The characterisation of natural organic matter (NOM) in South African waters

2012 ◽  
Vol 12 (5) ◽  
pp. 648-657
Author(s):  
T. I. Nkambule ◽  
R. W. M. Krause ◽  
J. Haarhoff ◽  
B. B. Mamba
Keyword(s):  
Organic Matter ◽  
Water Treatment ◽  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Humic Substances ◽  
South African ◽  
Natural Organic Matter ◽  
Water Samples ◽  
Sand Filtration ◽  
Water Treatment Plants

The removal of natural organic matter (NOM) from water is becoming increasingly important in order to prevent the formation of carcinogenic disinfection by-products (DBPs). The inadequate removal of NOM has a bearing on the capacity of other treatment processes to remove organic micro-pollutants or inorganic species that may be present in water. In order to effectively study the nature of South African water sources in terms of their NOM composition, water samples were collected from drinking water treatment plants in the five geographic water regions of South Africa. A raw water sample, an intermediate sample taken before sand filtration and a final sample after sand filtration were collected three times from these water treatment plants at two-month intervals and over three different seasons. Fluorescence excitation-emission matrices (FEEM), biodegradable dissolved organic carbon (BDOC), ultraviolet (UV) characterisation (200–900 nm) and dissolved organic carbon (DOC) analyses were used to characterise the NOM in the water samples. The FEEM and UV results revealed that the samples were composed mainly of non-humic substances with low UV-254 absorbance, while some samples had high humic substances with high UV-254 values. The samples' DOC results were within the range of 3.25–21.44 mg/L carbon, which was indicative of the varying nature of the NOM composition in the regions where samples were collected. The BDOC fraction of the NOM, on the other hand, ranged from 20 to 65%, depending on the geographical location of the sampling site.

scholarly journals Natural organic matter removal by ion exchange at different positions in the drinking water treatment lane

2013 ◽  
Vol 6 (1) ◽  
pp. 1-10 ◽  
Author(s):  
A. Grefte ◽  
M. Dignum ◽  
E. R. Cornelissen ◽  
L. C. Rietveld
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Organic Matter ◽  
Water Treatment ◽  
Organic Carbon ◽  
Natural Organic Matter ◽  
Drinking Water Treatment ◽  
Biological Stability ◽  
Sand Filtration ◽  
Slow Sand Filtration

Abstract. To guarantee a good water quality at the customers tap, natural organic matter (NOM) should be (partly) removed during drinking water treatment. The objective of this research was to improve the biological stability of the produced water by incorporating anion exchange (IEX) for NOM removal. Different placement positions of IEX in the treatment lane (IEX positioned before coagulation, before ozonation or after slow sand filtration) and two IEX configurations (MIEX® and fluidized IEX (FIX)) were compared on water quality as well as costs. For this purpose the pre-treatment plant at Loenderveen and production plant Weesperkarspel of Waternet were used as a case study. Both, MIEX® and FIX were able to remove NOM (mainly the HS fraction) to a high extent. NOM removal can be done efficiently before ozonation and after slow sand filtration. The biological stability, in terms of assimilable organic carbon, biofilm formation rate and dissolved organic carbon, was improved by incorporating IEX for NOM removal. The operational costs were assumed to be directly dependent of the NOM removal rate and determined the difference between the IEX positions. The total costs for IEX for the three positions were approximately equal (0.0631 € m−3), however the savings on following treatment processes caused a cost reduction for the IEX positions before coagulation and before ozonation compared to IEX positioned after slow sand filtration. IEX positioned before ozonation was most cost effective and improved the biological stability of the treated water.

An urban water cycle perspective of natural organic matter (NOM): NOM in drinking water, wastewater effluent, storm water, and seawater

2008 ◽  
Vol 8 (6) ◽  
pp. 701-707 ◽  
Author(s):  
S. A. Baghoth ◽  
S. K. Maeng ◽  
S. G. Salinas Rodríguez ◽  
M. Ronteltap ◽  
S. Sharma ◽  
...  
Keyword(s):  
Drinking Water ◽  
Organic Matter ◽  
Surface Water ◽  
Organic Carbon ◽  
Humic Substances ◽  
Natural Organic Matter ◽  
Water Samples ◽  
Soil Column ◽  
Wastewater Effluent ◽  
Size Exclusion

Natural organic matter (NOM) occurs throughout the hydrologic cycle, varying in both amount and character. In this paper, a description of NOM in surface and drinking water, in groundwater and in seawater is presented. Water samples representing these environments were collected and characterized using multiple NOM characterization techniques, including fluorescence excitation emission matrices (F-EEM) and size exclusion liquid chromatography with organic carbon detection (LC-OCD). The results show that the raw surface water as well as the treated water comprises mainly (>70%) of humic substances. The biopolymers, which are more readily biodegradable, contribute up to 2% of the NOM in the raw water but this is completely removed after treatment. For sea water samples, humic substances represent about 50% of the dissolved organic carbon concentration (DOC), while the fraction with size bigger than 20 kDa (biopolymers) represents about 7%. During soil passage, there was preferential removal of non-humic substances (i.e., biopolymers) from wastewater effluent-impacted surface water while the specific ultraviolet absorbance (SUVA), which reflects the aromatic characteristics of organics in a sample, showed an increasing trend along the depth of the soil column. This is a consequence of the removal of non-humic substances (biopolymers) which results in an increase in aromaticity.

PARAFAC model as an innovative tool for monitoring natural organic matter removal in water treatment plants

2020 ◽  
Vol 81 (8) ◽  
pp. 1786-1796 ◽  
Author(s):  
Sikelelwa N. Ndiweni ◽  
Michael Chys ◽  
Nhamo Chaukura ◽  
Stijn W. H. Van Hulle ◽  
Thabo T. I. Nkambule
Keyword(s):  
Organic Matter ◽  
Water Treatment ◽  
South African ◽  
Natural Organic Matter ◽  
Principal Component ◽  
Drinking Water Treatment ◽  
Fluorescence Excitation ◽  
Factors Affecting ◽  
Water Treatment Plants ◽  
Filter Clogging

Abstract The increase of fluorescent natural organic matter (fNOM) fractions during drinking water treatment might lead to an increased coagulant dose and filter clogging, and can be a precursor for disinfection by-products. Consequently, efficient fNOM removal is essential, for which characterisation of fNOM fractions is crucial. This study aims to develop a robust monitoring tool for assessing fNOM fractions across water treatment processes. To achieve this, water samples were collected from six South African water treatment plants (WTPs) during winter and summer, and two plants in Belgium during spring. The removal of fNOM was monitored by assessing fluorescence excitation–emission matrices datasets using parallel factor analysis. The removal of fNOM during summer for South African WTPs was in the range 69–85%, and decreased to 42–64% in winter. In Belgian WTPs, fNOM removal was in the range 74–78%. Principal component analysis revealed a positive correlation between total fluorescence and total organic carbon (TOC). However, TOC had an insignificant contribution to the factors affecting fNOM removal. Overall, the study demonstrated the appearance of fNOM in the final chlorinated water, indicating that fNOM requires a customised monitoring technique.

The occurrence of natural organic matter in South African water treatment plants

2019 ◽  
Vol 31 ◽  
pp. 100809 ◽  
Author(s):  
Pfano Tshindane ◽  
Phumlile P. Mamba ◽  
Lerato Moss ◽  
Umhle U. Swana ◽  
Welldone Moyo ◽  
...  
Keyword(s):  
Organic Matter ◽  
Water Treatment ◽  
South African ◽  
Natural Organic Matter ◽  
Water Treatment Plants ◽  
South African Water

Advanced oxidation processes: flowsheet options for bulk natural organic matter removal

2004 ◽  
Vol 4 (4) ◽  
pp. 113-119 ◽  
Author(s):  
C.A. Murray ◽  
S.A. Parsons
Keyword(s):  
Molecular Weight ◽  
Organic Matter ◽  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Natural Organic Matter ◽  
Advanced Oxidation Processes ◽  
Advanced Oxidation ◽  
Fenton’S Reagent ◽  
Fenton's Reagent ◽  
Oxidation Processes

Advanced oxidation processes have been reported to have the potential to remove natural organic matter from source waters. Of these Fenton's reagent, photo-Fenton's reagent and titanium dioxide photocatalysis are the three most promising processes. Compared to conventional coagulation/flocculation processes they have higher removal efficiencies in terms of both dissolved organic carbon and UV254 absorbance. Under optimum reaction conditions all three remove over 80% dissolved organic carbon and 0% UV254 absorbance. In addition the enhanced removal of natural organic matter leads to a corresponding reduction in the formation of disinfection by-products following chlorination of the treated water. Advanced oxidation processes give enhanced removal of organic species ranging from low to high molecular weight while coagulation/flocculation is inefficient at removing low molecular weight species. One additional benefit is all three processes produce less residuals compared to conventional coagulation, which is advantageous as the disposal of such residuals normally contributes a large proportion of the costs at water treatment works.

Determination of Hydrophobic and Hydrophilic Fractions of Natural Organic Matter in Raw Water of Jalalieh and Tehranspars Water Treatment Plants (Tehran)

2007 ◽  
Vol 7 (18) ◽  
pp. 2651-2655 ◽  
Author(s):  
M.A. Zazouli ◽  
S. Nasseri . ◽  
A.H. Mahvi . ◽  
A.R. Mesdaghinia . ◽  
M. Younecian . ◽  
...  
Keyword(s):  
Organic Matter ◽  
Water Treatment ◽  
Natural Organic Matter ◽  
Raw Water ◽  
Water Treatment Plants
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