Water Osmosis Research Articles

Three-segmented counterflow pilot-scale electrodialysis for ammonia and potassium treatment in liquid anaerobic digestate: A trade-off among advanced ion removal, nutrients concentration limitation, and energy consumption

In this paper, a three-segmented counterflow (COUN) electrodialysis (ED) for ammonia (NH4+-N) and potassium (K+) treatment in liquid anaerobic digestate (LAD) was proposed to break the high-concentration limit of nutrient recovery without sacrificing the ion removal performance and energy efficiency. The effects of the COUN operation mode on ED performance were studied based on pilot-scale experiments. The results indicate that the COUN mode improves the distribution of concentration difference (Δc). Hence, the ion fluxes of NH4+-N and K+ have increased by 51.0% and 25.3%, respectively. A highly concentrated product (NH4+-N at 10428 ± 225 mg/L and K+ at 7500 ± 156 mg/L) can be obtained, and the concentration multiples of NH4+-N and K+ have increased by 14.1% and 9.8%, respectively, with slight effects on their removal rates. The current efficiency for NH4+-N and K+ was increased by 38.1% and 14.5%, reaching 54.7 ± 3.5% and 12.4 ± 0.5%, respectively, and the final energy consumption of 3.8 ± 0.2 kWh/kg-N) has reduced by 31.8%. The non-ideal transport mechanisms associated with the Δc (back-diffusion and water osmosis) have been taken into consideration. The COUN mode is a new exploration of the ED operating patterns to alleviate the detrimental effect of high Δc. It will provide a reference for designing and operating large-scale engineering projects for nutrient recovery by ED process and a trade-off among advanced ion removal, high-concentration limitation, and energy consumption.

Restoring capacity and efficiency of vanadium redox flow battery via controlled adjustment of electrolyte composition by electrolysis cell

One of the major challenges in vanadium redox flow batteries (VRFB) is a gradual decrease of available capacity over operation time. The VRFB capacity fade is a complex issue that affects volume, total content, and average valence of vanadium ions in posolyte and negolyte. Imbalances that occur due to crossover of vanadium ions, osmosis and electroosmosis of water can be dealt with by intermittent mixing of posolyte and negolyte, thereby prolonging VRFB operation at high capacity rates. However, the change in the average oxidation state (AOS) should be considered for stable VRFB operation. The imbalance of vanadium valence arises due to side reactions during charge–discharge processes. This work proposes a novel operando method for restoration of the initial VRFB capacity. Partial posolyte reduction on the cathode and oxygen evolution reaction on the RuO2/Ti electrode of the electrolysis cell, following which electrolytes mix and recharge, allow to recover initial performance parameters. Optimizing electrolysis conditions ensures high energy efficiency of the rebalancing procedure. Coulometric sensors data provide the charge required for posolyte reduction. The proposed approach for VRFB capacity recovery allows for complete restoration of performance parameters regardless of the magnitude of a capacity drop.

Exploring the water osmosis within physical and chemical controlled confinement for protein sensing.

Proteins play a prominent role in life activities and the occurrence of disease, which is highly determined by their amino acid sequences and conformations. Therefore, protein sensing, including detection, sequencing, and confirmation characterization, has been attracting increasing attention in almost all areas. While nanopore sensing is regarded as one of the most promising approaches for single-molecule protein sensing, the heterogeneity of the protein charges raises a great challenge for capturing individual proteins into nanopores. Conventionally, the main forces to drive a molecule into the nanopore are the electrophoresis force determined by the charge carried by the molecule with an applied voltage, and the electroosmotic flow determined by the asymmetric anion/cation flow inside the nanopore also with an applied voltage. Here, we proposed water osmosis that is independent of the applied voltage to drive the protein/peptide with all kinds of charges. With the highly physical and chemical controlled confinement of aerolysin nanopore, by constructing an asymmetric salt concentration between two sides of the detection system, water osmosis occupied the dominance of all the fluidics inside aerolysin, further promoting the capturing of individual peptides without applied voltage. By enhancing the salt concentration gradient, the capture efficiency of a neutral model peptide, Ang II, was observed to be improved by nearly 13-fold. Furthermore, we explore the factors beyond salt concentration gradient, including charge distribution of the nanopore, solution composition, and lipid composition to precisely regulate the water osmosis and promote the peptide characterization with only one amino acid difference. Overall, the application of water osmosis in aerolysin nanopore can not only increase peptide capture frequency but also promote the development of proteomics research.

Non-Aquaporin Water Channels.

Water transport through membrane is so intricate that there are still some debates. AQPs are entirely accepted to allow water transmembrane movement depending on osmotic gradient. Cotransporters and uniporters, however, are also concerned in water homeostasis. UT-B has a single-channel water permeability that is similar to AQP1. CFTR was initially thought as a water channel but now not believed to transport water directly. By cotransporters, such as KCC4, NKCC1, SGLT1, GAT1, EAAT1, and MCT1, water is transported by water osmosis coupling with substrates, which explains how water is transported across the isolated small intestine. This chapter provides information about water transport mediated by other membrane proteins except AQPs.

Effectiveness of a Water Disinfection Method Based on Osmosis and Chlorine Dioxide for the Prevention of Microbial Contamination in Dental Practices.

In dental clinics, the infections may be acquired through contaminated devices, air, and water. Aerosolized water may contain bacteria, grown into the biofilm of dental unit waterlines (DUWLs). We evaluated a disinfection method based on water osmosis and chlorination with chlorine dioxide (O-CD), applied to DUWL of five dental clinics. Municipal water was chlorinated with O-CD device before feeding all DUWLs. Samplings were performed on water/air samples in order to research total microbial counts at 22–37 °C, Pseudomonas aeruginosa, Legionella spp., and chlorine values. Water was collected from the taps, spittoons, and air/water syringes. Air was sampled before, during, and after 15 min of aerosolizing procedure. Legionella and P. aeruginosa resulted as absent in all water samples, which presented total microbial counts almost always at 0 CFU/mL. Mean values of total chlorine ranged from 0.18–0.23 mg/L. Air samples resulted as free from Legionella spp. and Pseudomonas aeruginosa. Total microbial counts decreased from the pre-aerosolizing (mean 2.1 × 102 CFU/m3) to the post-aerosolizing samples (mean 1.5 × 10 CFU/m3), while chlorine values increased from 0 to 0.06 mg/L. O-CD resulted as effective against the biofilm formation in DUWLs. The presence of residual activity of chlorine dioxide also allowed the bacteria reduction from air, at least at one meter from the aerosolizing source.

Desalination by endothermal generators

Many regions of the planet are under water stress that can create humanitarian disasters. Where available, seawater can undergo a desalination process to produce drinkable water. The desalination processes may use thermal and mechanical energy. Methods based on evaporation and flashing are thermal driven, whether water osmosis uses mechanical energy. An endothermal motor can generate both mechanical and thermal energy. This paper focuses on a Diesel generator able to supply an electrical power of 362 kW. It evaluates the water production of a combined system with a Multi-Effect Evaporator and a Reverse Osmosis system. The Multi-Effect Evaporator uses the thermal energy from the exhaust gases; the Reverse Osmosis uses the generator's electrical power. The generator is typical for marine applications and can be deployed in humanitarian operations. The system can produce 1,011 m3 per day of drinkable water, enough to supply the daily basic needs of a population of about 50,500 persons.

Covalent Organic Framework Membrane with Turing Structures for Deacidification of Highly Acidic Solutions

AbstractThe deacidification of highly acidic industrial wastewater, such as the spent fuel reprocessing feed liquid, is of great significance for the smooth progress of the subsequent treatment processes. Herein, a novel covalent organic framework (COF) membrane with bidirectional anisotropic Turing structures is synthesized for the first time and used for deacidification. The COF membrane presents linear and hydrophobic properties on one side and porous and superhydrophilic properties on the other side, which makes the water permeability of hydrophilic side 45 times higher than that of the hydrophobic side and effectively prevents the reverse osmosis of water. Impressively, the COF membrane has excellent thermal, acid, and irradiation stabilities, and an extraordinarily high ability to intercept metal ions in a complex multi‐ion solution containing 5 m HNO3, with the interception rate up to 100%. However, H+ can easily pass through the membrane with the permeation flux of 1015.7 mol L−1 m−2, which realizes the efficient deacidification of high acidic solutions. This study provides not only a new idea for the design and preparation of Turing‐structural membranes, but also a feasible strategy for the deacidification and process simplification of spent fuel reprocessing feed liquid and other industrial wastewater with high acidity.

INNOVATIVE POTENTIAL OF FRESHWATER RESOURCES OF UKRAINE: STATE, REGIONAL FEATURES AND DEVELOPMENT PROSPECTS

Introduction. Restoration and cleaning of freshwater resources remains a fairly relevant issue both at the national level and in the world. The strategic goals of sustainable development remain providing clean water to all the population. There is water pollution, which is quite acutely puts in prior to humanity. The study of the current state of the innovative potential of freshwater resources and prospects of technological development in world trends are quite relevant and important. The purpose of the article is the process of studying the current state, regional features and prospects for the development of innovative potential of freshwater resources of Ukraine. The results. Analyzed, the current state of expenditures for innovation in the protection and rational use of freshwater resources. It is determined that the structure of protection costs and rational use of freshwater resources is divided into the costs of protection and rehabilitation of soil, underground and surface water, cleaning of reciprocal water and research work of environmental orientation. Analysis show that the largest share in 2020 in the structure of expenses occupy current expenses – 75,02%, with capital investments – 24,97%. The structure of capital investments amounted to 61,83% in defense and rehabilitation of soil, underground and surface water, 12,80% for the purification of reciprocal waters and 7.67% on research and research activities of environmental orientation. It is determined that the largest amount of capital investment was aimed at protecting and rehabilitation of soil, underground and surface waters – 2554224,5 thousand UAH and to clean reciprocity – 1578201,4 thousand UAH. Conclusions. It is substantiated that the costs are aimed at scientific research of environmental protection unreasonably insignificant in volumes. The analysis showed that during the last three years they did not exceed 0.3% of the total environmental expenses in Ukraine, this negatively affects the development and implementation of advanced innovation technologies in the sphere of resource conservation. It is determined that modern trends of technological development in the water and its purification can be: reverse osmosis (RO) of sea, brackish and river water – for the desalination of salty water; Nanofiltration, reverse osmosis, membrane bioreactors, microfiltration and disinfection – for water and sewage treatment. Keywords: freshwater resources, innovations, expenses, capital investments.

Preparation of LiOH through BMED process from lithium-containing solutions: Effects of coexisting ions and competition between Na+ and Li+

Bipolar membrane electrodialysis (BMED) is a promising method to produce LiOH from lithium containing solutions. However, the coexisting ions will significantly affect the current efficiency of preparing LiOH. Herein, the influence of the ion's property on the mass transfer behavior of the BMED was investigated, establishing the relations between hydration number and ion's migration as well as water osmosis. Effects of coexisting ions on the lithium migration and current efficiency were studied. The results show that the competition from Na+ and K+ reduced the migration rate of Li+ and increased the energy consumption of producing LiOH, and the coexisting K+ had greater impact compared with Na+. The coexisting SO42− in feed solution generated severer lithium leakage into the acid compartment than Cl− did. In addition, influences of the Na/Li molar ratio in feed solution, current density, and characteristics of cation exchange membrane (CEM) on competitions between Na+ and Li+ were discussed. With increasing the Na/Li molar ratio, lithium concentration in base solution decreased, while the energy consumption increased, owing to the dominant role of Na+ in competitive migration and backward diffusion. Larger ion exchange capacity and lower resistivity of CEMs were beneficial for avoiding negative-transfer and enhancing current efficiency.

Continuous separation of alkali and salt through pressure-concentration double driven diffusion dialysis and its mathematic model

• A novel membrane process was investigated to separate NaOH/Na 2 WO 4 continuously. • The alkali recovery ratio here was much higher than that of conventional process. • A model based on irreversible thermodynamics was built to simulate the process. • The calculated results of the model fit very well with the experimental results. • The novel membrane process was proved to have the potential to be industrialized. Conventional diffusion dialysis has two main shortages, including low processing capacity and serious water osmosis. Pressure-concentration double driven (PCDD) diffusion dialysis was proved to cover the two shortages effectively. To further study the PCDD diffusion dialysis, the continuous separation of the common alkali/ metal salt mixture (NaOH/Na 2 WO 4 ) was realized by adopting it in this work. Results illustrate that 0.04 MPa is an optimum pressure difference. That is because the pressure difference realized the highest recovered NaOH concentration and a high alkali recovery ratio, and a good separation effect were obtained simultaneously. The increment of initial alkali concentration in the feed from 0.5 to 2.0 mol/L can enhance the alkali recovery ratio from 24.93% to 35.15%. As the initial salt concentration in the feed increases from 0.05 to 0.20 mol/L, the recovered NaOH concentration at the operation time of 180 mins improves from 0.24 to 0.36 mol/L, and the alkali recovery ratio increases from 27.86% to 30.34% slowly. Second, a mass transfer mathematical model was established to simulate the continuous PCDD diffusion dialysis separation process. There shows acceptable and satisfactory agreement between the experimental and calculated fluxes, experimental and calculated alkali recovery ratios and salt leakage ratios. The work presented here suggests that the continuous PCDD diffusion dialysis is feasible and promising to be industrialized in the future.

Converting softening nanofiltration brine into high-solubility liquid salts (HSLS) via electrodialysis metathesis: Effect of membrane type

A fundamental aspect of developing electrodialysis-metathesis (EDM) process involves the selection of an appropriate membrane for converting softening nanofiltration (SNF) brine into high-solubility liquid salts (HSLS). Three types of ion-exchange membranes (heterogeneous, Ss; semi-homogeneous, Lh; and homogeneous, Yl, Tb, Aj) were investigated herein by assessing the overall performances (running resistance, salt removal ratio, energy consumption, etc.) and the transport of ions and water during the EDM process. The results showed that increasing the fixed ion density promoted counter-ions migration, while decreasing the permselectivity or increasing the water uptake or ion-exchange capacity enhanced the co-ion flux. The membrane thickness constitutes an efficient barrier for water osmosis, which could lead to more concentrated HSLS. As a result, the investigated membranes could be ranked using the flux of counter-ions and water as indices: Aj > Tb > Yl ≈ Lh > Ss. The Lh membrane exhibited similar energy consumption characteristics to the Yl and Tb membranes. Regardless of the membrane type, the Cl-type HSLS obtained had higher purity, while the Na-type HSLS had higher concentration. Overall, the membranes with higher fixed ion density and permselectivity, and lower resistance and water uptake, were best suited for the zero liquid discharge desalination of typical high-hardness brine using the described EDM process. Finally, considering the performance and cost of the semi-homogeneous Lh membrane, this membrane type is recommended for application in EDM to convert SNF brine into HSLS.

EFFECT OF SALINE STRESS ON GROWTH OF FRUIT PLANTS (REVIEW ARTICLE)

Soil and irrigation water salinity are among the main problems hindering agricultural development, especially in arid and semi-arid regions, which depends on especially surface irrigation as the main means in agriculture. The salinity lead to low growth and production of plants, including fruit, as a result of the temporal, azalotic, or nutrients imbalance. Salinity of the soil or irrigation water greatly reduces the growth, productivity and quality of fruit crops by affecting their physiological, chemical and biological functions as they cause obstruction to the absorption of some elements by the plant and if it increased absorption of salts, it causes ion poisoning of the cell, as well as increased salts cause less absorption of water by the plant due to the high osmosis of soil water. There are many ways to reduce the salt stress in the growth of fruit plants, the most important of which is adding organic fertilizers such as humic acid or spraying with the amino acid proline.

Design of a unidirectional water valve in Tillandsia

The bromeliad Tillandsia landbeckii thrives in the Atacama desert of Chile using the fog captured by specialized leaf trichomes to satisfy its water needs. However, it is still unclear how the trichome of T. landbeckii and other Tillandsia species is able to absorb fine water droplets during intermittent fog events while also preventing evaporation when the plant is exposed to the desert’s hyperarid conditions. Here, we explain how a 5800-fold asymmetry in water conductance arises from a clever juxtaposition of a thick hygroscopic wall and a semipermeable membrane. While absorption is achieved by osmosis of liquid water, evaporation under dry external conditions shifts the liquid-gas interface forcing water to diffuse through the thick trichome wall in the vapor phase. We confirm this mechanism by fabricating artificial composite membranes mimicking the trichome structure. The reliance on intrinsic material properties instead of moving parts makes the trichome a promising basis for the development of microfluidics valves.

Energy Harvesting and Storage by Water Infiltration of Eggshell Membrane

As a domestic waste in daily life, eggshell membrane (ESM) is a unique biomaterial due to its biocompatibility, bioadsorption, and the structure of interwoven and coalescing fibers with many pores which can be utilized in many fields. Herein, a new kind of potentially biocompatible energy harvesting and storage device based on polymer polyaniline/carbon nanotube (PANI/CNT) composite electrodes and ESM is designed. Without external electric power, a single device can extract a maximal output voltage of 0.26 V from water osmosis. The energy can be stored directly and released circularly, and the output voltage can achieve superposition by integrating devices in series. This self‐charging bioelectric phenomenon can be explained by the membrane potential of the ESM induced by water movement. Due to the biocompatible feature of the ESM, and sufficiently high electric output, this study provides a new idea for sustainable and biocompatible energy harvesting and storage devices.

Low salinity effect on the recovery of oil trapped by nanopores: A molecular dynamics study

Low salinity waterflooding (LSW) is an effective method for enhancing the oil recovery from many reservoirs, and its success has been traced to a host of low salinity effects. In this work, we perform molecular dynamics simulations to study the feasibility of recovering oil trapped by nanopores by lowering the reservoir salinity. The oil is initially trapped by a slit nanopore, with a portion of the oil protruding from the pore entrance. After the reservoir salinity is lowered, the thin brine films that separate the oil and pore walls become thicker to drive some of the trapped oil out of the pore. We quantify the free energy profile of this process and clarify the underlying molecular mechanisms. Interestingly, the brine film growth is dominated by the water transport from the brine reservoir into the pore rather than by the depletion of ions from the brine film. These results provide molecular evidence that low salinity brines benefit the recovery of the oil trapped by nanopores. They highlight that when ion depletion from thin brine films is suppressed, the osmosis of water can play a fundamental role in the expansion of the brine films; thus, the enhanced oil recovery. The slow osmosis of water through thin brine films and thus the slow displacement of oil from the pore may help explain the anomalously slow oil recovery reported in micro-modeling experiments of LSW.

Tubular membrane used in continuous and semi-continuous diffusion dialysis

Tubular membrane is firstly developed from the polyvinyl alcohol based casting solution. The membrane is compact with the diameter of 1.27–1.72 cm and the length of 30–60 cm, which is like a piece of “sieve tube” or “blood vessel” from bionic aspect. The membrane can be used in the static and continuous diffusion dialysis (DD) processes to separate an acidic liquor containing HCl and glyphosate (Gly). The acidic liquor is filled or pumped into the tubular membrane, while the membrane is immersed in the matrix solution of water. The matrix solution can also be static while the acidic liquor is continuous to form a semi-continuous process.Static DD process shows that the recovery ratio (RH) can reach up to 70.2% with the Gly rejection of 95.3% after 1 h. Continuous process shows that the water osmosis coefficient (UH2O) is in the range of 1.54–3.09 × 10−4 m h−1. The RH increases from 64% to 74% as the water flow rate increases. The Gly productivity is 43–72% after precipitation from the residual liquor. Finally, semi-continuous process shows high feed flow rate of 1.86 L m−2 h−1, stable RH values of 71.1–75.5%, and high Gly productivity of 65.1–87.9%.

Application and modeling of pressure-concentration double-driven diffusion dialysis

Diffusion dialysis (DD) is an ion exchange membrane separation process driven by concentration differences. DD is simple to operate and has excellent stability, low energy consumption, and a low installation cost. To overcome the limitations of the traditional DD process, such as low processing capacity and serious water osmosis, the authors propose a pressure-concentration double-driven (PCDD) DD process. This novel DD is double driven because the concentration difference is the main mass transfer force, and the pressure difference is the assistant mass transfer force. The common FeSO4/H2SO4 mixed solution system is used to investigate the PCDD DD process. Our first area of interest is the operating parameters' effects (the pressure difference as well as the initial H2SO4 and FeSO4 concentrations in feed) on the PCDD DD process performance. Results show that the high pressure difference can significantly promote the increment of the H+ dialysis coefficient from 0.0012 to 0.0039 m/h and the Fe2+ dialysis coefficient from 1.25 × 10−5 to 5.95 × 10−5 m/h. Pressure differences in high value can also change the direction of water osmosis (from the dialysate to diffusate). All these are employed to maintain the separation factor in an acceptable range (∼65). Moreover, the increment of the initial FeSO4 concentration in the feed can improve the H+ dialysis coefficient and reduce the Fe2+ dialysis coefficient to increase the separation factor further. However, increasing the initial H2SO4 concentration in the feed is not a commonly accepted method to improve the PCDD DD process performance. A mathematical model based on non-equilibrium thermodynamics is established to quantify the PCDD DD mass transfer process. Notably, the fitting results of the calculated fluxes based on the model and the experimental fluxes are very satisfactory. The research presented here indicates that the PCDD DD process can increase the DD's processing capacity, maintain a good separation effect, and inhibit the water osmosis simultaneously.

Recovery of sulfuric acid from a stone coal acid leaching solution by diffusion dialysis

Diffusion dialysis was employed to recover sulfuric acid from a stone coal acid leaching solution. The dialysis coefficients of H+, V, Al, Fe, Mg, K, F, P, and S ions in a stone coal acid leaching solution for an anion exchange membrane were determined. The effects of the flow rate, flow rate ratio, and water osmosis rate as well as ion rejection on sulfuric acid recovery were investigated. The results demonstrated that the DF120-III anion exchange membrane showed a good separation performance for separating sulfuric acid from the stone coal acid leaching solution. In the diffusion dialysis process, the water osmosis rate, sulfuric acid recovery, ion rejection, water equilibrium and processing ability were taken into consideration. Controlling water osmosis was more important than obtaining a higher acid recovery. Under the optimum operating conditions of a feed flow rate of 12mL/min and flow rate ratio of water to feed of 1–1.1, sulfuric acid recovery reached 71.12%, the water osmosis rate was controlled at approximately 14.95%, and vanadium rejection was approximately 95.50%. The rejection of impurity ions, such as Al, Fe, Mg, K, F, P, and S was approximately 99.04%, 97.37%, 98.01%, 85.12%, 98.33%, 91.16%, and 69.96%, respectively. The high rejections of F in the form of complexes and P in the form of incompletely dissociated acid were disadvantageous to the recovery of sulfuric acid. The recovered acid was able to be reused in the acid leaching process by the addition of fresh acid.

Water osmosis in separating acidic HCl/glyphosate liquor by continuous diffusion dialysis

Abstract Acidic HCl/glyphosate liquor is the intermediate product during the production of glyphosate herbicide. The liquor contains about 2.4 mol/L ( M ) HCl, 1.1 M glyphosate and 35 wt% other organic components, which can be separated by continuous diffusion dialysis (DD) to recover HCl. The residual solution is further precipitated to obtain glyphosate product at pH around 1.5. The continuous DD dialyzer equipped with commercial membrane TWDD-III shows high water osmosis coefficients of 2.23–5.98 × 10 −4 m/h, while the self-prepared QPPO/PVA membrane shows the lower values of 1.95–2.93 × 10 −4 m/h. The water osmosis is mainly attributed to the high content of organic solvent in the acidic liquor. The water osmosis reduces the Gly concentration and productivity together with the HCl recovery ( R H ), but the recovered HCl concentration (C d-H ) and Gly rejection ( η Gly ) are less affected. The flow rate and flow ratio between water and acidic liquor are optimized (0.63 L/(m 2 h), 3:1) to obtain C d-H of 1.01 M, R H of 80.9% and η Gly of 83.2% for the commercial membrane. The residual solution contains only 0.43 M Gly and thus needs to be highly concentrated to obtain 60.7% Gly productivity with the purity of 71.3%. The QPPO/PVA membrane under optimized running conditions (0.83 L/(m 2 h), 2:1) can obtain C d-H of 0.95 M, R H of 68.1% and η Gly of 94.2%. The residual solution contains 0.65 M Gly and thus needs less to be concentrated to precipitate Gly product due to the lower water osmosis.

Membrane cross-linking to restrict water osmosis in continuous diffusion dialysis

Membrane cross-linking to restrict water osmosis in continuous diffusion dialysis