Direct coagulation pretreatment in nanofiltration of waters rich in organic matter and calcium

2001 ◽  
Vol 1 (4) ◽  
pp. 25-33
Author(s):  
A. I. Schäfer ◽  
A.G. Fane ◽  
T.D. Waite
Keyword(s):  
Organic Matter ◽  
Natural Organic Matter ◽  
Surface Waters ◽  
Process Efficiency ◽  
Nanofiltration Membranes ◽  
Multivalent Ions ◽  
Flux Decline ◽  
Calcium Complexes ◽  
The Impact ◽  
Significant Flux

Nanofiltration (NF) can remove natural organic matter (NOM) and multivalent ions from surface waters. Large hydrophobic organics and calcium ions are responsible for irreversible fouling of nanofiltration membranes and thus a decrease of process efficiency and increase in cleaning requirements. Fouling due to the precipitation of organic-calcium complexes and the impact of colloids and coagulant (FeCl3) on the precipitation of these species was investigated. Coagulation in solution (as opposed to in the boundary layer) did not cause significant flux decline and was able to prevent irreversible fouling under conditions which were previously determined as detrimental. The rejection was varied if a strongly charged solid was deposited on the membrane.

Natural organic matter removal and flux decline with charged ultrafiltration and nanofiltration membranes

2011 ◽  
Vol 376 (1-2) ◽  
pp. 179-187 ◽  
Author(s):  
Hongchen Song ◽  
Jiahui Shao ◽  
Yiliang He ◽  
Juan Hou ◽  
Wenpo Chao
Keyword(s):  
Organic Matter ◽  
Natural Organic Matter ◽  
Nanofiltration Membranes ◽  
Organic Matter Removal ◽  
Flux Decline

Fouling of a polyethersulfone ultrafiltration membrane by natural organic matter

2004 ◽  
Vol 4 (4) ◽  
pp. 205-212 ◽  
Author(s):  
G. Makdissy ◽  
J.-P. Croué ◽  
G. Amy ◽  
H. Buisson
Keyword(s):  
Natural Organic Matter ◽  
Surface Waters ◽  
Membrane Fouling ◽  
Adsorption Mechanism ◽  
Transmembrane Pressure ◽  
Membrane Flux ◽  
Dead End ◽  
Flux Decline ◽  
Hydrophilic Fraction ◽  
Significant Flux

This research focused on membrane flux decline trends observed during ultrafiltration (UF) of solutions of NOM fractions isolated from surface waters. All filtration experiments were performed with a non-stirred dead-end cell unit equipped with flat sheet polyethersulfone PES UF membrane coupons under a constant transmembrane pressure of 1 bar. Results showed that the most significant flux decline was due to the organic colloid fraction, a hydrophilic fraction consisting mostly of bacterial cell wall residues. This research demonstrated that these colloids which incorporate 2/3 of dissolved organic structures (<0.45 μm) and 1/3 of particulate organics exert strong fouling properties due to both rejection phenomena and the adsorption mechanism. The fouling contribution by humic-like materials depends on their origin and nature. Aromaticity appears to be a secondary parameter which influences membrane fouling. Polysaccharides, proteins and amino sugars also largely present in humic-like structures (supramolecular structure) play an important role in UF membrane fouling. The perspective of NOM as a biopolymer mixture can contribute to an understanding of membrane fouling.

scholarly journals Groundwater nanofiltration process efficiency improvement with additional concentrate membrane treatment

2016 ◽  
Vol 70 (5) ◽  
pp. 501-509 ◽  
Author(s):  
Miroslav Kukucka ◽  
Nikoleta Kukucka
Keyword(s):  
Waste Water ◽  
Drinking Water ◽  
Organic Matter ◽  
Natural Organic Matter ◽  
Membrane Surface ◽  
Process Efficiency ◽  
Transmembrane Pressure ◽  
Nanofiltration Membranes ◽  
Water Plant ◽  
Concentrate Yield

Nanofiltration (NF) of waste water originated from nanofiltration drinking water plant stationed in town of Kikinda (Northern Serbia) was investigated. Experiments on removal characteristics of nanofiltration membranes when exposed to influent rich in arsenic and natural organic matter under different flux and transmembrane pressure (TMP) conditions were conducted in order to obtain drinking water from waste water and reduce total amount of waste water. Applied NF membranes showed remarkable removal characteristic. Also, obtained result for concentrate yield, an indicator of reduced concentrate amount, of 8.89% under optimum flux value presents considerable amount of reclamated drinking water. Calculated empirical and theoretical concentration factors quotients were indicated to probable accumulation of some inlet water components at NF membrane surface. Based on the obtained results that nanofiltration membranes remove natural organic matter, arsenic, ammonia and sodium with high efficiencies of 98%, 96%, 80% and 93% respectively, conceptual design of drinking water plant for City of Kikinda was defined and presented.

Long-term performance of biological ion exchange for the removal of natural organic matter and ammonia from surface waters

2018 ◽  
Vol 146 ◽  
pp. 1-9 ◽  
Author(s):  
Nargess Amini ◽  
Isabelle Papineau ◽  
Veronika Storck ◽  
Pierre R. Bérubé ◽  
Madjid Mohseni ◽  
...  
Keyword(s):  
Organic Matter ◽  
Ion Exchange ◽  
Natural Organic Matter ◽  
Surface Waters ◽  
Long Term Performance ◽  
Term Performance

Investigation of membrane fouling by synthetic and natural particles

2004 ◽  
Vol 50 (12) ◽  
pp. 279-285 ◽  
Author(s):  
J.H. Kweon ◽  
D.F. Lawler
Keyword(s):  
Organic Matter ◽  
Natural Organic Matter ◽  
Membrane Fouling ◽  
Membrane Surface ◽  
Research Articles ◽  
Clay Material ◽  
Dramatic Effect ◽  
Flux Decline ◽  
Scanning Electron

The biggest impediment for applying membrane processes is fouling that comes from mass flux (such as particle and organic matter) to the membrane surface and its pores. Numerous research articles have indicated that either particles or natural organic matter (NOM) has been the most detrimental foulant. Therefore, the role of particles in membrane fouling was investigated with two synthetic waters (having either particles alone or particles with simple organic matter) and a natural water. Membrane fouling was evaluated with flux decline behavior and direct images from scanning electron microscopy. The results showed that the combined fouling by kaolin and dextran (a simple organic compound selected as a surrogate for NOM) showed no difference from the fouling with only the organic matter. The similarity might stem from the fact that dextran (i.e., polysaccharide) has no ability to be adsorbed on the clay material, so that the polysaccharide behaves the same with respect to the membrane with or without clay material being present. In contrast to kaolin, the natural particles showed a dramatic effect on membrane fouling.

Comparison of disinfection byproduct (DBP) formation from different UV technologies at bench scale

2002 ◽  
Vol 2 (5-6) ◽  
pp. 515-521 ◽  
Author(s):  
W. Liu ◽  
S.A. Andrews ◽  
J.R. Bolton ◽  
K.G. Linden ◽  
C. Sharpless ◽  
...  
Keyword(s):  
Organic Matter ◽  
Carboxylic Acids ◽  
Natural Organic Matter ◽  
Uv Irradiation ◽  
Direct Action ◽  
Disinfection Byproduct ◽  
Pressure Medium ◽  
The Impact ◽  
As Effects

The impact of UV irradiation on disinfection byproduct (DBP) formation was investigated for low pressure, medium pressure and pulsed UV technologies using a broad range of UV doses. Four classes of DBPs (THMs, HAAs, aldehydes and carboxylic acids) were examined. This enabled the determination of effects resulting from the direct action of UV irradiation on natural organic matter (aldehydes, carboxylic acids) as well as effects on the ultimate formation of chlorinated DBPs (THMs and HAAs) from secondary chlorination. For doses of less than 1,000 mJ/cm2, UV irradiation did not affect THM and HAA formation in subsequent chlorination processes, however higher UV doses resulted in lower ultimate concentrations of THMs and HAAs. UV irradiation also resulted in the formation of aldehydes and carboxylic acids at UV doses above 500 mJ/cm2, compounds that are known to adversely effect drinking water biostability.

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