Effect of SiO2 nanoparticles on the removal of natural organic matter (NOM) by coagulation

Abstract

In order to evaluate effect of engineered nanoparticles on the removal of natural organic matter (NOM), ENPs water sample (WATER_NP), and common water sample (WATER_COMMON) were prepared by mixing the SiO2 nanoparticles (SiO2 NPs, 50 nm) and common SiO2 particles (2 [mu]m) with water from Xiaoqing River. The removal variation, NOM fractionation, flocs properties, and IR spectra were investigated after polyaluminum chloride (PAC) coagulation. The results revealed that although the removal efficiencies of turbidity and NOM from WATER_NP were moderately lower than those from WATER_COMMON, the fluorescence intensities of soluble microbial byproduct-like, humic acid-like, and aromatic protein II in coagulated WATER_NP were lower than that in coagulated raw water and WATER_COMMON. What's more, flocs of WATER_NP showed the smallest size and highest fractal dimension as compared with other water samples, except for those obtained at B=2.0.