Dewatering processes, such as carpet dewatering in the textile industry and pulp dewatering in the paper industry, are excellent opportunities for incorporating current rotary-lobe blower technology, and improving system efficiency and lowering operating costs. A rotary-lobe, positive-displacement blower set up for vacuum operation and coupled with a moisture separator before the blower provides a new dewatering method that is more energy efficient and significantly more controllable. In dewatering applications, the rotary-lobe blower acts as a vacuum pump but does not require water for sealing and cooling. Some pumps in wet processes require water that must be continuously introduced and circulated. Additionally, because this water mixes with the process contaminants, the resulting liquids must be treated. Even a closed-loop sealing water system does not completely eliminate make-up water and there are costs to pump, filter, and cool the seal water. The absence of sealing water when using a rotary-lobe blower offers significant cost savings by reducing process water and water treatment costs.