24VDC Centrifugal and Diaphragm Pumps

Hi! 

We are currently manufacturing a small scale wastewater treatment plant (1000 L/day) and I am looking to procure 4 pumps that must be powered via 24 VDC power with flow rates ranging between 300 to 2200 L/h. 

Could you please advise where I can procure these pumps?