Shirasu porous glass (SPG) membrane emulsification in the absence of shear flow at the membrane surface: Influence of surfactant type and concentration, viscosities of dispersed and continuous phases, and transmembrane pressure

Ultrafiltration is a promising, environment-friendly alternative to the current physicochemical-based tannery wastewater treatment. In this work, ultrafiltration was employed to treat the tanning wastewater as an upstream process of the Zero Liquid Discharge (ZLD) system in the leather industry. The filtration efficiency and fouling behaviors were analyzed to assess the impact of membrane material and operating conditions (shear rate on the membrane surface and transmembrane pressure). The models of resistance-in-series, fouling propensity, and pore blocking were used to provide a comprehensive analysis of such a process. The results show that the process efficiency is strongly dependent on the operating conditions, while the membranes of either PES or PVDF showed similar filtration performance and fouling behavior. Reversible resistance was the main obstacle for such process. Cake formation was the main pore blocking mechanism during such process, which was independent on the operating conditions and membrane materials. The increase in shear rate significantly increased the steady-state permeation flux, thus, the filtration efficiency was improved, which resulted from both the reduction in reversible resistance and the slow-down of fouling layer accumulate rate. This is the first time that the fouling behaviors of tanning wastewater ultrafiltration were comprehensively evaluated, thus providing crucial guidance for further scientific investigation and industrial application.

Download Full-text

Pilot Study on the Combination of Different Pre-Treatments with Nanofiltration for Efficiently Restraining Membrane Fouling While Providing High-Quality Drinking Water

Membranes ◽

10.3390/membranes11060380 ◽

2021 ◽

Vol 11 (6) ◽

pp. 380

Author(s):

Yan Chen ◽

Huiping Li ◽

Weihai Pang ◽

Baiqin Zhou ◽

Tian Li ◽

...

Keyword(s):

Drinking Water ◽

Activated Carbon ◽

Membrane Fouling ◽

Membrane Surface ◽

Post Treatment ◽

Size Exclusion ◽

Transmembrane Pressure ◽

Feed Water ◽

High Quality ◽

Treated Water

Nanofiltration (NF) is a promising post-treatment technology for providing high-quality drinking water. However, membrane fouling remains a challenge to long-term NF in providing high-quality drinking water. Herein, we found that coupling pre-treatments (sand filtration (SF) and ozone–biological activated carbon (O3-BAC)) and NF is a potent tactic against membrane fouling while achieving high-quality drinking water. The pilot results showed that using SF+O3-BAC pre-treated water as the feed water resulted in a lower but a slowly rising transmembrane pressure (TMP) in NF post-treatment, whereas an opposite observation was found when using SF pre-treated water as the feed water. High-performance size-exclusion chromatography (HPSEC) and three-dimensional excitation–emission matrix (3D-EEM) fluorescence spectroscopy determined that the O3-BAC process changed the characteristic of dissolved organic matter (DOM), probably by removing the DOM of lower apparent molecular weight (LMW) and decreasing the biodegradability of water. Moreover, amino acids and tyrosine-like substances which were significantly related to medium and small molecule organics were found as the key foulants to membrane fouling. In addition, the accumulation of powdered activated carbon in O3-BAC pre-treated water on the membrane surface could be the key reason protecting the NF membrane from fouling.

Download Full-text

Synthesis of microcapsules using inverse emulsion periphery RAFT polymerization via SPG membrane emulsification

Polymer Chemistry ◽

10.1039/c6py01584k ◽

2016 ◽

Vol 7 (46) ◽

pp. 7047-7051 ◽

Cited By ~ 4

Author(s):

Fumi Ishizuka ◽

Rhiannon P. Kuchel ◽

Hongxu Lu ◽

Martina H. Stenzel ◽

Per B. Zetterlund

Keyword(s):

Particle Size ◽

Size Distribution ◽

Raft Polymerization ◽

Good Control ◽

Membrane Emulsification ◽

Inverse Emulsion ◽

Novel Approach ◽

Spg Membrane Emulsification

Synthesis of polymeric capsules with good control over the particle size and size distribution is demonstratedviaa novel approach involving SPG membrane emulsification.

Download Full-text

A Comparative Study of SPG Membrane Emulsification in the Presence and Absence of Continuous-Phase Flow

JOURNAL OF CHEMICAL ENGINEERING OF JAPAN ◽

10.1252/jcej.08we314 ◽

2009 ◽

Vol 42 (7) ◽

pp. 520-530 ◽

Cited By ~ 11

Author(s):

Masato Kukizaki ◽

Masahiro Goto

Keyword(s):

Comparative Study ◽

Continuous Phase ◽

Phase Flow ◽

Membrane Emulsification ◽

Presence And Absence ◽

Spg Membrane Emulsification

Download Full-text

Impact of FO Operating Pressure and Membrane Tensile Strength on Draw-Channel Geometry and Resulting Hydrodynamics

Membranes ◽

10.3390/membranes10050111 ◽

2020 ◽

Vol 10 (5) ◽

pp. 111

Author(s):

Alexander J. Charlton ◽

Boyue Lian ◽

Gaetan Blandin ◽

Greg Leslie ◽

Pierre Le-Clech

Keyword(s):

Fluid Dynamics ◽

Computational Fluid Dynamics ◽

Reynolds Number ◽

Shear Rate ◽

Membrane Surface ◽

Forward Osmosis ◽

Transmembrane Pressure ◽

Channel Height ◽

Operating Pressure ◽

Channel Geometry

In an effort to improve performances of forward osmosis (FO) systems, several innovative draw spacers have been proposed. However, the small pressure generally applied on the feed side of the process is expected to result in the membrane bending towards the draw side, and in the gradual occlusion of the channel. This phenomenon potentially presents detrimental effects on process performance, including pressure drop and external concentration polarization (ECP) in the draw channel. A flat sheet FO system with a dot-spacer draw channel geometry was characterized to determine the degree of draw channel occlusion resulting from feed pressurization, and the resulting implications on flow performance. First, tensile testing was performed on the FO membrane to derive a Young’s modulus, used to assess the membrane stretching, and the resulting draw channel characteristics under a range of moderate feed pressures. Membrane apex reached up to 67% of the membrane channel height when transmembrane pressure (TMP) of 1.4 bar was applied. The new FO channels considerations were then processed by computational fluid dynamics model (computational fluid dynamics (CFD) by ANSYS Fluent v19.1) and validated against previously obtained experimental data. Further simulations were conducted to better assess velocity profiles, Reynolds number and shear rate. Reynolds number on the membrane surface (draw side) increased by 20% and shear rate increased by 90% when occlusion changed from 0 to 70%, impacting concentration polarisation (CP) on the membrane surface and therefore FO performance. This paper shows that FO draw channel occlusion is expected to have a significant impact on fluid hydrodynamics when the membrane is not appropriately supported in the draw side.

Download Full-text