Effect of organic molecular weight distribution on membrane fouling in an ultrafiltration system with ozone oxidation from the perspective of interaction energy

2017 ◽  
Vol 3 (6) ◽  
pp. 1132-1142 ◽  
Author(s):  
Yiwen Tan ◽  
Tao Lin ◽  
Wei Chen ◽  
Dongju Zhou
Keyword(s):  
Molecular Weight ◽  
Interaction Energy ◽  
Molecular Weight Distribution ◽  
Weight Distribution ◽  
Membrane Fouling ◽  
Ozone Oxidation

In this article, we have discussed the effect of MW distribution on membrane fouling and found the optimal ozone dosage via the XDLVO theory.

Influence and mechanism of different molecular weight organic molecules in natural water on ultrafiltration membrane fouling reversibility

RSC Advances ◽  
2016 ◽  
Vol 6 (86) ◽  
pp. 83456-83465 ◽  
Author(s):  
Weiguang Sun ◽  
Jun Nan ◽  
Jia Xing ◽  
Jiayu Tian
Keyword(s):  
Molecular Weight ◽  
Molecular Weight Distribution ◽  
Natural Water ◽  
Weight Distribution ◽  
Membrane Fouling ◽  
Organic Molecules ◽  
Ultrafiltration Membrane ◽  
Ultrafiltration Membrane Fouling ◽  
Different Molecular Weight

To investigate the influence of different molecular weight distribution to UF membrane fouling, NOM in natural water was fractionated into five components based on their size and their potential to develop the membrane fouling was conducted.

Analysis of organic matter causing membrane fouling in drinking water treatment

2000 ◽  
Vol 41 (10-11) ◽  
pp. 59-67 ◽  
Author(s):  
Y. Kaiya ◽  
Y. Itoh ◽  
S. Takizawa ◽  
K. Fujita ◽  
T. Tagawa
Keyword(s):  
Molecular Weight ◽  
Organic Matter ◽  
Molecular Weight Distribution ◽  
Weight Distribution ◽  
Membrane Fouling ◽  
Drinking Water Treatment ◽  
Gas Chromatography Mass Spectrometry ◽  
Raw Water ◽  
Cleaning Efficiency ◽  
Chemical Cleaning

A study was conducted on characteristics of membrane-fouling matter and chemical cleaning of fouled membranes. The membranes were those used for the filtration of raw water taken from the Lake Kitaura, Ibaraki, Japan. Analysis of the molecular weight distribution of extracted foulants by ultrafilters showed that 23% of organic matter was in the fraction exceeding a molecular weight of 100,000 daltons and 33% between 10,000 to 100,000 daltons. Analysis by gel permeation chromatography (GPC) revealed a void peak and five peaks at a molecular weight of less than 6,000 daltons. Assessment by Fourier transform infrared spectroscopy( FTIR) and pyrolysis gas chromatography mass spectrometry (Py-GC-MS) revealed that organic fouling matter contained polysaccharides, proteins, amino sugars and aromatic compounds that constitute humic substances. A comparison of the apparent molecular weight distribution and the FTIR spectra of both the raw water and fouled membrane extracts revealed the attachment of membrane-fouling matter nonexistent in the raw water, which was considered to be extracellular organic matter. Chemical cleaning of fouled membranes suggested that sodium hypochlorite and hydrogen peroxide were effective for the recovery of membrane permeability. In most of the experiments, the higher the cleaning temperature is between 5°C and 40°C, the more effective the chemical cleaning. However, chemical cleaning by a mixture of 1%-NaOCl and 4%-NaOH showed a comparable cleaning efficiency at 5°C as chemical cleaning at 40°C after two hours.

Extraction and Partial Purification of Protease from Bilimbi (Averrhoa bilimbi L.)

2013 ◽  
Vol 10 (2) ◽  
pp. 29
Author(s):  
Normah Ismail ◽  
Nur' Ain Mohamad Kharoe
Keyword(s):  
Molecular Weight ◽  
Protein Content ◽  
Ammonium Sulfate ◽  
Molecular Weight Distribution ◽  
Weight Distribution ◽  
Protease Activity ◽  
Protein Concentration ◽  
Temperature Stability ◽  
Partial Purification ◽  
Ammonium Sulfate Precipitation

Unripe and ripe bilimbi (Averrhoa bilimbi L.) were ground and the extracted juices were partially purified by ammonium sulfate precipitation at the concentrations of 40 and 60% (w/v). The collected proteases were analysed for pH, temperature stability, storage stability, molecular weight distribution, protein concentration and protein content. Protein content of bilimbi fruit was 0.89 g. Protease activity of both the unripe and ripe fruit were optimum at pH 4 and 40°C when the juice were purified at 40 and 60% ammonium sulfate precipitation. A decreased in protease activity was observed during the seven days of storage at 4°C. Molecular weight distribution indicated that the proteases protein bands fall between IO to 220 kDa. Protein bands were observed at 25, 50 and 160 kDa in both the unripe and ripe bilimbi proteases purified with 40% ammonium sulfate, however, the bands were more intense in those from unripe bilimbi. No protein bands were seen in proteases purified with 60% ammonium sulfate. Protein concentration was higher for proteases extracted with 40% ammonium sulfate at both ripening stages. Thus, purification using 40% ammonium sulfate precipitation could be a successful method to partially purify proteases from bilimbi especially from the unripe stage. 

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