Natural Organic Matter (NOM) Transformations and their Effects on Water Treatment Process: A Contemporary Review

One of the several significant concerns related to water treatment plants is the transformation of natural organic matter (NOM) concerning quality and quantity due to the changing climatic conditions. The NOM consists of heterogeneous functionalized groups. Phenolic and carboxyl groups are the dominant groups that are pH-dependent and show a stronger affinity towards the metals. Properties of natural organic matter and trace elements govern the binding kinetics, influencing cations' binding to functionalized groups at lower pH. The water treatment process mechanisms like adsorption, coagulation, membrane filtration, and ion exchange efficiencies are sturdily influenced by the presence of NOM with cations and by the natural organic matter alone. The complexation among the natural organic matter and coagulants enhances the removal of NOM from the coagulation processes. The current review illustrates detailed interactions between natural organic matter and the potential impacts of cations on NOM in the water and wastewater treatment facilities.