Dishwasher appliances are provided. A dishwasher appliance includes a tub defining a chamber for the receipt of articles for cleaning, a sump for collecting liquid from the chamber, a fluid circulation conduit for circulating liquid in the tub, and a first pump downstream of and in fluid communication with the sump. The dishwasher appliance further includes an adsorption assembly, the adsorption assembly including a desiccant module and an adsorption conduit extending through the desiccant module. The dishwasher appliance further includes a second pump downstream of and in fluid communication with the adsorption conduit, the second pump further upstream of the sump. The dishwasher appliance further includes a first heater spaced from the adsorption assembly, the first heater operable to heat liquid flowed therethrough from the first pump.