Membrane Technology for N-Nitrosamine Compounds Removal from Water: A Critical Review of Experimental and Simulation Practices and Enhancement Opportunities

N-nitrosamine compounds, a disinfection byproduct of chlorination and chloramination in water and wastewater treatment processes, are classified as a probable human carcinogen. The current review focuses on analysing the feasibility of membrane technology while examining the challenges and opportunities in the elimination of N-nitrosamine compounds, particularly NDMA, from wastewater. To systematically attain this goal, this paper uses a systematic literature review that screens and critically assesses peer-reviewed experimental and numerical published papers on N-nitrosamine removal, occasioning in 37 high-quality papers for synthesis. In this regard, a detailed analysis of experimental and numerical studies elaborates that conventional RO membranes often introduce a specific low removal of NDMA from wastewater due to their low molecular weight and neutral charge, which addresses a critical issue. The critical analysis of the experimental and numerical studies depicts that the membrane type, structural properties, and chemical interaction have a key role in the removal of NDMA. To systematically improve the NDMA removal, a wide set of investigations have explored innovative treatment methods, including Nano pore plugging and hydrophilic coatings. This demonstrates potential for improving NDMA removal, albeit at the penalty of reduced water permeability. Additionally, the heat treatment of membranes has attained a notable improvement, ensuing in NDMA rejection of up to 92%. A multi-stage RO configuration model has depicted a maximum NDMA rejection of 93.1%. The future research should focus on investigating possible improvement of NDMA removal from wastewater such as Nano pore plugging and hydrophilic coatings, besides optimising RO configurations and membrane designs with a deeper understanding of membrane fouling.