Systems include:

• Two-pass RO
• RO followed by continuous electrodeionization (CEDI)
• RO followed by CEDI and ultrafiltration (UF) that may operate continuously hot (80+ degrees C)
• Vapor-compression and multiple-effect distillation

All of these systems have proven effective in producing WFI to meet USP standards.

Read a case study about a biotech firm that successfully used RO for WFI production.