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Jay Ryan Werber, Cassandra J Porter, Menachem Elimelech
Reverse osmosis (RO) has become a premier technology for desalination and water purification. The need for increased selectivity has incentivized research into novel membranes, such as biomimetic membranes that incorporate the perfectly-selective biological water channel aquaporin or synthetic water channels like carbon nanotubes. In this study, we consider the performance of composite biomimetic membranes by projecting water permeability, salt rejection, and neutral-solute retention based on the permeabilities of the individual components, particularly the water channel, the amphiphilic bilayer matrix, and potential support layers that include polymeric RO, nanofiltration (NF), and porous ultrafiltration membranes...
August 14, 2018: Environmental Science & Technology
Zhongyong Qiu, Xiaofei Ji, Chunju He
It is still a challenge to design and fabricate a robust nanoporous membrane in large scale and of fundamental importance for practical application. Here, a robust three/two-dimensional polyacrylonitrile/graphene oxide (PAN/GO) homogeneous nanoporous membrane is fabricated in large scale via thermally induced phase separation method, which guarantees the membrane with high mechanical strength and selective separation properties. Differing from conventional nanofiltration (NF) membrane with high rejection to both salt and dye, the resulting hybrid membrane is relative loose, which shows outstanding performances, i...
August 3, 2018: Journal of Hazardous Materials
Eddy R Ostarcevic, Joseph Jacangelo, Stephen R Gray, Marlene J Cran
Ideally, pressure driven membrane processes used in wastewater treatment such as reverse osmosis and nanofiltration should provide a complete physical barrier to the passage of pathogens such as enteric viruses. In reality, manufacturing imperfections combined with membrane ageing and damage can result in breaches as small as 20 to 30 nm in diameter, sufficient to allow enteric viruses to contaminate the treated water and compromise public health. In addition to continuous monitoring, frequent demonstration of the integrity of membranes is required to provide assurance that the barrier to the passage of such contaminants is intact...
August 9, 2018: Membranes
Rosa Tundis, Monica R Loizzo, Marco Bonesi, Vincenzo Sicari, Claudia Ursino, Ilaria Manfredi, Carmela Conidi, Alberto Figoli, Alfredo Cassano
For the first time the chemical profile, physico-chemical parameters, inhibition of carbohydrate hydrolysing enzymes associated with type 2 diabetes, and radical scavenging properties of Sambucus nigra L. (elderberry) juice treated by nanofiltration (NF) were investigated. Three commercial NF membranes with different molecular weight cut-off (MWCO) (400 and 1000 Da) and polymeric material (composite fluoro-polymer and polyethersulphone) were tested. According to HPLC analyses, most part of bioactive compounds were retained by the NF membranes producing a retentate fraction of interest for the production of functional foods...
August 8, 2018: Plant Foods for Human Nutrition
A Criscuoli, A Figoli
The presence of arsenic in water beyond the admitted limits is becoming an important concern for many Countries. Methods usually employed for the arsenic removal from water are based on coagulation followed by filtration, ion-exchange, adsorption. Drawbacks like the use of chemicals and the production of sludges (in case of coagulation) have, however, to be mentioned. Membrane operations, based on the features of membrane materials involved in the separation, do not need chemicals and are easy to scale-up, due to their modularity...
July 12, 2018: Journal of Hazardous Materials
Zhe Yang, Zhi-Wen Zhou, Hao Guo, Zhikan Yao, Xiao-Hua Ma, Xiaoxiao Song, Shien-Ping Feng, Chuyang Y Tang
Conventional thin-film composite (TFC) membranes suffer from the trade-off relationship between permeability and selectivity, known as the "upper bound". In this work, we report a high performance thin-film composite membrane prepared on a tannic acid (TA)-Fe nanoscaffold (TFCn ) to overcome such upper bound. Specifically, a TA-Fe nanoscaffold was first coated onto a polysulfone substrate, followed by performing an interfacial polymerization reaction between trimesoyl chloride (TMC) and piperazine (PIP)...
August 6, 2018: Environmental Science & Technology
Bin Liang, Hui Wang, Xinghua Shi, Baoying Shen, Xiao He, Zahid Ali Ghazi, Niaz Ali Khan, Haksong Sin, Abdul Muqsit Khattak, Lianshan Li, Zhiyong Tang
Conventional technology for the purification of organic solvents requires massive energy consumption, and to reduce such expending calls for efficient filtration membranes capable of high retention of large molecular solutes and high permeance for solvents. Herein, we report a surface-initiated polymerization strategy through C-C coupling reactions for preparing conjugated microporous polymer (CMP) membranes. The backbone of the membranes consists of all-rigid conjugated systems and shows high resistance to organic solvents...
July 23, 2018: Nature Chemistry
Alexandre Giacobbo, Andréa Moura Bernardes, Maria João Filipe Rosa, Maria Norberta de Pinho
Concentration polarization is intrinsically associated with the selective character of membranes and often means flux decline and which causes a subsequent decrease of ultrafiltration and nanofiltration performance. More important is the fact that it acts as a precursor of membrane fouling and creates severe fouling problems in the longer times range. The quantification of its dependence on the operating parameters of cross-flow velocities and transmembrane pressures makes recourse to the film theory to introduce mass-transfer coefficients that generally are calculated by dimensionless correlations of the Sherwood number as a function of the Reynolds and Schmidt numbers...
July 21, 2018: Membranes
Muhammad B Asif, Faisal I Hai, Bipro R Dhar, Huu H Ngo, Wenshan Guo, Veeriah Jegatheesan, William E Price, Long D Nghiem, Kazuo Yamamoto
This study systematically compares the performance of ultrafiltration (UF) and nanofiltration (NF) based enzymatic membrane bioreactors (EMBRs) for the degradation of five micropollutants, namely atrazine, carbamazepine, sulfamethoxazole, diclofenac and oxybenzone to elucidate the impact of effective membrane retention of micropollutants on their degradation. Based on the permeate quality, NF-EMBR achieved 92-99.9% micropollutant removal (i.e., biodegradation + membrane retention), while the removal of these micropollutants by UF-EMBR varied from 20 to 85%...
July 20, 2018: Bioresource Technology
Sylvie Cointe, Karim Harti Souab, Tarik Bouriche, Loris Vallier, Amandine Bonifay, Coralie Judicone, Stéphane Robert, Romain Armand, Philippe Poncelet, Jacques Albanese, Françoise Dignat-George, Romaric Lacroix
Among extracellular vesicles, leukocyte-derived microvesicles (LMVs) have emerged as complex vesicular structures. Primarily identified as procoagulant entities, they were more recently ascribed to plasmin generation capacity (MV-PGC). The objectives of this work were (1) to develop a new hybrid bio-assay combining the specific isolation of LMVs and measurement of their PGC, and compare its performance to the original method based on centrifugation, (2) to validate MV-PGC in septic shock, combining increased levels of LMVs and fibrinolytic imbalance...
2018: Journal of Extracellular Vesicles
Chuanjie Fang, Jian Sun, Bin Zhang, Yuchen Sun, Liping Zhu, Hideto Matsuyama
Developing nanofiltration (NF) membranes with highly efficient and precise separation ability is of great significance for the molecular and ionic separations. In this work, positively charged composite NF membranes were engineered via soaking of polysulfone (PSF) ultrafiltration membranes in poly(N-vinyl imidazole) (PVI) solutions followed by a quaternization crosslinking step. The PVI was firmly attached to the PSF membrane by this method and acted as an active separation layer of the composite NF membrane...
July 18, 2018: Journal of Colloid and Interface Science
Thomas R Kreil, David Roush
The manufacturing processes of biological medicinal products are expected to be capable of removing and/or inactivating viruses, to primarily provide for adequate safety margins for patients and to thus satisfy the corresponding regulatory expectations. To achieve this goal, process segments specifically dedicated to the task of virus removal or inactivation are designed into manufacturing flows. The State-of-the-Art now includes virus removal by nanofiltration, but also the more traditional low pH or (solvent-) detergent treatments are widely in use, often to provide for two complementary and mechanically different means of virus clearance...
July 20, 2018: PDA Journal of Pharmaceutical Science and Technology
Dayue Chen, Glen Bolton
"Cell lines such as CHO, C127, BHK and murine hybridoma cell lines have frequently been used as substrates for drug production with no reported safety problems related to viral contamination of the products" (ICH Q5A). However, viral contamination events in GMP cell culture processes, while rare, do sometimes occur. When contamination happens, it could result in serious consequences, including supply risk of life-saving drugs and substantial financial loss. To mitigate the potential risk of viral contamination, one of the approaches taken by industry is to implement preventative measures upstream...
July 20, 2018: PDA Journal of Pharmaceutical Science and Technology
Merve Atasoy, Isaac Owusu-Agyeman, Elzbieta Plaza, Zeynep Cetecioglu
Bio-based volatile fatty acid (VFA) production from waste-stream is getting attention due to increasing market demand and wide range usage area as well as its cost-effective and environmentally friendly approach. The aim of this paper is to give a comprehensive review of bio-based VFA production and recovery methods and to give an opinion on future research outlook. Effects of operation conditions including pH, temperature, retention time, type of substrate and mixed microbial cultures on VFA production and composition were reviewed...
July 11, 2018: Bioresource Technology
Hans Wijaya, Kengo Sasaki, Prihardi Kahar, Yopi, Hideo Kawaguchi, Takashi Sazuka, Chiaki Ogino, Bambang Prasetya, Akihiko Kondo
The aim of this study was to construct a cost-effective method for repeated bioethanol production using membrane (ultrafiltration permeation and nanofiltration concentration)-concentrated sweet sorghum juice by using flocculent Saccharomyces cerevisiae F118 strain. With low initial dry cell concentrations at around 0.28-0.35 g L-1 , the S. cerevisiae F118 strain provided an ethanol titer of 86.19 ± 1.15 g L-1 (theoretical ethanol yield of 70.77%), which was higher than the non-flocculent S. cerevisiae BY4741 strain at 33...
October 2018: Bioresource Technology
Phuoc H H Duong, Kevin Daumann, Pei-Ying Hong, Mathias Ulbricht, Suzana P Nunes
A simple scalable strategy is proposed to fabricate highly permeable antifouling nanofiltration membranes. Membranes with a selective thin polyamide layer were prepared via interfacial polymerization incorporating building blocks of zwitterionic copolymers. The zwitterionic copolymer, poly(aminopropyldimethylaminoethyl methacrylate)- co-poly(sulfobetaine methacrylate) with an average molecular weight of 6.1 kg mol-1 , was synthesized in three steps: (i) polymerization of dimethylaminoethyl methacrylate to yield the base polymer by atom transfer radical polymerization (ATRP), (ii) fractional sulfobetainization via quaternization, and (iii) amination via quaternization...
July 23, 2018: Langmuir: the ACS Journal of Surfaces and Colloids
Taeseon Yun, Jae Woo Chung, Seung-Yeop Kwak
We used a nanofiltration (NF) membrane process to produce purified aqueous sulfuric acid from copper-refining sulfuric acid wastewater. Wastewater generated from a copper-refining process was used to explore the membrane performances and acid stabilities of six commercial NF membranes. A combination of permeate flux, sulfate permeation, and metal ion rejection clearly showed that two polyamide membranes and a polyacrylonitrile-based membrane achieved recovery of a purified sulfuric acid solution. Acid-stability and long-term performance tests showed that the polyamide membranes were unsuitable for copper-refining wastewater treatment because of their low acid stabilities...
June 30, 2018: Journal of Environmental Management
David T Yonge, Paul G Biscardi, Steven J Duranceau
In this research, we investigated the influence of feedwater ionic strength on diffusion of divalent ions through a hollow-fiber nanofiltration membrane. The results indicated that solute flux of magnesium was increased as a result of elevating the ionic strength in the feedwater. Specifically, the feedwater ionic strength was observed to have a nonlinear impact on the diffusion of magnesium during the nanofiltration process, which was under-predicted by the homogeneous solution diffusion (HSD) model. This result suggested that elevating the feedwater ionic strength had reduced the strength of the electrostatic double layer at the membrane surface...
July 4, 2018: Membranes
Chao Lang, Yue-Xiao Shen, Jacob A LaNasa, Dan Ye, Woochul Song, Tawanda J Zimudzi, Michael A Hickner, Enrique D Gomez, Esther W Gomez, Manish Kumar, Robert J Hickey
The long-standing goal in membrane development is creating materials with superior transport properties, including both high flux and high selectivity. These properties are common in biological membranes, and thus mimicking nature is a promising strategy towards improved membrane design. In previous studies, we have shown that artificial water channels can have excellent water transport abilities that are comparable to biological water channel proteins, aquaporins. In this study, we propose a strategy for incorporation of artificial channels that mimic biological channels into stable polymeric membranes...
July 4, 2018: Faraday Discussions
Zhendong Gan, Xing Du, Xuewu Zhu, Xiaoxiang Cheng, Guibai Li, Heng Liang
To investigate how the organic fouling layers on nanofiltration (NF) membrane surface and the strong matrix effect (particularly by Ca2+ ) influence the rejection of trace organic compounds (TOrCs), filtration experiments with two TOrCs, bisphenol A (BPA) and sulfamethazine (SMT), were carried out with virgin and organic-fouled NF membrane. Organic fouling layer on the membrane was induced by sodium alginate (SA) at different concentrations of Ca2+ . The results indicated that NF membrane maintained consistently rejection of TOrCs with little influence by membrane fouling at lower Ca2+ concentration...
June 11, 2018: Environmental Science and Pollution Research International
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