Imperial College London
Portrait Picture

Emeritus ProfessorNigelGraham

Faculty of Engineering, Department of Civil and Environmental Engineering

Senior Research Investigator
 
 
 
//

Contact

 

n.graham Website

 
 
//

Assistant

 

Miss Judith Barritt +44 (0)20 7594 5967

 
//

Location

 

406Skempton BuildingSouth Kensington Campus

//

Summary

 

Publications

Citation

BibTex format

@article{Siddique:2023:10.1016/j.scitotenv.2023.162695,
author = {Siddique, MS and Lu, H and Xiong, X and Fareed, H and Graham, N and Yu, W},
doi = {10.1016/j.scitotenv.2023.162695},
journal = {Science of the Total Environment},
title = {Exploring impacts of water-extractable organic matter on pre-ozonation followed by nanofiltration process: Insights from pH variations on DBPs formation},
url = {http://dx.doi.org/10.1016/j.scitotenv.2023.162695},
volume = {876},
year = {2023}
}
Download

RIS format (EndNote, RefMan)

TY  - JOUR
AB  - This study investigated the influence of pH (4-10) on the treatment of water-extractable organic matter (WEOM), and the associated disinfection by-products (DBPs) formation potential (FP), during the pre-ozonation/nanofiltration treatment process. At alkaline pH (9-10), a rapid decline in water flux (> 50 %) and higher membrane rejection was observed, as a consequence of the increased electrostatic repulsion forces between the membrane surface and organic species. Parallel factor analysis (PARAFAC) modeling and size exclusion chromatography (SEC) provides detailed insights into the WEOM compositional behavior at different pH levels. Ozonation at higher pH significantly reduced the apparent molecular weight (MW) of WEOM in the 4000-7000 Da range by transforming the large MW (humic-like) substances into small hydrophilic fractions. Fluorescence components C1 (humic-like) and C2 (fulvic-like) exhibited a predominant increase/decrease in concentration for all pH conditions during pre-ozonation and nanofiltration treatment process, however, the C3 (protein-like) component was found highly associated with the reversible and irreversible membrane foulants. The ratio C1/C2 provided a strong correlation with the formation of total trihalomethanes (THMs) (R2 = 0.9277) and total haloacetic acids (HAAs) (R2 = 0.5796). The formation potential of THMs increased, and HAAs decreased, with the increase of feed water pH. Ozonation markedly reduced the formation of THMs by up to 40 % at higher pH levels, but increased the formation of brominated-HAAs by shifting the formation potential of DBPs towards brominated precursors.
AU  - Siddique,MS
AU  - Lu,H
AU  - Xiong,X
AU  - Fareed,H
AU  - Graham,N
AU  - Yu,W
DO  - 10.1016/j.scitotenv.2023.162695
PY  - 2023///
SN  - 0048-9697
TI  - Exploring impacts of water-extractable organic matter on pre-ozonation followed by nanofiltration process: Insights from pH variations on DBPs formation
T2  - Science of the Total Environment
UR  - http://dx.doi.org/10.1016/j.scitotenv.2023.162695
UR  - https://www.ncbi.nlm.nih.gov/pubmed/36898544
UR  - http://hdl.handle.net/10044/1/107845
VL  - 876
ER  -
Download