Removal of trihalomethanes from water using nanofiltration membranes

Trihalomethanes (THMs) are dominant and well-known disinfection by-products (DBPs). The THMs formation and removal from water as well as the parameters influencing their formation and removal using nanofiltration (NF) membranes are presented in this paper. Molecular weight cutoff (MWCO) of membrane, materials used in making a membrane, concentration of THMs, transmembrane pressure, and co-pollutants play significant role in THMs formation and removal from water. Membranes with higher MWCO generally have lower removal efficiency compared to those with lower MWCO. Higher removal of natural organic matters (NOM), which is a precursor for THMs formation from water using NF membranes resulted in reduced THMs up to 99%. Higher hydrophobicity of membranes results in higher THMs rejection due to hydrophobic-hydrophobic interaction between the membranes and THMs molecules. Increase in THMs concentrations result in increasing rejection of THMs.