NOVELTY - Method for separating pretreated liquid organic waste, involves (a) subjecting organic waste to hydrolysis and acidogenesis or to anaerobic digestion, adjusting pH of the liquid organic waste, (b) subjecting the obtained product to vacuum compression and distillation and collecting the distillate and residue, and (c) discharging the residue obtained in the step (b), obtaining aqueous solution as separate products chosen from distillate comprising at least 85-88 weight/weight% soluble carbon, and less than 3 weight/weight% or less nutrients, and residue.    USE - The method is useful for separating pretreated liquid organic waste (claimed) which is useful in activated sludge plant, biofuel production, biogasification plants, bioplastics production, bio-refineries which is useful for producing useful chemicals, electricity using microbial fuel cells, and other industrial uses which requires usage of carboxylic acids.    ADVANTAGE - The method separates pretreated liquid organic waste rich in nutrients.    DETAILED DESCRIPTION - Method for separating pretreated liquid organic waste, involves (a) subjecting organic waste to hydrolysis and acidogenesis or to anaerobic digestion and adjusting pH of the liquid organic waste to below 2 by adding acid, (b) subjecting the obtained product to vacuum compression and distillation, collecting the distillate and residue and constantly measuring the total dissolved solid concentration of the residue, (c) discharging the residue obtained in the step (b) in which total dissolved solids (TDS) concentration of the residue is of 10 times to that of the product obtained in step (a), obtaining aqueous solution as separate products chosen from distillate comprising at least 85-88 weight/weight% soluble carbon, and less than 3 weight/weight% or less nutrients and residue comprising more than 82 weight/weight% nutrients and less than 14 weight/weight% soluble carbon. The liquid organic waste comprises water-soluble organic compounds comprising water-soluble organic fatty acids with 2-7C, preferably soluble carbon, and water-soluble mineral compounds (nutrients) other than liming materials comprising nitrogen in the form of ammonium or nitrate, phosphorus in the form of phosphates, potassium, calcium, magnesium, sodium, sulfur, boron, cobalt, copper, manganese, iron, molybdenum and zinc or their mixtures.