TOC removal in reclamation of municipal wastewater by RO

A pilot study on total organic carbon (TOC) removal in reclamation of municipal wastewater by RO has been conducted in Singapore. Secondary effluent from final clarifier was used as a feed to the system. RE4040-FL and RE4040-FE RO membranes from Saehan were applied in the study. The pilot results showed that on-line TOC measurements of the RO permeate were in range of 36-66 ppb for RE4040-FL membrane at operating pressure of 60 psi. For RE4040-FE membrane, they were in the range of 32-44 and 30-36 ppb at operating pressure of 70 and 107 psi, respectively. The low TOC level of the reclaimed water does not appear to be reported previously for the application of RO in reclamation of municipal wastewater. TOC and salt rejections of the RE4040-FE membrane were over 99.5 and 97.8%, respectively. The permeate quality and salt rejections of RE4040-FE membrane were better than that of RE4040-FL, which was comparable to High Grade Water (NEWater) quality.