Abstract: Methods and systems are described for treating a fluid that includes a particulate fraction and a soluble fraction, such as wastewater fluid including biosolids. The treatment includes biochemically transforming solids in the particulate fraction of the fluid in a biochemical process while simultaneously subjecting the fluid to a vacuum pressure, and evaporating off at least a portion of the soluble fraction of the fluid and thereby thickening a remaining portion of the fluid. A residence time of the particulate fraction can be controlled to be at least 25% greater than a residence time of the soluble fraction, for example. A solids content of the particulate fraction can be controlled to be in a range of from 2% to 99%, for example.

Abstract: A system and method for treating a fluid that includes a particulate fraction and a soluble fraction includes feeding the fluid to a hydrothermal treatment apparatus and subjecting the fluid to heating to a temperature of 121° C. or more to obtain treated fluid, subsequently feeding the hydrothermally treated fluid to a vacuum-integrated reactor, wherein at least the particulate fraction is subjected to fermentation or digestion, during the fermentation or digestion, subjecting the fluid in the vacuum-integrated reactor to a vacuum pressure, and collecting from the vacuum-integrated reactor at least a portion of the soluble fraction of the fluid as condensate and thereby thickening a remaining portion of the fluid, and recovering thickened fluid from the vacuum-integrated reactor. The vacuum may also be applied upstream or downstream of and separate from a non-vacuum-integrated reactor.

Abstract: Methods and systems are described for treating a fluid that includes a particulate fraction and a soluble fraction, such as wastewater fluid including biosolids. The treatment includes biochemically transforming solids in the particulate fraction of the fluid in a biochemical process while simultaneously subjecting the fluid to a vacuum pressure, and evaporating off at least a portion of the soluble fraction of the fluid and thereby thickening a remaining portion of the fluid. A residence time of the particulate fraction can be controlled to be at least 25% greater than a residence time of the soluble fraction, for example. A solids content of the particulate fraction can be controlled to be in a range of from 2% to 99%, for example.