26 research outputs found
Editorial: Fouling in Membrane Filtration Systems
No full textEditorial: Fouling in Membrane Filtration System
Fabrication of Meso-Porous Sintered Metal Thin Films by Selective Etching of Silica Based Sacrificial Template
Get PDFMeso-porous metal materials have enhanced surface energies offering unique surface properties with potential applications in chemical catalysis, molecular sensing and selective separation. In this paper, commercial 20 nm diameter metal nano-particles, including silver and copper were blended with 7 nm silica nano-particles by shear mixing. The resulted powders were cold-sintered to form dense, hybrid thin films. The sacrificial silica template was then removed by selective etching in 12 wt% hydrofluoric acid solutions for 15 min to reveal a purely metallic meso-porous thin film material. The impact of the initial silica nano-particle diameter (7–20 nm) as well as the sintering pressure (5–20 ton·m−2) and etching conditions on the morphology and properties of the final nano-porous thin films were investigated by porometry, pyknometery, gas and liquid permeation and electron microscopy. Furthermore, the morphology of the pores and particle aggregation during shear mixing were assessed through cross-sectioning by focus ion beam milling. It is demonstrated that meso-pores ranging between 50 and 320 nm in average diameter and porosities up to 47% can be successfully formed for the range of materials tested
Integrating Arid Areas in the Global Bioeconomy: Opportunities and Challenges toward Sustainable Biomass Generation and Management
No full textFunding Information: B.L.T. is the recipient of the Khalifa University of Science and Technology (KUST) Faculty Startup Project (Project code: 84741140-FSU-2022-021). Financial support from the “2021 Euskampus Missions 1.0. Programme” granted by Euskampus Fundazioa and the University of the Basque Country (Convocatoria de ayudas a grupos de investigacion GIU21/010) is acknowledged. Publisher Copyright: © 2023 The Authors. Published by American Chemical Society.Biosystems and bioprocesses are typically not connected to arid areas, where the produced biomass and its availability are low. There is however a large potential for arid areas to become major bioeconomical actors via more localized biomass generation strategies. Indoor farming, bioengineering, and aquaculture have a great potential to be at the center of this transition. They are expected to address important challenges associated with food and (bio)materials supply and, ultimately, to climate and environment. Specifically, the utilization of the by- and coproducts deriving from these strategies could synergistically connect into a range of circular processes toward sustainable bioproducts’ supply and the greening of arid areas. These topics are at the center of this perspective, where emerging biomass generation and management strategies in arid areas are introduced. The potential positive feedback loops between their coproducts are then put in relation with the development of more diverse and thriving biosystems as well as the generation of a range of bioproducts. These approaches are contextualized with the current and alternative energy sectors and water treatments processes, which have well-established economical portfolios across most arid areas. The mapping of innovative bioeconomical actors in arid areas and their synergistic interactions, as put forward herein aims to intensify research efforts toward a fully integrated and global sustainable bioeconomy.Peer reviewe
Thermo-responsive nanofibrous composite membranes for efficient self-cleaning of protein foulants
Get PDFThis study developed a self-clean thermo-responsive nanofibrous poly(vinylidene fluoride) (PVDF)/nylon-6,6/poly(N-isopropylacrylamide) (PNIPAAm) composite ultrafiltration membrane consisting of a nylon-6,6/PNIPAAm functional nanofibre layer integrated into a PVDF substrate. The morphological analysis showed the presence of electrospun nano-nets branching out from the main nanofibres as PNIPAAm concentration increased, affecting the pore size distribution and solute rejection. The PVDF/nylon-6,6/PNIPAAm membranes showed improved surface hydrophilicity below the low critical solution temperature (LCST) and strong thermo-switchability. With bovine serum albumin (BSA) as the model foulant, the rejection of the 4 wt% PNIPAAm membranes was greatly improved to above 96%. Through a two-cycle ultrafiltration study using feed solution containing BSA and CaCl2, the membrane with 4 wt% PNIPAAm showed superior recovery of water permeance up to 97% assisted with temperature-change cleaning, compared to the control membrane that only recovered 56%. Filtration experiments with and without intermediate temperature-change cleaning proved that the anti-fouling mechanism of the PNIPAAm membranes was strongly associated with surface wettability and rapid conformation of PNIPAAm polymer chains induced by volume-phase transition, resulting in reduced protein adsorption and ‘shaking-off’ of the absorbed proteins from the membrane surface. Such smart responsive membranes have great potential for the development of easy-to-clean membranes for food and wastewater treatment.sponsorship: This work was supported by Victoria India Institute via Victoria India Doctoral Scholarship. Dr. L. DUMEE acknowledges the Australian Research Council (ARC) for his DECRA fellowship (DE180100130). Dr Xing Yang would like to acknowledge Victoria University for the Industry Postdoctoral Fellowship. The Microscopy platform at Deakin University and support from the technical team is also acknowledged. (Victoria India Institute via Victoria India Doctoral Scholarship, Australian Research Council (ARC)|DE180100130, Victoria University)status: Publishe
Investigation of hybrid ion-exchange membranes reinforced with non-woven metal meshes for electro-dialysis applications
No full textSalt and solvent permeations across ion-exchange membranes used in electro-dialysis are directly related to the membrane material structure and chemistry. Although primarily used for aqueous effluents desalination, electro-dialysis was recently shown to be a promising technology for industrial wastewater and co-solvent mixtures purification. The harsh working conditions imposed by these liquid effluents, including high suspended solids, require the development of more chemically and mechanically resistant membranes. In this study, commercial porous stainless steel media filters (240. μm thick) were used as a backbone to prepare hybrid ion-exchange membranes by casting ion-exchange materials within the porous metal structure. The surface of the metal reinforcements was modified by plasma treatment prior to sol-gel silane grafting to improve the interface between the metal and the ion-exchange resins. The morphology of novel hybrid materials and the interface between the metal fibers and the ion-exchange material have been characterized using techniques such as scanning electron microscopy and FTIR mapping. The thickness of the silane coating was found to lie between 1 and 2. μm while water contact angle tests performed on membrane surfaces and corrosion test behaviors revealed the formation of a thin passivating oxide layer on the material surfaces providing anchoring for the silane grafting and adequate surface energy for the proper incorporation of the ion-exchange material. The hybrid membranes desalination performance were then tested in a bench top electro-dialysis cell over a range of flow rate, current densities and salt concentration conditions to evaluate the ability of the novel hybrid materials to desalinate model streams. The performance of the hybrid membranes were benchmarked and critically compared against commercially available membranes (Selemion™). Although the salt transfer kinetics across the hybrid ion-exchange composite membranes were shown to be comparable to that of the commercial membranes, the low porosity of the stainless steel reinforcements, around 60%, was shown to impede absolute salt permeations. The hybrid ion-exchange membranes were however found to be competitive at low current density and low flow velocity desalination conditions
Boulton and Fothergill silver.
No full textPhDThis thesis is about the silver business of Matthew Boulton and John
Fothergill at their Soho Manufactory near Birmingham. Their
partnership lasted from 1762 until 1782.
A rounded discussion of the topic is attempted. Within the contexts
of industry elsewhere and Soho's other activities, successive chapters
cover the early development, marketing, production, design, and later
decline of the partners' silver.
Silver plate was prestigious and, untypically for Boulton, he
concentrated on sales to the public rather than trade customers. To
attract orders he made modest charges. This was viable where mainly
machinery was used to make plate, even though sales were not high,
since the expense of machinery was substantially covered by the larger
sales of non-silver items. However, where Boulton relied to a
greater degree upon hand methods, he lacked technical means to
compensate for low profit-margins. Moreover, inefficiency and the
firm's lack of capital which led to substantial bankers' interest
charges on payment for bullion, particularly when customers paid late,
caused losses. These problems applied particularly to silver plate
and were mainly responsible for the decision to reduce production
drastically; however, the manufacture of a large range of small items
remained relatively consistent.
The thesis includes appendices. Some contain new information about
annual totals for the following aspects of the business: the volume of
assay silver; each type of article; pieces sold on commission; and
sterling silver supplies. Other appendices provide details about the
partners' silversmiths and extracts from a Soho inventory.
This thesis involves a more detailed use of sources than previous
studies of the topic. Apart from the silver itself (which is
selectively illustrated), the Matthew Boulton Papers and statistics
derived from The Birmingham Assay office provide the main sources.
Manuscripts covering silver production elsewhere provide contextual
material for understanding the partners' silver business
Recent developments in carbon nanotube membranes for water purification and gas separation
No full textCarbon nanotubes (CNTs) are nanoscale cylinders of graphene with exceptional properties such as high mechanical strength, high aspect ratio and large specific surface
area. To exploit these properties for membranes, macroscopic structures need to be designed with controlled porosity and pore size. This manuscript reviews recent progress on two such structures: (i) CNT Bucky-papers, a non-woven, paper like structure of randomly entangled CNTs, and (ii) isoporous CNT membranes, where the hollow CNT
interior acts as a membrane pore. The construction of these two types of membranes will be discussed, characterization and permeance results compared, and some promising applications presented
Next generation membranes for membrane distillation and future prospects
No full textThis chapter presents the most recent advances in membrane materials technology and module configurations for membrane distillation (MD), as well as their novel applications. The impact of the material morphology, surface energy, and pore structure on MD performance is discussed. The differences between hollow fibres and flat sheet membrane materials are also examined and promising novel structures or module configurations reviewed. In addition, novel materials and module configuration strategies are also identified that may lead to superior MD systems. Also, this chapter identifies current gaps where further work may lead to ongoing improvements to MD
A critical assessment of technical advances in pharmaceutical removal from wastewater – A critical review
Get PDFUse of pharmaceutical products has seen a tremendous increase in the recent decades. It has been observed that more than thirty million tons of pharmaceuticals are consumed worldwide. The used pharmaceutical products are not completely metabolized in human and animal body. Therefore, they are excreted to the environment and remain there as persistent organic chemicals. These compounds emerge as toxic contaminants in water and affect the human metabolism directly or indirectly. This literature review is an endeavour to understand the origin, applications and current advancement in the removal of pharmaceuticals from the environment. It discusses about the pharmaceuticals used in medical applications such diagnosis and disease treatment. In addition, it discusses about the recent approaches applied in pharmaceutical removal including microbial fuel cells, biofiltration, and bio nanotechnology approaches. Moreover, the challenges associated with pharmaceutical removal are presented considering biological and environmental factors. The review suggest the potential recommendations on pharmaceutical removal.The corresponding author Prof. Vinay Kumar is thankful to all the co-authors for their collaborative efforts in writing this paper. This work was supported by Department of Community Medicine, Saveetha Medical College and Hospital, Saveetha Institute of Medical and Technical Sciences (SIMATS), Chennai, India.Peer reviewe
Amine Enrichment of Thin-Film Composite Membranes via Low Pressure Plasma Polymerization for Antimicrobial Adhesion
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