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CONTENTS
Volume 7, Number 4, July 2016
 

Abstract
The aim of this research was to investigate the ability of nanofiltration (NF) and ultrafiltration (UF) membranes as a filtration unit for groundwater treatment for drinking water resources. Commercial membranes denoted as TS40, TFC-SR3 and GHSP were used to study the performance based on rejections and fluxes. The investigation has been conducted using natural groundwater obtained from a deep tube well with initial concentration of iron (Fe) and manganese (Mn) at 7.15 mg/L and 0.87 mg/L, respectively. Experimental results showed that NF membranes exhibited higher fluxes than UF membrane with pure water permeability at 4.68, 3.99 and 3.15 L.m-2.h-1.bar-1, respectively. For metal rejection, these membranes have performed higher removal on Fe with TS40, TFC-SR3 and GHSP membranes having more than 82%, 92% and 86% respectively. Whereas, removal on Mn only achieved up to 60%, 80% and 30%, for TS40, TFC-SR3 and GHSP membranes respectively. In order to achieve drinking water standard, the membranes were efficient in removing Fe ion at 1 and 2 bar in contrast with Mn ion at 4 and 5 bar. Higher rejection of Fe and Mn were achieved when pH of feed solution was increased to more than 7 as TFC-SR3 membrane was negatively charged in basic solution. This effect could be attributed to the electrostatic effect interaction between membrane material and rejected ions. In conclusion, this study proved that NF membrane especially the TFC-SR3 membrane successfully treated local groundwater sources for public drinking water supply in line with the WHO standard.

Key Words
iron and manganese; drinking water; groundwater treatment; membrane filtration

Address
(1) Norherdawati Kasim, Abdul Wahab Mohammad, Siti Rozaimah Sheikh Abdullah:
Department of Chemical and Process Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor, Malaysia;
(2) Abdul Wahab Mohammad:
Research Centre for Sustainable Process Technology (CESPRO), Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor, Malaysia;
(3) Norherdawati Kasim:
Department of Chemistry, Centre for Defence Foundation Studies, National Defence University of Malaysia, Kem Sg. Besi, 57000 Kuala Lumpur, Malaysia.

Abstract
Modeling and simulation of air humidification by hollow fiber membrane contactors are investigated in the current study. A computational fluid dynamic model was developed by solving the k-epsilon turbulence 2D Navier.Stokes equations as well as mass conservation equations for steady-state conditions in membrane contactors. Finite element method is used for the study of the air humidification under different operating conditions, with a focus on the humidity density, total mass transfer flux and velocity field. There has been good agreement between simulation results and experimental data obtained from literature. It is found that the enhancement of air stream decreases the outlet humidity from 0.392 to 0.340 (module 1) and from 0.467 to 0.337 (module 2). The results also indicated that there has been an increase in air velocity in the narrow space of shell side compared with air velocity wide space of shell side. Also, irregular arrangement has lower dead zones than regular arrangement which leads to higher water flux.

Key Words
membrane processes; simulation; mass transfer; humidification; cross flow

Address
(1) Azam Marjani, Ali Baghdadi:
Department of Chemistry, Arak Branch, Islamic Azad University, Arak, Iran;
(2) Mehdi Ghadiri:
Young Researchers and Elite Club, South Tehran Branch, Islamic Azad University, Tehran, Iran.

Abstract
South Africa recognises piped water as the main source of safe drinking water supply. Remote areas do not have access to this resource and they rely solely on surface water for survival, which exposes them to waterborne diseases. Interim point of use solutions are not practiced due to their laboriousness and alteration of the taste. Bio-ultra low pressure driven membrane system has been noted to be able to produce stable fluxes after one week of operation; however, there is limited literature on South African waters. This study was conducted on three rivers namely; Umgeni, Umbilo and Tugela. Three laboratory systems were setup to evaluate the performance of the technology in terms of producing stable fluxes and water that is compliant with the WHO 2008 drinking water guideline with regards to turbidity, total coliforms and E.coli. The obtained flux rate trends were similar to those noted in literature where they are referred to as stable fluxes. However, when further comparing the obtained fluxes to the normal dead-end filtration curve, it was noted that both the Umbilo and Tugela Rivers responded similarly to a normal dead-end filtration curve. The Umgeni River was noted to produce flux rates which were higher than those obtainable under normal dead-end. It can be concluded that there was no stabilisation of flux noted. However, feed water with low E.coli and turbidity concentrations enhances the flux rates. The technology was noted to produce water of less than 1 NTU and 100% removal efficiency for E.coli and total coliforms.

Key Words
flux stabilisation; point of use; surface water treatment; remote rural areas; ultrafiltration membranes; Bio-UF

Address
(1) Maipato I. Thoola, Sudesh Rathilal, Lingam V. Pillay:
Department of Chemical Engineering, Durban University of Technology, P.O. Box 1334, Durban, 4000, South Africa;
(2) Lingam V. Pillay:
Department of Process Engineering, Stellenbosch University, Private Bag x1, Matieland, 7602, South Africa.

Abstract
Nanofiltration is useful to concentrate propolis extract. During the selection of membrane, both compound rejection and permeate flux are important indicators of process economy. Brazilian green propolis extract was studied to evaluate the separation performance of Startmen 122 and NF270 membranes. Compared to Starmen 122, NF270 membrane showed better rejection of bioactive compounds. The flux decline patterns were further studied using Hermia's model. Cake formation is the major fouling mechanism on the hydrophobic surface of Starmen 122. While the fouling mechanism for NF270 is pore blocking. The fouled membranes were further characterized using SEM and FT-IR to confirm on the predicted fouling mechanisms.

Key Words
nanofiltration; fouling; propolis; polyphenols; flavonoids

Address
School of Chemical Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Pulau Pinang, Malaysia.


Abstract
Papermaking reconstituted tobacco is an important strategy for recycling the waste tobacco residues. To indentify the influences of the inorganic components on harmful components delivery in cigarette smoke, a selfmade electrodialysis stack was assembled to desalt the tobacco extract. The influences of the applied current and extract content on the removal rate of the inorganic ions were investigated. Results indicated that the applied current was a dominant impact on the desalination performance. High currents lower than the limiting current density could accelerate the desalting efficiency but cause higher energy consumption. A current of 2 A, or current density of ~11 mA

Key Words
reconstituted tobacco; tobacco extract; electrodialysis; ion exchange membranes

Address
(1) Shaolin Ge, Chuanrun Li, Yaoming Wang:
CAS Key Laboratory of Soft Matter Chemistry, Laboratory of Functional Membranes, School of Chemistry and Materials Science, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China;
(2) Shaolin Ge, Zhao Zhang,
China Tobacco Anhui Industrial Co., LTD, Hefei, Anhui,230088, People's Republic of China;
(3) Wei Li, Chuanrun Li:
Hefei ChemJoy Polymer Materials, Co., LTD, Hefei, Anhui,230601, People's Republic of China.

Abstract
The improvement of fouling resistance of porous polymeric membrane is one of the most important targets in membrane preparation for water purification in many process like wastewater treatment. Membranes can be modified by various techniques, including the treatment of polymer material, blending of hydrophilic polymer into polymer solution, and post treatment of fabricated membrane. This research proposed the modifications of morphology and surface property of hydrophobic membrane by blending polyethersulfone (PES) with three polymeric additives, polyvinylpyrrolidone (PVP), Pluronic F127 (Plu), and Tetronic 1307 (Tet). PES hollow fiber membranes were fabricated via dry-wet spinning process by using a spinneret with inner and outer diameter of 0.7 and 1.0 mm, respectively. The morphology changes of PES blend membrane by those additives, as well as the change of performance in ultrafiltration module were comparatively observed. The surface structure of membranes was characterized by atomic force microscopy and Fourier transform infra red spectroscopy. The cross section morphology of PES blend hollow fiber membranes was investigated by scanning electron microscopy. The results showed that all polymeric additives blended in this system affected to improve the performances of PES membrane. The ultra-filtration experiment confirmed that PES-PVP membrane showed the best performance among the three membranes on the basis of filtration stability.

Key Words
polymeric additive; ultrafiltration; solute rejection; water permeability

Address
(1) Nasrul Arahman, Sri Mulyati, Mirna Rahmah Lubis, Fachrul Razi:
Chemical Engineering Department, Syiah Kuala University, Jl. Syeh A Rauf, 7, Darussalam, Banda Aceh, 23111, Indonesia;
(2) Ryosuke Takagi, Hideto Matsuyama:
Department of Chemical Engineering, Kobe University, 1-1 Rokkodai Cho, Kobe Shi, Japan.

Abstract
Although the bucky paper (BP) made from carbon nanotubes (CNTs) possesses beneficial characteristics of hydrophobic nature and high porosity for membrane distillation (MD) application, weak mechanical strength of BP has often prevented the stable operation. This study aims to fabricate the BP with high mechanical strength to improve its MD performance. The strategy was to increase the purity level of CNTs with an assumption that purer CNTs would increase the Van der Waals attraction, leading to the improvement of mechanical strength of BP. According to this study results, the purification of CNT does not necessarily enhance the mechanical strength of BP. The BP made from purer CNTs demonstrated a high flux (142 kg/m2

Key Words
bucky paper; carbon nanotube; membrane distillation; mechanical strength; mixed matrix membrane

Address
Civil Engineering Department, Kyungnam University, 7 Kyungnamdaehak-ro, Masanhappo-gu, Changwon, 631-701, Republic of Korea.



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