A study on the fouling phenomena of a microfiltration membrane

2004 ◽  
Vol 4 (5-6) ◽  
pp. 223-231
Author(s):  
H.-H. Yeh ◽  
W.-H. Wang
Keyword(s):  
Salicylic Acid ◽  
Humic Acid ◽  
Calcium Ion ◽  
Colloidal Particles ◽  
Alginic Acid ◽  
Particle System ◽  
Feed Water ◽  
Permeate Flux ◽  
Widespread Application ◽  
Latex Beads

The utilization of membrane processes for drinking water treatment has become more popular. However, fouling by source water probably is the major factor prohibits its widespread application. In this research, the fouling phenomena of a microfiltration (MF) membrane were studied. The interactions among colloidal particles, calcium ion, and dissolved organics, such as salicylic acid, humic acid, and alginic acid, on MF fouling were focused. A lab-scale single hollow fiber MF membrane, made of polyvinylidenefluoride (PVDF), module was used. The results show that, for single organic compound, the extent of fouling caused by humic acid was higher that of alginic acid. For the latter, the permeate flux decrease at lower pH was more significant than those at higher pH. For low MW salicylic acid, both rejection and flux decrease were minor. It seems that solubility have strong correlation with fouling rate. The higher the solubility is, the lower the fouling rate. For sole colloidal particle system, latex beads with diameter close to the pore size of MF membrane showed severe fouling. Adding Ca can aggregate the latex beads, and alleviate fouling. However, calcium ion also found to increase fouling of alginic acid on membrane under neutral or alkali pH condition, probably via charge neutralization and/or bridging. In conclusion, MF fouling seems to be strongly related to the type of organics, size of colloidal particles, and the existence of divalent ions, in the feed water.

Hybrid TiO2 photocatalytic oxidation and ultrafiltration for humic acid removal and membrane fouling control

2011 ◽  
Vol 11 (3) ◽  
pp. 324-332 ◽  
Author(s):  
Hongwei Bai ◽  
Darren Delai Sun
Keyword(s):  
Humic Acid ◽  
Membrane Fouling ◽  
Photocatalytic Oxidation ◽  
Removal Rate ◽  
Optimal Choice ◽  
Feed Water ◽  
Permeate Flux ◽  
Hydrophobic Membrane ◽  
Fouling Control ◽  
And Control

Hybrid UV/TiO2 photocatalytic oxidation (PCO) and ultrafiltration (UF) process (PCO-UF) were used to remove humic acid (HA) and control membrane fouling. The PCO-UF process showed advantages in terms of higher removal rate of HA, higher permeate flux and less membrane fouling over UF alone and PCO alone on HA removal and membrane fouling control. Membrane material and pH of feed water were shown to be the influence on the performance of PCO-UF process. It was observed that higher pH of HA feed water and a hydrophobic membrane lead to better removal of HA with relatively higher permeate flux. The experimental results in this study demonstrated that 100 kDa ultraflic UF membrane and pH 9 of HA feed water would be the optimal choice for HA removal in the combined PCO-UF process.

scholarly journals Vapor Trapping Membrane for Reverse Osmosis

2010 ◽  
Author(s):  
Jongho Lee ◽  
Sean O’Hern ◽  
Rohit Karnik ◽  
Tahar Laoui
Keyword(s):  
Water Vapor ◽  
Reverse Osmosis ◽  
Calcium Ion ◽  
Size Range ◽  
Salt Water ◽  
Applied Pressure ◽  
Flux Measurement ◽  
Feed Water ◽  
Self Assembled Monolayer ◽  
Microfluidic Flow

This paper presents a concept for desalination by reverse osmosis (RO) using a vapor-trapping membrane. The membrane is composed of hydrophobic nanopores and separates the feed salt water and the fresh water (permeate) side. The feed water is vaporized by applied pressure and the water vapor condenses on the permeate side accompanied by recovery of latent heat. A probabilistic model was developed for transport of water vapor inside the nanopores, which predicted 3–5 times larger mass flux than conventional RO membranes at temperatures in the range of 30–50°C. An experimental method to realize short and hydrophobic nanopores is presented. Gold was deposited at the entrance of alumina pores followed by modification using an alkanethiol self-assembled monolayer. The membranes were tested for defective or leaking pores using a calcium ion indicator (Fluo-4). This method revealed the existence of defect-free areas in the 100–200 μm size range that are sufficient for flux measurement. Finally, a microfluidic flow cell was created for characterizing the transport properties of the fabricated membranes.

KNT-artificial neural network model for flux prediction of ultrafiltration membrane producing drinking water

2004 ◽  
Vol 50 (8) ◽  
pp. 103-110 ◽  
Author(s):  
H.K. Oh ◽  
M.J. Yu ◽  
E.M. Gwon ◽  
J.Y. Koo ◽  
S.G. Kim ◽  
...  
Keyword(s):  
Neural Network ◽  
Experimental Data ◽  
Artificial Neural Network ◽  
Correlation Coefficient ◽  
Network Model ◽  
Operating Conditions ◽  
Transmembrane Pressure ◽  
Feed Water ◽  
Permeate Flux ◽  
Artificial Neural

This paper describes the prediction of flux behavior in an ultrafiltration (UF) membrane system using a Kalman neuro training (KNT) network model. The experimental data was obtained from operating a pilot plant of hollow fiber UF membrane with groundwater for 7 months. The network was trained using operating conditions such as inlet pressure, filtration duration, and feed water quality parameters including turbidity, temperature and UV254. Pre-processing of raw data allowed the normalized input data to be used in sigmoid activation functions. A neural network architecture was structured by modifying the number of hidden layers, neurons and learning iterations. The structure of KNT-neural network with 3 layers and 5 neurons allowed a good prediction of permeate flux by 0.997 of correlation coefficient during the learning phase. Also the validity of the designed model was evaluated with other experimental data not used during the training phase and nonlinear flux behavior was accurately estimated with 0.999 of correlation coefficient and a lower error of prediction in the testing phase. This good flux prediction can provide preliminary criteria in membrane design and set up the proper cleaning cycle in membrane operation. The KNT-artificial neural network is also expected to predict the variation of transmembrane pressure during filtration cycles and can be applied to automation and control of full scale treatment plants.

Evaluation of refractory organic removal in combined biological powdered activated carbon - microfiltration for advanced wastewater treatment

2001 ◽  
Vol 43 (11) ◽  
pp. 67-74 ◽  
Author(s):  
G. T. Seo ◽  
S. Ohgaki
Keyword(s):  
Activated Carbon ◽  
Humic Acid ◽  
Growth Parameter ◽  
Powdered Activated Carbon ◽  
Sewage Effluent ◽  
Permeate Flux ◽  
Arabic Gum ◽  
Biological Growth ◽  
Toc Removal ◽  
Refractory Organic Matter

Biological powdered activated carbon (BPAC) was incorporated with a microfiltration (MF, 0.2 μm pore size) system to remove the refractory organic matter contained in secondary sewage effluent. A synthetic secondary sewage effluent was used as influent in this study, containing both non-biodegradable organic substances (such as humic acid, lignin sulfonate, tannic acid and arabic gum powder) and biodegradable ones. These refractory organic materials were possibly degraded in contact with microorganisms for 20-27 days. Although humic acid and arabic gum were weakly adsorbed on the activated carbon, they could be effectively removed in the BPAC reactor. The TOC removal at a powdered activated carbon (PAC) concentration of 20 g/L was higher than at 0.5-2 g PAC/L (83% and 66-68%, respectively). The higher removal efficiency was due to the increased rejection at the membrane module in which most of the PAC was accumulated. More than 90% of non-biodegradable compounds removal (detected as E280 , UV absorption at 280 nm) occurred in the BPAC reactor. The biological growth parameter b/Y, used in system design, was estimated to be 0.017 d-1. Relatively high permeate flux of 1.88 m/d could be obtained even at higher PAC concentration of 20 g/L.

scholarly journals Low-Pressure Membrane for Water Treatment Applications

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Huda AlFannakh ◽  
Heba Abdallah ◽  
S. S. Ibrahim ◽  
Basma Souayeh
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Drinking Water ◽  
Humic Acid ◽  
Tap Water ◽  
Permeate Flux ◽  
Membrane Performance ◽  
Polyethersulfone Membrane ◽  
Contaminated Drinking Water

Three ultrafiltration membranes were prepared using phase separation techniques. The membranes were characterized by scan electron microscope, porosity, pore size distribution measurement, and mechanical properties. The membrane performance was carried out using synthetic solutions from humic acid and tap water to express the contaminated drinking water. The polyvinylidene difluoride (M2) has the highest tensile strength 33.2 MPa with elongation of 52.3%, while polyacrylonitrile (M3) has the lowest mechanical properties, tensile strength 16.4 MPa with elongation of 42.7%. Polyethersulfone membrane (M1) provides the highest removal of humic acid, which was 99.5, 98.8, and 98.2% using feed concentrations 0.1, 0.3, and 0.5 g/l, respectively, while M3 provides the highest permeate flux which was 250, 234.4, and 201.4 l/m2 h using feed concentrations 0.1, 0.3, and 0.5 g/l, respectively. Analysis of water samples indicates that the prepared membranes can be used to treat the contaminated drinking water which produced the high quality of drinking water after treatment.

Effect of calcium ion on the fouling of nanofilter by humic acid in drinking water production

1998 ◽  
Vol 32 (7) ◽  
pp. 2180-2186 ◽  
Author(s):  
Seong-Hoon Yoon ◽  
Chung-Hak Lee ◽  
Kyu-Jin Kim ◽  
Anthony G. Fane
Keyword(s):  
Drinking Water ◽  
Humic Acid ◽  
Calcium Ion ◽  
Water Production ◽  
Drinking Water Production
Sign in / Sign up

Export Citation Format

Share Document