Hi Das, for brackish water ...
Published by Arturo Constante, Wastewater Purification - Zero Emissions
Hi Das, for brackish water you ever need less energy to treat it than seawater if we speak about conventional natural water qualities, but some times not because organic material charge; all depends.
But you should consider a wastewater re-purification system of very low operating costs, 95% efficiency and zero emissions between another sustainable and profitable advantages.
Regards