Natural Organic Matter (NOM)
Boreal surface waters contain high amount of dissolved and colloidal natural organic matter (NOM) from natural sources. In spite of improved water treatment processes the residual NOM is still a problem and may cause several problems in drinking water quality and distribution system, taste and odor, bacterial regrowth and formation of disinfection by-products. We have studied the occurrence, concentration and characteristic of NOM by conventional analytical techniques as well as by advanced chromatographic and spectrophotometric methods. Removal of natural organic matter in the different stages of the drinking water treatment processes has also been determined in our studies.
One of the most common research topic among the M.Sc thesis has been the enhancement of the NOM removal in the drinking water treatment process. The removal of dissolved high molecular matter is relatively complete by chemical coagulation but intermediate or small molecular matter is difficult to be removed. The smallest molecular weight fraction of dissolved NOM is so hydrophilic that traditional treatment techniques, which are based on the coagulation/flocculation followed by solid separation, are ineffective. A major problem has been competition kinetics of micro- and macropollutants when the micropollutants occur at trace level in natural organic/inorganic matrix. Following processes have been studied by WWE research team in order to enhance the removal of residual NOM: artificial groundwater research, enhanced coagulation, ozonation, advanced oxidation and nanofiltration.
Researchers
Hilda Szabo
Tuula Tuhkanen