NOVELTY - Processing waste liquid of organic waste e.g. livestock farming waste material in methane fermentation processing system, involves dehydrating the waste liquid in methane fermentation processing, isolating the dehydrated product as a dehydration cake and filtrate, concentrating the filtrate to produce a condensate having high concentration of ammonia and a concentrate having low concentration of ammonia.    USE - For processing waste liquid of organic waste such as livestock farming waste material in methane fermentation processing system.    ADVANTAGE - The method enables to recover ammonia from waste liquid with high efficiency and economically.    DETAILED DESCRIPTION - Processing waste liquid of organic waste, such as livestock farming waste material in methane fermentation processing system, involves dehydrating the waste liquid in methane fermentation processing, isolating the dehydrated product as a dehydration cake and a dehydration filtrate, using the dehydrated cake as a compost, concentrating the dehydrated filtrate, using the concentrate as a compost, further concentrating the first condensate produced by concentrating the dehydrated filtrate to produce a second condensate containing high concentration of ammonia and a second concentrate containing low concentration of ammonia less than the environmental-standard value, using the second condensate as a liquid fertilizer and discharging the second concentrate into river etc.    An INDEPENDENT CLAIM is also included for waste liquid processing apparatus (2) in methane fermentation processing of organic waste, comprising digester (1) for fermenting organic waste and producing methane gas, a processing system (S) for containing the waste liquid processing apparatus which comprises first heat pump type evaporator (2A) and second heat pump evaporator (2B).    DESCRIPTION OF DRAWING(S) - The figure shows a block diagram of methane fermentation processing system of the waste liquid processing apparatus. (Drawing includes non-English language text).    digester (1)    waste liquid processing apparatus (2)    first heat pump type evaporator (2A)    second heat pump type evaporator (2B)    waste liquid tank (11)    dehydrator (12)    processing system (S)