Pilot study on nanofiltration membrane in advanced treatment of drinking water

Abstract

Abstract In this study, nanofiltration (NF) was used to further treat the water from the disinfection process of a drinking water treatment plant (DWTP). The results indicate that the NF process reduced the dissolved organic carbon (DOC) by 92.87%, UV absorbance at 254 nm (UVA254) by 88.68%, conductivity by 94% and total dissolved solids by 94.49%. The removal efficiencies of trihalomethanes (THMs), 2-methylisoborneol (2-MIB) and trans-1,10-dimethyl-trans-9-decalol (geosmin) were also evaluated for both the DWTP and NF treatment processes. High-performance size-exclusion chromatography (HPSEC) analysis, three-dimensional excitation–emission matrix (3D-EEM) fluorescence spectroscopy and parallel factor (PARAFAC) analysis were applied to characterize the changes in different organic compounds in each process. A correlation analysis was carried out for samples of the raw water, feed water and permeate water to determine the correlations between the maximum fluorescence intensities (Fmax) of the PARAFAC components and the DOC, UVA254 and high specific UV absorbance (SUVA) of the samples. The results showed that a significant correlation (p < 0.01) existed between UVA254 and the Fmax of the three PARAFAC components as well as between DOC and Fmax.