Natural Organic Matter Removal in Surface Water Treatment via Coagulation-Current Issues, Potential Solutions, and New Findings

Considerable changes have been observed in surface waters' quality in recent years. They include an increase in dissolved organic carbon (DOC) concentrations, as well as a shift of natural organic matter (NOM) composition in favor of low molecular weight (LMW), and they are expected to occur on a wider scale in the future. Those predictions are particularly worrying given the importance of surface water as the main potable water source for numerous communities across the globe. Conventional methods of surface water treatment for drinking purposes mostly focus on the process of coagulation. The progressing changes in the quality of surface waters, however, render the conventional treatment via coagulation inefficient. The issue of the presence of natural organic matter in drinking water sources, its anticipated changes, and the related treatment problems are all complex and pressing matters that need addressing. This paper aims to provide a critical review of recent findings regarding NOM removal via coagulation in reference to the current NOM-related issues and their potential solutions. The paper discusses the application of different types of coagulants, and their respective advantages and disadvantages. Coagulation-integrated processes including adsorption, membrane filtration, biological processes, and oxidation are also addressed. Lastly, insights on the future approach to the discussed issues and conclusions are presented.

Automated summary

Considerable changes have been observed in recent years in surface waters' quality, such as an increase in dissolved organic carbon (DOC) concentrations and a shift in natural organic matter (NOM) composition towards low molecular weight (LMW), and these changes are expected to occur on a larger scale in the future. Given that surface water is the main source of potable water for many communities globally, these predictions are particularly concerning. Traditional treatment methods for surface water using coagulation are becoming inefficient due to the evolving water quality. The presence of natural organic matter in drinking water sources, its anticipated changes, and the related treatment problems are complex and urgent issues that require attention.