Abstract:
In this study, the effect of pre-treatment of flocculation followed by adsorption on the performance
of nanofiltration (NF) was investigated using biologically treated sewage effluent and synthetic
wastewater. The organic rejection and permeate flux were studied using a nanofilter module (NTR-
729HF: Nitto Denko Corp., negative surface electric charge, polyvinylalcohol material, and 0.44 nm
pore size) operated at a low pressure. Long term NF experiments were conducted with synthetic
wastewater. The crossflow NF results indicated that the operation at low pressure of 150 kPa and
300 kPa was feasible without permeate flux decline (at 0.06 and 0.175 m3/m2·d, respectively) for 50
days. The TOC removal efficiency was approximately 92%.
A detailed study conducted with biologically treated sewage effluent indicated that the pretreatment of
flocculation followed by adsorption improved the normalized flux (JJo) from 0.69 to 0.99 and the
TOC removal efficiency from 78% to 88%.
