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.

scholarly journals Fouling analysis of polysulfone ultrafiltration membranes used for drinking water treatment

2011 ◽  
Vol 11 (6) ◽  
pp. 668-674 ◽  
Author(s):  
B. Q. Zhao ◽  
C. P. Huang ◽  
S. Y. Chen ◽  
D. S. Wang ◽  
T. Li ◽  
...  
Keyword(s):  
Drinking Water ◽  
Organic Matter ◽  
Water Treatment ◽  
Fulvic Acid ◽  
Humic Substances ◽  
Natural Organic Matter ◽  
Drinking Water Treatment ◽  
Ultrafiltration Membranes ◽  
Fluorescence Excitation ◽  
Hydrophobic Fraction

Natural organic matter (NOM) plays a significant role in the fouling of ultrafiltration membranes in drinking water treatment processes. For a better understanding of the interaction between fractional components of NOM and polysulfone (PS) ultrafiltration membranes used for drinking water treatment, fouling and especially the physically irreversible fouling of natural organic matter were investigated. Resin fractionation, fluorescence excitation–emission matrix (EEM) spectroscopy, fourier transform infrared spectroscopy (FTIR), contact angle and a scanning electron microscope (SEM) were employed to identify the potential foulants. The results showed that humic acid and fulvic acid of small size were likely to permeate the membrane, while the hydrophobic fraction of humic and fulvic acid and aromatic proteins tended to be rejected and retained. Organic compounds such as proteins, humic substances, and polysaccharide-like materials, were all detected in the fouling layer. The physically irreversible fouling of the PS membrane seemed to be mainly attributed to the hydrophobic fraction of humic substances.

Contributions of spatial, temporal, and treatment impacts on natural organic matter character using fluorescence-based measures

2015 ◽  
Vol 15 (3) ◽  
pp. 589-598
Author(s):  
Nicolás M. Peleato ◽  
Robert C. Andrews
Keyword(s):  
Organic Matter ◽  
Water Treatment ◽  
Fluorescence Spectroscopy ◽  
Natural Organic Matter ◽  
Rayleigh Scattering ◽  
Treatment Plant ◽  
Principal Component ◽  
Fluorescence Excitation ◽  
Polyaluminum Chloride ◽  
Fluorescence Methods

The potential application of fluorescence spectroscopy for monitoring of organic matter concentration and character at four water treatment facilities was investigated. Results are presented showing impacts on natural organic matter (NOM) due to intake location on the same water body and from individual unit processes including ozonation, granular-activated carbon filtration, and coagulation/flocculation. For validation and comparison of fluorescence methods, organic matter was quantified and characterized using liquid chromatography-organic carbon detection (LC-OCD). Principal component analysis (PCA) and parallel factors analysis were used for dimensionality reduction and to represent individual organic components observed through fluorescence excitation-emission matrices. Fluorescence results generally agreed with LC-OCD characterization, indicating that complete treatment reduced organic concentrations and preferential removal of humic-like material was associated with coagulation/flocculation. PCA results indicated higher concentrations of humic-like material at the Island water treatment plant intake that was not well reduced by inline polyaluminum chloride coagulation and direct filtration. Through fluorescence spectroscopy, ozonation increased Rayleigh scattering, which is correlated to small colloidal/particulate concentrations. Full-scale results from four water treatment plants presented demonstrate that fluorescence methods can characterize NOM, providing similar identification of trends to LC-OCD, with possible online application and use in real-time water treatment process control.

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

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.

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