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reverse osmosis

Veena Nagaraj, Lucy Skillman, Goen Ho, Dan Li, Alexander Gofton
Microbiomes of full-scale seawater reverse osmosis membranes are complex and subject to variation within and between membrane units. The pre-existing bacterial communities of unused membranes before operation have been largely ignored in biofouling studies. This study is novel as unused membranes were used as a critical benchmark for comparison. Fouled seawater reverse osmosis membrane biofilm communities from an array of autopsied membrane samples, following a 7-year operational life-span in a full-scale desalination plant in Western Australia, were characterised by 16S rRNA gene metabarcoding using the bacterial primers 515F and 806R...
2017: NPJ Biofilms and Microbiomes
Aleksandra Szczuka, Kimberly M Parker, Cassandra Harvey, Erin Hayes, Avner Vengosh, William A Mitch
Coastal utilities exploiting mildly saline groundwater (<150 mg/L chloride) may be challenged by disinfection byproduct (DBP) formation, a concern likely to increase with sea-level rise. Groundwater from North Carolina coastal aquifers is characterized by large variations in concentrations of halides (bromide up to 10,600 μg/L) and dissolved organic carbon (up to 5.7 mg-C/L). Formation of 33 regulated and unregulated halogenated DBPs, including trihalomethanes (THMs), haloacetic acids (HAAs), haloacetonitriles, haloacetamides, and haloacetaldehydes, was measured after simulated chlorination of 24 coastal North Carolina groundwater samples under typical chlorination conditions...
June 12, 2017: Water Research
L Chekli, E Corjon, S A A Tabatabai, G Naidu, B Tamburic, S H Park, H K Shon
During algal bloom periods, operation of seawater reverse osmosis (SWRO) pretreatment processes (e.g. ultrafiltration (UF)) has been hindered due to the high concentration of algal cells and algal organic matter (AOM). The present study evaluated for the first time the performance of titanium salts (i.e. titanium tetrachloride (TiCl4) and polytitanium tetrachloride (PTC)) for the removal of AOM in seawater and results were compared with the conventional FeCl3 coagulant. Previous studies already demonstrated that titanium salts not only provide a cost-effective alternative to conventional coagulants by producing a valuable by-product but also minimise the environmental impact of sludge production...
June 18, 2017: Journal of Environmental Management
Qingchun Ge, Gary Lee Amy, Tai-Shung Chung
Forward osmosis (FO) has demonstrated its merits in hybrid FO seawater desalination. However, FO may have a potential for other applications if suitable draw solutes are available. In this study, a series of novel draw solutes based on oxalic acid (OA)-transitional metal complexes are presented. Influential factors of FO performance have been systematically investigated by varying the transitional metals, cations of the complex draw solutes as well as the experimental conditions. Compared to NaCl and other recently synthesized draw solutes, the OA complexes show superior FO performance in terms of high water fluxes up to 27...
June 10, 2017: Water Research
Qiuze Wang, Cyril Aubry, Yaxin Chen, Huaihe Song, Linda Zou
In this research, rGO laminates were prepared by a controlled partial reduction step, aimed to avoid aggregation and tune the interlayer spacing (d) between the rGO layers. The mild reducing agent vitamin C (L-AA) and cross-linker polycarboxilic acids were used to improve the stability of the assembled rGO laminate membranes. AFM was used for the first time to further investigate the statistical size distribution of spacing between rGO layers. Topographical images of the edges of the rGO layers were obtained with an AFM instrument, interlayer spacing profiles were extracted and then the data was plotted and fitted with Gaussian curves...
June 16, 2017: ACS Applied Materials & Interfaces
Hendrik J de Vries, Ian P G Marshall, Lars Schreiber, Caroline M Plugge
We report here the high-quality draft genome sequence of Sphingomonas sp. strain Sph1(2015), isolated from a fouled reverse osmosis membrane used for the production of high-quality drinking water. The draft sequence provides insights into the modus operandi of this strain to form biofilms on membrane surfaces. This knowledge offers tools to develop novel antifouling strategies.
June 15, 2017: Genome Announcements
Mohammed Kadhom, Weiming Hu, Baolin Deng
Knowing that the world is facing a shortage of fresh water, desalination, in its different forms including reverse osmosis, represents a practical approach to produce potable water from a saline source. In this report, two kinds of Metal-Organic Frameworks (MOFs) nanoparticles (NPs), UiO-66 (~100 nm) and MIL-125 (~100 nm), were embedded separately into thin-film composite membranes in different weight ratios, 0%, 0.05%, 0.1%, 0.15%, 0.2%, and 0.3%. The membranes were synthesized by the interfacial polymerization (IP) of m-phenylenediamine (MPD) in aqueous solution and trimesoyl chloride (TMC) in an organic phase...
June 14, 2017: Membranes
Brian M Pecson, Sarah C Triolo, Simon Olivieri, Elise C Chen, Aleksey N Pisarenko, Chao-Chun Yang, Adam Olivieri, Charles N Haas, R Shane Trussell, R Rhodes Trussell
To safely progress toward direct potable reuse (DPR), it is essential to ensure that DPR systems can provide public health protection equivalent to or greater than that of conventional drinking water sources. This study collected data over a one-year period from a full-scale DPR demonstration facility, and used both performance distribution functions (PDFs) and quantitative microbial risk assessment (QMRA) to define and evaluate the reliability of the advanced water treatment facility (AWTF). The AWTF's ability to control enterovirus, Giardia, and Cryptosporidium was characterized using online monitoring of surrogates in a treatment train consisting of ozone, biological activated carbon, microfiltration, reverse osmosis, and ultraviolet light with an advanced oxidation process...
June 6, 2017: Water Research
Youngpil Chun, Dennis Mulcahy, Linda Zou, In S Kim
Interest in forward osmosis (FO) research has rapidly increased in the last decade due to problems of water and energy scarcity. FO processes have been used in many applications, including wastewater reclamation, desalination, energy production, fertigation, and food and pharmaceutical processing. However, the inherent disadvantages of FO, such as lower permeate water flux compared to pressure driven membrane processes, concentration polarisation (CP), reverse salt diffusion, the energy consumption of draw solution recovery and issues of membrane fouling have restricted its industrial applications...
June 12, 2017: Membranes
S Choudhari, O Habimana, J Hannon, A Allen, E Cummins, E Casey
In an effort to mitigate biofouling on thin film composite membranes such as nanofiltration and reverse osmosis, a myriad of different surface modification strategies has been published. The use of silver nanoparticles (Ag-NPs) has emerged as being particularly promising. Nevertheless, the stability of these surface modifications is still poorly understood, particularly under permeate flux conditions. Leaching or elution of Ag-NPs from the membrane surface can not only affect the antimicrobial characteristics of the membrane, but could also potentially present an environmental liability when applied in industrial-scale systems...
July 2017: Biofouling
Shengyong Jia, Yuxing Han, Haifeng Zhuang, Hongjun Han, Kun Li
A lab-scale membrane bioreactor (MBR) with intermittent aeration was operated to treat the reverse osmosis concentrate derived from coal gasification wastewater. Results showed intermittent aeration represented slight effect on organic matter reduction but significant effect on nitrite and nitrate reduction, with 6h aeration and 6h non-aeration, removal efficiencies of organic matter, chloride, sulfate, nitrite and nitrate reached 48.35%, 40.91%, 34.28%, -36.05% and 64.34%, respectively. High-throughput sequencing showed a microorganisms succession from inoculated activated sludge (S1) to activated sludge in MBR (S2) with high salinity...
May 29, 2017: Bioresource Technology
Steven Earl Strong, Joel David Eaves
Porous two-dimensional crystals like graphene have the potential to revolutionize reverse osmosis membrane technology. The permeability is a common figure of merit that describes the ease with which water flows through a membrane. For two-dimensional crystals, the permeability can be orders of magnitude higher than it is in conventional reverse osmosis membranes. We apply our Gaussian Dynamics nonequilibrium molecular dynamics simulation method to very hydrophobic membranes and find that the current-pressure drop relationship becomes nonlinear...
June 9, 2017: Journal of Physical Chemistry. A
Antonin Azaïs, Julie Mendret, Guillaume Cazals, Eddy Petit, Stephan Brosillon
Considerable interest has been given to using nanofiltration (NF) in lieu of reverse osmosis for water reclamation schemes due to lower energy consumption, higher flux rates while ensuring good micropollutants rejection. The application NF results in the generation of a large concentrated waste stream. Treatment of the concentrate is a major hurdle for the implementation of membrane technologies since the concentrate is usually unusable due to a large pollutants content. This work focuses on the application of ozonation as pretreatment of urban NF concentrates, the generation of transformation products and their relative toxicity...
May 30, 2017: Journal of Hazardous Materials
Rong Cheng, Ling Zhao, Pinghe Yin
Toxicity assessment of nitration/ultrafiltration/reverse osmosis (nitration/UF/RO) project, which has recently been widely used as an efficient process with applications in practical leachate treatment, was very limited. In the present study, DNA damage of leachates was investigated before and after the nitration/UF/RO process by a battery of assays with human hepatoma cells. Methyletrazolium assay showed a high cytotoxicity of 97.1% after being exposed to the highest concentration of raw leachate for 24 h, and a cytotoxicity of 26% in effluent at a concentration of 30% (v/v)...
June 6, 2017: Journal of Applied Toxicology: JAT
Lu Lin, Wenbin Jiang, Pei Xu
The synergistic impact of salts and organic matter on adsorption of ibuprofen and sulfamethoxazole by three types of biochar and an activated carbon was investigated using reclaimed water reverse osmosis (RO) concentrate and synthetic solutions spiked with target organic compounds and non-target water constituents (e.g., Na(+), Ca(2+), Mg(2+), K(+), Cl(-), SO4(2-), alkalinity, humic acid (HA), and bovine serum albumin (BSA)). Kinetic modeling was used to better understand the adsorption process between the carbon adsorbents and pharmaceuticals and to elucidate the impact of water chemistry on pharmaceuticals adsorption...
June 1, 2017: Science of the Total Environment
Steven M Jones PhD Pe Michael J Watts PhD Pe Zaid K Chowdhury PhD Pe Bcee And S Ranil Wickramasinghe PhD Pe
Effluent samples from three (3) WRRFs were individually characterized for presence and concentration of 94 different chemicals of emerging concern (CECs), utilizing analytical methods with reporting limits in the low-parts-per-trillion. Following CEC analysis, each sample was subjected to dead-end, pressurized membrane filtration with either a nanofiltration (NF) or reverse osmosis (RO) membrane. The majority of the measured CECs were rejected by both membranes by 1-log removal (90%) or greater. However, nine (9) of the 94 CECs had average rejection rates by the NF membrane less than 90%...
May 12, 2017: Water Environment Research: a Research Publication of the Water Environment Federation
S J Judd
A reflection of the place cost analysis holds in membrane process technology research and development is provided. The review encompassed two membrane processes and applications: (a) reverse osmosis (RO) for seawater desalination, and (b) membrane bioreactor (MBR) technology for wastewater treatment. The cost analysis undertaken extended to (i) the determination of operating expenditure (OPEX) trends using simple analytical expressions, (ii) the subsequent estimation of the sensitivity of OPEX to individual system parameters, and (iii) published data on CAPEX for individual full-scale installations or from cost analyses...
May 16, 2017: Water Research
Laura Blanco, Daphne Hermosilla, Carlos Negro, Nathalie Swinnen, David Prieto, Ángeles Blanco
To reduce fresh water consumption in a polyvinyl chloride (PVC) plant, the effluent from a biological treatment must be demineralized to be re-used in the resin polymerization process. Demineralization is a critical process, since the quality and the stability of the PVC resins are highly influenced by the water quality used in the process. The main target values for water parameters are the following: conductivity <10 μScm(-1), TOC < 10 mg L(-1), and Al < 0.1 mg L(-1). To achieve this quality, several reverse osmosis membranes from different materials and suppliers were tested and compared in the demineralization treatment...
May 29, 2017: Environmental Science and Pollution Research International
Michele Totaro, Beatrice Casini, Paola Valentini, Mario Miccoli, Serena Giorgi, Andrea Porretta, Gaetano Privitera, Pier Luigi Lopalco, Angelo Baggiani
BACKGROUND: Patients receiving haemodialysis are exposed to a large volume of dialysis fluid. The Italian Society of Nephrology (ISN) published guidelines and microbial quality standards on dialysis water (DW) and solutions to ensure patient safety. AIM: Aim of the study was to identify microbial and chemical hazards and to evaluate disinfection treatments quality in DW plants. METHODS: In the years 2015 and 2016 water networks and DW plants (closed loop and online monitors) of nine dialysis wards of Italian hospitals, hosting 162 dialysis beds overall, were sampled on a monthly basis to determine the parameters provided by ISN guidelines...
May 22, 2017: Journal of Hospital Infection
Zhonglong Yin, Cheng Yang, Chao Long, Aimin Li
Reverse osmosis (RO) is a promising technology for treating and reusing textile secondary effluent (SE). To better understand the effect of membrane surface properties on membrane fouling, the performances of three commercial polyamide thin-film composite RO membranes (BW30-4040, CPA2-4040, and RE-4040-FEN) with different roughness and hydrophilicity were investigated for treating textile SE. The RO membranes were characterized by ATR-FTIR, SEM, AFM, and contact angle, respectively. The results showed that the flux increased with an increase in the surface hydrophilicity of membrane...
May 24, 2017: Environmental Science and Pollution Research International
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