Characteristics of natural organic matter removed from water along with its treatment

Abstract

The object of this study was to examine the nature of natural organic matter (NOM) removed on each stage of water treatment train used in the "Mokry Dwór" Wrocław Water Treatment Plant (WTP) and to compare obtained results with water treatment efficiencies achieved with the use of membrane ultrafiltration, ion-exchange and UF/ion-exchange integrated processes. In the experiments fractional analysis with the use of polymeric resins (DAX-8, XAD-4 and IRA-958) was used. Obtained results have shown that most (56%) of the raw water NOM was found in fraction characterized by presence of humic and fulvic acids (VHA and SHA fractions). VHA fraction made the most of DOC removed in examined water treatment train and coagulation was mainly responsible for this effect. Integrated process consisting of MIEX ® DOC ion exchange and PES 10 kDa ultrafiltration turned out to be very effective at high molecular weight hydrophobic compounds removal from water being much less efficient with hydrophilic compounds.

The effectiveness of organic matter removal in unit processes of the technological groundwater treatment system

“…humic, fulvic and humic acids) and high molecular weight carboxylic acids [11]. Literature reports indicate that in water treated for drinking purpose, the content of the hydrophobic fraction may range from 56% to as much as 79% of DOC [3][4][5][6][7]11]. In the structure of both NOM fractions, fundamental differences are observed.…”

“…Change in the content of NOM fraction in unit processes of the technological system. The research carried out by [11] showed that in the removal of dissolved organic compounds, the most effective was the coagulation process, where the removal of DOC in 40.1% was observed. The biofiltration process removed only 6.3% DOC.…”

“…The studies were carried out according to the fractionation method described in the work [11]. The fractionation procedure involved the sorption of organic compounds present in water on three polymeric resins type: Supelite DAX-8, Amberlite XAD-4 and Amberlite IRA-958.…”

“…One of the basic methods allowing to characterize NOM is the fractionation method using polymeric resins. This procedure allows to estimate the content of fractions such as: (1) very hydrophobic acids (VHA), (2) slightly hydrophobic acids (SHA), (3) hydrophilic charged compounds (CHA) and (4) hydrophilic neutral compounds (NEU) [11][12][13].…”

Biostability of Tap Water—A Qualitative Analysis of Health Risk in the Example of Groundwater Treatment (Semi-Technical Scale)

“…The effectiveness of removing organic pollutants on active carbon beds has been confirmed by numerous studies [15,19,[26][27][28][29]. Conventional water treatment systems eliminate natural organic substances up to 40% [11,21,24], while systems extended by biofiltration, depending on the time of biofilter exploitation, achieve from 24-100% [15,19,[30][31][32].…”