Heterogeneous Fenton-like reaction followed by GAC filtration improved removal efficiency of NOM and DBPs without adjusting pH

This paper explores the removal of natural organic matter (NOM) and disinfection by-products (DBPs) in drinking water by heterogeneous Fenton-like oxidation and granular activated carbon (GAC) filtration in a pilot scale test without adjusting pH of the water. pH of the used water in this study was from 7.5 to 8.7. Comparing with conventional water treatment processes, heterogeneous Fenton-like reaction and GAC filtration increased the removal rate of dissolved organic carbon (DOC), NOM with different apparent molecular weight (AMW) (F1 F7) and with different compositions (C1-C5) to 75.11%, 88.65% and 58.73%, respectively. Moreover, heterogeneous Fenton-like reaction and GAC filtration increased the removal rate of DBPs to 88.18%. The multivariate statistical analysis indicated that haloacetic acids (HAAs) and haloketones (HKs) mainly came from fulvic-like and humic-like NOM with AMW lower than 1.5 K Da. These substances with AMW between 1.5 K Da and 3.5 K Da were the main precursors of trihalomethanes (THMs). The main precursors of halonitriles (HANs) were soluble microbial byproduct-like (SMP-like), tyrosine-like and tryptophan-like substance with the AMW between 3.5 K Da and 4.5 K Da. Overall, without adjusting pH of water, heterogeneous Fenton-like reaction and GAC filtration improved the removal efficiency of NOM and DBPs, and controlled the genotoxicity of drinking water.

Automated summary

This study demonstrates that without adjusting the pH of water, the use of heterogeneous Fenton-like oxidation and GAC filtration can effectively remove NOM and DBPs from drinking water, improving removal efficiency and controlling the genotoxicity of drinking water.