Application of coagulation–ultrafiltration hybrid process for drinking water treatment: Optimization of operating conditions using experimental design

2009 ◽  
Vol 65 (2) ◽  
pp. 193-210 ◽  
Author(s):  
A.W. Zularisam ◽  
A.F. Ismail ◽  
M.R. Salim ◽  
Mimi Sakinah ◽  
T. Matsuura
Catalysts ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 521
Author(s):  
Fernando J. Beltrán ◽  
Ana Rey ◽  
Olga Gimeno

Formation of disinfection byproducts (DBPs) in drinking water treatment (DWT) as a result of pathogen removal has always been an issue of special attention in the preparation of safe water. DBPs are formed by the action of oxidant-disinfectant chemicals, mainly chlorine derivatives (chlorine, hypochlorous acid, chloramines, etc.), that react with natural organic matter (NOM), mainly humic substances. DBPs are usually refractory to oxidation, mainly due to the presence of halogen compounds so that advanced oxidation processes (AOPs) are a recommended option to deal with their removal. In this work, the application of catalytic ozonation processes (with and without the simultaneous presence of radiation), moderately recent AOPs, for the removal of humic substances (NOM), also called DBPs precursors, and DBPs themselves is reviewed. First, a short history about the use of disinfectants in DWT, DBPs formation discovery and alternative oxidants used is presented. Then, sections are dedicated to conventional AOPs applied to remove DBPs and their precursors to finalize with the description of principal research achievements found in the literature about application of catalytic ozonation processes. In this sense, aspects such as operating conditions, reactors used, radiation sources applied in their case, kinetics and mechanisms are reviewed.


2013 ◽  
Vol 777 ◽  
pp. 467-471 ◽  
Author(s):  
Liang Wang ◽  
Ying Chun Li ◽  
He Zhao ◽  
Zhao Hui Zhang ◽  
Bin Zhao ◽  
...  

Calcium ions, magnesium ions, and silicate were the main reasons for the high silting density index (SDI) of natural waters. Therefore, they posed serious membrane fouling problems in the nanofiltration (NF) system, which restricted the wide application of this excellent drinking water treatment technology. In this study, the sand filtration and the micro-flocculation/sand filtration hybrid process were investigated as the pretreatment process of NF for SDI reduction. Compared with the sand filtration, the hybrid process of micro-flocculation/sand filtration was more effective for SDI reduction. When polyaluminium chloride (PAC) was used as the flocculant at a dose of 10 mg/L and the filtration rate of the sand filter was controlled at 10 m/h, the SDI value in the effluent of the pretreatment process maintained below 3. As a result, the subsequent NF system stably ran for one year. 68% CODMn was removal by NF. The membrane fouling during the operation was quite slight as the transmembrane pressure (TMP) increased by 17% after one-year use. Chemical cleaning with sodium tripolyphosphate (2%) and sodium dodecyl benzene sulfonate (0.25%) at 6 months interval could effectively recover the flux loss of the NF membrane.


2017 ◽  
Vol 66 ◽  
pp. 210-220
Author(s):  
Rahma Fakhfekh ◽  
Elodie Chabanon ◽  
Denis Mangin ◽  
Raja Ben Amar ◽  
Catherine Charcosset

2006 ◽  
Vol 6 (4) ◽  
pp. 89-98 ◽  
Author(s):  
A. Loi-Brügger ◽  
S. Panglisch ◽  
P. Buchta ◽  
K. Hattori ◽  
H. Yonekawa ◽  
...  

A new ceramic membrane has been designed by NGK Insulators Ltd., Japan, to compete in the drinking water treatment market. The IWW Water Centre, Germany, investigated the operational performance and economical feasibility of this ceramic membrane in a one year pilot study of direct river water treatment with the hybrid process of coagulation and microfiltration. The aim of this study was to investigate flux, recovery, and DOC retention performance and to determine optimum operating conditions of NGK's ceramic membrane filtration system with special regards to economical aspects. Temporarily, the performance of the ceramic membrane was challenged under adverse conditions. During pilot plant operation river water with turbidities between 3 and 100 FNU was treated. Membrane flux was increased stepwise from 80–300 l/m2h resulting in recoveries between 95.9 and 98.9%. A DOC removal between about 20–35% was achieved. The pilot study and the subsequent economical evaluation showed the potential to provide a reliable and cost competitive process option for water treatment. The robustness of the ceramic membrane filtration process makes it attractive for a broad range of water treatment applications and, due to low maintenance requirements, also suitable for drinking water treatment in developing countries.


2011 ◽  
Vol 11 (1) ◽  
pp. 23-29 ◽  
Author(s):  
P. M. Huck ◽  
S. Peldszus ◽  
C. Hallé ◽  
H. Ruiz ◽  
X. Jin ◽  
...  

Fouling remains one of the major constraints on the use of low pressure membranes in drinking water treatment. Work over the last few years has shown the importance of biopolymers (carbohydrates and protein-like material) as foulants for ultrafiltration (UF) membranes. The purpose of this study was to investigate at pilot scale the use of rapid biofiltration (without prior coagulation or ozone addition) as an innovative pretreatment to reduce fouling of UF membranes. The investigation was carried out on a water with a higher than average DOC and significant temperature variation. The biofilters, each operated at a hydraulic loading of 5 m/h, had empty bed contact times of 5, 10 and 15 minutes. The membrane unit was operated at a flux equivalent to 60 LMH at 20°C. The investigation confirmed the encouraging results obtained in an earlier smaller scale study with essentially the same water. Increased biofiltration contact time (i.e. increased bed depth) led to lower rates of hydraulically irreversible fouling. The initial biofiltration backwash procedure, involving air scour as is common in chemically assisted filtration, led in some cases to an increased rate of membrane fouling immediately after the backwash. An alternative backwashing strategy was developed, however the feasibility of operating with this approach over very long periods of time needs to be confirmed. To assist in full-scale implementation of this “green” and simple pretreatment, the design and operating conditions for the biofilters should be optimized for various types of waters. It is expected that biofiltration pretreatment will be of particular interest for small and/or isolated systems where a higher initial capital cost may be acceptable because of operational simplicity and reduced chemical requirements.


2014 ◽  
Vol 64 ◽  
pp. 226-236 ◽  
Author(s):  
Carson O. Lee ◽  
Rasmus Boe-Hansen ◽  
Sanin Musovic ◽  
Barth Smets ◽  
Hans-Jørgen Albrechtsen ◽  
...  

2012 ◽  
Vol 12 (2) ◽  
pp. 148-156
Author(s):  
C. Sun ◽  
L. Fiksdal

The biofouling of an ultrafiltration (UF) membrane unit applied for drinking water treatment was investigated under three different operating conditions, i.e. flux 50, 60 and 70 L m−2 h−1. The biofouling was monitored by analyzing the enzyme (esterase and peptidase) activity on the sacrificed membrane fibers of a test unit installed in the same reactor as the membrane pilot module. At a given flux, a decrease of membrane permeability generally corresponded to an increase of enzyme activity. Enzyme activity could therefore be used to predict the permeability decline and potentially be used for e.g. at-line monitoring of membrane biofouling.


Sign in / Sign up

Export Citation Format

Share Document