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Worldwide, the harmful ion contamination of water has become a serious problem because of unregulated industry, energy production, and mining, which greatly increase the concentration of pollutants in water. The novel membranes through adsorbent self-assembly, such as protein amyloids, were explored for wastewater treatment. Herein, we report amyloid fibril (AF)-embedded bacterial cellulose nanohybrid membrane for efficient removal of heavy metal from industrial effluent. AFs are synthesized by heat treatment using bovine serum albumin and embedded with bacterial cellulose nanomembrane (BCN). The AF-embedded BCN (AF/BCN) was characterized using microscopy and spectroscopic methods. In addition, the well-ordered multi-layered AF/BCN filtration assembly was fabricated in the commercial cartridge and validated for the removal of heavy metals (Pb2+ and Hg2+) from wastewater and treatment of industrial wastewater sample containing heavy metals. Our multi-layered filtration assembly removed Hg2+ and Pb2+ with efficiency of 95 and 78.34%, respectively. A computational study using molecular docking has also been performed for the identification of metal entrapment sites. Moreover, our AF/BCN filtration assembly showed high regeneration capacity up to four cycles. The isotherm model also revealed a strong fit and good adsorption behaviour. This makes potential filtration assembly for low-cost, high-efficiency for the removal of heavy metal from wastewater. HIGHLIGHTS Computational approaches methods for the study of bovine serum albumin.; Synthesis of amyloid fibril, amyloid-embedded bacterial cellulose nanomembrane (BCN), and fabrication of amyloid-embedded BCN filtration assembly.; Heavy metal removal analysis from industrial wastewater.;

In this study, the performance of four different pre-treatment alternatives for granular media filtration, namely, settling, aeration, coarse media filtration and chemical coagulation were compared experimentally. Further, analytical hierarchy process (AHP) was used to compare their performance based on economic, environmental, technical and performance criteria. Performance of settling and aeration were evaluated up to 24 h duration. The coarse media filter was intermittently operated with 10 L of greywater in downflow mode while alum was used for chemical coagulation. Experimental results showed that settling up to 6 h did not show significant removal of different pollutants whereas 24 h settling resulted in moderate removal of turbidity and organic content but was not efficient in the removal of nutrients and faecal coliforms. Chemical coagulation reduced 93, 66, 48 and 97% of turbidity, COD, NH4-N and faecal coliforms, respectively from greywater but resulted in excessive sludge generation and is difficult to adopt on-site and requires skilled supervision. Coarse filtration of greywater resulted in 61, 41, 36 and 35% removal of turbidity, COD, PO4-P and faecal coliforms, respectively. Considering different criteria AHP gave coarse filtration as the best pre-treatment option to the granular media filters treating greywater. HIGHLIGHTS The performance of four pre-treatment options namely, settling, aeration, coarse media filtration and chemical coagulation was compared experimentally.; Economic, environmental, technical and performance criteria were considered.; AHP gave coarse media filtration as the best pre-treatment alternative to the granular media filters treating greywater.;

An increase in slaughtering animals will have an impact on increasing the liquid waste produced. The resulting RPH liquid waste can damage the environment if it is not treated, so it is necessary to conduct research to reduce pollutant levels so that it is suitable for disposal into the environment. The technique used in processing RPH wastewater is iron sand filtration method. Iron sand filtration is a filtering process using renewable media, namely iron sand. Iron sand is known to contain the mineral magnetite (Fe3O4) which has the ability to absorb colloidal solids, so it has the potential to be used to remove pollutant content of RPH liquid waste. This research objective to determine the effect of variations in the thickness of the filtration media (cm) and grain size (mesh) on pollutant parameters. The thickness variations used were 20, 25, and 30 cm, with grain sizes of iron sand 40, 60 and 100 mesh. The experimental results showed that the iron sand filtration method was able to reduce Chemical Oxygen Demand (COD) and Total Suspended Solid (TSS) levels, increase the Dissolve Oxygen Meter (DO) value, and change the pH value. The highest reduction in COD was in the thickness variation of 30 cm with 100 mesh. the percentage of decrease in the value of Chemical Oxygen Demand (COD) was 95.05%, the highest decrease in Total Suspended Solid (TSS) value was in the media thickness variation of 30 cm with 100 mesh, the percentage of TSS value reduction was 97.11%, the pH value increased in the thickness variation media 30 cm with a mesh number of 100 from 5.8 to 7.4, and the value of Dissolve Oxygen Meter (DO) increased with variations in thickness of 30 cm with 100 mesh, increased from 1.2 to 15.2. Based on the parameter test results, it was concluded that iron sand filtration is effective in reducing pollutant levels below the quality standard, so that it is expected to be applied directly on a larger scale.

This article discusses a mathematical model of tumor dynamics. The tissue is considered as a multiphase three-component medium consisting of extracellular matrix, tumor cells, and extracellular fluid. The extracellular matrix is generally deformable. In the case of the predominant extracellular fluid — tumor cell interaction, the original system of equations is reduced to the one parabolic equation degenerating on the solution with a special right-hand side. The property of a finite perturbation propagation velocity for tumor cell saturation is revealed. The introduction describes the essence of the problem. The second part presents the derivation of a mathematical model of tumor dynamics as a three-phase medium. The third part describes a mathematical model for the case when mechanical interaction with extracellular fluid is neglected. The fourth part considers the case of predominant fluid-cell interaction. The fifth part provides a proof of the theorem on the localization of the solution to the equation for the saturation of tumor cell.

Irrigation water contaminated by human fecal material may elevate the risk of produce contamination with the enteric parasite Cyclospora cayetanensis. Oocysts of C. cayetanensis are resistant to commonly used disinfectants and a method of removing C. cayetanensis from irrigation water would mitigate this risk. We evaluated zero valent iron (ZVI) sand filtration as one such method. We sought to determine if sand filters containing ZVI outperformed those without ZVI. We first evaluated the abundant poultry parasites Eimeria maxima, E. tenella and E. acervulina as surrogates for C. cayetanensis. We determined if a miniaturized gravity fed ZVI-sand filter, scaled to evaluate scarce supplies of C. cayetanensis oocysts, provided useful information about the performance of larger filtration systems. Filters were inoculated with oocysts, rinsed, and the resulting filtrate examined microscopically for oocysts. We performed experiments to measure the effect of varying ZVI concentrations, repeated filter use, simulated agricultural water, and oocyst size and condition. We then compared the performance of mini filters to that of larger, gravity-fed pool filters and found that ZVI-sand filtration was far more effective at removing Eimeria spp. from water when compared to sand filtration, at both scales. Sand mini filters retained 13–54 % of E. acervulina oocysts, and pool filters retained 82 %, but when combined with 50 % (mini filter) or 35 % (pool filter) v/v ZVI, mini filters retained 89–99 % of oocysts and pool filters retained >99 %. The effectiveness of the mini filters increased with increasing ZVI concentration, and the addition of ZVI far outweighed the influence of any other measured variable. We then performed experiments including C. cayetanensis, which provided similar results to those utilizing Eimeria; 59 % of inoculated C. cayetanensis oocysts were retained in sand mini filters, and 97 % in mini filters composed of 35 % v/v ZVI. In sum, ZVI is highly effective in removing oocysts from water and Eimeria is a useful surrogate for C. cayetanensis to assess filtration. ZVI-sand filtration shows promise as a tool to mitigate the risk of C. cayetanensis contamination of irrigation water. Further studies should evaluate the performance of ZVI-sand in pressurized fast filtration systems under a range of field conditions.

The retreat of mountain glaciers inevitably leads to an increase in the number of outburst moraine lakes. One of the possible mechanisms of moraine dam outburst along with overflow over the crest is the formation of a filtration channel in the body of the moraine dam (piping). An algorithm for calculating the outburst flood hydrograph, describing the development of a filtration channel in the body of a moraine dam and the subsequent formation of water overflow when the soil above the channel collapses, is proposed in this paper. Verification of proposed methodology was carried out on the basis of experimental data and published data of real outbursts. Satisfactory results verifying this methodology made it possible to use the proposed methodology for the calculation of the hydrograph of the outburst of Lake Bashkara in the Elbrus region, which occurred on 1 September 2017. It is shown that the simulation results are quantitatively comparable with the estimates obtained from field data: the time of water discharge through the channel was 16 min, the period of the outburst wave passage was 40 min, and the maximum discharge was 636 m3/s. Thus, the possibility of applying the proposed methodology for calculating the destruction of natural moraine dams has been demonstrated. [ABSTRACT FROM AUTHOR]

In order to develop a standardized nomenclature for the mechanisms and materials utilized during extracorporeal blood purification, a consensus expert conference was convened in November 2022. Standardized nomenclature serves as a common language for reporting research findings, new device development, and education. It is also critically important to support patient safety, allow comparisons between techniques, materials, and devices, and be essential for defining and naming innovative technologies and classifying devices for regulatory approval. The multidisciplinary conference developed detailed descriptions of the performance characteristics of devices (membranes, filters, and sorbents), solute and fluid transport mechanisms, flow parameters, and methods of treatment evaluation. In addition, nomenclature for adsorptive blood purification techniques was proposed. This report summarizes these activities and highlights the need for standardization of nomenclature in the future to harmonize research, education, and innovation in extracorporeal blood purification therapies. [ABSTRACT FROM AUTHOR]

Bench tests were conducted on ore slurry filtration using the leaf test method, varying scales, pressures, and water/solids ratios. These results were compared with analytical outcomes derived from applying the dimensionless Buckingham pi method to the general equation of slurry filtration with incompressible cakes under constant pressure. The aim was to validate the tests by corroborating experimental findings with calculated parameters for scale-up purposes. Vacuum pressure was employed to facilitate slurry dewatering, forming a cake comprising solids from the slurry. This cake's thickness evolved over time, introducing specific resistivity that impeded filtering efficiency. Parameters such as cake resistance and filter media resistance were computed. Filtrate volume was measured over time to determine the filtration rate. These values were then adjusted using factors obtained through dimensional analysis. These factors facilitated comparisons to validate the feasibility of employing the Buckingham pi method for predicting slurry filtration results at larger scales. The results indicated lower errors when analyzing the filtrate rate over time with a solids/water ratio of 20/80%. When evaluating cake resistance, the method yielded lower errors at a ratio of 70/30%, while results for medium resistance were inconclusive. It's important to consider the ratio and associated errors when predicting the behavior of an industrial filter based on bench test results, aiming to achieve theoretical scaled filtration rates and cake resistances. However, it's not advisable to rely on the Buckingham pi method for scale-up purposes when evaluating medium resistance. [ABSTRACT FROM AUTHOR]

Environmental DNA (eDNA) is used for biodiversity assessments in a variety of ecosystems across the globe, whereby different eDNA concentration, preservation and extraction methods can outperform others depending on the sampling conditions and environment. Tropical and subtropical ecosystems in Africa are among the less studied systems concerning eDNA‐based monitoring. Waterholes in arid parts of southern Africa represent important agglomeration points for terrestrial mammals, and the eDNA shed into such waterbodies provides a powerful source of information for monitoring mammalian biodiversity in the surrounding area. However, the applied methods for eDNA sampling, preservation and filtering in different freshwater systems vary greatly, and rigorous protocol testing in African freshwater systems is still lacking. This study represents the first attempt to examine variations in eDNA concentration, preservation and extraction methods under remote field conditions using waterborne eDNA in a savanna system. Collected samples were heavily affected by microalgal and bacterial growth, impeding eDNA capture and PCR success. We demonstrate clear effects of the methodological choices, which also depend on the state of eDNA. A preliminary metabarcoding run showed little taxonomic overlap in mammal species detection between two metabarcoding primers tested. We recommend water filtering (using filters with pore sizes >1 μm) over centrifugation for eDNA concentration, Longmire's solution for ambient temperature sample preservation and Qiagen's DNeasy PowerSoil Pro Kit for DNA extraction of these inhibitor‐prone samples. Furthermore, at least two independent metabarcoding markers should be utilized in order to maximize species detections in metabarcoding studies. [ABSTRACT FROM AUTHOR]

On the basis of standard data for the density and the initial and final temperatures in the decomposition (pyrolysis) of thermoprotective binder composites, the law describing their decomposition is identified. That law permits determination of the mass of gases generated at the thermal wavefront, which takes the form of a narrow pyrolytic zone. The gases filter through the porous coke residue to the external boundary, and so affect the thermal state of the thermoprotective composite. On the basis of the law derived, the analysis of the composite's pyrolysis is simplified, because there is no need to take account of the chemical kinetics. [ABSTRACT FROM AUTHOR]

Identification of the decomposition law of the binder in composites provides the basis for a mathematical model and analysis of the thermal state of most composites in significantly nonsteady high-temperature loading. The decomposition law of the binder permits analysis of the thermal state of composites without considering the chemical kinetics. Verification of the numerical results confirms the validity of this approach to modeling the thermal state of composites for use in hypersonic aircraft. [ABSTRACT FROM AUTHOR]

A mathematical model of non-isothermal filtration of methane, carbon dioxide and water is constructed based on the methods and equations of multiphase media mechanics considering the replacement of methane in the gas hydrate with carbon dioxide. The equations of the mathematical model and the methodology for their numerical solution are presented. The numerical solutions for one-dimensional plane-parallel approximation are constructed for the problem of injecting carbon dioxide into a reservoir initially saturated with methane and its hydrate. Those solutions describe the distributions in the reservoir of pressure, temperature, mass concentrations of gas phase components and saturations of methane and carbon dioxide hydrates. [ABSTRACT FROM AUTHOR]

In this study, the changes in groundwater temperature at the base of the future dam of the Rogun hydropower plant are studied, with the aim of assessing the filtration characteristics of the base rock and determining the filtration coefficient and concentrated filtration path. In addition, the equation for the filtration coefficient is derived, which is used to calculate the filtration coefficient and rate of the filtered turbulent water movement. [ABSTRACT FROM AUTHOR]

The ingestion of Ti-containing nanoparticles from drinking water has emerged as a concern in recent years. This study therefore aimed to characterize Ti-containing nanoparticles in water samples collected from four water treatment plants in Taiwan and to explore the challenges associated with measuring them at low levels using single particle-inductively coupled plasma mass spectrometry. Additionally, the study sought to identify the most effective processes for the removal of Ti-containing nanoparticles. For each water treatment plant, two water samples were collected from raw water, sedimentation effluent, filtration effluent, and finished water, respectively. Results revealed that Ti-containing nanoparticles in raw water, with levels at 8.69 μg/L and 296.8 × 103 particles/L, were removed by approximately 35% and 98%, respectively, in terms of mass concentration and particle number concentration, primarily through flocculation and sedimentation processes. The largest most frequent nanoparticle size in raw water (112.0 ± 2.8 nm) was effectively reduced to 62.0 ± 0.7 nm in finished water, while nanoparticles in the size range of 50–70 nm showed limited changes. Anthracite was identified as a necessary component in the filter beds to further improve removal efficiency at the filtration unit. Moreover, the most frequent sizes of Ti-containing nanoparticles were found to be influenced by salinity. Insights into the challenges associated with measuring low-level Ti-containing nanoparticles in aqueous samples provide valuable information for future research and management of water treatment processes, thereby safeguarding human health. [ABSTRACT FROM AUTHOR]

The use of additives from renewable sources in drilling fluids has received special attention due to crescent environmental regulations. At the same time, increasing demand for energy sources stimulates the search for products that can withstand severe perforation conditions. In this scenario, this work aimed at the chemical modification of a polysaccharide, carboxymethylcellulose (CMC), through insertion of hydrophobic groups of dodecylamine (DDA), and its investigation as an additive in aqueous fluids. The performance was evaluated via rheological and filtration standards measurements in oil industry for low and high temperature reservoirs. Rheological parameters did not change significantly either with aging or with temperature of data acquisition. Fluid with CMC exhibited higher filtrate volume than the corresponding CMC–DDA for all conditions studied. In the presence of CMC, the filtrate volume increased after aging under low (10% of increase) and high (69.2% of increase) temperature and pressure. On the other hand, CMC–DDA provided more controlled filtration after aging at low (8.3% of reduction) and high (only 25.9% of increase) temperature and pressure. This behavior indicates that CMC–DDA is a promising additive to control the filtration of aqueous drilling fluids at different reservoir conditions. [ABSTRACT FROM AUTHOR]

This article explores a non-parametric clustering algorithm that incorporates outlier removal. The algorithm is based on topological data analysis and introduces a new filtration on metric spaces that provides additional information about the points' nearest neighbor to the persistence diagram. The algorithm is evaluated on different datasets and shows promising results compared to other methods. The article also provides an introduction to topological data analysis, explains the concept of 0-dimensional persistent homology, and discusses the use of the Nearest Neighbor Vietoris-Rips filtration method for analyzing data. The effectiveness of the algorithm is demonstrated through experiments on various datasets, and the article concludes by highlighting its potential applications and suggesting future research directions. [Extracted from the article]

Here, polyaniline/polyvinylidene fluoride (PANI/PVDF) nanofiber composite membrane was fabricated using electrostatic spinning technology to remove hexavalent chromium Cr(VI). The employment of PANI not only extremely enhanced the hydrophilic property of the nanofiber membrane, but also facilitated the transfer of Cr2O72− from water to the membrane. The PANI/PVDF membrane had an extremely excellent performance in getting rid of Cr(VI) and a quite large flux (250 L/m2 h). The maximum adsorption quantity of the membrane could reach 334.5 mg/g in which adsorption played 52.12% part and reduction played 47.87% part. The removal rate could reach nearly 100% immediately in the permeate solution under filtration while it needed 240 min to reach 100% only by static adsorption. Therefore, the interception of the membrane and the adsorption reduction of PANI had synergistic effect on removal of Cr(VI). Furthermore, the removal rate of Cr(VI) could still reach 95.97% after reused 8 times. The membrane showed a very good reusability and application prospect. [ABSTRACT FROM AUTHOR]

Low-cost lignocellulosic filters were made from soybean hulls (SH), sugarcane bagasse fibers (SBF), cellulose nanofibers (CNF), and Kraft-bleached pulp (BP) as renewable feedstocks and applied in Cu (II) and Cd (II) removal from aqueous medium. Filtration was performed with a vacuum pump; filtration times ranged from 3 to 1200 seconds. For the same filter, the best permeate flow was 13,333 L.h.m-2 for both cations. The best Cd (II) removal (77.2 %) was achieved within 7 seconds at a permeate flow of 5,714 L.h.m-2. The same filter was also the best at removing Cu (II) (46.5 %), which was achieved within 7 seconds at a permeate flow of 5,714 L.h.m-2, as well. This short time evidenced that a long contact time is not needed to achieve higher removal. The best filter was made of BP, CNF, and SH. The presence of SBF and SH increased the contact angle and decreased the solid free energy surface. By FTIR-ATR it was possible to verify with which groups present in the chemical structures of the filter components the Cd (II) and Cu (II) cations interacted best. These results demonstrate the potential use of lignocellulosic biomass for producing composites aimed at water decontamination. [ABSTRACT FROM AUTHOR]

Volatile organic compounds (VOCs) are common organic pollutants that can cause adverse effects on human health. Treatment techniques, including photocatalytic oxidation, have been studied to remediate VOCs. Acetone was used as a model pollutant to investigate the photocatalytic degradation performance of electrospun photocatalytic nanofibers with synthesized flower-like titanium dioxide (F-TiO2) and cellulose acetate (CA). The synthesized F-TiO2 and photocatalytic nanofibers were characterized using FE-SEM, XRD, FTIR, UVVis, XPS, and a pore size and porosity analyzer. The addition of F-TiO2 decreases the diameter of the nanofibers. The photocatalytic degradation performance test showed an enhanced acetone degradation efficiency on F-TiO2/CA photocatalytic nanofibers (FT-CFs), with an up to 95.0% acetone degradation efficiency under optimum conditions, over P25 TiO2/CA photocatalytic nanofibers (T-CFs). The filtration efficiency of 3.0%FT-CF reached 99.9% with a filter basis weight of 0.660 g m−2 and face velocity of 5.0 cm−1 s. The filtration and photocatalytic degradation cycle tests revealed excellent reusability, with 97% particle filtration and no sign of material deterioration. Moreover, the biodegradability tests showed that the material can biodegrade in water and in soil for 30 and 40 days, respectively. This study demonstrates that electrospun FT-CFs exhibit exceptional photocatalytic degradation of acetone, a high filtration efficiency, excellent reusability, and biodegradability, making them a promising solution for VOC remediation. [ABSTRACT FROM AUTHOR]

This review underscores the fundamental aspects of filtration, focusing on the key factors influencing filtration performance and filter cake structure. It highlights the critical parameters for evaluating filtration performance, particularly the flow rate and moisture content of the filter cake, which are significantly influenced by the cake’s pore structure. Additionally, advanced cake evaluation methods such as NMR spectroscopy, SEM microscopy, and MicroCT (µCT) imaging were explored, along with their limitations. Among these, the µCT imaging technique emerges as a powerful method, offering highly accurate insights into cake structure compared to other methods. The review also discusses emerging techniques and provides insights into future perspectives in the field. [ABSTRACT FROM AUTHOR]

Stick-slip in drilling happens when the drill bit and assembly repeatedly stop and slide due to factors like friction and torque. Using better lubricants in the drilling mud can help reduce friction, lessening stick-slip issues. Nanotechnology has improved drilling mud, making it more resistant to heat and enhancing its viscosity and friction properties. This research extensively investigates the use of nanofluids in drilling processes through thorough lab tests. It examines the impact of introducing NanoSiO2 into two types of drilling mud—freshwater bentonite (FWB) and polymer-based mud—at concentrations of 0.04%, 0.08%, 0.15%, and 0.31% under higher temperatures. The study also explores two methods of dispersing NPs using ultrasonic and solvent techniques. The results show that SiO2 nanoparticles notably improve the flow and filtering abilities of FWB mud but have negative effects on polymer-based mud. A 0.05% addition of NanoSiO2 significantly reduces friction by 52% in FWB mud. In FWB mud, all NanoSiO2 concentrations lead to a 25% decrease in mud cake thickness. Furthermore, adding NanoSiO2 to FWB mud decreases torque, with the most substantial reduction of 40% observed at 0.09% concentration (0.35 gm). On the contrary, incorporating NanoSiO2 into polymer-based mud increases fluid loss volume for all concentrations, reaching up to 36% compared to the base mud. Additionally, filter cake thickness increases eightfold, while lubricity factor doubles. This study offers insights into the advantages of using SiO2 nanoparticles in drilling mud and their impact on the fluid properties during drilling. [ABSTRACT FROM AUTHOR]

Baghouse filters applied for gas cleaning are subject to digitalization concepts, including process modeling and the development of digital twins in order to improve energy efficiency and lower particle emissions. Modeling equations from literature were adapted to match experimental data from part 1 of this study to calculate the effect of varying filter face velocities, dust concentrations, or tank pressures on energy demand and particle emissions. Based on the model approaches, an operation curve that enables the evaluation of filter operation regarding the trade‐off between energy demand and particle emissions can be constructed. The identification of energetically optimal cycle times and favorable operation regions is possible due to the extensive experimental framework of the model. [ABSTRACT FROM AUTHOR]

Pig wastewater is often characterized by the complex composition of the protein, oil, cellulose, suspended and dissolved particulate solids. Among them, the suspended solids have posed a serious impact on biological fermentation. The granular sludge can clog to reduce the flocculation activity in the particle disintegration and inactivation. The reactor of sludge production can lead to shorten the age of sludge, thus affecting the reactor processing efficiency. The efficiency of the reactor can depend mainly on the shortening of sludge age, due to the increase of sludge production. Alternatively, the waste resources of corn stover are very rich in the annual output in China. Furthermore, the corn stover with a rich natural porous structure can be expected to adsorb and then maintain the suspended and dissolved particulate solids in the pig wastewater. Taking the corn stover after crushing and compaction as the filtration medium, negative-pressure filtration was carried out to remove the suspended and insoluble particulate solids in the pig wastewater, together with the parts of organic matter. The upper-flow anaerobic sludge bed/blanket (UASB) reactor was used for the anaerobic fermentation of filtered pig wastewater. The chemical oxygen demand (COD) removal rate, pH value and gas production were also explored with the increase of organic load in the fermentation. High-throughput sequencing was used to analyze the composition, bacterial and archaeal communities in the anaerobically digested sludge under the optimal load at the beginning of the experiment. The test results showed that the best performance of pig wastewater filtration was achieved, when the pressure was 40 kPa, the thickness of the filter layer was 15cm, and the compaction degree of filter media was 1.6 times the density. The removal rates of the total solid, volatile solid, and COD were 33.08%, 28.05%, and 23.01%, respectively. The anaerobic fermentation test showed that the maximum load of reactor was 11 kg/(m³·d) for the stable operation at the temperature of (35±1)℃, at which the influent COD concentration was 6 093 mg/L, the COD removal rate was 76.46%, The optimal treatment load was 10.00 kg/(m³·d), at which the influent COD concentration was 6 068 mg/L, the COD removal rate was 60.26%, and the gas production rate per unit volume was 1.51 m³/(m³·d). The reactor was operated stably in the anaerobic fermentation without extreme acidification. The microbial diversity showed that the anaerobic fermentation was synergistic by a variety of microbial flora, where the main bacterial groups were Firmicutes and Bacteroidota in the hydrolysis and acidification stage; Specifically, the main archaeal group was Halobacterota at the phylum level. There was an abundant distribution of efficient methanogens in the UASB reactor at the methanogenic stage of anaerobic fermentation; The rich distribution of high-efficiency methanogens was also found with three methanogenic pathways, including the methyl-, acetate- and hydrogen-nutrient type. The findings can provide the technical application of crop straws to filter the pig wastewater in the waste treatment. [ABSTRACT FROM AUTHOR]

The concentration of microplastics (MPs) in two important Hungarian freshwater habitats was determined in the size range of 50 μm–1 mm. Lake Balaton (LB) is the largest shallow lake in Central Europe, with a significant role in recreation and tourism. Its main inflow, the Zala River, enters the lake through an artificially constructed wetland, the Kis-Balaton Water Protection System and its catchment area (KB), which helps preserve the water quality of the lake. From these two areas, 15 samples were taken with an in situ filtration sampling method. After preparation, the samples were analyzed automatically by FT-IR microscopy. All samples, from both areas, contained MPs; the dominant microplastic (MP) shape was the fragment, while the most frequently polymer types were polyethylene, polypropylene and alkyd. Small MPs were dominant in both areas; around 90% of the MPs were smaller than 500 μm. On average, LB contained more MPs (21.0 ± 12.5 MPs/m3) compared to the KB, which presented an average concentration of MPs of 7.8 ± 5.9 MPs/m3. In the examined areas, two potential MP sources were determined, i.e., treated wastewater and road traffic. The importance of tourism should also be further investigated. [ABSTRACT FROM AUTHOR]

In this work, nanocomposite membranes were prepared using silver nanoparticles (Ag) attached to poly(amidoamine) dendrimer (P)-functionalised multi-walled carbon nanotubes (CNTs) blended with poly(vinylidene fluoride-co-hexafluoropropene) (PVDF-HFP) polymeric membranes (i.e., AgP-CNT/PVDF-HFP) via the phase inversion method. The nanocomposites were characterised and analysed via transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDX), thermal gravimetric analysis (TGA) and Brunauer–Emmett–Teller (BET) analysis. The TEM and EDX analyses confirmed the presence of Ag nanoparticles on the nanocomposites, while the SEM and BET data showed the spongy morphology of the nanocomposite membranes with improved surface areas. The sample analysis of surface water collected from the Sekhukhune district, Limpopo Province, South Africa indicated that the water could not be used for human consumption without being treated. The nanocomposite membranes significantly reduced the physicochemical parameters of the sampled water, such as turbidity, TSS, TDS and carbonate hardness, to 4 NTU, 7 mg/L, 7.69 mg/L and 5.9 mg/L, respectively. Significant improvements in microbial load (0 CFU/mL) and BOD (3.0 mg/L) reduction were noted after membrane treatment. Furthermore, toxic heavy metals such as chromium, cadmium and nickel were remarkably reduced to 0.0138, 0.0012 and 0.015 mg/L, respectively. The results clearly suggest that the AgP-CNT/PVDF-HFP nanocomposite membrane can be used for surface water treatment. [ABSTRACT FROM AUTHOR]

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Purpose. Research is aimed at integrating multi-stage hydraulic fracturing in horizontal wells with hydrodynamic simulation as a mandatory part of planning the mining of any shale oil or gas reservoir. Methods. Geological and hydrodynamic reservoir modeling is part of the research. The properties and geometries of the hydraulic fracture network and its representation in the dynamic reservoir model were assessed. The comparative characterization was carried out based on the two methods of fracture modeling: cell dimension reduction for explicit fracture modeling (LGR - local grid refinement) and implicit fracture modeling method, presented in this paper, with additional pseudo-connections between well and reservoir. Findings. A hydrodynamic model for low-permeable reservoir, produced by horizontal well, hydraulically fractured with 5 stages, has been generated. This model is calibrated to the production history and flowing bottom hole pressure by applying two methods of fracture modeling. Modeling results show that it is possible to replicate historical well production by using both methods. However, the proposed method with pseudo connections has several advantages compared to the generally accepted, local grid refinement (LGR) method. Originality. For the first time, a system of pseudo connections between well and reservoir was constructed to model a multi-stage hydraulic fracturing for a hydrodynamic model of tight reservoir. Hydrodynamic simulation results were refined and calibrated to the history of hydrocarbon production and flowing bottom hole pressure data using the pseudo-connections and LGR methods. The similarity of the results by applying LGR and pseudo-connections methods was revealed. Practical implications. The use of pseudo connections for hydraulic fracturing modeling can reduce simulation run time for cases where multi-stage hydraulic fracturing has already been carried out or is planned in the future. Additionally, the use of this method allows testing a larger number of realizations and scenarios, including hydraulic fracturing design (number of stages, size and conductivity of resulted fracture systems, fracture orientation, etc.), well placement and fracture growth relative to well trajectory. Also, there is no need to rebuild a model every time for each realization, as is the case with the LGR method. [ABSTRACT FROM AUTHOR]

Indoor air pollution is a critical health issue. We studied particle emissions, concentration changes and size distribution mechanisms using an indoor space with air quality monitors, incense stick burning, and ventilation. Temporal changes in the concentrations of particles with sizes of 10 nm to 10 µm were monitored. Our findings show that particles affecting particle number concentration (PNC) were mainly in the Aitken mode (50–100 nm) and accumulation mode I (100–200 nm). Particle surface area concentration (PAC) was primarily in the 100–300 nm range, while particle volume concentration (PVC) was in the 100–200 nm and 300–1000 nm ranges. After extinguishing the incense sticks, ventilation was initiated. The ventilation period was split into FAO1–3 (i.e., the first 3 min, 1–3 min of ventilation system operation) and FAO4–15 (i.e., the last 12 min, 4–15 min of ventilation system operation). During FAO1–3, particle concentrations increased by 18.3 to 21.5%. This rise was due to the initial activation of the ventilation system, dispersing settled particles (mostly ≥ 41.2 nm) into the air. The FAO4–15/FAO1–3 ratio for 12.3−2489.3 nm particles was always < 1, indicating that as the ventilation continued, it effectively removed particles of < 2.5 μm. After subsequent ventilation of 15-min operation, total PNC, PAC, and PVC were 70.3%, 70.0%, and 67.8% lower than during FAO1–3 and the particle number mode diameter was 106.0 nm, with geometric standard deviations of 1.50 and 1.51 (left and right), indicating that the ventilation system was successful in removing smoke particles of all sizes simultaneously and evenly and achieved an approximate total removal efficiency of 70%, effectively filtering particles and reducing indoor air pollution. [ABSTRACT FROM AUTHOR]

This study focuses on the optimization of polyethersulfone (PES) hollow fiber membranes fabricated with the phase inversion method. A Box–Behnken experimental design was employed with three different PES concentration ratios (11, 14, 17 wt.%), three polyvinylpyrrolidone (PVP) molecular weight ratios (K30/K90 ratios of 6:0, 3:3, 0:6 wt.%), three different bore fluid (BF) composition ratios (water/alcohol ratios of 20:80, 60:40, 100:0), and three different air gap values (24, 37, and 50 cm). The results were analyzed in terms of pure water permeability (PWP) and porosity as optimization parameters using response surface methodology and the classification and regression tree (CART) model. ANOVA results revealed significant effects of PES concentration, PVP molecular weight, and BF composition on the outcomes. After optimization, the maximum PWP and the maximum porosity were obtained as 360.15 L/m2 h bar, 60.57%, respectively. The CART model achieved sufficient accuracy in classifying samples. [ABSTRACT FROM AUTHOR]

The rise in oil spill incidents has led to a surge in environmental and ecological issues, making it crucial to create efficient oil-cleaning materials. Green approaches to address various aquatic pollution nowadays is the most important subject of environmental remediation. Among the available options, aerogel material stands out due to its low density, high porosity, and exceptional surface area, making it a remarkable choice for oil–water separation. Nonetheless, the usage of aerogels is limited by their low strength and flexibility, which hinder their application. In this study, strong alginate aerogel fibers reinforced with cotton have been synthesized with 88% porosity, 123 nm average pore size, and 0.24 g cm−3 density using a wet spinning technique followed by freeze-drying for the separation of oil/water mixtures. The morphology, chemical, and microstructural characterization of the prepared alginate aerogel fibers were performed by scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray diffraction. These characterization results demonstrated the three-dimensional porous, rough structure of aerogel fibers and cotton fibers are successfully incorporated into the aerogel fiber structure. Single fiber strength tester indicated that the addition of cotton increased the strength from 2 to 16 cN of aerogel fibers but decreased the elongation. The prepared alginate aerogel fibers showed good oleophobicity underwater and excellent oil/water separation efficiency (up to 99.4%). Therefore, synthesized aerogel fiber with ease of fabrication and excellent separation of oil/water mixture is a promising candidate for commercial applications in water filtration. [ABSTRACT FROM AUTHOR]

This study delves into the properties and behavior of xanthan TNCS-ST, a specialized variant designed for enhanced oil recovery (EOR) purposes. A notable aspect of this polymer is its transparency and capability to dissolve in high salt concentrations, notably up to 18% total dissolved solids. Various laboratory methods are employed to assess the polymer's distinctive traits, including transparency, salt tolerance, and high pyruvylation. These methods encompass preparing xanthan solutions, conducting filtration tests, assessing energy consumption, and measuring rheological properties. The findings highlight the influence of salt concentration on xanthan's filterability, indicating increased energy requirements for dissolution with higher salt and xanthan concentrations. Additionally, this study observes temperature-dependent viscosity behavior in different solutions and evaluates the shear stability of xanthan. A significant and novel characteristic of TNCS-ST is its high salt tolerance, enabling complete dissolution at elevated salt concentrations, thus facilitating the filterability of the xanthan solution with sufficient time and energy input. Core flooding experiments investigate fluid dynamics within porous rock formations, particularly sandstone and carbonate rocks, while varying salinity. The results underscore the substantial potential of the new xanthan polymer, demonstrating its ability to enhance oil recovery in sandstone and carbonate rock formations significantly. Remarkably, the study achieves a noteworthy 67% incremental recovery in carbonate rock under the high salinity level tested, suggesting promising prospects for advancing enhanced oil recovery applications. [ABSTRACT FROM AUTHOR]

Phenomena, kinematics and risk assessment strategies of internal erosion Internal soil erosion due to seeping water in natural sediments as well as in earthworks can lead to a significant change in soil properties and could even destroy the structural integrity. The physical process of erosion always is induced by loosening, migration, and deposition of predominant fine particles within the soil structure. Depending on the kinematics, the phenomena are divided into contact erosion, suffusion, colmation and backward erosion piping. The kinematics is controlled by the energy of a seepage on the one hand, on the other by the degrees of freedom and the boundary conditions of an individual grain movement within the pore space. This article provides an overview of the characteristic, specifics, and conditions of the different phenomena considering their kinematics within the soil structure. Internationally used approaches and methods of assessment are listed, their significance and their limitations will be evaluated. The impact parameters that control the different processes are shown. Strategies for assessing and controlling the risk of structural damage are discussed for the different phenomena of internal soil erosion. [ABSTRACT FROM AUTHOR]

The paper considers the statistical concept of causality in continuous time, which is based on Granger's definition of causality. We give necessary and sufficient conditions, in terms of statistical causality, for the preservation of the strong property of predictable representation for stopped martingales when filtration is decreased. This concept of causality is also connected to the preservation of the strong property of predictable representation under a change in measure. In addition, we give conditions, in terms of statistical causality, for martingales to have strong and weak properties of predictable representation. The results are applied to the problem of pricing claims in incomplete financial markets. [ABSTRACT FROM AUTHOR]

The mining industry is confronted with substantial challenges in achieving environmental sustainability, particularly regarding water usage, waste management, and dam safety. The increasing global demand for minerals has led to increased mining activities, resulting in significant environmental consequences. By 2025, an estimated 19 billion tons of solid tailings are projected to accumulate worldwide, exacerbating concerns over their management. Tailings storage facilities represent the largest water sinks within mining operations. The mismanagement of water content in tailings can compromise their stability, leading to potential dam failures and environmental catastrophes. In response to these pressing challenges, the mining industry is increasingly turning to innovative solutions such as tailings dewatering and water reuse/recycling strategies to promote sustainable development. This review paper aims to (I) redefine the role of mine tailings and explore their physical, chemical, and mineralogical characteristics; (II) discuss environmental concerns associated with conventional disposal methods; (III) explore recent advancements in dewatering techniques, assessing their potential for water recovery, technical and economic constraints, and sustainability considerations; (IV) and present challenges encountered in water treatment and recycling within the mining industry, highlighting areas for future research and potential obstacles in maximizing the value of mine tailings while minimizing their environmental impact. [ABSTRACT FROM AUTHOR]

Baleen whales are ecosystem sentinels of microplastic pollution. Research indicates that they likely ingest millions of anthropogenic microparticles per day when feeding. Their immense prey consumption and filter-feeding behavior put them at risk. However, the role of baleen, the oral filtering structure of mysticete whales, in this process has not been adequately addressed. Using actual baleen tissue from four whale species (fin, humpback, minke, and North Atlantic right) in flow tank experiments, we tested the capture rate of plastics of varying size, shape, and polymer type, as well as chemical residues leached by degraded plastics, all of which accumulated in the baleen filter. Expanded polystyrene foam was the most readily captured type of plastic, followed by fragments, fibers, nurdles, and spherical microbeads. Nurdle and microbead pellets were captured most readily by right whale baleen, and fragments were captured by humpback baleen. Although not all differences between polymer types were statistically significant, buoyant polymers were most often trapped by baleen. Plastics were captured by baleen sections from all regions of a full baleen rack, but were more readily captured by baleen from dorsal and posterior regions. Baleen–plastic interactions underlie various risks to whales, including filter clogging and damage, which may impede feeding. We posit that plastics pose a higher risk to some whale species due to a combination of factors, including filter porosity, diet, habitat and geographic distribution, and foraging ecology and behavior. Certain whale species in specific marine regions are of the greatest concern due to plastic abundance. It is not feasible to remove all plastic from the sea; most of what is there will continue to break into ever-smaller pieces. We suggest that higher priorities be accorded to lessening humans' dependence on plastics, restricting entry points of plastics into the ocean, and developing biodegradable alternatives. [ABSTRACT FROM AUTHOR]

The scope of multifunctional surfaces in mechanical engineering and instrumentation is constantly expanding. Examples are products with multilayer coatings, products made of composite materials or using additive manufacturing technologies. A feature of multifunctional surfaces is two levels of texture with different parameter values. Various types of filters are used to decomposition and then analyze texture components. Traditionally, for such problems, a robust Gaussian regression filter and a morphological filter are used. The advantage of the morphological filter lies in the lower computational complexity and the ease of removing the shape component from the profile. This research presents generalized analysis of various types of an asymmetric morphological filter based on simulation. The asymmetric filter differs from the standard morphological filter by using different nesting indexes for combinations of morphological opening and closing operations. We have designed a compositional model of profile, which is superposition of two Gaussian distributions with different parameters and waviness. Relative filtering error of the arithmetic mean heights Ra was chosen as evaluation parameter. Based on the Monte Carlo experiments technique, the relative errors of the filters are determined. The main result of the research is algorithm for choosing nesting indexes depending on the type of primary profile. Thus, we give scientifically justified choice of the filter type and its task-specific parameters for applied use. The choice of filter type and two different nesting indexes in accordance with the developed algorithm provide relative error with a coverage interval less 3 % for 95 % coverage probability. The asymmetric morphological filter is effective for scale space analysis of surfaces with significant shape errors and waviness. The results obtained can be used to analyze the tribological properties of multifunctional surfaces of products. • Evaluation of roughness for multifunctional surfaces using standard filters is not always effective. • We designed an asymmetric morphological filter for roughness estimation. • Algorithm for choosing the type of PMADA filter and its task-specific parameters depending on primary profile isproposed. • Error ranges of the asymmetric morphological filter were determined using statistical Monte Carlo experiments technique. [ABSTRACT FROM AUTHOR]

This study investigates the synthesis and the antibacterial properties of bacterial cellulose (BC) incorporated zinc phosphate nanocomposite-mediated dragon fruit extract (BC-ZP-DF). The composite was prepared by a three-step process that involved bacterial cellulose (BC), zinc phosphate (ZP), and nanocomposite BC-ZP synthesis. BC was prepared by fermenting coconut water with the components of ammonium sulfate, acetic acid, and Acetobacter xylinum culture. Zinc phosphate was made through the green synthesis method by reacting zinc nitrate and diammonium hydrogen phosphate using a sensitizer agent from red dragon fruit peel extract (DF) with volume variations of 5, 10, 20, 30, 40, and 50 mL. The composite was prepared by immersing BC with zinc phosphate. Phase crystallinity, functional group, and morphology of the samples were characterized using XRD, FTIR, and SEM. It was found that the nanocomposite was constructed by the nano green of zinc phosphate in the form of a hopeite structure with antibacterial PO43- and OH functional groups. Morphological analysis using SEM revealed that the nanocomposites contained various small powder grains. Based on the FTIR spectrum, XRD pattern, and surface morphology of composite film, the incorporation of zinc phosphate in the BC framework was confirmed. The antibacterial activity tests of nanocomposite films using Staphylococcus aureus and Pseudomonas aeruginosa bacteria revealed that the nanocomposite was highly effective in inhibiting both bacteria, and the nanocomposite BC-ZP-DF10 film had the strongest inhibition. The results of the air filter test exhibited that the composition was efficient on all films with the highest percent of efficiency (%E) of 90.10%. [ABSTRACT FROM AUTHOR]

In this paper, novel UiO‐66‐AO‐based adsorption‐filtration hybrid membranes (UAMs) are prepared via an irradiation‐mediated growth strategy to simultaneously improve water flux and accelerate uranium extraction from water resources. The UAM shows an equilibrium adsorption that is four times faster than UiO‐66‐AO powder and an adsorption capacity that is over two times higher. UAM also achieves a record synergy of high flux and high uranium removal ratio from simulated seawater (1358.8 L m−2 h−1, 84.5%) by one‐time filtration under ambient temperature and pressure (the adsorption is 1.83 mg g−1 in 90 min). The excellent uranium extraction performance is attributed to the unique UAM structure, in which water flows through the channels of thin metal‐organic framework (MOF) film without blocking by substrate leading to the high flux during filtration, and the full contact of uranium with abundant exposed active sites promotes the adsorption. This work will be conducive to overcoming the bottleneck problems of uranium extraction from water resources. [ABSTRACT FROM AUTHOR]

Ceramic water filters, are a promising household water treatment technology. Filters were produced using clay as the base material and two locally available burnout materials (sawdust and maize cob). The clay which was classified as an Inorganic clay of low to medium plasticity has a liquid limit of 41.1% and plasticity index of 37.4%. The sizes of the combustible materials are 5,10, 22 microns mixed in proportions of 1:1 and 1:2 by proportions of clay and burnout materials respectively, moulded and fired to a temperature of 1000℃. In the end, ten filters were produced from various particles sizes and proportions of the sawdust and maize cob. The bulk density of the filters ranged from 1.67 to 3.5 g/cm3 with a typical value of 2.63±0.57 g/cm³ . Apparent porosity ranged from 94.94 to 99.87% with a typical value of 99.10±1.13%; while water absorption varied from 28.6 to 59.71 % with a mean of 40.02±9.49 %. Flow rate ranged from very slow rate of 0.051 to 0.92 L/h with a typical value of 0.354±0.226 L/h. Based on type of burnout material, filters made with sawdust had higher flow rates (0.433 L/hr) than those made from maize cob (0.291 L/hr). The percent turbidity removal ranged from 9.1% - 43.7% on the first week to 30.6 – 70.4% on the fifth week of the test for filters made from maize cob; whereas the percent turbidity removal ranged from 5.7 – 35.3% on the first week to 44.9 – 75.6% on the fifth day for sawdust. Filters made from sawdust performed significantly better than those made from maize cob (p = 0.044) at 95% confidence level. In terms of particle size, there was an increase in efficiency of Coliform removal efficiency from 99.6 to 99.8% as the particle size of burnout materials increased from 5 μm to 22 μm. Filters made with lower proportion (1:1) of burnout materials exhibited higher Coliform removal (99.76%) than those made with higher (2:1) proportion (99.63%). However, the proportion of burnout materials within the range used in this study did not significantly affect percentage Coliform removal (p = 0.247). Filters made from sawdust generally performed better than those made from maize cob. [ABSTRACT FROM AUTHOR]

During the construction of the tailings dump of Udokan Mining and Metallurgical Works, filtration appeared at the base of the western dam. To increase the filtration density of the dam, a diaphragm wall made of bored-secant piles was constructed in the ground. Developing a composition of clay-cement concrete for the wall in the ground requires a significant amount of manufacturing and testing of samples. [ABSTRACT FROM AUTHOR]

Water being the most important fluid supporting the life as well as industry is getting sparse and polluted day by day. Activated carbon (AC) can be utilized in various applications of significant environmental impact and sustainable living such as carbon dioxide sensing and capturing, air purification, and water recycling. However, in the wake of the recent corona pandemic which resulted in global lockdown and took the entire world by shock, a cost-effective and simple synthesis of such a useful material remains dire need of time. Therefore, this paper describes a simple and cost-effective synthesis of activated carbon (AC) of high porosity and surface area derived from the pruning of conocarpus and azadirachta trees. In reference to the study under consideration, alongside numerous others, a furnace was employed to synthesize activated carbon. However, our approach utilized a more conventional methodology wherein the environmental parameters were not optimized. In furnace-based procedures, factors such as temperature, pressure, and humidity are meticulously regulated, contrasting with the conventional methodologies where such parameters lack optimal control. Consequently, employing a furnace does not constitute a cost-effective approach for the physical activation of organic samples thus proving a furnace is not imperative for physical activation. The synthesis was carried out by physical activation in the form of carbonization followed by chemical activation with potassium hydroxide (KOH). The influence of activated carbon from each pruning over filtration of water containing industrial dye was investigated. Activation temperature and impregnation ratio of 600–800 °C and 1:5 were selected respectively. X-ray diffraction patterns (XRD) for all AC samples indicted the appearance of broad peaks at 2θ value of 20–30° which confirms the presence of carbon in the sample. The physical morphology arrangement by SEM analysis showed uneven arrangement of pores of conocarpus which indicated higher iodine number and hence higher adsorption capacity of 442.13 mg/g. [ABSTRACT FROM AUTHOR]