_wastewater
The suggestion to differentiate between organic and inorganic TDS is spot on. You did not say if you have a biological wastewater treatment process in your description, as this will take out the organic fraction. RO and evaporation of reject is very energy intensive unless you have a lot of excess land and can use an evaporative pond.