Effect Of Osmotic Pressure Research Articles

Analysis of the effect of permeant solutes on the hydraulic resistance of the plasma membrane in cells of Chara corallina.

In the cells of Chara corallina, permeant monohydric alcohols including methanol, ethanol and 1-propanol increased the hydraulic resistance of the membrane (Lpm-1). We found that the relative value of the hydraulic resistance (rLpm-1) was linearly dependent on the concentration (Cs) of the alcohol. The relationship is expressed in the equation: rLpm-1 = ρmCs + 1, where ρm is the hydraulic resistance modifier coefficient of the membrane. Ye et al. (2004) showed that membrane-permeant glycol ethers also increased Lp-1. We used their data to estimate Lpm-1 and rLpm-1. The values of rLpm-1 fit the above relation we found for alcohols. When we plotted the ρm values of all the permeant alcohols and glycol ethers against their molecular weights (MW), we obtained a linear curve with a slope of 0.014M-1/MW and with a correlation coefficient of 0.99. We analyzed the influence of the permeant solutes on the relative hydraulic resistance of the membrane (rLpm-1) as a function of the external (π0) and internal (πi) osmotic pressures. The analysis showed that the hydraulic resistance modifier coefficients (ρm) were linearly related to the MW of the permeant solutes with a slope of 0.012M-1/MW and with a correlation coefficient of 0.84. The linear relationship between the effects of permeating solutes on the hydraulic resistance modifier coefficient (ρm) and the MW can be explained in terms of the effect of the effective osmotic pressure on the hydraulic conductivity of water channels. The result of the analysis suggests that the osmotic pressure and not the size of the permeant solute as proposed by (Ye et al., J Exp Bot 55:449-461, 2004) is the decisive factor in a solute's influence on hydraulic conductivity. Thus, characean water channels (aquaporins) respond to permeant solutes with essentially the same mechanism as to impermeant solutes.

Dual-mode draw resonance instability regulated by concentration fluctuation in the polymer solutions casting

Based on the two-fluid model, we successfully simulated the film casting process of the polymer solution system and observed the unique response wave of the film thickness and the concentration via applying perturbation. We identify that this instability pattern is essentially the product under the coupling effect of viscoelastic stress and osmotic pressure from fluctuations on different scales, which causes it to exhibit biperiodic characteristics. We call this new instability mode known as dual-mode draw resonance instability. Among them, the concentration oscillation predominates, thereby limiting the critical draw ratio Drc of the system. Through sorting out the molecular image of the polymer concentration response to perturbation, the relevant parameters are extracted, and the law of their influence on the Drc further verifies our conclusion and provides guidance for actual production.

Effects of hydrostatic pressure, osmotic pressure, and confinement on extracellular matrix associated responses in the nucleus pulposus cells ex vivo

Spinal movement in both upright and recumbent positions generates changes in physicochemical stresses including hydrostatic pressure (HP), deviatoric stress, and confinement within the intradiscal compartment. The nucleus pulposus (NP) of the intervertebral disc is composed of highly negatively charged extracellular matrix (ECM), which increases osmotic pressure (OP) and generates tissue swelling. In pursuing regenerative therapies for intervertebral disc degeneration, the effects of HP on the cellular responses of NP cells and the ECM environment remain incompletely understood. We hypothesized that anabolic turnover of ECM in NP tissue is maintained under HP and confinement. We first clarified the effects of the relationships among HP, OP, and confinement on swelling NP explants isolated from bovine caudal intervertebral discs over 12 hours. We found that the application of confinement and constant HP significantly inhibits the free swelling of NP (p < 0.01) and helps retain the sulfated glycosaminoglycan. Since confinement and HP inhibited swelling, we incubated confined NPs under HP in high-osmolality medium mimicking ECM-associated OP for 7 days and demonstrated the effects of HP on metabolic turnover of ECM molecules in NP cells. The aggrecan core protein gene was significantly upregulated under confinement and constant HP compared to confinement and no HP (p < 0.01). We also found that confinement and constant HP helped to significantly retain smaller cell area (p < 0.01) and significantly prevent the severing of actin filaments compared to no confinement and HP (p < 0.01). Thus, we suggest that NP's metabolic turnover and cellular responses are regulated by the configuration of intracellular actin and fibrillar ECMs under HP.

An analytical solution model of oil–water dynamic imbibition considering dynamic contact angle effect and osmotic pressure at micro-nano scale

Spontaneous imbibition is one of the important mechanisms to enhance oil recovery during hydraulic fracturing process of shale reservoirs. The dynamic contact angle effect in imbibition kinetics of liquid–liquid system is complicated due to the large number of micro-nano pores in shale reservoir. Moreover, the content of clay minerals is high, the chemical osmosis effect is significant, and the impact of osmotic pressure on imbibition is not clear. In order to clarify the dynamic contact angle effect in imbibition kinetics and correctly understand the role of osmotic pressure in imbibition process. In this paper, based on the molecular kinetic theory (MKT), the dynamic contact angle effect is successfully coupled with imbibition kinetic equation, and a capillary pressure equation is developed. On the basis, considering the effects of osmotic pressure, external displacement pressure and boundary layer effect on imbibition, An analytical solution model of oil–water dynamic imbibition model is developed. The results shows that under the respective effects of capillary pressure and osmotic pressure, the imbibition velocity initially stabilizes before increasing over time; under the action of displacement pressure, the imbibition velocity increases with time. Imbibition velocity is directly proportional to interfacial tension and capillary radius, but inversely proportional to contact angle and oil viscosity. With the salt concentration difference increasing from 80 mol/m3 to 4710 mol/m3, the imbibition velocity increased by about 54 times. Compared with the membrane efficiency of 30 % and 5 %, the imbibition velocity is increased by 4.95 times. In this work, the dynamic contact angle effect in the imbibition kinetics of liquid–liquid system was accurately characterized, clarified the action mechanism of osmotic pressure, and provided theoretical support for enhancing oil recovery of shale reservoirs.

Chelate extraction of metal ions in aqueous/chloroform system based on molecular crowding environment

Abstract In this study, we propose a novel concept for the solvent extraction of metal ions (Co, Zn, and Pb) by mimicking a molecular crowding environment using dextran (Dex). The metal ions were extracted from the aqueous phase into the organic phase (chloroform) in the presence of 8-hydroxyquinoline (HQ). The extraction constant of the metal complex (Kex) increased with increasing Dex concentration (CDex) for all metal ions. When examining the dependence of CDex on the four equilibrium constants (distribution coefficient of HQ, acid dissociation of HQ, complexation constant of metal complex (β), and distribution coefficient of the metal complex) that contribute to Kex, only β increased with CDex. This suggests that an increase in, β, a parameter reflecting the molecular crowding effect, results in an increase in Kex. The increase in β was analyzed based on volume exclusion and osmotic pressure effects. The analytical model effectively explained the enhanced the complexation due to the increase in β and volume exclusion, whereas the osmotic pressure suppressed β. Consequently, we unveiled the effect of molecular crowding on the solvent extraction of metal ions for the first time.

Effect of osmotic pressure and simultaneous heat-moisture phosphorylation treatments on the physicochemical properties of mung bean, water caltrop, and corn starches

This study aimed to investigate the physicochemical properties of modified starch prepared through the simultaneous heat-moisture and phosphorylation treatment (HMPT) and osmotic pressure treatment (OPT) for water caltrop starch (WCS), mung bean starch (MBS), and amylose-rich corn starch (CS) for different time periods. Furthermore, variations in starch content [amylose and resistant starch (RS)], swelling powder (SP), water solubility index (WSI), crystallinity, thermal properties, gelatinization enthalpy (ΔH), and glycemic index (GI) were examined. This study demonstrates that neither HMPT nor OPT resulted in a significant increase in the resistant starch (RS) content, whereas all samples succeeded in heat-treating at 105 °C for another 10 min exhibited a significant increase in RS content compared to their native counterparts. Moreover, the gelatinization temperatures of the three starches increased (To, Tp, and Tc), whereas their gelatinization enthalpy (ΔH) and pasting viscosity decreased. In particular, the GI of all three modified starches subjected to HMPT or OPT showed a decreasing trend with modification time, with OPT exhibiting the best effect. Therefore, appropriate modification through HMPT or OPT is a viable approach to develop MBS, WCS, and CS as processed foods with low GI requirements, which exceptionally may be suitable for canned foods, noodles, and bakery products.

OSMOTIC DRUG DELIVERY SYSTEM OF NICORANDIL: DESIGN AND EVALUATION

Objective: The purpose of the current research was to design a nicorandil formulation with controlled drug release using the principles of osmotic pump technology. Nicorandil is a biopharmaceutical classification system (BCS) class 3 drug, having a shorter plasma elimination half-life and bioavailability of 75 to 80%. Methods: The elementary osmotic pump (EOP) was prepared by coating a cellulose acetate polymer on the prepared core tablet. A 24-factorial design was applied to optimize the parameters for the osmotic tablet. A surface orifice was drilled. Results: Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and powder X-ray diffraction (PXRD) results showed that there was no interaction between drugs and excipients. A 24-factorial design was applied to optimize the parameters for the elementary osmotic pump. The optimized batch was characterized for in vitro drug release studies, and the effects of pH, osmotic pressure, and agitation intensity were analyzed. All the batches showed a drug release ranging from 90.48% to 98.78% after 12 hours. There was no change in the drug release pattern at different pHs and agitation intensities. The drug release was found to decrease with the increasing osmotic pressure of the dissolution medium. The results showed that the amounts of sodium chloride and mannitol were positively affecting the drug release, while the plasticizers PEG400 and DBP were not critical. Scanning electron microscopic studies (SEM) showed the integrity and surface morphology of the coating membrane before and after dissolution. The prepared EOP was found to deliver nicorandil at zero-order for up to 12 hours. Conclusion: Nicorandil was developed successfully as a controlled drug delivery during a 12-hour period, with variables optimized by the use of a 24-factorial design.

Osmotic Pressure and Its Biological Implications.

Gaining insight into osmotic pressure and its biological implications is pivotal for revealing mechanisms underlying numerous fundamental biological processes across scales and will contribute to the biomedical and pharmaceutical fields. This review aims to provide an overview of the current understanding, focusing on two central issues: (i) how to determine theoretically osmotic pressure and (ii) how osmotic pressure affects important biological activities. More specifically, we discuss the representative theoretical equations and models for different solutions, emphasizing their applicability and limitations, and summarize the effect of osmotic pressure on lipid phase separation, cell division, and differentiation, focusing on the mechanisms underlying the osmotic pressure dependence of these biological processes. We highlight that new theory of osmotic pressure applicable for all experimentally feasible temperatures and solute concentrations needs to be developed, and further studies regarding the role of osmotic pressure in other biological processes should also be carried out to improve our comprehensive and in-depth understanding. Moreover, we point out the importance and challenges of developing techniques for the in vivo measurement of osmotic pressure.

Nanoparticles insertion and dimerization in polymer brushes.

Molecular dynamics simulations are conducted to systematically investigate the insertion of spherical nanoparticles (NPs) in polymer brushes as a function of their size, strength of their interaction with the polymers, polymer grafting density, and polymer chain length. For attractive interactions between the NPs and the polymers, the depth of NPs' penetration in the brush results from a competition between the enthalpic gain due to the favorable polymer-NP interaction and the effect of osmotic pressure resulting from displaced polymers by the NP's volume. A large number of simulations show that the average depth of the NPs increases by increasing the strength of the interaction strength. However, it decreases by increasing the NPs' diameter or increasing the polymer grafting density. While the NPs' effect on the polymer density is local, their effect on their conformations is long-ranged and extends laterally over length scales larger than the NP's size. This effect is manifested by the emergence of laterally damped oscillations in the normal component of the chains' radius of gyration. Interestingly, we found that for high enough interaction strength, two NPs dimerize in the polymer brush. The dimer is parallel to the substrate if the NPs' depth in the brush is shallow. However, the dimer is perpendicular to the substrate if the NPs' are deep in the brush. These results imply that polymer brushes can be used as a tool to localize and self-assemble NPs in polymer brushes.

Non specific immune response of batik lobster (Panulirus longipes) at different salinity

Salinity has gave significant impact to stress levels that trigger of adjustment hemocyst with surroundings.The research aims to identify the Ideal maintenance of salinity on batik lobster (Panulirus longipes). It was conducted during at ninety days for maintanance period from September 2019 to Januari 2020 in Mata Shrimp Seeds Center, Kendari City. The Animals studied were batik lobsters (P. longipes) caught by nature with the male lobsters weighed 235±60 g and females were 237±50 g and total lobster under testing of 36 lobsters. The research had several test paremeters used to determine the effect of salinity such Osmotic Pressure (TKO), Total Hemocyte Count (THC) and histology of female gills. The statistical test Univariate Analysis of Variance and Duncan Test if (P&lt;0.05) just used TKO parameters. The study discovered that TKO value of 833-1318 mOsmo/L with salinity exerting a strong influences (P&lt;0.05). THC parameters of males showed a low stress response with a range of 3x106 - 14x106 cells/mL, it contrasts with the females had a high stress response with a range of 3x106 - 25x106cells/mL. The Conclusion was the male lobsters gave a low stress response with the ideal salinity of the cultivation, especially at 31⁰/ₒₒ and 34⁰/ₒₒ ware based on good response of maintenance TKO values and low stress levels on THC values

A novel POSS-based nanoplatform for repairing of poisoning cells and its application in tracking and detoxification of Hg2+ in vivo

Self-repair is a fundamental mechanism that enables organisms to adapt and survive in dynamic environments. However, the self-repair capacity of individual cells is usually insufficient to cope with environmental changes, leading to developmental limitations. Herein, we designed and developed a novel nanohybrid molecule based on POSS, PRHAP -with a nanometer-scale size of 25 ± 5 nm. It can identify Hg2+ significantly in DMSO/H2O (v/v, 6:4) solution with a highly sensitive detection limit of 25 nM. When the sensor PRHAP was combined with Hg2+, it exhibits a pronounced increase in fluorescence intensity at 586 nm, accompanied with the color of the solution changed from colorless to orange-red. When cells are exposed to Hg2+, a toxic pollutant that induces cell apoptosis, PRHAP with better cell permeability can efficiently penetrate cell membranes through the process of osmotic pressure and bind with Hg2+, facilitating its removal from the cells and promoting their repair based on synergism between osmotic pressure and coordination field effect. Additionally, owing to its exceptional permeability and extended in vivo presence, PRHAP can simultaneously detoxify Hg2+ in mice and enable its monitoring. This intelligent material significantly enhances cellular repair capability and detoxifies poisoned mice, demonstrating promising potential for applications in biologically repairing and detoxifying materials.

Nanofiltration through cylindrical nanopores end-grafted with polyelectrolytes

Taking account of the effects of polyelectrolytes friction, osmotic pressure, and dielectric saturation, a continuum model is adopted to investigate the rejection and permeability of cylindrical nanopores end-grafted with pH-regulated polyelectrolytes (PEs). In addition to a detailed simulation for the behavior of the system considered under various conditions, the intriguing phenomena and underlying mechanisms are also discussed. The results gathered suggest that end-grafted nanopores show a better rejection than the corresponding bare nanopores, and the real rejection is dictated by the mean volumetric flux. Complete coverage of PEs over the cross section of a nanopore will not improve its rejection due to the hindrance in flow rate. However, both partial grafting of nanopore feed side and reducing membrane thickness can promote permeability and maintain the level of rejection. The rejection for the case where the subunits of a PE layer are localized near the outer ring of a nanopore cross section is better than that for the case where they are localized near its inner ring. The former also shows a higher permeability than the latter. By end-grafting a nanopore with 8-nm radius, its rejection for 100 mM KCl is comparable to that for a bare nanopore with 2-nm radius, although the flow rate in the former is one-order-of-magnitude larger than in the latter. This reveals that end-grafting has the potential for enlarging nanopore, thereby opening a new avenue of raising permeability while maintaining rejection simultaneously.

Application of Poly(diallyl dimethylammonium chloride) as a Forward Osmosis Draw Agent: The Quantified Effect of Osmotic Pressure and Viscosity

Application of Poly(diallyl dimethylammonium chloride) as a Forward Osmosis Draw Agent: The Quantified Effect of Osmotic Pressure and Viscosity

Dexmedetomidine ameliorates diabetic cardiomyopathy by inhibiting ferroptosis through the Nrf2/GPX4 pathway

ObjectiveDexmedetomidine (DEX) has been shown to have anti-apoptotic effects in diabetes mellitus, but its role in mitigating diabetic cardiomyopathy (DCM) through ferroptosis regulation is unclear.MethodsAn in vitro DCM model was established using H9C2 cells induced with high glucose (HG) and treated with DEX at varying doses and a nuclear factor erythroid 2-realated factor 2 (Nrf2) specific inhibitor ML385. Cell viability was evaluated using the MTT method after treatment with DEX or mannitol (MAN), and the dosage of DEX used in subsequent experimentation was determined. The effects of HG-induced high osmotic pressure were assessed using MAN as a control. Cell apoptosis was evaluated using flow cytometry. Protein levels of Bcl2, Bax, nuclear Nrf2, and glutathione peroxidase 4 (GPX4) were measured using Western blot. Superoxide dismutase (SOD) activity, malondialdehyde (MDA) levels, Fe2+ concentration and reactive oxygen species (ROS) levels were measured using corresponding kits and dichlorodihydrofluorescein diacetate, respectively.ResultsTreatment with DEX or MAN had no effect on H9C2 cell viability. HG induction reduced H9C2 cell viability, increased cell apoptosis, upregulated levels of Bax, Fe2+, MDA, and ROS, and downregulated Bcl2 protein levels, SOD activity, and protein levels of nuclear Nrf2 and GPX4. DEX inhibited HG-induced H9C2 cell apoptosis, promoted Nrf2 nuclear translocation, and activated the Nrf2/GPX4 pathway. Inhibition of Nrf2 partially reversed the protective effects of DEX against HG-evoked H9C2 cell injury.ConclusionOur findings demonstrate that DEX attenuates HG-induced cardiomyocyte injury by inhibiting ferroptosis through the Nrf2/GPX4 pathway, providing potential therapeutic targets for DCM treatment.

Modeling and experimental validation of forward osmosis process: Parameters selection, permeate flux prediction, and process optimization

The forward osmosis (FO) process has recently gained significant attention due to low energy consumption. The concentration polarizations of external concentration polarization (ECP) and internal concentration polarization (ICP) in the FO process substantially reduce the water flux through the semi-permeable membrane. Thus, the understanding of process limitations is essential to design the FO process based on application goals. The design parameters can be evaluated by fitting experimental data with appropriate model equations. So, the process performance can be predicted as per process conditions. This study explored the theoretical prediction of water flux behavior with varying process conditions along with consideration of concentration polarization. The estimated water flux due to concentration polarization correlates with experimental flux data after considering the convective-diffusion equations. A Lab-scale cross-flow FO experiment was conducted to account for ICP and ECP. The predicted water flux as a function of DS’s concentration and time was using algorithm-based MATLAB programs under varying experimental conditions. This model was used to predict the water flux in the FO process for two different draw solutes of NaCl and urea. The extent of the mitigation of membrane fouling after 24 h of FO run with industrial wastewater as FS was noted ∼92% by simple reverse water washing. It may help to understand better the effects of concentration polarization, solute diffusivity, and osmotic pressure on the performance of the FO process.

Thermodynamic complexation mechanism of zinc ion with 8-hydroxyquinoline-5-sulfonic acid in molecular crowding environment

A crowded molecular environment, which is universally observed in biological cells, changes the thermodynamics and kinetics of biochemical reactions compared to bulk solution. Although molecular crowding has received significant attention, a fundamental explanation of the molecular crowding effect based on thermodynamic parameters, including enthalpy (ΔH) and entropy changes (ΔS), is insufficient. Herein, the complexation mechanism of zinc ions with quinolinol derivative in a molecular crowding environment was investigated using polyethylene glycol (PEG) based on the changes in ΔH and ΔS. For 1:1 complexation, which is only promoted by the osmotic pressure effect, ΔH and ΔS decreased with increasing PEG concentration (CPEG) because the number of dehydration molecules decreased. In the 1:2 complexation system, which is affected by the osmotic pressure and volume exclusion effects, no obvious dependences of ΔH and ΔS on CPEG were observed. This is because the osmotic pressure and volume exclusion effects contributed oppositely to ΔH and ΔS. The results presented herein provide fundamental knowledge for protein-metal interactions, and it is expected that these data will attract the attention of many physical chemists and biochemists.

Laboratory Experiment on Emulsions: Study of the Effect of Osmotic Pressure on Double Emulsions Preparation

Double emulsions are ternary systems commonly used in several disciplines in areas such as food technology, applied chemistry, chemical engineering, materials science, pharmacology and environmental science. In several courses related to these areas, the implementation of laboratory experiment is required to strengthen the knowledge acquired by students during the theoretical lessons. However, it is difficult to find published practical experiments in this field. This work presents a four-hour hands-on laboratory experiment in which students can easily formulate and prepare water-in-oil-in-water double emulsions for vitamin B12 encapsulation. In this experiment, students can analyze the effect of the osmotic pressure produced by the addition of different NaCl concentrations in each aqueous phase, which could lead to the swelling and deswelling phenomena of the inner aqueous droplets and, therefore, affect the encapsulation efficiency of the formulated systems. The double emulsions are analyzed by the students in terms of size and encapsulation efficiency.

Effects of glucose and osmotic pressure on the proliferation and cell cycle of human chorionic trophoblast cells.

This study investigated the effects of glucose and osmotic pressure on the proliferation and cell cycle of trophoblast cells. HTR8/SVneo cells were treated with 0 (no glucose), 1 (low glucose), 5 (normal), and 25 mmol/L (high glucose) glucose. In addition, the cells were treated with 5 mmol/L glucose (normal) and 5 mmol/L glucose + 20 mmol/L mannitol (mannitol). The cell morphology and proliferation were determined by microscopy and a cell counting kit-8 assay. The cell cycle and apoptosis were examined by flow cytometry. The cell number was relatively decreased and morphological changes were intermediate in the high-glucose group compared with the low-glucose groups. The proportion of cells in the G2/M phase was higher in the low-glucose group than in the other groups, and it was lower in the G1 phase and higher in the S phase in the high-glucose group than in the other groups. Compared with 24 h, cell proliferative activity was restored to a certain extent after 48 h in the high-glucose group. In summary, the blood glucose concentration might influence the proliferation of trophoblast cells. A high-glucose environment inhibited initial cell proliferation, which could be moderately restored after self-regulation. Furthermore, the proliferation of trophoblasts was not affected by the osmotic pressure.

Life in Multi-Extreme Environments: Brines, Osmotic and Hydrostatic Pressure─A Physicochemical View.

Elucidating the details of the formation, stability, interactions, and reactivity of biomolecular systems under extreme environmental conditions, including high salt concentrations in brines and high osmotic and high hydrostatic pressures, is of fundamental biological, astrobiological, and biotechnological importance. Bacteria and archaea are able to survive in the deep ocean or subsurface of Earth, where pressures of up to 1 kbar are reached. The deep subsurface of Mars may host high concentrations of ions in brines, such as perchlorates, but we know little about how these conditions and the resulting osmotic stress conditions would affect the habitability of such environments for cellular life. We discuss the combined effects of osmotic (salts, organic cosolvents) and hydrostatic pressures on the structure, stability, and reactivity of biomolecular systems, including membranes, proteins, and nucleic acids. To this end, a variety of biophysical techniques have been applied, including calorimetry, UV/vis, FTIR and fluorescence spectroscopy, and neutron and X-ray scattering, in conjunction with high pressure techniques. Knowledge of these effects is essential to our understanding of life exposed to such harsh conditions, and of the physical limits of life in general. Finally, we discuss strategies that not only help us understand the adaptive mechanisms of organisms that thrive in such harsh geological settings but could also have important ramifications in biotechnological and pharmaceutical applications.

UV/Fe(II) synergistically activated S(IV) per-treatment on HA-enhanced Ca2+ scaling in NF filtration: Fouling mitigation, mechanisms and correlation analysis of membrane resistance in different filtration stage

The aim of this study was to investigate the feasibility and fouling mitigation mechanisms of UV/Fe(II) synergistically activated sulfite (S(IV)) (UFS) pretreatment to alleviate membrane fouling caused by HA-enhanced Ca2+ scaling. After UFS treatment, hydrophobic substances and carboxyl groups structure were destroyed by the in-situ-generated SO•–4, resulted in a significant reduction of hydrophobic substances ratio and carboxyl group concentration. Due to the formation of more electropositive in-situ-generated Fe(III), the complexation between Ca2+ and carboxyl groups was weakened so that the bulk crystallization size on the membrane surface was greatly reduced. The filter cake enhanced osmotic pressure effect (CEOP) and concentration polarization effect were hence alleviated, as well as the surface roughness. At the microcosmic perspective, as the energy barrier between the membrane and foulants was increased significantly after pretreatment, the anti-foulants adsorption ability of the membrane was enhanced. Correlation analysis showed that the carboxyl concentration and density, HPO ratio, larger particle size (>100 nm) ratio, the Ca2+ concentration in the scaling layer and energy barrier all had a good correlation with the membrane resistance. This research not only provides an advanced oxidation technology that can effectively alleviate the synergistically-fouling effect of HA and Ca2+ of nanofiltration process, but also proposes a guidance for the UV/Fe(II) synergistically activated sulfite.