NOVELTY - Process-I for recovering ammonium carbonate and ammonium bicarbonate from a liquid solution comprising e.g. ammonia, comprises (a) adjusting the pH of the liquid solution to produce a converted solution, (b) stripping ammonia from a converted solution in a stripping vessel to produce ammonia stream, (c) contacting the ammonia stream with a scrubbing liquid in a scrubbing vessel, (d) withdrawing an ammonium liquid from the vessel, (e) recovering a first portion (95) of the ammonium liquid, and (f) contacting a second portion (75) of the ammonium liquid with a carbon dioxide gas stream.    USE - The process is useful for recovering ammonium carbonate and ammonium bicarbonate from an ammonium containing solution generated in the treatment of biomass derived syngas (claimed) and waste water.    ADVANTAGE - The process easily and economically recovers ammonium carbonate and ammonium bicarbonate with good stripping efficiency, without using conventional strippers, without adjusting pH and using expensive mineral acids, and is capable of recycling the ammonium rich solution to the fermentation zone thus providing the cellular maintenance and growth needs of the microorganisms.    DETAILED DESCRIPTION - Process-I for recovering ammonium carbonate and ammonium bicarbonate from a liquid solution comprising at least one of ammonia or ammonium, comprises (a) adjusting the pH of the liquid solution comprising ammonium to convert ammonium in the solution to free ammonia and produce a converted solution, (b) stripping ammonia from the converted solution in an ammonia stripping vessel to produce a gas phase ammonia stream, (c) contacting the ammonia stream with a scrubbing liquid comprising dissolved carbon dioxide in a scrubbing vessel to produce ammonium bicarbonate and ammonium carbonate, (d) withdrawing an ammonium liquid comprising ammonium carbonate and ammonium bicarbonate from the scrubbing vessel, (e) recovering a first portion (95) of the ammonium liquid as an ammonium product stream, and (f) contacting a second portion (75) of the ammonium liquid with a carbon dioxide containing gas stream and a make-up liquid to produce the scrubbing liquid. An INDEPENDENT CLAIM is included for a process-II for recovering ammonium carbonate and ammonium bicarbonate from an ammonium containing solution generated in the treatment of biomass derived syngas, comprising either (1) generating a syngas stream by the gasification of biomass, (2) scrubbing at least a portion of the syngas stream in a syngas scrubber to generate a syngas scrubbing liquid containing ammonium and a scrubbed syngas stream, (3) passing the scrubbed syngas stream to a fermentation zone to produce a fermentation product and a tail gas stream comprising carbon dioxide, (4) passing the syngas scrubbing liquid to an ammonia stripping vessel and adjusting the pH in the ammonia stripping vessel to at least the pKa of ammonia to maintain free ammonia in the ammonia stripping vessel, (5) stripping ammonia from the ammonia stripping vessel with a stripping gas stream to produce an ammonia gas stream, (6) contacting the ammonia gas stream with an ammonia scrubbing liquid comprising dissolved carbon dioxide in a scrubbing vessel to produce the ammonium liquid, (7) recovering a first portion of the ammonium liquid as an ammonium product stream, and (8) passing a second portion of the ammonium liquid into contact with the tail gas stream and a make-up liquid in a gas contacting vessel to produce the ammonia scrubbing liquid, or (i) generating a raw syngas stream by the gasification of biomass, (ii) cooling and scrubbing the raw syngas stream in a scrubber/cooler to generate a scrubbed syngas stream and a condensate stream containing volatile compounds and ammonium, (iii) passing the scrubbed syngas stream to the fermentation zone to produce the fermentation product, the tail gas stream and a biosolid stream, (iv) passing the biosolid to a digester to decompose the biosolids and recover an ammonium containing solution from the digester, (v) removing volatile compounds from the condensate stream to generate a scrubbed condensate stream containing ammonium, (vi) passing at least a portion of the scrubbed condensate stream and the ammonium containing solution to an ammonia stripping vessel and maintaining the pH in the ammonia stripping vessel at least one unit above the pKa of ammonia to maintain free ammonia in the ammonia stripping vessel, (vii) stripping ammonia from the ammonia stripping vessel with a stripping gas stream to produce an ammonia gas stream, (viii) step (6) as above per se, (ix) withdrawing an ammonium liquid comprising ammonium bicarbonate and ammonium carbonate from the scrubbing vessel, (x) recovering a first portion of the ammonium liquid as an ammonium product stream and passing at least a portion of the ammonium product stream to the fermentation zone, and (xi) contacting a second portion of the ammonium liquid with the tail gas stream and a make-up liquid in a gas contacting vessel to produce the ammonia scrubbing liquid comprising dissolved carbon dioxide.    DESCRIPTION OF DRAWING(S) - The figure shows a flow chart of a process for stripping and recovery of ammonium from syngas scrubbing using a carbon dioxide rich gas stream.    Scrubbed water stream (25)    Gas stripping stream (34)    Carbon dioxide absorption column (70)    Second portion (75)    First portion. (95)