Optimization of Chemical Cleaning for Improvement of Membrane Performance and Fouling Control in Drinking Water Treatment

2015 ◽  
Vol 50 (12) ◽  
pp. 1835-1845 ◽  
Author(s):  
R. Bogati ◽  
C. Goodwin ◽  
K. Marshall ◽  
K. T. Leung ◽  
B. Q. Liao
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Drinking Water Treatment ◽  
Chemical Cleaning ◽  
Membrane Performance ◽  
Fouling Control

scholarly journals Improving chemical cleaning of fouled membranes in a drinking water treatment plant

2019 ◽  
Vol 19 (8) ◽  
pp. 2330-2337
Author(s):  
Susumu Hasegawa ◽  
Yasuhiro Tanaka ◽  
Naokazu Wake ◽  
Ryosuke Takagi ◽  
Hideto Matsuyama
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Humic Substances ◽  
Sodium Hypochlorite ◽  
Membrane Fouling ◽  
Treatment Plant ◽  
Drinking Water Treatment ◽  
Water Treatment Plant ◽  
Chemical Cleaning ◽  
Water Treatment Plants

Abstract Recently, membrane filtration systems have become increasingly common in drinking water treatment plants. In this industry, preventing membrane fouling is of utmost importance. Many studies on the relationship between raw water components and membrane fouling have been performed in laboratory conditions. However, very few studies have analyzed the components of foulants on the fouled membrane as operated in actual drinking water treatment plants. By analyzing these components in plant-conditions, membrane fouling will be more effectively prevented. In this study, we analyzed the components of foulants extracted with 0.1 N NaOH from a fouled membrane operated in a drinking water treatment plant in Japan. Our analysis revealed that the main foulants were humic substances. In order to dissolve the accumulated humic substances, additional chemical cleaning was attempted with 500 ppm sodium hypochlorite. As a result, it was found that humic substances were dissolved and filtration resistance significantly decreased. Additionally, the removal of inorganic foulants was also greater after chemical cleaning with 500 ppm sodium hypochlorite, as inorganic foulants trapped within humic substances were released to the membrane surface as hydroxides by the additional sodium hypochlorite cleaning and were dissolved by the periodic citric acid cleaning.

Characterization of hydraulically reversible and irreversible fouling species in ultrafiltration drinking water treatment systems using fluorescence EEM and LC–OCD measurements

2013 ◽  
Vol 13 (5) ◽  
pp. 1220-1227 ◽  
Author(s):  
R. H. Peiris ◽  
M. Jaklewicz ◽  
H. Budman ◽  
R. L. Legge ◽  
C. Moresoli
Keyword(s):  
Drinking Water ◽  
Particulate Matter ◽  
Citric Acid ◽  
Water Treatment ◽  
Lake Water ◽  
Drinking Water Treatment ◽  
Metal Species ◽  
Chemical Cleaning ◽  
Membrane Cleaning

The application of the fluorescence excitation-emission matrix (EEM) approach and liquid chromatography–organic carbon detection (LC–OCD) analysis for the characterization of hydraulically reversible and irreversible fouling species, extracted from hollow fiber ultrafiltration (UF) membranes used in drinking water treatment, was demonstrated. Hydraulically reversible and irreversible fouling species were extracted from two pilot UF membrane systems operated in parallel with lake water as the feed. Two membrane cleaning protocols, hydraulic- and chemical-based (NaOCl and citric acid) cleaning, were considered. Colloidal/particulate matter together with protein-like and metal species in water appeared to contribute to the formation of a hydraulically removable fouling layer on the membranes. Hydraulically irreversible fouling, in contrast, was impacted considerably by humic substances (HS) and protein-like matter. The formation of an irreversible fouling layer was also likely influenced by interactions between the colloidal/particulate matter and metal species together with HS and protein-like matter. LC–OCD analysis revealed the presence of predominant levels of lower molecular weight HS-like matter – compared to the HS-like matter commonly present in lake water – in the citric acid extracted foulant fraction. The permeability loss due to hydraulically irreversible UF fouling was considerably greater than the permeability loss due to hydraulically reversible UF fouling. A permanent permeability loss (∼25–35% of the initial permeability) was present even after the application of considerably strong chemical cleaning protocols on both pilot systems. This study indicated that the fluorescence EEM approach can be applied for monitoring and characterization of membrane cleaning procedures and as a potential diagnostic tool for assessing the effectiveness of hydraulic- and chemical-based cleaning protocols employed in UF drinking water treatment operations using rapid off-line measurements. On the other hand, since the LC–OCD analysis technique is a comparatively time consuming method, it may be used for verification of the fluorescence EEM-based results of the foulant fractions.

Application of microfiltration for reuse of backwash water in a conventional water treatment plant - a case study

2001 ◽  
Vol 1 (5-6) ◽  
pp. 199-206 ◽  
Author(s):  
H. Song ◽  
X. Fan ◽  
Y. Zhang ◽  
T. Wang ◽  
Y. Feng
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Treatment Plant ◽  
Drinking Water Treatment ◽  
Water Treatment Plant ◽  
Transmembrane Pressure ◽  
Total Production ◽  
Chemical Cleaning ◽  
Direct Filtration ◽  
Filter Backwash Water

In conventional drinking water treatment processes, the amount of the filter backwash water covers nearly 3% of the total production. To reduce the water loss and waste discharge in the conventional drinking water treatment process, the Macao Water Supply Co. Ltd (SAAM) plans to recover the backwash water by Microfiltration (MF) membrane process as water resources are scarce and new environmental regulations are mandated in Macao. Generally, the filter backwash water from the conventional water treatment plant with sedimentation process is recycled to the source water to be treated again under certain conditions, and the sedimentation tank discharges most of the sludge. However, it is possible to recycle the backwash water directly to the inlet for direct filtration process due to the limitation of inlet turbidity. This paper describes how to apply MF technology to treat the backwash water of the direct filtration plant and to optimize MF operation. Without pre-treatment of the settling basin for backwash water, the operation of the MF pilot plant is proved to be stable and the permeate quality can meet EU drinking water standards. The pilot study shows that it is both economically and technically feasible to adopt MF technology in backwash water treatment. The main parameters to test MF process include flux, chemical cleaning duration and transmembrane pressure (TMP). They are 150-200 L/m2.h, 20 days and <1 bar respectively. The estimated cost including O&M and investment for a 1320-1760 m3/d backwash water treatment plant is USD 0.126-0.168/m3.

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