Removal Of Substances Research Articles

Impact of Polarization Reversal during Photoelectrocatalytic Treatment of WWTP Effluents

Photoelectrocatalysis (PEC) has been already proposed as a polishing treatment for wastewater treatment plants (WWTPs) effluents. In this work, the impact of polarization reversal during PEC process has been studied and evaluated on the basis of the removal of organic substance and color, biodegradability of the matrix, and inactivation of the catalyst. Effluents were sampled from a full-scale WWTP and alternatively treated by electrochemical oxidation (EC), photolysis (PL), photocatalysis (PC), photoelectrocatalysis, and photoelectrocatalysis with reverse polarization (PECr). The efficiency and the kinetics of the process, in terms of removal of organic substance and color, were not affected by reverse polarization and very similar results were obtained by PEC and PECr. The biodegradability of the effluents strongly increased both by PECr (RSBR: 0.84 ± 0.07), and by PEC and PL (0.89 ± 0.11, and 0.78 ± 0.02, respectively). In the selected polarization reversal mode (100 s at −0.1 V every 500 s at 4 V, cell voltage), a similar photocurrent loss after PEC and PECr was observed, suggesting no effect on the activity of the TiO2 mesh. This study can serve as a base for future research on polarization reversal to optimize operation parameters and exploit the procedure to preventing fouling and inactivation of the catalyst.

Using circular economy principles in the optimisation of sludge-based activated carbon production for the removal of perfluoroalkyl substances

Massive sewage sludge (SS) production from municipal wastewater treatment plants and the presence of numerous pollutant types render the process of SS treatment and disposal costly and complex. Here, resource recovery from SS was maximised via the optimisation of sludge-based activated carbon (SBAC) production for the removal of poly- and perfluoroalkyl substances (PFASs), while considering economic factors and minimising environmental impacts. SBAC production optimisation was realised under different operating conditions (different ZnCl2 impregnation ratios and different pyrolysis activation temperatures and durations). The sorption capacity of the optimised SBAC with respect to the removal of nine commonly detected PFASs, with environmentally relevant concentrations (∽50 μg/L), from simulated wastewater was evaluated. Economic analysis and life-cycle assessment (LCA) were also performed to determine the feasibility of the process and its potential role in the circular economy. Batch adsorption tests confirmed the high efficiency of the optimised SBACs for PFAS removal (93–100 %), highlighting the possibility of converting SS to SBAC. Economically speaking, the optimised SBAC at 1.5 M ZnCl2, 500 °C, and 0.75 h reduced total production cost by 49 %. Further, the cost could be reduced to as little as 1087 US $/metric-ton compared with that corresponding to the original conditions (2.5 M ZnCl2, 500 °C, 2 h; 2144 US $/metric-ton). LCA results also showed that freshwater ecotoxicity, marine ecotoxicity, and human non-carcinogenic toxicity were the most affected environmental impact indicators, showing a 49 % decrease when ZnCl2 impregnation ratio was reduced from 2.5 to 1.5 M. These findings highlighted the optimal conditions for the production of SBAC with high sorption capacity at a reduced cost and with reduced environmental impacts. Thus, they can serve as valuable tools for decision making regarding the selection of the most sustainable and economically feasible process for PFAS removal.

Photocatalytic Organic Contaminant Degradation of Green Synthesized ZrO2 NPs and Their Antibacterial Activities

The green synthesis of metal oxide nanoparticles is an efficient, simple, and chemical-free method of producing nanoparticles. The present work reports the synthesis of Murraya koenigii-mediated ZrO2 nanoparticles (ZrO2 NPs) and their applications as a photocatalyst and antibacterial agent. Capping and stabilization of metal oxide nanoparticles were achieved by using Murraya koenigii leaf extract. The optical, structural, and morphological valance of the ZrO2 NPs were characterized using UV-DRS, FTIR, XRD, and FESEM with EDX, TEM, and XPS. An XRD analysis determined that ZrO2 NPs have a monoclinic structure and a crystallite size of 24 nm. TEM and FESEM morphological images confirm the spherical nature of ZrO2 NPs, and their distributions on surfaces show lower agglomerations. ZrO2 NPs showed high optical absorbance in the UV region and a wide bandgap indicating surface oxygen vacancies and charge carriers. The presence of Zr and O elements and their O=Zr=O bonds was categorized using EDX and FTIR spectroscopy. The plant molecules’ interface, bonding, binding energy, and their existence on the surface of ZrO2 NPs were established from XPS analysis. The photocatalytic degradation of methylene blue using ZrO2 NPs was examined under visible light irradiation. The 94% degradation of toxic MB dye was achieved within 20 min. The antibacterial inhibition of ZrO2 NPs was tested against S. aureus and E. coli pathogens. Applications of bio-synthesized ZrO2 NPs including organic substance removal, pathogenic inhibitor development, catalysis, optical, and biomedical development were explored.

A pilot study on the dual membrane process of ultrafiltration and nanofiltration to treat algae-laden raw water compared to O3-BAC

AbstractIn this study, a dual membrane process that combines seven-hole ultrafiltration and nanofiltration was designed and compared to O3-biological activated carbon (O3-BAC) for high-quality drinking water production. The pollutant removal, membrane fouling, long-term operational characteristics, and technical economy were systematically investigated using raw water from Tai Lake, which has a high algae content. The results elucidate that the dual membrane process has superb decontamination. This method has much better removal of turbidity, CODMn, UV254, and algae than O3-BAC. Its removal of ammonia nitrogen and fluorescent substances is slightly lower than that of O3-BAC, but the effluent still satisfies the drinking water standard. The dual membrane process is also much more capable of dealing with high algae-laden raw water. Compared to O3-BAC, the cost of the dual membrane process is 46.4% higher per ton without consuming chemicals, so it is more environmentally friendly. In summary, the dual membrane process offers a promising and effective technology to treat high algae-laden water with the advantages of high stability, reliable effluent, and zero emissions.

Sorptive removal of short-chain perfluoroalkyl substances (PFAS) during drinking water treatment using activated carbon and anion exchanger

Laboratory tests and column tests were carried out in a waterwoks to investigate the removal of short- and long-chain PFAS using activated carbon filtration and ion exchange treatment. For all adsorbents, the sorption affinity of short-chain per- and polyfluoroalkyl carboxylic acids (PFCA) was significantly lower than that of long-chain PFAS or short-chain per- and polyfluoroalkyl sulfonic acids (PFSA). In the PFAS-polluted groundwater matrix, the short-chain PFCA PFBA and PFPeA could only be sufficiently removed with activated carbon over short run times of 6000 and 11,000 bed volumes (BV), respectively. Longer PFCA with a chain length of C6 or more were removed over longer run times.The removal of short-chain PFCA using ion exchange media could also only be achieved over relatively short run times of 5000 BV for PFBA, 10,000BV for PFPeA and 18,000 BV for PFHxA. These are sometimes significantly longer than those of activated carbon. Due to the higher material costs for ion exchange media, there are nevertheless no lower operating costs when the ion exchangers are used in single-use mode. However, ion exchangers can be regenerated and then reused which can result in economic advantages compared to activated carbon filtration. However, for the extensive regeneration, especially for the elution of the long-chain PFAS, the additional use of ethanol is needed in the process. In contrast, the short-chain PFBA and PFPeA can be extracted without organic solvent from a weakly basic ion exchanger.

Polymer-flooding produced water treatment using an electro-hybrid ozonation-coagulation system with novel cathode membranes targeting alternating filtration and in situ self-cleaning

Polymer-flooding produced water is more difficult to treat for reinjection compared with normal produced water because of the presence of residual hydrolyzed polyacrylamide (HPAM). A novel cathode membrane integrated electro-hybrid ozonation-coagulation (CM-E-HOC) process was proposed for the treatment of polymer-flooding produced water. This process achieved in situ self-cleaning by generated microbubbles in the cathode membrane. The CM-E-HOC process achieved a higher suspended solid (SS), turbidity and PAM removal efficiency than the CM-EC process. The SS in the CM-E-HOC effluent was ≤ 20 mg/L SS, which met the reinjection requirements of Longdong, Changqing Oilfield, China (Q/SYCQ 08,011–2019) at different current densities (3, 5 and 10 mA/cm2). The CM-E-HOC process greatly mitigated both reversible and irreversible membrane fouling. Therefore, excellent flux recovery was obtained at different in situ self-cleaning intervals during the CM-E-HOC process. Furthermore, alternating filtration achieved continuous water production during the CM-E-HOC process. On one hand, the effective removal of aromatic protein-like substances and an increase in oxygen-containing functional groups were achieved due to the enhanced oxidation ability of the CM-E-HOC process, which decreased membrane fouling. On the other hand, the CM-E-HOC process showed improved coagulation performance because of the increased oxygen-containing functional groups and polymeric Fe species. Therefore, larger flocs with higher fractal dimensions were generated, and a looser and more porous cake layer was formed on the membrane surface during the CM-E-HOC process. Consequently, the CM-E-HOC process exhibited better in situ self-cleaning performance and lower filtration resistance than the CM-EC process.

Enhanced Removal of Polyfluoroalkyl Substances by Simple Modified Biochar: Adsorption Performance and Theoretical Calculation

To cope with the widespread polyfluoroalkyl substance (PFAS) pollution in the global aquatic environment, this study prepared an acid-modified biochar adsorbent derived from sludge with satisfactory performance. The theoretical maximum adsorption capacities of the adsorbent for perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) were determined to be 72.17 and 45.88 mg·g–1, respectively. The theoretical calculation of the adsorption of biochar surface functional groups with PFOS and PFOA was first performed in this study, and the mechanism of the adsorption process was inferred with a combination of experimental results and redundancy analysis. The adsorption mechanism is composed mainly of the following three aspects: (I) electrostatic interaction between the positively charged biochar and the deprotonated PFAS; (II) hydrogen bonding between anionic species of PFAS and functional groups; and (III) hydrophobic interaction between long-chain hydrophobic PFAS and biochar. Electrostatic interaction plays a major role in the three main adsorption mechanisms under acidic media. Meanwhile, different functional groups have different adsorption energies for PFAS, and C═O has the highest adsorption energy. The findings in this work could provide great insights into the adsorption of PFAS on modified biochar as an environmentally friendly adsorbent to promote resource reuse, improve water quality, and ensure human health.

Development of softening and ballasted flocculation as a pretreatment process for seawater desalination through a reverse osmosis membrane

Efficient desalination through a reverse osmosis (RO) membrane requires the prior removal of blockade-causing substances from raw seawater. To achieve ultrahigh-speed processing of a pretreatment process for seawater RO desalination, we combine traditional softening with ballasted flocculation (SBF) for Ca2+ and Mg2+ removal. An alkaline mixture of Ca(OH)2 and Na2CO3 was the most suitable softening agent for Ca2+ and Mg2+ removal with a reduced amount of generated sludge. This softening treatment simultaneously removed the suspended solids and bacteria from actual seawater. The settling velocity of the suspended solids generated via seawater softening was extremely low. Under the optimum conditions for desalinating actual seawater using an anionic polymer flocculant and microsand, the settling velocity exceeded 3.5 cm/s, 833 times higher than that of softening without ballasted flocculation. The amount of sludge after standing for 3 min was 76.5% lower in SBF than in conventional softening. The silt density index of the treated seawater met the water-supply standard of RO membranes (i.e., <3.0). Furthermore, the SBF-generated sludge exhibited considerably improved dewatering property than the sludge obtained via conventional softening. SBF can efficiently and quickly remove the causative substances of RO membrane fouling from seawater, thereby improving the treatability of generated sludge. SBF provides a new pretreatment process for seawater desalination using RO membranes.

Towards Waste-to-Energy-and-Materials Processes with Advanced Thermochemical Combustion Intelligence in the Circular Economy

Waste-to-energy processes remain essential to ensure the safe and irreversible removal of materials and substances that are (or have become) unsuitable for reuse or recycling, and hence, to keep intended cycles of materials in the circular economy clean. In this paper, the behavior of inorganic compounds in waste-to-energy combustion processes are discussed from a multi-disciplinary perspective, against a background of ever tightening emission limits and targets of increasing energy efficiency and materials recovery. This leads to the observation that, due to the typical complexity of thermally treated waste, the intelligence of combustion control systems used in state-of-the-art waste-to-energy plants needs to be expanded to better control the behavior of inorganic compounds that typically end up in waste furnaces. This paper further explains how this goal can be achieved by developing (experimentally validated) predictive numerical models that are engineering-based and/or data-driven. Additionally, the significant economic potential of advanced thermochemical intelligence towards inorganic compounds in waste-to-energy combustion control systems is estimated on the basis of typical operational figures.

Extraction of methylene orange and humic acid from aqueous solutions by using polymer inclusion membrane

Dyes and organic matters which are highly toxic to marine life and form a large part of industrial waste are commonly used colorants in textile and other related industries. Extractions of methylene orange dye and humic acid organic matter solution were investigated by using polymer inclusion membrane (PIM). PIM was made of poly (vinyl chloride) (PVC) and cellulose triacetate (CTA) as base polymer, trioctylamine (TOA) as a carrier, and methyltrioctyl ammonium chloride (Aliquat 336) as a plasticizer. The composition of the components was changed to determine the optimum composition of the membrane with better extraction ability. 10 ppm methylene orange and 100 ppm humic acid solution were passed through the produced membranes. Synthetic solutions prepared in the feed phase and HCl in the receiving phase were added in the system and the experiment continued until the system came to equilibrium. The PIM-6 membrane containing 40 wt% PVC, 40 wt% A336, and 20 wt% TOA had the highest removal efficiency of dye (93.57 %) and the highest organic matter removal efficiency (86.03 %). When the performance of PIM was examined, it was observed that it was an excellent method for the removal of dyes and organic substances from industrial wastewater.

A technological approach using a metal-free immobilized photocatalyst for the removal of pharmaceutical substances from urban wastewaters

The presence of micropollutants (MPs) in aquatic compartments poses a great risk to the ecosystems and human health. Advanced oxidation processes (AOPs), such as light-induced systems employing a variety of powder optical semiconductors, have been widely investigated to remove MPs from water and wastewater. In this work, a metal-free photocatalyst (GCN-T) immobilized in the form of a film (GCN-T/PVDF) was activated by visible light (λexc = 417 nm) and successfully tested in both batch and continuous flow mode reactors for the degradation of two pharmaceutical model compounds (metoprolol and venlafaxine) spiked in ultrapure water (UP) and urban wastewater (WW) samples. A total removal of MPs was reached after 3 h reaction using GCN-T/PVDF film in a batch reactor. Under continuous mode operation, a steady state was attained after 2 h, with ca. 64 % removal for both MPs being obtained. The photocatalytic system was also examined using a non-spiked WW sample to study its performance to remove trace concentrations of these and other MPs in this type of complex matrix. MPs, such as bezafibrate, carbamazepine, diclofenac, isoproturon, and tramadol, were detected and efficiently degraded using the GCN-T/PVDF film. Finally, the ecotoxicity of the WW samples was also investigated using the aquatic invertebrate microcrustacean Daphnia magna. The results showed that the toxicity of WW samples decreases with the photocatalytic treatment.

Advanced Treatment of Digested Restaurant Wastewater Using a Combination of Anaerobic/OxicUnit, Fenton, and a Biological Aerated Filter in Pilot-Scale Treatment

Biological treatment is the most economical and practical wastewater treatment method; however, for highly concentrated organic wastewater, such as digested restaurant wastewater, a single biological treatment method does not meet the discharge requirements. Herein, an anaerobic/oxic-Fenton-biological aerated filter (A/O-Fenton-BAF) system was employed to treat digested restaurant wastewater with a high concentration of organic compounds in a pilot-scale experiment. The degradation process and mechanism of chemical oxygen demand (COD), total nitrogen (TN), NH4+-N, NO3−-N, and dissolved organic nitrogen (DON) in each stage of the process were analyzed. Gas chromatography–mass spectrometry and fluorescence spectrum characteristics were also studied. The average removal rate of both COD and NH4+-N in the entire process was 98%. The removal rates of COD, TN, NH4+-N, and DON reached 78.5%, 66.0%, 95.3%, and 51%, respectively, using the A/O unit. Although Fenton was ineffective in the removal of nitrogenous organic and inorganic substances, the fluorescence spectra and GC–MS showed that the nitrogen-containing organic compounds of macromolecules were transformed into small molecules after the Fenton reaction and could be removed by the BAF unit. The removal rate of DON was up to 24.3% in the Fenton + BAF process, which reduced the TN concentration in the effluent. The dominant species in all biological processes were nitrifying and organic matter-decomposing bacteria. This study provides key data for the design of a full-scale system for treating digested restaurant wastewater.

Performance and Mechanism of Improved Soluble Organic Carbon Recovery from Municipal Wastewater through the Coagulation-Enhanced High-Rate Contact Stabilization Process

High-rate contact stabilization is promising to capture organic carbon from municipal wastewater; however, its engineering application is restricted due to its poor capability of removing soluble organic matter (particle size < 0.1 μm). In this work, the carbon capture efficiency and robustness of the coagulation-enhanced high-rate contact-stabilized process for treating municipal wastewater with a varied content of soluble organic matter was comprehensively evaluated. Results showed that the high-rate contact stabilization process did not perform well in the removal and capture of influent organic substances with a high proportion of soluble components. Adding coagulants into the above process favored organic carbon capture, whose recovery efficiency could reach up to 60% even under the 90% influent soluble chemical oxygen demand condition. Mechanism analysis revealed that the hydrolyzed product of the coagulant would adsorb dissolved components to form colloid and subcolloid particles, which was favored for further capture by sludge. The fitting result of the neutral community model indicated that both deterministic environmental factors and random processes influence the succession of sludge community. This work implied that the coagulation-enhanced high-rate contact stabilization process is feasible to recover organic carbon from municipal wastewater, which may shed a promising light for sustainable carbon control and management.

Mining phosphorus from waste streams at wastewater treatment plants: a review of enrichment, extraction, and crystallization methods.

Two interrelated problems exist: the non-renewability of phosphate rock as a resource and the excess phosphate in the water system lead to eutrophication. Removal and recovery of phosphorus (P) from waste streams at wastewater treatment plants (WWTPs) is one of the promising solutions. This paper reviews strategies for P recovery from waste streams in WWTPs are reviewed, and the main P recovery processes were broken down into three parts: enrichment, extraction, and crystallization. On this basis, the present P recovery technology was summarized and compared. The choice of P recovery technology depends on the process of sewage treatment and sludge treatment. Most P recovery processes can meet the financial requirements since the recent surge in phosphate rock prices. The safety requirements of P recovery products add a high cost to toxic substance removal, so it is necessary to control the discharge of toxic substances such as heavy metals and persistent organic pollutants from the source.

Inverse opal-structured all-in-one water purification filter designed for the effective removal of multi-pollutants

Despite the dominance of centralized water treatment systems in the past decades, there is increased demand for instant water treatment in isolated areas, i.e., decentralized water treatment. Moreover, as wastewater contains multiple pollutants such as heavy metals, anionic substances, and organic matter, research on their simultaneous removal is one of the most significant issues for practical application. In this study, we reported a novel all-in-one multi-pollutants removal filter based on inverse opal (IO) structures for decentralized water treatment. This IO-based all-in-one filter consists of three adsorbents: Fe2O3, NiOx, and S-doped graphene, for the simultaneous removal of heavy metals, anionic substances, and organic matter. The filter was particularly designed to enhance the water flux of nano-absorbents with high absorption capacity under a water-flow system. As a result, the all-in-one multi-pollutants removal filter exhibited excellent adsorption performance (phenol: 108.16 mg/g; Zn: 209.26 mg/g; and phosphate: 202.54 mg/g) at ultrafast water flux (1167 L/m2·h). We successfully designed an efficient multi-pollutants removal system considering the removal mechanisms suitable for different pollutants, the correlation of pollutants, and the water flow by IO structure. Moreover, our results demonstrated the simultaneous removal of multi-pollutants from wastewater using a single-unit purification system, which would provide great significance to decentralized water purification systems.

The implications of Vitamin E acetate in E-cigarette, or vaping, product use-associated lung injury.

In the summer of 2019, a cluster of cases were observed with users of battery-operated or superheating devices presenting with multiple symptoms, such as dyspnea, cough, fever, constitutional symptoms, gastrointestinal upset, and hemoptysis, that is now termed e-cigarette, or vaping, product use-associated lung injury (EVALI). The Centers for Disease Control and Prevention reported 2807 cases within the USA leading to at least 68 deaths as of February 18, 2020. The heterogeneous presentations of EVALI make diagnosis and treatment difficult; however, treatment focused on identifying and removal of the noxious substance and providing supportive care. Vitamin E acetate (VEA) is a likely cause of this lung injury, and others have reported other components to play a possible role, such as nicotine and vegetable glycerin/propylene glycol. EVALI is usually observed in adolescents, with a history of vaping product usage within 90 days typically containing tetrahydrocannabinol, and presenting on chest radiograph with pulmonary infiltrates or computed tomography scan with ground-glass opacities. Diagnosis requires a high degree of suspicion to diagnose and exclusion of other possible causes of lung disease. Here, we review the current literature to detail the major factors contributing to EVALI and primarily discuss the potential role of VEA in EVALI. We will also briefly discuss other constituents other than just VEA, as a small number of EVALI cases are reported without the detection of VEA, but with the same clinical diagnosis.

Обзор нейротропных эффектов витаминов группы B

The importance of pain syndromes is obvious not only medically but also socially. Dissatisfaction with the pain relief efficacy, a variety of pathogenetic mechanisms dictate the need to search for new and/or additional analgesics. Previously, the role of neurotropic B vitamins, potentiating analgesic therapy, and having their base potential, including additional effects, was convincingly shown. However, the role of vitamins in this group turned out to be much more important and covers a wide range of vital aspects of the body functioning as a whole and the nervous system in particular. The article considers the importance of vitamins in the following: ensuring the energy metabolism of nervous tissue, regulation of neurons key processes, key neurotransmitters metabolism, structural components, as well as removal of neurotoxic substances. The article also emphasizes synergistic, cooperative effect of these vitamins, as well as it describes their role in the normal state and in the pathology development, including those mediated by vitamin deficiencies. The available data on the use of the entire B vitamins palette, both experimental and clinical, in the treatment of pain syndromes, pathology of the central and peripheral nervous system is analyzed. KEYWORDS: pain, nervous system, neurodegeneration, B vitamins, thiamine, riboflavin, pyridoxine, folic acid, cyanocobalamin. FOR CITATION: Vertkin A.L., Knorring G.Yu., Aliev Z.K. Neurotropic B vitamins effects: overview. Russian Medical Inquiry. 2023;7(10):650–657 (in Russ.). DOI: 10.32364/2587-6821-2023-7-10-6.

Determining the Removal of Harmful Substances During the Construction Period

The construction industry is a fairly capacious consumer of various fuel and energy resources, the period of construction of buildings deserves special attention, which is comparable to the stage of operation in terms of average annual costs. A document containing maximum allowable emissions is mandatory for categories of enterprises, including construction industries, which, in the course of their work, pollute the atmosphere with emissions of various substances: combustion products, exhaust gases, dust, etc. The article assesses atmospheric air pollution with harmful substances from the operation of machines and mechanisms at the construction site during the construction of an apartment building. The values of harmful emissions by types of mechanization of construction works are considered. The maximum allowable total emissions into the atmosphere for the considered construction object were calculated in order to control the quality and composition of pollutants into the atmosphere from mechanized sources located at the construction site. The results of calculations of maximum allowable emissions make it possible to assess the level of impact on the atmospheric air. If the emission values are exceeded, monitoring of compliance with environmental pollution is introduced in order to take corrective measures to improve the environmental situation.

Removing tannins and debittering brewer’s spent yeasts by Tween 80

Introduction: Yeast extract from brewer's spent yeast cells is a promising nutrition source for many applications in the food industry and biomass production. However, because of the impurities that cause the bitter and astringent flavor attributed to hop resins during fermentation, brewer's spent yeasts in the industry have not been widely used. Contaminants have been withdrawn by using a variety of techniques. However, most reported methods have focused on removing iso-alpha acid rather than tannin, which has anti-digestive and antimicrobial properties. This study focuses on removing tannins and evaluating their impact on reusing brewer's spent yeast in biomass production. Methods: In this work, Tween 80 was employed for the removal of tannins and other bitter substances from brewer’s spent yeasts. In addition to biochemical approaches, the efficiency of cultivating probiotics with autolysates from yeasts cleaned by various buffers is used to evaluate the effectiveness of eliminating tannins and bitter compounds. Results: In tannin removal, the outstanding efficiency of Tween 80 was four times higher than that of water and hypotonic 0.5% NaCl solution. The debittering efficiency increases from 77% to 83.6% by using Tween 80. Therefore, the cell density of Lactobacillus fermentum 4C cultures with the autolysate from Tween 80-treated spent yeast cells increased by 16.5% and 10.2% compared to that of cultures washed with distilled water or 0.5% NaCl, respectively. The autolysate of Tween 80-treated yeast cells is rich in protein and α-amino nitrogen. It shows advantages in culturing different strains of probiotics. Conclusions: By skipping the first stage of biomass creation, the reuse of spent yeasts in the production of yeast extracts will not only address environmental issues but also have a positive economic impact.

PS-C09-13: NEW COMPREHENSIVE THERAPEUTIC STRATEGY FOR HYPERTENSION AND UREMIA USING INORGANIC SUBSTANCES WITH SPECIAL ADSORPTION PROPERTIES

Background: In order to remove uremic toxins accumulated in patients with chronic kidney disease (CKD), removal of uremic toxin-causing substances from the intestinal tract by administration of spherical adsorbed charcoal and removal of uremic toxins from the blood by hemodialysis are being performed. However, existing treatment methods are still inadequate for the removal of protein-bound uremic toxins (PBUT) and other medium- to large-sized uremic toxins, which leads to a decreased quality of life and worse prognosis in CKD patients. In order to solve this remaining problem, we are currently investigating the use of inorganic materials for the treatment of uremia. Methods: To evaluate the adsorption performance of our inorganic material, we compared the adsorption performance of various uremic substances in solution, healthy subjects’ plasma, and hemodialysis patients’ plasma, using Kremezin® as a control. Results: Kremezin® was able to adsorb small molecular weight substances in each solution and plasma, while medium to large molecules were poorly adsorbed. On the other hand, the inorganic material we are developing has high adsorption performance not only for small molecules but also for medium to large molecules including inflammatory cytokines and PBUT, and selectively adsorbs cations such as sodium, potassium, and inorganic phosphorus. Conclusion: Inorganic substances with special adsorption performance adsorbed not only uremic substances but also cations, whose accumulation is a problem in CKD patients. Therefore, the inorganic adsorbent may contribute not only to the treatment of uremia but also to the comprehensive treatment of hypertension, hyperkalemia, and CKD-MBD, which are common complications in CKD patients.