Wetlands as a potential multifunctioning tool to mitigate eutrophication and brownification.

Eutrophication and brownification are ongoing environmental problems affecting aquatic ecosystems. Due to anthropogenic changes, increasing amounts of organic and inorganic compounds are entering aquatic systems from surrounding catchment areas, increasing both nutrients, total organic carbon (TOC), and water color with societal, as well as ecological consequences. Several studies have focused on the ability of wetlands to reduce nutrients, whereas data on their potential to reduce TOC and water color are scarce. Here we evaluate wetlands as a potential multifunctional tool for mitigating both eutrophication and brownification. Therefore, we performed a study for 18 months in nine wetlands allowing us to estimate the reduction in concentrations of total nitrogen (TN), total phosphorus (TP), TOC and water color. We show that wetland reduction efficiency with respect to these variables was generally higher during summer, but many of the wetlands were also efficient during winter. We also show that some, but not all, wetlands have the potential to reduce TOC, water color and nutrients simultaneously. However, the generalist wetlands that reduced all four parameters were less efficient in reducing each of them than the specialist wetlands that only reduced one or two parameters. In a broader context, generalist wetlands have the potential to function as multifunctional tools to mitigate both eutrophication and brownification of aquatic systems. However, further research is needed to assess the design of the generalist wetlands and to investigate the potential of using several specialist wetlands in the same catchment.

Optimizing the method for removing MSNs templates using an ionic liquid ([C4mim]Cl).

The key step in preparing mesoporous silica is to remove the organic template agent, and the most common method used to achieve this goal is high-temperature calcination. However, this method has many disadvantages, one of which is that it reduces the silanol density on the surface of mesoporous silica, which affects its subsequent modification. Ionic liquids (ILs) are often used as extractants. In this work, the 1-butyl-3-methylimidazolium chloride ([C4mim]Cl) IL is considered, and the effects of its concentration, reaction temperature, and reaction time as well as HCl concentration on the extraction rate and silanol density were investigated using an IL extraction template agent (cetyl trimethyl ammonium bromide (CTAB)). The results show that an IL concentration of 10%, a reaction temperature of 120 °C, a reaction time of 12 h, and an HCl concentration of 1% are the best reaction parameters; with these parameters, the extraction rate and the silanol density were found to be 93.19% and 2.23%, respectively. The silanol density of mesoporous silica treated by calcination is only 0.81%. A higher silanol density provides more reaction sites, so that the modified mesoporous silica treated with the IL can be loaded with more Zn ions.

Effect of freeze-dried protectants on the survival rate and fermentation performance of fermented milk's directed vat set starters.

A directed vat set (DVS) starter was proposed to improve the drawbacks of liquid starters in fermented production and enhance the survival rates of B. animalis subsp. lactis BZ11, S. thermophilus Q-1, and Lactiplantibacillus plantarum LB12. The protective agent formula was optimized using the response surface method (RSM), with the survival rate as the benchmark. The best combination of cryoprotectants was determined to be BZ11: 10 % skimmed milk powder, 3 % sodium glutamate, and 15 % trehalose; LB12: 10 % skim milk powder, 5 % glutamate sodium, and 10 % trehalose; Q-1: 10 % skimmed milk powder, 3 % sodium glutamate, and 10 % trehalose. The survival rate of BZ11 significantly increased to 92.87 ± 1.25 %. The DVS fermented milk did not differ significantly from the control group regarding cholesterol removal, live cell counts and pH (p > 0.05). All DVS can be stored for at least 2500 d at -20 °C-this DVS starter for fermented milk benefits from its large-scale and automated commercial production.

Wastewater treatment in lagoons: A systematic review and a meta-analysis.

This study has carried out a systematic review of 36 scientific papers (reporting 63 case studies) published in the last 15 years about the treatment of industrial, agri-food and municipal wastewater in lagoons. A concentration of studies from a few countries (Italy, Algeria and Iran) and about municipal wastewater (70% of papers) was revealed by the bibliographic analysis. Aeration was supplied in more than 50% of case studies; the storage capacity of lagoons (adopted as a measure of size) was extremely variable (over seven orders of magnitude), while their depth was generally lower than a few metres. The efficiency of lagoon treatments at removing COD was in a wide range (25-98%). Very few studies analysed the energy intensity of treatments in lagoons. The meta-analysis applied to a further selection of 10 papers with 29 case studies revealed significant differences in pH and dissolved oxygen concentration, due to aeration or type of treated wastewater. Treatment efficiency was higher in aerated lagoons compared to non-aerated systems, and did not depend on the type of treated wastewater. Based on the analysis of the reviewed papers, an urgent research need on this topic arises, mainly due to the oldness of most analysed studies. Practical suggestions are given to optimise the depuration performances of lagoons: (i) application of intermittent and night aeration; (ii) reduced air flow rates; (iii) adaptation of microbial biomass to high contents of inhibiting compounds in wastewater; (iv) construction of baffles to keep the planned hydraulic retention time avoiding short-circuit; (v) integration of lagoons with other treatments (e.g., constructed wetlands); (vi) ferti-irrigation of crops with lagoon effluents rather than disposal into water bodies.

Immobilization of Cd2+ in an aqueous environment using a two-step microbial-induced carbonate precipitation method.

Previous researches indicate that the potent toxicity of cadmium hinders the efficacy of the microbial-induced carbonate precipitation (MICP) process for bioremediation of Cd2+ in aqueous environment. Increasing urea and calcium resource doses, introducing synergists, and utilizing urease-producing consortia can improve bio-immobilization performance of MICP. However, such measures may incur cost increases and/or secondary contamination. This study first verifies the substantial biotoxicity of Cd2+ for urease activity and then analyzes the practical limitation of traditional MICP using Bacillus pasteurii for bioremediation of Cd2+ in an aqueous environment containing 1-40 mM Cd2+ by a series tube tests and numerical simulation. Subsequently, a two-step MICP method, which separates urea hydrolysis and heavy metal precipitation, is introduced in this study to eliminate the inhibitory effect of heavy metal on urease activity. The concentrations of ammonium, Cd2+, and pH were monitored over time. The results indicate that the urease expression in B. pasteurii can be significantly inhibited by Cd2+ particularly at the concentration ranging from 10 to 40 mM, leading to pretty low efficacy of traditional MICP for bioremediation of Cd2+ (Cd2+ removal rate as low as 21.55-38.47% when the initial Cd2+ concentration = 40 mM). In contrast, when the two-step MICP method is applied, the Cd2+ can be almost completely immobilized, even though the concentration ratio of urea to Cd2+ is as low as 1.5:1.0, which is close to the theory minimum concentration ratio for the complete precipitation of carbonate to cadmium ions(1.0:1.0). Therefore, the cost-effective, environmentally sustainable, and straightforward two-step MICP method holds great potential for application in the bioremediation of Cd2+-contaminated solutions in high concentration.

Preparation and Screening of SRB Gel Particles Used for Deep Purification of Acid Mine Drainage.

The progressive decline of the coal industry necessitates the development of effective treatment solutions for acid mine drainage (AMD), which is characterized by high acidity and elevated concentrations of heavy metals. This study proposes an innovative approach leveraging sulfate-reducing bacteria (SRB) acclimated to contaminated anaerobic environments. The research focused on elucidating the physiological characteristics and optimal growth conditions of SRB, particularly in relation to the pH level and temperature. The experimental findings reveal that the SRB exhibited a sulfate removal rate of 88.86% at an optimal temperature of 30 °C. Additionally, SRB gel particles were formulated using sodium alginate (SA) and carboxymethyl cellulose (CMC), and their performance was assessed under specific conditions (pH = 6, C/S = 1.5, T = 30 °C, CMC = 4.5%, BSNa = 0.4 mol/L, and cross-linking time = 9 h). Under these conditions, the SRB gel particles demonstrated an enhanced sulfate removal efficiency of 91.6%. Thermal analysis via differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) provided further insights into the stability and properties of the SRB gel spheres. The findings underscore the potential of SRB-based bioremediation as a sustainable and efficient method for AMD treatment, offering a novel and environmentally friendly solution to mitigating the adverse effects of environmental contamination.

Improved Properties and Enhancement Strategies of Hydroxyapatite-Based Functional Granular Sludge for a High-Rate Partial Nitritation/Anammox System.

Retaining sufficient anammox bacteria (AnAOB) while keeping the anammox-based process stable is the focus of the study of anammox technology, especially in a one-stage partial nitritation/anammox (PNA) process. The use of hydroxyapatite (HAP) granules in an anammox-based process is innovative for its potential to improve the nitrogen removal rate and achieve simultaneous removal of phosphorus. In this study, the HAP-based granular sludge was employed using enhancement strategies for an excellent nitrogen removal performance in a one-stage PNA process. Compared to those of other granular sludge PNA systems, a remarkable sludge volume index of 7.8 mL/g and an extremely high mixed liquor volatile suspended solids of 15 g/L were achieved under a low hydraulic retention time of 2 h. Consequently, an unprecedented nitrogen removal rate as high as 4.8 kg N/m3/d at 25 °C was obtained under a nitrogen loading rate of 6 kg N/m3/d. After a long-term operation of 870 days, the enhancement strategies underlying the superior performance of the granular sludge were identified. These findings clearly demonstrate that the enhancement strategies are crucial for the superior operating performance of the PNA process, and they can promote the application of the anammox-based process.

Hysteroscopy for retained products of conception: a single-institution experience.

BACKGROUND: Retained products of conception can occur with induced abortion during early-term pregnancy, induction of labor during mid-term pregnancy, drug-induced abortion, miscarriage, cesarean delivery, or full-term normal delivery. Compared with traditional dilation and curettage, hysteroscopy is a safer and more effective treatment method for retained products of conception. This study aimed to report the efficacy of hysteroscopy for treating retained products of conception and to share our new clinical perspectives. METHODS: This retrospective, single-center study was conducted at a tertiary hospital in Chengdu, China. We included 36 patients with retained products of conception who underwent hysteroscopy at our hospital. RESULTS: Our study reported a complete removal rate of 80.5% (29/36) with one procedure. The normal menstruation recovery rate during 1 year of follow-up was 91.6% (33/36). A low rate of postoperative intrauterine adhesions (2.8% [1/36]) was also reported. CONCLUSION: Our retrospective study elucidated the use of hysteroscopy for retained products of conception. We also shared new perspectives regarding hysteroscopy and optimal surgical methods for treating retained products of conception as well as our experience treating residual products with hysteroscopy. To our knowledge, no other study has shared similar experiences.

Energetic evaluation of phenol wastewater treatment by reverse electrodialysis reactor using different anodes.

Efficient electrode materials are essential to convert salinity gradient energy into oxidative degradation energy and electrical energy by reverse electrodialysis reactor (REDR). In this context, comparative experiments of REDR using different anodes (Ti/IrO2-RuO2, Ti/PbO2 and Ti/Ti4O7) were conducted. The effects of output current and electrode rinse solution (ERS) flowrate on mineralization efficiency and energy output were discussed. Results demonstrated that the COD removal rate(ηCOD) rose almost linearly with output current and ERS flowrate when using Ti/Ti4O7 anode, but excessive operating conditions caused a slow increase or even decrease of ηCOD when using Ti/IrO2-RuO2 or Ti/PbO2 anodes. The order of electrode system potential loss (Eele) for the three anodes was Ti/Ti4O7> Ti/PbO2> Ti/IrO2-RuO2. High Eele was beneficial to ηCOD but had a negative effect on the net output power (Pnet) of REDR. Regardless of the applied anodes, increasing the current and decreasing the ERS flowrate was detrimental to Pnet due to higher Eele. Based on these findings, four energy efficiency parameters were defined to evaluate energy recovery from multiple perspectives by linking energy output with mineralization capacity. They were electrode efficiency (ηele), energy efficiency (EE), general current efficiency (GCE) and energy consumption (EC), respectively. Results showed that REDR with Ti/Ti4O7 anodes and suitable operating conditions achieved the optimal energy indicators and mineralization efficiency, which provided an efficient and economical option for wastewater treatment and energy recovery.

The Leaching Kinetics of Iron from Titanium Gypsum in a Citric Acid Medium and Obtain Materials by Leaching Liquid.

In this study, the effect of citric acid on iron leaching from titanium gypsum (TiG) was systematically investigated. The conditions for the leaching of valuable metals were optimized while varying such parameters as the leaching time, citric acid mass fraction, leaching temperature, and the liquid-solid ratio. It was found that under the conditions of a citric acid mass fraction of 10%, at a 80 °C leaching temperature, a leaching duration of 80-90 min and a liquid-solid ratio of 8, the whiteness of titanium gypsum (TiG) increased from 8.1 to 36.5, and the leaching efficiencies of iron reached 84.37%. The kinetic analysis indicated that the leaching process of iron from TiG was controlled by the reaction product layer from 0-20 min, while the leaching process of iron from TiG was controlled by internal diffusion from 20-90 min. The apparent activation energy of the leaching reactions was 33.91 kJ/mol and 16.59 kJ/mol, respectively. High-value-added calcium oxalate and ferrous oxalate were prepared from the calcium and iron in the filtrate of the oxalic acid extraction. The leaching liquid could be recycled, which will provide a new way to utilize titanium gypsum.

Ultrasound-Assisted Fermentation to Remove Cadmium from Rice and Its Application.

Rice, which is a major part of the daily diet, is becoming more and more contaminated by cadmium (Cd). This study combined low-intensity ultrasonic waves with the Lactobacillus plantarum fermentation method and optimized this technique by a single-factor and response surface experiment, aiming to solve the practical problems that the current Cd removal methods for rice cannot address, due to the fact that they require a long time (nearly 24 h), which prevents meeting the rice production demands. The described technique required a short time (10 h), and the highest Cd removal reached 67.05 ± 1.38%. Further analysis revealed that the maximum adsorption capacity of Lactobacillus plantarum for Cd increased by nearly 75%, and the equilibrium adsorption capacity increased by almost 30% after the ultrasonic intervention. Additionally, a sensory evaluation and other experiments proved that the properties of the rice noodles prepared from Cd-reduced rice obtained by ultrasound-assisted fermentation were comparable to those of traditional rice noodles, indicating that this method can be used in actual rice production.

Experimental studies of particle removal and probability of COVID-19 infection in passenger railcars.

A series of experiments in stationary and moving passenger railcars was conducted to measure the removal rates of particles in the size ranges of SARS-CoV-2 viral aerosols, and the air changes per hour provided by the existing and modified air handling systems. The effect of ventilation and air filtration systems on removal rates and their effects on estimated probability (i.e., risk) of infection was evaluated in a range of representative conditions: (1) for two different ratios of recirculated air (RA) to outdoor air (OA) (90:10 RA:OA and 67:33 RA:OA); (2) using minimum efficiency reporting value (MERV) filters with standard (MERV-8) and increased (MERV-13) filtration ratings; and (3) in the presence and absence of a portable high-efficiency particulate-air (HEPA) room air purifier system operated at clean air delivery rate (CADR) of 150 and 550 cfm. The higher-efficiency MERV-13 filters significantly increased particle removal rates on average by 3.8 to 8.4 hr-1 across particle sizes ranging from 0.3 to 10 µm (p < 0.01) compared to MERV-8 filters. The different RA:OA ratios and the use of a portable HEPA air purifier system had little effect on particle removal rates. MERV-13 filters reduced the estimated probability of infection by 42% compared to the MERV-8 filter. The use of a HEPA-air purifier with a MERV-13 filter causes a 50% reduction in the estimated probability of infection. Upgrading the efficiency of HVAC filters from MERV-8 to MERV-13 in public transit vehicles is the most effective exposure control method resulting in a clear reduction in the removal rates of aerosol particles and the estimated probability of infection.

Enhancement of nitrate-dependent anaerobic methane oxidation via granular activated carbon.

Denitrifying anaerobic methane oxidation (DAMO) is a bioprocess utilizing methane as the electron source to remove nitrate or nitrite, but denitrification rate especially for nitrate-dependent DAMO is usually limited due to the low methane mass transfer efficiency. In this research, granular active carbon (GAC) was added to enhance the nitrate-dependent DAMO process. The results showed that the maximum nitrate removal rate of GAC assisted DAMO system reached as high as 61.17 mg L-1 d-1, 8 times higher than that of non-amended control SBR. The porous structure of GAC can not only adsorb methane, but also keep the internal DAMO archaea from being washed out, and thus benefits for DAMO archaea enrichment. The relative abundance of DAMO archaea accounted for 96.3% in GAC-SBR, which was significantly higher than that of non-amended control SBR system (29.9%). Furthermore, GAC amendment up-regulated metabolic status of denitrification and methane oxidation based on gene sequence composition. The absolute abundances of function genes (NC10 pmoA and ANME mcrA) in GAC-SBR were almost 20 times higher than that of non-amended control SBR. This study provides a novel technique to stimulate the nitrate-dependent DAMO process.

Construction of a prediction model for drug removal rate in hemodialysis based on chemical structures.

In designing drug dosing for hemodialysis patients, the removal rate (RR) of the drug by hemodialysis is important. However, acquiring the RR is difficult, and there is a need for an estimation method that can be used in clinical settings. In this study, the RR predictive model was constructed using the RR of known drugs by quantitative structure-activity relationship (QSAR) analysis. Drugs were divided into a model construction drug set (75%) and a model validation drug set (25%). The RR was collected from 143 medicines. The objective variable (RR) and chemical structural characteristics (descriptors) of the drug (explanatory variable) were used to construct a prediction model using partial least squares (PLS) regression and artificial neural network (ANN) analyses. The determination coefficients in the PLS and ANN methods were 0.586 and 0.721 for the model validation drug set, respectively. QSAR analysis successfully constructed dialysis RR prediction models that were comparable or superior to those using pharmacokinetic parameters. Considering that the RR dataset contains potential errors, we believe that this study has achieved the most reliable RR prediction accuracy currently available. These predictive RR models can be achieved using only the chemical structure of the drug. This model is expected to be applied at the time of hemodialysis.

Application of QSAR for investigation on coagulation mechanisms of textile wastewater.

Coagulation is an effective preliminary treatment process for textile wastewater. In order to evaluate the effectiveness of the coagulation process, we performed quantitative structure activity relationship (QSAR) analyses with total organic carbon (TOC) removal rates (Rexp) as an index by three different coagulants (AlCl3, FeCl3, and MgCl2). The experimental results showed that the average Rexp of the three coagulants was 39.12% ± 2.60%, 51.60% ± 2.88%, and 49.95% ± 3.17%. Subsequently, 42 molecular descriptors of dye molecules were calculated by quantitative calculation softwares Gaussian 09, Material Studio 7.0, and Multiwfn 3.7, and then QSAR models were constructed by a multiple linear regression (MLR) method for the three coagulation systems. The developed QSAR models demonstrated excellent stability, robustness, and predictability with values of R2 = 0.7677, 0.8015, and 0.7035, Q2INT = 0.6067, 0.7026, and 0.5898, Q2EXT = 0.5505, 0.5076, and 0.5697, respectively. Based on the analysis of quantum parameters, the coagulation mechanism for AlCl3, FeCl3 is primarily electrostatic adsorption as well as hydrogen bonding, while MgCl2 coagulates dyes mainly by electrostatic adsorption. This study provides an assessment of the removal rules and a feasible method for predicting dye removal rates in AlCl3, FeCl3, and MgCl2 coagulation process.

Research on Bayer Red Mud Slurry Electrolysis.

The Bayer red mud is the solid waste generated during the production of alumina by the Bayer process. At present, the stock of red mud in China exceeds 1.1 billion tons, covering an area of more than 120,000 mu, and the annual production volume is increasing by 100 million tons. The comprehensive utilization of red mud is still a difficult problem. Therefore, it is of great significance to actively explore new methods for removing sodium from red mud. In this study, the traditional red mud desalination process and the slurry electrolysis process are combined, and the influence of three different leaching agents on the leaching and sodium removal of red mud slurry in the presence of an electric field is explored. In the slurry electrolysis experiment, it was found that the sodium removal rate obtained by different leaching agents was CaO > CaCl2 > HCl. The red mud leached with pure dilute hydrochloric acid has the highest Na removal rate, which is 93.11%. In view of this situation, a pre-slurry-electrolysis cycle process with HCl as leaching agent was proposed. The core of slurry electrolysis is electrolyzing NaCl solution, and HCl only participates in the process as circulating medium. The design of this process reduces cost and increases efficiency.

Utilization of Chlorella pyrenoidosa for Remediation of Common Effluent Treatment Plant Wastewater in Coupling with Co-relational Study: An Experimental Approach.

Earlier investigations on biological methods of wastewater treatment have revealed that algal based wastewater treatment could be a green, cost effective and efficient approach for the removal of heavy metals. So, this study aimed to assess the potential of microalga Chlorella pyrenoidosa for remediation of heavy metals (Cr, Cu, Pb, Zn, Cd, Mn, and Ni) from varying concentration (25%, 50%, 75 and 100%) of wastewater collected from Common Effluent Treatment Plant. Heavy metals such as Cr, Cu, Pb, Zn, Cd, Mn, and Ni have been removed significantly from the wastewater, with percentage removal ranging from 73%, 60%, 75%, 66%, 87%, 83%, and 74% with 50% test solution, 57%, 59%, 70%, 56%, 72%, 66%, and 62% with 75% test solution, and 47%, 55%, 56%, 71%, 61%, 77%, and 72% with 100% test solution respectively. Studies on biochemical assay (protein, carbohydrate, and pigment) of Chlorella pyrenoidosa were also an important part of the present investigation to understand the interaction of heavy metals with algal biochemical compounds using Pearson correlation co-efficient. Biomass grown in CETP wastewater can be used for synthesis of various fruitful value-added end products like bio-diesel, pharmaceutical products, cosmetic products, bio-adsorbent etc.

Achieving High-Quality Freshwater from a Self-Sustainable Integrated Solar Redox-Flow Desalination Device.

Solar-assisted electrochemical desalination has offered a new energy-water nexus technology for sustainable development in recent studies. However, only a few reports have demonstrated insufficient photocurrent, a low salt removal rate, and poor stability. In this study, a high-quality freshwater level of 5-10 ppm (from an initial feed of 10 000 ppm), an enhanced salt removal rate (217.8 µg cm-2 min-1 of NaCl), and improved cycling and long-term stability are achieved by integrating dye-sensitized solar cells (DSSCs) and redox-flow desalination (RFD) under light irradiation without additional electrical energy consumption. The DSSC redox electrolyte (I- /I3- ) is circulated between the photoanode (N719/TiO2 ) and intermediate electrode (graphite paper). Two DSSCs in parallel or series connections are directly coupled to the RFD device. Overall, this hybrid system can be used to boost photo electrochemical desalination technology. The energy-water nexus technology will open a new route for dual-role devices with photodesalination functions without energy consumption and solar-to-electricity generation.

Improved Formula for Predicting Hemodialyzability of Intravenous and Oral Drugs.

BACKGROUND: The rate of drug removal by hemodialysis needs to be considered when designing drug dosage regimens for patients on hemodialysis. We previously developed a simplified equation to predict the removal rates of intravenously administered drugs by hemodialysis. Here, we addressed shortcomings of this equation and developed a more accurate equation that can also predict the removal rates of orally administered drugs. METHODS: A total of 70 drugs with known pharmacokinetic and physical parameters and drug removal rates that were measured during hemodialysis in clinical cases were randomly assigned at a 4:1 ratio to a training data group or a test data group. A prediction equation was developed by performing stepwise multiple regression analyses using the training data (i.e., the removal rate by hemodialysis) as the objective variable and pharmacokinetic parameters as the explanatory variables. The equation was validated using the test data. RESULTS: Multiple regression analyses revealed that molecular weight (MW), protein binding rate, and fraction excreted unchanged in urine relative to the volume of distribution (Vd) were independently correlated with the drug clearance rate (adjusted coefficient of determination, 0.83; p = 2.2e-16). The following equation was obtained: drug removal rate by hemodialysis (%) = -17.32 × [log (MW)] - 0.39 × [protein binding rate (%)] + 0.06 × [fraction excreted unchanged in urine (%)/Vd (L/kg)] + 83.34. Validation of the equation using the test data showed a very high correlation between predicted and measured reduction rate (R = 0.93, p = 1.87e-6). Mean error was -3.34 (95% confidence interval: -10.03, 3.35), mean absolute error was 9.59, and root mean square error was 16.48. CONCLUSION: The modified equation derived in this study using pharmacokinetic and physical parameters as variables precisely predicted the removal rates of both intravenous and oral drugs by hemodialysis.

Efficacy of Medium Cut-Off Dialyzer and Comparison with Standard High-Flux Hemodialysis.

BACKGROUND: A new medium cut-off (MCO) membranes has been designed to achieve better removal capacities for middle and large middle molecules in hemodialysis (HD) treatment. AIM: The aim of this study was to evaluate the removal efficacy of Theranova® in standard HD in comparison with standard high-flux HD. METHODS: Four HD patients (M/F 1/4) were included in 12-week observational pilot study in HD with Theranova® 400 and Theranova® 500 dialyzers. Each patient was assessed 4 times, T0 with high-flux dialyzers, T1 at 1 month, T2 at second month, and T3 at third month, by measuring pre- and post-HD samples of urea, Cr, ß2-microglobilin (ß2M), myoglobin, albumin, free light chains kappa (FLC-k), and free light chains lambda (FLC-λ). RESULTS: The data showed a higher average removal rate for all the uremic toxins with Theranova® dialyzers for ß2M, myoglobin, FLC-k, and FLC-λ (62.7, 56.9, 63.5, and 54.6%, respectively) during the 3 months. Albumin retention was observed and did not change between T0 and T3 (p = 0.379). CONCLUSION: Compared to high-flux membranes, MCO membranes show greater permeability for middle molecules in midterm report.