scholarly journals Capillary-driven desalination in a synthetic mangrove

2020 ◽  
Vol 6 (8) ◽  
pp. eaax5253 ◽  
Author(s):  
Yunkun Wang ◽  
Jongho Lee ◽  
Jay R. Werber ◽  
Menachem Elimelech
Keyword(s):  
Reverse Osmosis ◽  
Pure Water ◽  
Stable Operation ◽  
Nanoporous Membranes ◽  
Membrane Separations ◽  
Plant Hydraulics ◽  
Salty Water ◽  
Water Conduction ◽  
Capillary Pressures ◽  
Mangrove Trees

According to the cohesion-tension theory, mangrove trees desalinate salty water using highly negative pressure (or tension) that is generated by evaporative capillary forces in mangrove leaves. Here, we demonstrate a synthetic mangrove that mimics the main features of the natural mangrove: capillary pumping (leaves), stable water conduction in highly metastable states (stem), and membrane desalination (root). When using nanoporous membranes as leaves, the maximum osmotic pressures of saline feeds (10 to 30 bar) allowing pure water uptake precisely correspond to expected capillary pressures based on the Young-Laplace equation. Hydrogel-based leaves allow for stable operation and desalination of hypersaline solutions with osmotic pressures approaching 400 bar, fivefold greater than the pressure limits of conventional reverse osmosis. Our findings support the applicability of the cohesion-tension theory to desalination in mangroves, provide a new platform to study plant hydraulics, and create possibilities for engineered membrane separations using large, passively generated capillary pressures.

Biomimetic Membrane Simulation for Water Desalination

2018 ◽  
Author(s):  
Peter Ozaveshe Oviroh ◽  
Rokhsareh Akbarzadeh ◽  
Tien-Chien Jen
Keyword(s):  
Water Purification ◽  
Saline Water ◽  
New Technology ◽  
Pure Water ◽  
Water Desalination ◽  
Membrane Thickness ◽  
Nanoporous Membranes ◽  
Factors Affecting ◽  
Biomimetic Membrane ◽  
Low Efficiency

Reverse Osmosis (RO) for the desalination of saline water is associated with tremendous energy costs and low efficiency. Improvements in nanotechnology have led to the development of a variety of nanoporous membranes for water purification. Biomimetic membrane is an emerging new technology for water purification. Consequently, there is still much to study about the function and structure of these kinds of membranes. The purpose of this work was to determine which factors influence membrane performance. The focus was on those factors affecting membranes in pure water. Biomimetic membrane using MoS2 which has a higher rate of ion rejection and higher water permeability was studied through molecular dynamics simulations using reactive force fields (ReaxFF). The behaviour of the membrane before subjecting it to desalination was studied. The effect of water temperature, atmospheric pressure and membrane thickness on performance of membrane was studied. The permeability flux was calculated and compared in different conditions and the relation between these factors was revealed.

scholarly journals An Experimental Study on Wetting of Coal Dust by Surfactant Solution

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Yidan Jiang ◽  
Pengfei Wang ◽  
Ronghua Liu ◽  
Ye Pei ◽  
Gaogao Wu
Keyword(s):  
Surface Tension ◽  
Contact Angle ◽  
Reverse Osmosis ◽  
Sodium Sulfate ◽  
Moisture Absorption ◽  
Coal Dust ◽  
Pure Water ◽  
Surfactant Solution ◽  
Limited Range ◽  
Dust Reduction

Surfactants can improve the wetting performance of the dust-reduction spraying water, thus improving the dust-reduction effect by spray. In this study, the performance of surfactant solution in wetting coal dust was investigated through experiments. In addition, the effects of surfactant type, mass fraction, metamorphic degree of coal, particle size, and additives were investigated. According to the results of surface tension experiments, the surface tension of the solution decreased with the increase of the concentration of surfactant. However, after reaching CMC, the surface tension did not have significantly decrease. SDBS and OP-10 had higher efficiency in decreasing the surface tension than the other two types of surfactants. The addition of sodium sulfate additives can further reduce the surface tension of the surfactant solution by a limited range. The coal dust wetting experiment showed that with the increase in the concentration of the surfactant, the contact angle of the droplets on the coal dust tablet was continuously reduced, and the wettability of the solution was continuously improved. The wettability of the OP-10 solution was optimal. At the same concentration, the minimum contact angle can be obtained in the OP-10 solution. As the contact angle of the coal dust increased, the growth rate in the coal dust reverse osmosis moisture absorption of the surfactant solution relative to the pure water increased. After the addition of sodium sulfate, the reverse osmosis moisture absorption of coal dust increased to varying degrees. In addition, as the concentration of additives increased, the moisture absorption of coal dust increased.

scholarly journals Optimization of In Situ Backwashing Frequency for Stable Operation of Anaerobic Ceramic Membrane Bioreactor

Processes ◽  
2020 ◽  
Vol 8 (5) ◽  
pp. 545 ◽  
Author(s):  
Rathmalgodage Thejani Nilusha ◽  
Tuo Wang ◽  
Hongyan Wang ◽  
Dawei Yu ◽  
Junya Zhang ◽  
...  
Keyword(s):  
Membrane Fouling ◽  
Membrane Filtration ◽  
Membrane Bioreactor ◽  
Ceramic Membrane ◽  
Pure Water ◽  
Ex Situ ◽  
Stable Operation ◽  
Chemical Cleaning ◽  
Cake Layer

The cost-effective and stable operation of an anaerobic ceramic membrane bioreactor (AnCMBR) depends on operational strategies to minimize membrane fouling. A novel strategy for backwashing, filtration and relaxation was optimized for stable operation of a side stream tubular AnCMBR treating domestic wastewater at the ambient temperature. Two in situ backwashing schemes (once a day at 60 s/day, and twice a day at 60 s × 2/day) maintaining 55 min filtration and 5 min relaxation as a constant were compared. A flux level over 70% of the initial membrane flux was stabilized by in situ permeate backwashing irrespective of its frequency. The in situ backwashing by permeate once a day was better for energy saving, stable membrane filtration and less permeate consumption. Ex situ chemical cleaning after 60 days’ operation was carried out using pure water, sodium hypochlorite (NaOCl), and citric acid as the order. The dominant cake layer was effectively reduced by in situ backwashing, and the major organic foulants were fulvic acid-like substances and humic acid-like substances. Proteobacteria, Firmucutes, Epsilonbacteria and Bacteroides were the major microbes attached to the ceramic membrane fouling layer which were effectively removed by NaOCl.

scholarly journals Application of reverse osmosis at NPP and verification of the process for primary coolant treatment in temelín nuclear power

2021 ◽  
Vol 7 (2) ◽  
pp. 1-7
Author(s):  
Skala M. ◽  
Kůs P. ◽  
Kotowski J. ◽  
Kořenková H.
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Boric Acid ◽  
Reverse Osmosis ◽  
Nuclear Power ◽  
Power Plants ◽  
Pure Water ◽  
Feed Solution ◽  
Primary Coolant ◽  
Purification System

Drained primary coolant from nuclear power plants containing boric acid is currently treated in the system of evaporators and by ion exchangers. Reverse osmosis as an alternative process to evaporator was investigated. Using reverse osmosis, the feed primary coolant is separated into two output streams: retentate and permeate. Retentate stream consists of concentrated boric acid solution together with other components, while permeate stream consists of purified water. In the first phase ofthe project the reverse osmosis modules from several manufactures were tested on a batch laboratory apparatus. Certain modifications to the pH of the feed solution were needed to enable the tested membranes to concentrate the H3BO3 in the retentate stream, separate from the pure water in the permeate stream. Furthermore, the separation capability for other compounds present in primary coolant such as K, Li or NH3 were evaluated. In the final phase of the project the pilot-plant unit of reverse osmosis was tested in nuclear power plant Temelín. It was installed in the Special Purification System SVO-6 for the regeneration of boric acid. The aim of the tests performed in Temelín nuclear power plant was to verify possible use of reverse osmosis for the treatment of primary coolant.

scholarly journals Surface grafting of polyvinyl alcohol (PVA) cross-linked with glutaraldehyde (GA) to improve resistance to fouling of aromatic polyamide thin film composite reverse osmosis membranes using municipal membrane bioreactor effluent

2019 ◽  
Vol 14 (3) ◽  
pp. 614-624 ◽  
Author(s):  
Godwill Kasongo ◽  
Chad Steenberg ◽  
Bradley Morris ◽  
Gracia Kapenda ◽  
Nurah Jacobs ◽  
...  
Keyword(s):  
Surface Modification ◽  
Reverse Osmosis ◽  
Membrane Bioreactor ◽  
Pure Water ◽  
Water Flux ◽  
Film Composite ◽  
Thin Film Composite ◽  
Flux Decline ◽  
Pure Water Flux ◽  
The Impact

Abstract Membrane surface modification is a favourable method to handle fouling during wastewater treatment processes. In this study, grafting of polyvinyl alcohol (PVA) through cross-link with Glutaraldehyde was applied to a thin film composite reverse osmosis membrane to enhance the resistance to flux decline. The analytical analyses attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and scanning electron microscopy were performed to evaluate the impact of surface modification. Biofouling using Escherichia coli (E. coli) bacterial solution and fouling tests using a bench scale reverse osmosis system with a simulated secondary effluent from a membrane bioreactor were used to assess the impact of the surface modification initiated on antifouling properties of the membrane. It was shown that the morphological structure and the chemical properties of the membrane were altered, whereas the pure water flux slightly decreased after modification. Although a slight decrease of salt rejection was observed, the membrane resistance to fouling improved and the biofouling model used revealed the anti-biofouling capacity of the membrane. The flux decline and flux recovery ratios improved with an increase in PVA concentration. The sterilization ratio increased from 33.8 to 36.8% and the pure water flux decline decreased from 46.04 to 25.94% after modification.

Experimental Study on Instability Behavior of Thermosyphon and Grooved Heat Pipe with TiO2-Nanofluid

2013 ◽  
Vol 711 ◽  
pp. 285-290
Author(s):  
Dong Ryun Shin ◽  
Seok Ho Rhi ◽  
Kyung Il Cha
Keyword(s):  
Heat Pipe ◽  
Pure Water ◽  
Volume Ratio ◽  
Heat Pipes ◽  
Temperature Perturbation ◽  
Stable Operation ◽  
Stability Behavior ◽  
Inner Diameter ◽  
Cooling Media ◽  
The Stability

In the present study, TiO2-nanofluid with different volume ratio was used as working fluids of thermosyphon and grooved heat pipe to investigate working stability. The stability behavior of system was studied with various parameters such as volume concentration of nanoparticle, orientation, heat flux, and cooling media were investigated. Specially, the present experimental unstable working behaviors between TiO2-nanofluid and pure water were compared. In the present study, the TiO2-nanoparticles were dispersed into pure water with each of cross blended concentrations of 0.05%, 0.1%, 0.5%, and 1%. In the present study, the rate of growth of unstable disturbances is expressed in terms of temperature perturbation. The best stable operation was observed with thermosyphon of 0.5 % TiO2-nanofluid. The best operation state with nanofluidic TS was observed in the 90° inclination and α = 0.5. In the present study, the enhancement of heat pipe performance with TiO2-nanofluid is presented. The both heat pipes were fabricated from the straight stainless pipe with the inner diameter and length of 10, 500 mm, respectively.

scholarly journals Development of low pressure reverse osmosis membrane for desalination process

2019 ◽  
Vol 4 (3) ◽  
Author(s):  
Abdul Rahman Hassan ◽  
Al Dabbaas Khuzama Mansoor A ◽  
Nor Azirah Sulaiman ◽  
Nurul Hannan Mohd Safari ◽  
Sabariah Rozali
Keyword(s):  
Reverse Osmosis ◽  
Sodium Dodecyl Sulphate ◽  
Brackish Water ◽  
Pure Water ◽  
Sodium Dodecyl ◽  
Low Pressure ◽  
Real Problem ◽  
Sustainable Solutions ◽  
Water Permeation ◽  
Sds Surfactant

Water shortage has become a real problem at global level and therefore, new and innovative technologies were established to provide sustainable solutions to water crisis. One of the effective approaches to resolve the global challenges is introducing the membrane-based desalination. Reverse Osmosis (RO) is a pressure driven membrane process which becoming increasingly popular and widely used for water purification applications that require high salt rejection such as brackish and seawater desalination. In this study, the influence of Sodium dodecyl sulphate (SDS) surfactant in producing the finest membrane for desalination were investigated in terms of performance, morphological structure and molecular orientation. From a polymer blending of polysulfone (PSF)/N-Methyl-2-Pyrrolidone (NMP)/polyvinylpyrrolidone (PVP)/sodium dodecyl sulphate (SDS) were formulated for making of low pressure reverse osmosis (LPRO) membrane. In order to examine the influence of SDS surfactant, different concentration from 0 wt% to 3 wt% were employed for desalination application of 10,000ppm (brackish water) and 50 000ppm (seawater). Experimental data showed that the increasing of 0.5wt% in surfactant produced higher pure water permeation (PWP) and flux. At 2.5wt% of SDS, the LPRO membranes showed the highest PWP of about 44.8L/m2h and brackish water flux at 45.58L/m2h. Meanwhile, at 3.0wt%, the highest flux of seawater at 39.37L/m2h was obtained. Moreover, the optimized LPRO (2wt% of SDS) membrane performed high rejection ratio of 90.9% for brackish water and 90.4% for seawater concentration of 10,000ppm and 50,000ppm, respectively. Therefore, the findings revealed that the fabricated LPRO membrane having a good potential to be used as eco-efficient desalination process of brackish water and seawater technology.

scholarly journals Uji Kinerja Instalasi Daur Ulang Air Limbah Industri Kaleng di Jakarta

2019 ◽  
Vol 20 (2) ◽  
pp. 225
Author(s):  
Satmoko Yudo ◽  
Rudi Nugroho
Keyword(s):  
Water Quality ◽  
Reverse Osmosis ◽  
Pure Water ◽  
Wastewater Reuse ◽  
Treatment Plant ◽  
Ph Control ◽  
Clean Water ◽  
Industry Growth ◽  
Washing Process ◽  
Wastewater Recycling

ABSTRACTThe need for clean water consumption continues to increase in line with the current population and industry growth. The canned industry is one of the industries that consume a considerable amount of water for the production process, while the availability of clean water sources is very limited, both in quantity and quality. One alternative solution to the problem above is by building a wastewater treatment plant into reusable water (recycling) to meet the needs of the washing process in the industry. This paper discusses the testing of wastewater recycling installations into clean water in a canned industry in Jakarta. The process of recycling wastewater is divided into several stages, namely chemical processes for pH control, biological processes of activated sludge, biofilter, and filtration. Afterward, the wastewater is filtered using a reverse osmosis membrane. The test results show that the water quality of recycling wastewater and filtered wastewater using RO membranes could produce pure water quality. The use of water for the process in the canned industry is large enough for canned washing processes. Therefore, by using the recycling technology, the use of water, especially for the washing process, can be saved up to 100%.Keyword : wastewater reuse, reverse osmosis, can industriesABSTRAKKebutuhan akan konsumsi air bersih terus meningkat sejalan dengan pertumbuhan penduduk dan industri saat ini. Industri kaleng merupakan salah satu industri yang mengkomsumsi air dalam jumlah yang cukup banyak untuk proses produksi, sedangkan  ketersediaan sumber air bersih sangat terbatas, baik secara kuantitas maupun kualitas. Salah satu alternatif solusi permasalahan di atas yaitu dengan membangun instalasi pengolahan air limbah menjadi air yang dapat digunakan kembali (daur ulang) guna memenuhi kebutuhan proses pencucian di industrinya. Makalah ini membahas tentang pengujian instalasi daur ulang air limbah menjadi air bersih di salah satu industri kaleng di Jakarta. Proses pengolahan daur ulang air limbah terbagi dalam beberapa tahap yaitu proses pengolahan air limbah produksi dengan proses kimia untuk kontrol pH, proses biologis lumpur aktif dan biofilter serta filtrasi. Kemudian berikutnya dengan proses filtrasi menggunakan membran reverse osmosis. Hasil pengujian menunjukkan bahwa kualitas air pengolahan daur ulang air limbah dan penyaringan dengan menggunakan membran RO menghasilkan kualitas air yang murni. Pemakaian air untuk proses di industri kaleng yang cukup besar adalah untuk proses pencucian kaleng. Sehingga dengan adanya teknologi daur ulang, maka pemakaian air khususnya untuk proses pencucian dapat dihemat sampai 100%.Kata kunci : Daur ulang air limbah, reverse osmosis, industri kaleng

scholarly journals The Permeability and Selectivity of the Polyamide Reverse Osmosis Membrane were Significantly Enhanced by PhSiCl3

Membranes ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 142
Author(s):  
Junjie Yu ◽  
Kaifeng Gu ◽  
Binbin Yang ◽  
Kaizhen Wang ◽  
Yong Zhou ◽  
...  
Keyword(s):  
Reverse Osmosis ◽  
Pure Water ◽  
Polymer Network ◽  
Water Flux ◽  
Covalent Bond ◽  
Phenyl Group ◽  
Household Water ◽  
Water Salt ◽  
Pure Water Flux ◽  
Polyamide Film

The work briefly introduces the nano-composite reverse osmosis (RO) membrane with more permeability and selective performance, and we adopted the phenyltrichlorosilane precursor with better chemical stability and greater spatial resistance. The phenyltrichlorosilane concentration was mainly discussed in this work. The in-situ hydrolysis of phenyltrichlorosilane and the occurrence of ammonia hydrolysis make it effectively incorporated into the polyamide film. The covalent bond and hydrogen bond of phenyltrichlorosilane and polyamide (PA) can be realized. The phenyl group can extend in the polyamide polymer network and give the film corresponding functions. There will be fewer non-selective defects between phenyltrichlorosilane and PA. Under the premise of maintaining the water-salt selectivity of the membrane, along with the increase of benzene trichlorosilane loading, the 300% pure water flux can be achieved and the desalination rate remains at 98.1–98.9%. This reverse osmosis (RO) is suitable for household water purification.

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