Increasing the separation of N-nitrosamines by modifying RO membranes using molecular plugs – linear amines and diamines

Authors: MOROVIC SILVIA, KOSUTIC KRESIMIR

Company/ Institution: Faculty of Chemical Engineering and Technology

Country: Croatia

e-mail: smorovic@fkit.unizg.hr; kkosutic@fkit.unizg.hr

web: https://www.fkit.unizg.hr/

The rapid expansion of urban areas and the increasing demand for water resources require the application of advanced technologies in the treatment of potable and process waters, which also enable the reuse of municipal wastewater for various purposes. Nonetheless, numerous challenges remain, particularly regarding disinfection by-products, especially carcinogenic compounds such as N-nitrosamines (NTRs). To tackle the ongoing issues associated with reverse osmosis (RO) membranes, this inovation aimed to improve rejection rates of NTRs by integrating molecular plugs into the nanopores of the polyamide layer of commercially available RO membranes. Linear chain amines and diamines have

been used as molecular plugs for enhancing the removal of NTRs. The application of molecular plugs led to decrease in membrane permeability (from 4-47″/”), while maintaining levels suitable for RO processes. Linear chain amines and diamines had a positive effect on NTR rejection with tested RO membranes. In particular, N-nitrosodimethyamine (NDMA) rejection, the smallest and a particularly dangerous compoundof the tested NTRs, was improved by 71%  and 70.6% after treatment with linear chain amine and diamine, respectively.