scholarly journals NOM removal and residual Al minimization by enhanced coagulation: roles of sequence dosing with PACl–FeCl3

2020 ◽  
Vol 69 (6) ◽  
pp. 616-628
Author(s):  
Ming-Han Tsai ◽  
Lap-Cuong Hua ◽  
Kochin Huang ◽  
Chihpin Huang
Keyword(s):  
Organic Matter ◽  
Water Treatment ◽  
Natural Organic Matter ◽  
Clean Water ◽  
Polyaluminum Chloride ◽  
Enhanced Coagulation ◽  
Water Treatment Plants ◽  
Promising Application ◽  
Residual Al ◽  
Single Dosing

Abstract To remove higher proportions of natural organic matter (NOM) in water treatment plants, over dosing of Al-based coagulant is frequently applied. However, this leads to the risk of an excess of coagulant residue in the clean water. In this study, sequential coagulation with polyaluminum chloride (PACl) and FeCl3 was proposed to improve the removal of NOM as well as to minimize residual Al. Single dosing with either PACl or FeCl3 in particular was compared with sequential coagulation, with different dosing sequences of PACl–FeCl3 (P–F) or FeCl3–PACl (F–P). At optimum dosage, sequential coagulation P–F showed twice as much dissolved organic carbon (DOC) removal from water containing algogenic organic matter, compared to single dosing of PACl and sequential coagulation F–P. However, sequential coagulation F–P was the most effective approach for humic substance removal that improved DOC removal up to >70% compared to other dosing approaches (<60%). Practical treatment with real water also showed the advantages of sequential coagulation with P–F in improving the removal of low SUVA NOM by 18% compared to the traditional single dosing of PACl. As expected, the Al residues found in both sequential coagulation (0.07 mg/L) were significantly reduced compared to single dosing with PACl (0.15 mg/L), indicating the promising application of sequential coagulation for future safe water treatment.

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

scholarly journals Monitoring the characteristics and removal of natural organic matter fractions in selected South African water treatment plants

2020 ◽  
Vol 15 (4) ◽  
pp. 932-946
Author(s):  
Welldone Moyo ◽  
Nhamo Chaukura ◽  
Machawe M. Motsa ◽  
Titus A. M. Msagati ◽  
Bhekie B. Mamba ◽  
...  
Keyword(s):  
Organic Matter ◽  
Water Treatment ◽  
Natural Organic Matter ◽  
Specific Treatment ◽  
Ultra Violet ◽  
Correlation Spectroscopy ◽  
Operational Parameters ◽  
Gaussian Peak ◽  
Coastal Plants ◽  
Water Treatment Plants

Abstract This study used spectroscopic methods to investigate the fate and dynamics of natural organic matter (NOM) as it traverses the treatment train at three water treatment plants (WTPs) in South Africa. The character, quantity, and removability of NOM at specific treatment stages was investigated by measuring changes in dissolved organic carbon (DOC) concentration, specific ultra-violet absorbance, UV absorbance, various spectroscopic indices, and maximum fluorescence intensity levels. A novel method of identifying and quantifying fluorescent fractions by combining synchronous fluorescence spectroscopy (SFS) and Gaussian peak fitting is presented. The dynamics of NOM removal were modeled using 2D-SFS correlation spectroscopy. Humic and fulvic substances dominated coastal plants and were the most amenable for removal by coagulation as shown by Hermanus WTP (plant H), which had a 42% DOC removal at the coagulation stage. Tyrosine-like, tryptophan-like and microbial humic-like substances were degraded or transformed concurrently at plant Flag Bushiole (FB) whereas, at plant H, fulvic-like matter was transformed first followed by tyrosine-like then humic-like matter. Through 2D-SFS, this study revealed that NOM transformation was varied as a consequence of NOM character, the type and dosage of treatment chemicals used, and WTPs operational parameters.

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.

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.

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