Application of a fractionation technique for better understanding of the removal of natural organic matter by alum coagulation

2002 ◽  
Vol 2 (5-6) ◽  
pp. 427-433 ◽  
Author(s):  
J. van Leeuwen ◽  
C. Chow ◽  
R. Fabris ◽  
N. Withers ◽  
D. Page ◽  
...  
Keyword(s):  
Organic Matter ◽  
Natural Organic Matter ◽  
High Performance ◽  
Relative Proportion ◽  
Water Source ◽  
Size Exclusion ◽  
Gas Chromatography Mass Spectrometry ◽  
Pyrolysis Gas ◽  
Alum Treatment ◽  
Hydrophobic Acids

To gain an improved understanding of the types of organic compounds that are recalcitrant to water treatment, natural organic matter (NOM) isolates from two drinking water sources (Mt. Zero and Moorabool reservoirs, Victoria, Australia) were separated into fractions of distinct chemical behaviour using resins. Four fractions were obtained from each water source and were organics absorbed to: (1) XAD-8 (very hydrophobic acids, VHA); (2) DAX-4 (slightly hydrophobic acids, SHA); (3) bound to an anion exchange resin (charged organics, CHAR); and (4) not absorbed or bound to resins (neutrals, NEUT). These fractions were then tested to determine the capacity of alum to remove them from water and to correlate this with the character of each isolate. The fractions were characterised by the application of high performance size exclusion chromatography (HPSEC), bacterial regrowth potential (BRP), trihalomethane formation potential (THMFP), pyrolysis gas-chromatography mass spectrometry (Py-GC-MS) and thermochemolysis. The highest removals of dissolved organic carbon (DOC) by alum treatment were in waters spiked with the CHAR fractions while the NEUT fractions were the most recalcitrant. The number average molecular weights (Mn) of DOC of the CHAR fractions before treatment were the highest, whilst those of the NEUT fractions were the lowest. After alum treatment, the Mn of the NEUT fractions were only slightly reduced. Results from Py-GC-MS and thermochemolysis indicate that the NEUT fractions had the highest relative proportion of saccharide derived organic material. Nonetheless, the BRP of waters spiked with the NEUT fractions differed markedly, indicating that organics recalcitrant to alum treatment can vary substantially in their chemical composition and capacity to support microbial growth.

The Impact of the Character of Natural Organic Matter in Conventional Treatment with Alum

1999 ◽  
Vol 40 (9) ◽  
pp. 97-104 ◽  
Author(s):  
C. W. K. Chow ◽  
J. A. van Leeuwen ◽  
M. Drikas ◽  
R. Fabris ◽  
K. M. Spark ◽  
...  
Keyword(s):  
High Performance ◽  
Conventional Treatment ◽  
Test Procedure ◽  
Water Source ◽  
Size Exclusion ◽  
Gas Chromatography Mass Spectrometry ◽  
Pyrolysis Gas ◽  
Jar Test ◽  
Freeze Dried ◽  
The Impact

The objective of this study was to determine if the removal of NOM in reservoir waters in conventional treatment with alum is limited by the character of the NOM. A sequential jar test procedure, which included five treatment steps was employed to study the character of the NOM which could not be removed by flocculation/sedimentation. The NOM in the raw and treated waters was characterised by techniques including dissolved organic carbon (DOC), UV absorbance (UVA), high performance size exclusion chromatography (HPSEC), pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS) and diffuse reflectance Fourier transform infrared spectroscopy (DRIFT). HPSEC analysis of the reservoir waters from three sources indicated that the organic fraction remaining after alum treatment was of lower molecular weight than that in the original raw waters. Pyrolysis of freeze dried material (FDM) from one raw water source (Hope Valley Reservoir) and following treatment with a high alum dose at pH 5 (coagulated and non coagulated material) gave by-products that indicated the presence of proteins, polyhydroxyaromatics and polysaccharides.

Humification of effluent organic matters through a surface-flow constructed wetland

2013 ◽  
Vol 68 (8) ◽  
pp. 1785-1794 ◽  
Author(s):  
Kyongmi Chon ◽  
Jongkwan Park ◽  
Jaeweon Cho
Keyword(s):  
Organic Matter ◽  
High Performance ◽  
Treatment Plant ◽  
Surface Flow ◽  
Size Exclusion ◽  
Gas Chromatography Mass Spectrometry ◽  
Treatment Wetland ◽  
Pyrolysis Gas ◽  
Organic Matters ◽  
Exclusion Chromatography

Dominant fractions of wastewater effluent organic matter (EfOM) were changed from polysaccharides (PS) to polyhydroxyaromatics (PHA), throughout the constructed treatment wetland connected to a wastewater treatment plant, as measured using pyrolysis gas chromatography-mass spectrometry (Py-GC/MS). The changes in the fractions were also identified, with respect to molecular weight (MW) distributions of the effluent organic matters, as measured using high performance size exclusion chromatography equipped with both UV and fluorescence detectors, for aromatic/hydrophobic and protein-like organic substances, respectively; organic matter, with MWs of approximately 2,500 and 20,000 Da, and approximately 38,000 Da, as measured by the UV and fluorescence detectors, respectively, were newly formed after the wetlands, especially for the samples of the Typha wetland in June and August against in December. Thus, with the above two different analyses, the humification type of transformation of EfOM through the treatment wetland, was believed to occur, probably due to biological transformation (from the comparison of results in June and August with those in December). It was anticipated that the humification of EfOM could reduce biodegradable organic portions of wastewater effluents even though total organic carbon levels were not reduced that much after the treatment wetland.

Evaluation of drinking water treatment processes focusing on natural organic matter removal and on disinfection by-product formation

2002 ◽  
Vol 2 (5-6) ◽  
pp. 459-464 ◽  
Author(s):  
S. Chae
Keyword(s):  
Drinking Water ◽  
Organic Matter ◽  
Water Treatment ◽  
Natural Organic Matter ◽  
High Performance ◽  
Drinking Water Treatment ◽  
Molecular Size ◽  
Product Formation ◽  
Size Exclusion ◽  
Activated Carbon Adsorption

The aim of this study was to characterize and compare natural organic matter (NOM) removal and disinfection by-product (DBP) formation in the drinking water treatment train that can give valuable information, while optimizing the treatment process. In this study, the determination of the hydrophobic (HPO), transphilic (THP) and hydrophilic (HPI) NOM distribution was used in parallel with more related drinking water parameters to compare the selected waters. High-performance size-exclusion chromatography (HPSEC) was applied to evaluate the relative changes of molecular size distribution of NOM in different treatment steps and source waters. This showed that the quantity, speciation and activated carbon adsorption of DBPs could vary not only by water quality, but also by the distribution and properties of the organic molecules that comprise NOM.

Characterization of River Natural Organic Matter by High-Performance Size Exclusion Chromatography

2015 ◽  
Vol 48 (18) ◽  
pp. 2936-2946 ◽  
Author(s):  
Dong Jin Lee ◽  
Jun Gu Gang ◽  
Su Young Lee ◽  
Ik Won Choi ◽  
Kang Min Chun ◽  
...  
Keyword(s):  
Organic Matter ◽  
Natural Organic Matter ◽  
Size Exclusion Chromatography ◽  
High Performance ◽  
Size Exclusion ◽  
Exclusion Chromatography

Experimental Evaluation of Cationic Polyelectrolytes for Removing Natural Organic Matter from Water

1999 ◽  
Vol 40 (9) ◽  
pp. 71-79 ◽  
Author(s):  
Brian Bolto ◽  
Gudrun Abbt-Braun ◽  
David Dixon ◽  
Rob Eldridge ◽  
Fritz Frimmel ◽  
...  
Keyword(s):  
Organic Matter ◽  
Charge Density ◽  
Natural Organic Matter ◽  
Molecular Size ◽  
Cationic Polyelectrolyte ◽  
Size Exclusion ◽  
Cationic Polymers ◽  
Treatment Processes ◽  
Exclusion Chromatography ◽  
Alum Treatment

The effectiveness of water treatment processes in removing natural organic matter varies with the nature of the natural organic matter (NOM), its molecular size, polarity and charge density, and with properties of the raw water such as turbidity and hardness. In some cases conventional alum treatment is inefficient. We have compared NOM removals achieved by conventional and polymer-based processes in bench-scale treatment of reconstituted ground and surface waters of varying colour, made from NOM isolated from the same waters. NOM isolates were fractionated by adsorption on non-functionalised resins and an anion exchanger, and characterised by size exclusion chromatography. Jar tests with the isolated NOM compared coagulation with polyelectrolytes, alum, clays and metal oxides, with each of the inorganics being in conjunction with a polyelectrolyte. Jar tests on reconstituted waters with alum and/or cationic polyelectrolyte show synergistic benefits from combinations of the two. The more hydrophobic NOM fractions were the most easily removed by polymer. The performance of cationic polymers improved significantly with increasing charge density and molecular weight. An alum/polymer combination is the most attractive treatment option.

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