Influence of eutrophication on the caracterization and coagulation efficiency of natural organic matter

Abstract

Eutrophication is a common problem caused by over enrichment of nitrogen and phosphorous in natural waters. It creates a human health risk for drinking water quality and water used with other purposes. Limits are set in drinking water standards for nitrate but no limit exist for phosphate. The aim of this study is to investigate the influence of eutrophication on the coagulation efficiency of natural organic matter, and to find the effects of the anthropogenic sources of nutrients that lead to eutrophication by algal growth on specific water quality parameters including nitrate, phosphate, along with other inorganic ions and dissolved organic carbon. Simulated water samples which were inocculated with freshwater algae were prepared by taking into account the quality of the natural sources using different combinations of nutrients and humic acid. Samples were then subjected to the application of optimized coagulation for the assessment of natural organic matter removal efficiency of coagulation in natural waters with a specific focus on algae-laden organic matter. The organic matter sample was also assessed through molecular size distribution profiles by ultrafiltration. The results indicated that coagulation resulted in an efficient removal of organic matter, and algal organic matter had both low and high molecular weight fractions, and coagulation treatment shifted the molecular weight distribution of the organic matter sample to lower ranges.|Keywords: Eutrophication, Natural Organic Matter, Drinking Water, Coagulation