Investigation of membrane fouling by synthetic and natural particles

2004 ◽  
Vol 50 (12) ◽  
pp. 279-285 ◽  
Author(s):  
J.H. Kweon ◽  
D.F. Lawler

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.

2014 ◽  
Vol 1073-1076 ◽  
pp. 751-754
Author(s):  
Jun Xia Liu ◽  
Bing Zhi Dong ◽  
Wei Wei Huang

The main objective of this study was to investigate membrane fouling caused by natural organic matter (NOM). Flux measurement, fourier transform spectroscopy (FTIR), scanning electron microscopy (SEM) were employed to compare the surface morphology of fouled membrane and chemically cleaned membrane. Sodium hypochlorite (NaClO), sodium hydroxide (NaOH), hydrochloric acid (HCl) were used as chemical cleaning agents respectively. Flux analysis demonstrated that chemical cleaning have little effect on flux recovery. FTIR spectrometry revealed that polysaccharide and protein took the major responsibility for membrane fouling. SEM showed that foulants filled the pores and blocked the membrane surface which led to the flux decline.


2004 ◽  
Vol 4 (5-6) ◽  
pp. 215-222 ◽  
Author(s):  
A.R. Costa ◽  
M.N. de Pinho

Membrane fouling by natural organic matter (NOM), namely by humic substances (HS), is a major problem in water treatment for drinking water production using membrane processes. Membrane fouling is dependent on membrane morphology like pore size and on water characteristics namely NOM nature. This work addresses the evaluation of the efficiency of ultrafiltration (UF) and Coagulation/Flocculation/UF performance in terms of permeation fluxes and HS removal, of the water from Tagus River (Valada). The operation of coagulation with chitosan was evaluated as a pretreatment for minimization of membrane fouling. UF experiments were carried out in flat cells of 13.2×10−4 m2 of membrane surface area and at transmembrane pressures from 1 to 4 bar. Five cellulose acetate membranes were laboratory made to cover a wide range of molecular weight cut-off (MWCO): 2,300, 11,000, 28,000, 60,000 and 75,000 Da. Severe fouling is observed for the membranes with the highest cut-off. In the permeation experiments of raw water, coagulation prior to membrane filtration led to a significant improvement of the permeation performance of the membranes with the highest MWCO due to the particles and colloidal matter removal.


Membranes ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 968
Author(s):  
Zhun Ma ◽  
Lu Zhang ◽  
Ying Liu ◽  
Xiaosheng Ji ◽  
Yuting Xu ◽  
...  

The fouling mechanism of the anion exchange membrane (AEM) induced by natural organic matter (NOM) in the absence and presence of calcium ions was systematically investigated via the extended Derjaguin–Landau–Verwey–Overbeek (xDLVO) approach. Sodium alginate (SA), humic acid (HA), and bovine serum albumin (BSA) were utilized as model NOM fractions. The results indicated that the presence of calcium ions tremendously aggravated the NOM fouling on the anion exchange membrane because of Ca-NOM complex formation. Furthermore, analysis of the interaction energy between the membrane surface and foulants via xDLVO revealed that short-range acid–base (AB) interaction energy played a significant role in the compositions of interaction energy during the electrodialysis (ED) process. The influence of NOM fractions in the presence of calcium ions on membrane fouling followed the order: SA > BSA > HA. This study demonstrated that the interaction energy was a dominating indicator for evaluating the tendency of anion exchange membranes fouling by natural organic matter.


2019 ◽  
Vol 5 (12) ◽  
pp. 2242-2250
Author(s):  
Xue Shen ◽  
Baoyu Gao ◽  
Kangying Guo ◽  
Qinyan Yue

Coagulation prior to the ultrafiltration (UF) process was implemented to improve natural organic matter (NOM) removal and membrane permeability.


2006 ◽  
Vol 6 (2) ◽  
pp. 25-30 ◽  
Author(s):  
M. Koh ◽  
M.M. Clark ◽  
K.P. Ishida

Rejection by membrane adsorption has been observed and widely reported. However, little is known about whether membranes possess an adsorption capacity. Experimental data showed that when a hydrophobic polypropylene (PP) microfilter was used to filter a large volume of particle-free surface water containing dissolved natural organic matter (NOM), later batches of microfiltration (MF) permeate caused more flux decline to a fresh 20K-Dalton polyethersulfone (PES) ultrafilter. This suggests that membranes can have an adsorption capacity for foulants. In this research, the gradual increase in absorbance of ultraviolet (UV) light by subsequent batches of MF permeate was observed, and supports the findings from previous studies, that only a small fraction of NOM causes membrane fouling. Attenuated total reflectance Fourier transform infrared spectrometry and energy dispersive spectroscopy of fouled PP and PES membranes suggests foulants containing amide, aromatic, ether, hydroxyl and silicate functional groups. Silicates appear to participate in membrane fouling, and its removal with the small fraction of fouling NOM can reduce the fouling potential of water. These data improve our understanding of membrane fouling by natural waters, and have implications for the design of membrane plants that filter natural waters.


2006 ◽  
Vol 6 (4) ◽  
pp. 117-124 ◽  
Author(s):  
H.C. Kim ◽  
J.H. Hong ◽  
S. Lee

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.


2003 ◽  
Vol 3 (5-6) ◽  
pp. 155-164 ◽  
Author(s):  
J.-M. Laîné ◽  
C. Campos ◽  
I. Baudin ◽  
M.-L. Janex

Since the first membrane applications at the end of the 1980s, the water treatment engineering community has been able to develop reliable low pressure membrane systems that are capable of producing high quality drinking water at a competitive price, making membrane technology an attractive solution to both upgrade existing plants and design new ones. A competitive price means low capital and operating cost, which are inversely proportional to membrane hydraulic performance (permeate flux). Porous membranes lose their hydraulic performance as materials accumulate on their surfaces and/or within their pores, a process called membrane fouling. Although a significant effort has been devoted to elucidating the fouling mechanisms of polymeric membranes by natural organic matter (NOM), no single model has yet been accepted. In fact, most of the existing literature is contradictory, showing that membrane fouling is far from being fully understood. This article reviews over a decade of Ondeo's experience on characterizing and preventing fouling of polymeric membranes by natural organic matter and inorganic compounds. The review focuses on the role of NOM size and hydrophobicity, of membrane chemistry, and of solution pretreatment (coagulation and/or adsorption). In addition, the efficacy of some currently used strategies to minimize membrane fouling is also discussed.


2002 ◽  
Vol 2 (5-6) ◽  
pp. 367-371 ◽  
Author(s):  
M. Ribau Teixeira ◽  
H. Lucas ◽  
M.J. Rosa

The effect of the pH on the ultrafiltration performance of natural surface waters with moderate NOM content was evaluated at a laboratory scale using a plate-and-frame polysulphone membrane of 47 kDa MWCO. The results at three different pH values (acid, neutral and basic) demonstrated the important role of the pH on the ultrafiltration (UF) performance controlling the membrane - fouling matter interactions. The higher fluxes and lower natural organic matter (NOM) rejections obtained, at basic pH when compared to acid pH, are explained in terms of the variation of membrane and NOM charge, due to electrostatic repulsion and adsorption effects.


2015 ◽  
Vol 17 (4) ◽  
pp. 56-64 ◽  
Author(s):  
Marek Gryta ◽  
Marta Waszak ◽  
Maria Tomaszewska

Abstract In this work a fouling study of polypropylene membranes used for microfiltration of glycerol solutions fermented by Citrobacter freundii bacteria was presented. The permeate free of C. freundii bacteria and having a turbidity in the range of 0.72–1.46 NTU was obtained. However, the initial permeate flux (100–110 L/m2h at 30 kPa of transmembrane pressure) was decreased 3–5 fold during 2–3 h of process duration. The performed scanning electron microscope observations confirmed that the filtered bacteria and suspensions present in the broth formed a cake layer on the membrane surface. A method of periodical module rinsing was used for restriction of the fouling influence on a flux decline. Rinsing with water removed most of the bacteria from the membrane surface, but did not permit to restore the initial permeate flux. It was confirmed that the irreversible fouling was dominated during broth filtration. The formed deposit was removed using a 1 wt% solution of sodium hydroxide as a rinsing solution.


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