Hi Alok,  also just wondering ...

Hi Alok,  also just wondering what you have in mind for zero liquid discharge.  Does this imply you need to contain all liquids at the treatment works.  In which case I see only one or two options - as Mike Bechtold said - evaporation of all the water in solar ponds, vacuum or with jet air sprayers (or by using waste heat if available); or secondly pumping it into the ground (and recharging an aquifer or pushing back a salt water/fresh water interface).  If however you mean zero sludge discharge but discharge of the treated wastewater, this is a totally different approach and there are a number of alternatives for producing a "dry" sludge while recycling or evaporating the extracted sludge water.