Towards new membrane-based technologies for water treatment and reuse in the textile industry

Tekstilne otpadne vode radi kompleksnog sastava i prisutnih reaktivnih komponenti predstavljaju izazov u obradi membranskom separacijom. U ovom radu su opisane tekstilne otpadne vode i mogućnosti povrata pri čemu je začepljivanje membrana istaknuto kao ključni parametar. Prikazani su membranski bioreaktori (MBR) i membrane za osmozu (FO), koje su interesantne radi slabe sklonosti začepljivanju, čime mogu biti dopuna postojećim metodama. Dodatno se ističe razvoj i perspektive biomimetičkih akvaporin membrana i osmotskih membranskih bioreaktora (OMBR).Textile wastewater represents challenging feed streams to be treated by membrane separation due to the complex composition and presence of reactive components. Here we first briefly present some characteristics of textile wastewater remediation where a key issue is (bio)fouling. We then present Membrane Bioreactors (MBRs) and Forward Osmosis (FO) membranes as both technologies have attracted considerable interest due to the low fouling propensity of FO membranes. This makes them an intriguing supplement to existing method and we conclude this communication by highlighting some new developments and perspectives involving biomimetic aquaporin FO membranes and Osmotic Membrane Bioreactors (OMBRs)

Recombinant Production of Human Aquaporin-1 to an Exceptional High Membrane Density in <em>Saccharomyces</em> <em>cerevisiae</em>.

In the present paper we explored the capacity of yeast Saccharomyces cerevisiae as host for heterologous expression of human Aquaporin-1. Aquaporin-1 cDNA was expressed from a galactose inducible promoter situated on a plasmid with an adjustable copy number. Human Aquaporin-1 was C-terminally tagged with yeast enhanced GFP for quantification of functional expression, determination of sub-cellular localization, estimation of in vivo folding efficiency and establishment of a purification protocol. Aquaporin-1 was found to constitute 8.5 percent of total membrane protein content after expression at 15°C in a yeast host over-producing the Gal4p transcriptional activator and growth in amino acid supplemented minimal medium. In-gel fluorescence combined with western blotting showed that low accumulation of correctly folded recombinant Aquaporin-1 at 30°C was due to in vivo mal-folding. Reduction of the expression temperature to 15°C almost completely prevented Aquaporin-1 mal-folding. Bioimaging of live yeast cells revealed that recombinant Aquaporin-1 accumulated in the yeast plasma membrane. A detergent screen for solubilization revealed that CYMAL-5 was superior in solubilizing recombinant Aquaporin-1 and generated a monodisperse protein preparation. A single Ni-affinity chromatography step was used to obtain almost pure Aquaporin-1. Recombinant Aquaporin-1 produced in S. cerevisiae was not N-glycosylated in contrast to the protein found in human erythrocytes

Recombinant Production of Human Aquaporin-1 to an Exceptional High Membrane Density in Saccharomyces Cerevisiae

In the present paper we explored the capacity of yeast Saccharomyces cerevisiae as host for heterologous expression of human Aquaporin-1. Aquaporin-1 cDNA was expressed from a galactose inducible promoter situated on a plasmid with an adjustable copy number. Human Aquaporin-1 was C-terminally tagged with yeast enhanced GFP for quantification of functional expression, determination of sub-cellular localization, estimation of in vivo folding efficiency and establishment of a purification protocol. Aquaporin-1 was found to constitute 8.5 percent of total membrane protein content after expression at 15°C in a yeast host over-producing the Gal4p transcriptional activator and growth in amino acid supplemented minimal medium. In-gel fluorescence combined with western blotting showed that low accumulation of correctly folded recombinant Aquaporin-1 at 30°C was due to in vivo mal-folding. Reduction of the expression temperature to 15°C almost completely prevented Aquaporin-1 mal-folding. Bioimaging of live yeast cells revealed that recombinant Aquaporin-1 accumulated in the yeast plasma membrane. A detergent screen for solubilization revealed that CYMAL-5 was superior in solubilizing recombinant Aquaporin-1 and generated a monodisperse protein preparation. A single Ni-affinity chromatography step was used to obtain almost pure Aquaporin-1. Recombinant Aquaporin-1 produced in S. cerevisiae was not N-glycosylated in contrast to the protein found in human erythrocytes

Obrada otpadne vode tekstilne industrije u anaerobno-aerobnom membranskom bioreaktoru i postupkom naknadnog ozoniranja

U ovom istraživanju procijenjena je učinkovitost rada poluindustrijskog uređaja za obradu realne otpadne vode tekstilne industrije nakon procesa bojadisanja primjenom biološko-fizikalnog procesa te naknadnog kemijskog procesa. Provedeni biološko-fizikalni proces obrade sastojao se od biološkog anaerobno-aerobnog procesa te procesa ultrafiltracije poznatog kao membranski bioreaktorski sustav s izdvojenom membranom (MBR). Kemijski proces obrade otpadne vode obuhvaćao je oksidaciju ozonom. Eksperimenti su provedeni kroz duže vrijeme na poluindustrijskom bioreaktorskom postrojenju. Promatrane su karakteristike rada pilot membranskog bioreaktora s vanjskom membranskom jedinicom uz kontinuirani dotok realne otpadne vode. Karakteristike i rad postrojenja procijenjeni su na osnovi mjerenja karakteristika permeata i promjena vrijednosti parametara kvalitete vode (kemijske potrošnje kisika, KPK, boje, ukupnog dušika, koncentracije nitrita, NO2- i amonijaka, NH4+). Također je pomoću UV-spektrometrije praćena učinkovitost obezbojavanja otpadne vode nakon procesa ozoniranja

Potential of dyes as draw solutions in forward osmosis for the south african textile industry

The textile industry produces large volumes of wastewater that requires appropriate treatment before being released into&nbsp;the environment. Research globally has focused on advanced desalination technologies to augment the limited freshwater&nbsp;resources. Forward osmosis (FO) technology has gained substantial interest as a possible lower-energy desalination&nbsp;technology. However, challenges such as the availability of effective draw solutions (DS) have limited its implementation.&nbsp;This study evaluated alternative feed water resources and assessed the potential of dye solutions as DS. The aim is to dilute&nbsp;a concentrated dye DS to a target concentration for direct dye-batch use, thereby reclaiming water resources. The measured&nbsp;osmotic pressure (OP) of the alternative feed solutions (synthetic brackish water; syntethic seawater; seawater from the&nbsp;Atlantic and Indian Oceans; and wastewater from two textile factories) were 414, 2 761, 2 580, 2 614; 1 716 and 7 822 kPa,&nbsp;respectively. Three basic dyes (Maxilon Turquoise, Red and Blue) and three reactive dyes (Carmine, Olive Green and Black)&nbsp;were selected based on common use in the South African textile industry. The dye samples were prepared without and with lt at different concentrations and different dye-to-salt mass ratios ranging from 1:10 to 1:60. The OP trends for the basic&nbsp;dyes followed Blue &gt;&gt; Red &gt; Turquoise and for the reactive dyes Black &gt;&gt; Olive &gt; Carmine. The overall OP trend was Black &gt; Olive &gt; Carmine &gt; Blue &gt; Red &gt; Turquoise. The OP at different dye concentrations and different dye-to-salt ratios was mostly&nbsp;influenced by the dye chemistry and molecular weight (Mw) rather than the type of dye, i.e., reactive vs basic.The OP trend&nbsp;for the dye-to-salt ratios was 1:60 &gt; 1:50 &gt; 1:40 &gt; 1:30 &gt; 1:20 &gt; 1:10. For both the basic and reactive dyes a linear relationship&nbsp;exists between OP and dye concentration; as well as between OP and Mw. The dye DS exhibited larger OP compared to that of the FS evaluated, thus rendering them suitable DS

Validation and analysis of forward osmosis CFD model in complex 3D geometries

In forward osmosis (FO), an osmotic pressure gradient generated across a semi-permeable membrane is used to generate water transport from a dilute feed solution into a concentrated draw solution. This principle has shown great promise in the areas of water purification, wastewater treatment, seawater desalination and power generation. To ease optimization and increase understanding of membrane systems, it is desirable to have a comprehensive model that allows for easy investigation of all the major parameters in the separation process. Here we present experimental validation of a computational fluid dynamics (CFD) model developed to simulate FO experiments with asymmetric membranes. Simulations are compared with experimental results obtained from using two distinctly different complex three-dimensional membrane chambers. It is found that the CFD model accurately describes the solute separation process and water permeation through membranes under various flow conditions. It is furthermore demonstrated how the CFD model can be used to optimize membrane geometry in such as way as to promote the mass transfer

流通生活ノ意義

The hERG potassium channel is essential for repolarization of the cardiac action potential. Due to this vital function, absence of unintended and potentially life-threatening interactions with hERG is required for approval of new drugs. The structure of hERG is therefore one of the most sought-after. To provide purified hERG for structural studies and new hERG biomimetic platforms for detection of undesirable interactions, we have developed a hERG expression platform generating unprecedented amounts of purified and functional hERG channels. Full-length hERG, with or without a C-terminally fused green fluorescent protein (GFP) His (8)-tag was produced from a codon-optimized hERG cDNA in Saccharomyces cerevisiae. Both constructs complemented the high potassium requirement of a knock-out Saccharomyces cerevisiae strain, indicating correct tetramer assembly in vivo. Functionality was further demonstrated by Astemizole binding to membrane embedded hERG-GFP-His (8) with a stoichiometry corresponding to tetramer assembly. The 156 kDa hERG-GFP protein accumulated to a membrane density of 1.6%. Fluorescence size exclusion chromatography of hERG-GFP-His (8) solubilized in Fos-Choline-12 supplemented with cholesteryl-hemisuccinate and Astemizole resulted in a monodisperse elution profile demonstrating a high quality of the hERG channels. hERG-GFP-His (8) purified by Ni-affinity chromatography maintained the ability to bind Astemizole with the correct stoichiometry indicating that the native, tetrameric structure was preserved. To our knowledge this is the first reported high-yield production and purification of full length, tetrameric and functional hERG. This significant breakthrough will be paramount in obtaining hERG crystal structures, and in establishment of new high-throughput hERG drug safety screening assays