Systems and methods related to desalination systems are described herein. According to some embodiments, the desalination systems are transiently operated and/or configured to facilitate transient operation. In some embodiments, a liquid stream comprising water and at least one dissolved salt is circulated through a fluidic circuit comprising a desalination system. In some embodiments, a portion of the desalination system (e.g., a humidifier) is configured to remove at least a portion of the water from the liquid stream to produce a concentrated brine stream enriched in the dissolved salt. In certain cases, the concentrated brine stream is recirculated through the fluidic circuit until the concentrated brine stream reaches a relatively high density (e.g., at least about 10 pounds per gallon) and/or a relatively high salinity (e.g., a total dissolved salt concentration of at least about 25 wt %). In certain embodiments, additional salt is added to the concentrated brine stream to produce an ultra-high-density brine stream (e.g., a brine stream having a density of at least about 11.7 pounds per gallon). Some aspects relate to a system that is configured to promote energy efficiency by recovering heat from the recirculated concentrated brine stream upon discharge from the fluidic circuit.