Performance of a GAC and ultrafiltration hybrid process under high humidity and temperature conditions

The performance of a granular activated carbon (GAC) and ultrafiltration (UF) hybrid process and changes in UF membrane properties were studied. This hybrid process reduced total organic carbon by 59 ± 12% and UV absorbance (UV₂₅₄) by 88 ± 31%, with GAC accounting for 93 and 98% of total reduction, respectively. Selected pharmaceuticals and personal care products were reduced by 32–92% during the hybrid process. Particles, bacteria and invertebrates were reduced by 98–99, 76–92 and 100%, respectively during the hybrid process. No invertebrates, including rotifers, cyclops and cladocera, were detected in the effluent of the hybrid process. Trans-membrane pressure (TMP) and membrane roughness increased while specific flux (SFLUX) decreased with prolonged operation time. Contact angle increased from 59 ± 1.2° to 70 ± 2.0° after one operation cycle, and then decreased to 66 ± 1.2° after ten cycles. Chemical enhanced backwashing was more effective to reduce TMP, increase SFLUX and control roughness and contact angle than backwashing by water. Membrane fouling not only changed roughness and contact angle, but also affected the removal of organics.