Membrane filtration of wastewater effluents for reuse: effluent organic matter rejection and fouling

2001 ◽  
Vol 43 (10) ◽  
pp. 225-232 ◽  
Author(s):  
C. Jarusutthirak ◽  
G. Amy
Keyword(s):  
Organic Matter ◽  
Membrane Filtration ◽  
Treated Wastewater ◽  
High Concentration ◽  
Effluent Organic Matter ◽  
Dead End ◽  
Flux Decline ◽  
Uf Membranes ◽  
Stirred Cell ◽  
Filtration Unit

The reuse of treated wastewater to augment natural drinking water supplies is receiving serious consideration. Treatment of secondary and tertiary effluent by membrane filtration was investigated by assessing nanofiltration (NF) membrane and ultrafiltration (UF) membranes in bench-scale experiments. It was found that secondary and tertiary effluent contained high concentration of effluent organic matter (EfOM), contributing EfOM-related fouling. Flux decline and EfOM rejection tests were evaluated, using a dead-end stirred cell filtration unit. Surface charge and molecular weight cut-off (MWCO) of membranes were significant factors in membrane performance including permeability and EfOM-rejection.

Identification and control of fouling of low-pressure (MF and UF) membranes by drinking-water natural organic matter

2003 ◽  
Vol 3 (5-6) ◽  
pp. 217-222 ◽  
Author(s):  
N. Lee ◽  
G. Amy ◽  
H. Habarou ◽  
J.C. Schrotter
Keyword(s):  
Organic Matter ◽  
Natural Organic Matter ◽  
Membrane Filtration ◽  
Gel Formation ◽  
Flux Decline ◽  
Organic Fouling ◽  
Pore Blockage ◽  
Uf Membranes ◽  
And Control ◽  
Filtration Flux

Natural organic matter (NOM) is responsible for organic fouling during membrane filtration. Flux decline can be affected by the characteristics of the NOM and its interaction with membranes and their associated properties. The results showed that serious flux decline observed for MF membranes may be caused by pore blockage associated with large (macromolecular) hydrophilic molecules. In the case of UF membranes, flux decline may be caused by sequential or simultaneous processes such as cake/gel formation with large (macromolecular) molecules and pore blockage with relatively smaller molecules during filtration. The flux decline tests with representative macromolecules showed that fouling was affected more by the physical characteristics (e.g. size and structure (shape)) of foulants than the characteristics (e.g. hydrophilicity) of foulants.

scholarly journals Potential Pitfalls in Membrane Fouling Evaluation: Merits of Data Representation as Resistance Instead of Flux Decline in Membrane Filtration

Membranes ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 460
Author(s):  
Bastiaan Blankert ◽  
Bart Van der Bruggen ◽  
Amy E. Childress ◽  
Noreddine Ghaffour ◽  
Johannes S. Vrouwenvelder
Keyword(s):  
Membrane Fouling ◽  
Membrane Filtration ◽  
Data Representation ◽  
Strong Impact ◽  
Experimental Conditions ◽  
Permeable Membrane ◽  
Dead End ◽  
Flux Decline ◽  
The Difference ◽  
Filtration Flux

The manner in which membrane-fouling experiments are conducted and how fouling performance data are represented have a strong impact on both how the data are interpreted and on the conclusions that may be drawn. We provide a couple of examples to prove that it is possible to obtain misleading conclusions from commonly used representations of fouling data. Although the illustrative example revolves around dead-end ultrafiltration, the underlying principles are applicable to a wider range of membrane processes. When choosing the experimental conditions and how to represent fouling data, there are three main factors that should be considered: (I) the foulant mass is principally related to the filtered volume; (II) the filtration flux can exacerbate fouling effects (e.g., concentration polarization and cake compression); and (III) the practice of normalization, as in dividing by an initial value, disregards the difference in driving force and divides the fouling effect by different numbers. Thus, a bias may occur that favors the experimental condition with the lower filtration flux and the less-permeable membrane. It is recommended to: (I) avoid relative fouling performance indicators, such as relative flux decline (J/J0); (II) use resistance vs. specific volume; and (III) use flux-controlled experiments for fouling performance evaluation.

Characteristic of algogenic organic matter and its effect on UF membrane fouling

2011 ◽  
Vol 64 (8) ◽  
pp. 1685-1691 ◽  
Author(s):  
T. Li ◽  
B. Z. Dong ◽  
Z. Liu ◽  
W. H. Chu
Keyword(s):  
Organic Matter ◽  
Membrane Fouling ◽  
Membrane Filtration ◽  
Size Exclusion ◽  
Fluorescence Excitation ◽  
Membrane Pore ◽  
Blue Green Algae ◽  
Flux Decline ◽  
Exclusion Chromatography ◽  
Hydrophilic Compound

Algogenic organic matter (AOM) was extracted from blue-green algae (cyanobacteria) and its characteristic was determined by various methods including high-pressure size-exclusion chromatography (HP-SEC), hydrophobic and hydrophilic fractionation, molecular weight (MW) fractionation and fluorescence excitation emission matrix (EEM). The results revealed that AOM was hydrophilic fractionation predominantly, accounting for 78%. The specific ultraviolet absorbance of AOM was 1.1 L/(mg m) only. The analysis for MW distribution demonstrated that organic matter greater than 30,000 MW accounted for over 40% and was composed of mostly neutral hydrophilic compound. EEM analyses revealed that protein-like and humic-substances existed in AOM. A test for membrane filtration exhibited that AOM could make ultrafiltration membrane substantial flux decline, which can be attributed to membrane pore clog caused by neutral hydrophilic compound with larger MW.

scholarly journals Mixing State of Submicrometer Sea Spray Particles Enriched by Insoluble Species in Bubble-Bursting Experiments

2014 ◽  
Vol 31 (1) ◽  
pp. 93-104 ◽  
Author(s):  
Ji Yeon Park ◽  
Sungil Lim ◽  
Kihong Park
Keyword(s):  
Organic Matter ◽  
Membrane Filtration ◽  
Volume Fraction ◽  
Silica Particles ◽  
Artificial Seawater ◽  
Sea Spray ◽  
Natural Seawater ◽  
Mixing State ◽  
High Concentration ◽  
Dissolved Salts

Abstract Measurements of size distribution, hygroscopicity, and volatility of submicrometer sea spray particles produced by the bubble busting of artificial and natural seawater were conducted to determine their mixing state and volume fractions of hygroscopic and nonhygroscopic species or volatile and nonvolatile species. The particles sprayed from artificial seawater having insoluble silica particles were found to be an external mixture of two groups of particles having hygroscopic growth factors (HGFs) of 1.33 (an internal mixture of nonhygroscopic silica particles and hygroscopic salt species) and 1.68 (a similar mixture having more salt species) when the mass ratio of insoluble particles to dissolved salts was higher than 2. For sea spray particles from natural seawater, the external mixing was not significantly observed because of a high concentration of dissolved salts. The HGFs of sea spray particles (80–140 nm) from natural seawater were in the range of 1.70–1.76, which were lower than from pure artificial seawater (1.87), and the HGFs had no change before and after membrane filtration of seawater, suggesting that the sea spray particles from natural seawater contained a significant amount of nonhygroscopic dissolved organic matter in addition to hygroscopic salt species. The volume fraction of the nonhygroscopic species ranged from 20% to 29%, and the highest value was observed for seawater samples from the site where strong biological activity occurred, suggesting that biological materials played an important role in the formation of nonhygroscopic organic matter. Volatility measurements also identified the existence of volatile organic species in single particles from natural seawater, with the volume fraction of volatile species evaporated at 100°C being 4%–5%.

The fouling of ultrafiltration membranes by natural organic matter after chemical coagulation treatment with different initial mixing conditions

2006 ◽  
Vol 6 (4) ◽  
pp. 117-124 ◽  
Author(s):  
H.C. Kim ◽  
J.H. Hong ◽  
S. Lee
Keyword(s):  
Organic Matter ◽  
Natural Organic Matter ◽  
Membrane Fouling ◽  
Membrane Filtration ◽  
Mixing Conditions ◽  
Mechanical Mixing ◽  
Chemical Coagulation ◽  
Flux Decline ◽  
Hydrophobic Fraction ◽  
Hydrophilic Membranes

The flux decline in the UF membrane filtration of water pretreated by chemical coagulation using different initial mixing conditions were compared and the influence of natural organic matter (NOM) on the fouling of membranes was investigated. It was suggested that organic matter in the molecular weight ranges 300–2,000 and 20,000–40,000 Daltons were mainly responsible for the fouling. The fouling was greater for hydrophobic than hydrophilic membranes. ATR-FTIR analysis of the fouled hydrophobic membranes indicated that aliphatic amide and alcoholic compounds as well as polysaccharides contributed to significant membrane fouling. These adsorptive foulants are considered as neutral fractions present in hydrophobic and hydrophilic NOM components. In the case of similar hydrophilic fractions, water precoagulated with a high hydrophobic content resulted in greater flux decline, which was presumed to be due to the organic matter with neutral properties contained within the hydrophobic fraction. The relative concentrations of each NOM fraction in coagulated water are important. Mechanical mixing for chemical coagulation, with a backmixing-type, rather than pump diffusion mixing, with an in-line type, is likely to be more effective at reducing the fouling caused by NOM.

Comparison of sand and membrane filtration as non-chemical pre-treatment strategies for pesticide removal with nanofiltration/low pressure reverse osmosis membranes

2014 ◽  
Vol 14 (4) ◽  
pp. 532-539 ◽  
Author(s):  
Krzysztof P. Kowalski ◽  
Henrik T. Madsen ◽  
Erik G. Søgaard
Keyword(s):  
Organic Matter ◽  
Reverse Osmosis ◽  
Membrane Filtration ◽  
Treatment Strategies ◽  
Low Pressure ◽  
Sand Filtration ◽  
Sand Filter ◽  
Pesticide Removal ◽  
Pre Treatment ◽  
Uf Membranes

Pilot plant investigations of sand and membrane filtration (microfiltration (MF)/ultrafiltration (UF)/nanofiltration (NF)/low pressure reverse osmosis (LPRO)) have been performed to treat groundwater polluted with pesticides. The results show that simple treatment, with use of aeration and sand filtration or MF/UF membranes, does not remove pesticides. However, by reducing the content of key foulants, the techniques can be used as a pre-treatment for nanofiltration and low pressure reverse osmosis that has proved to be capable of removing pesticides. It was found that a lower fouling potential could be obtained by using the membranes, but that sand filter was better at removing manganese and dissolved organic matter. The results indicate that combining aeration, sand filtration and membrane techniques might be a good option for pesticide removal without any addition of chemicals and minimized membrane maintenance.

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