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Water contamination is a major global threat, which requires effective treatment methodologies and monitoring to preserve precious resources of water. In comparison to other sides of environmental sanitation, grey water has traditionally received less attention. Kitchen grey water (KGW) is one of the largest wastewater discharged into the water bodies directly. The present study investigated the ability of waste ceramic filtration for the treatment of KGW. The treatment system was designed with ceramic wastes that are used in household applications. Response surface methodology (RSM) was employed to optimize the hydraulic retention time (HRT) and ceramic particle size. Total organic carbon (TOC), chemical oxygen demand (COD), total suspended solids (TSS) and turbidity were reduced effectively by ceramic filter media. The maximum percentage removal of TOC, COD, TSS and turbidity were 66, 60, 70 and 72%, respectively, for the 120 min HRT and 0.25 mm particle size.

Pulsed electric field disinfection is an effective non-thermal water disinfection technology. Compared to conventional disinfection techniques, PEF inactivation has several advantages including no by-products. In this context, the use of silver ions in conjunction with a reverse osmosis filtration system has been proposed as a safe and cost-effective treatment approach that can be used in a point of use technologies. This system contains two silver meshes as electrodes inside a reverse osmosis membrane with the application of a pulsed electric field on it as a disinfection method, After conducting chemical and physical tests of the water samples before and after the treatment system, it was noticed that most of these characteristics were significantly affected by increasing the number of electrical impulses and the intensity of the applied voltage as a result of the increase in the ionization process of silver in water.

Mixed or intermediate soils are widely used in the construction of embankment dams. Unfavourable climate conditions and poor quality control may result in the use of mixed soils as under-compacted dam cores, with moisture content highly in excess of the optimum. It is thus essential to design safe filters to prevent internal erosion and piping from wet, under-compacted mixed-soil cores in embankment dams. In this study, 87 no-erosion filter tests were performed on seven mixed core soils having dissimilar geotechnical specifications with diverse moisture contents and compaction ratios. The experimental findings showed that the filter performance (success or failure at preventing erosion) depends on moisture in excess of optimum, the filter D15 (particle size with 15% finer in filter gradation) and the fines content of the core soil. An increase in excess moisture necessitates a smaller D15 to inhibit erosion, to the extent that filters respecting accepted criteria may fail to hinder erosion in the case of excessively wet and under-compacted cores. Overall, for group II, cores the criterion of D15 15

There is a great demand for transparent films, membranes, or substrates in the fields of intelligent wearables, electronic skins, air filtration, and tissue engineering. Traditional materials such as glass and plastics cannot satisfy these requirements because of the lack of interconnected pores, undesirable porosity, and flexibility. Electrospun fibrous membranes offset these shortcomings because they contain small pores and have high porosity as well as outstanding flexibility. Thus, the development of transparent electrospun fibrous membranes is of great value. This work reports a simple and effective way to develop flexible and porous transparent fibrous membranes (TFMs) directly from electrospun fibrous membranes via mechanical pressing, without employing any other additives. In addition, the relationship between the transparency performance and the molecular structure of the polymers after pressing was summarized for the first time. After mechanical pressing, the membranes maintained fibrous morphology, micron-sized pores, and desired porosity. Polystyrene fibrous membranes, which exhibited excellent optical and mechanical properties, were used as a reference. The TFMs possessed high transparency (∼89% visible light transmittance at 550 nm), high porosity (10%–30%), and strong mechanical tensile strength (∼148 MPa), nearly 78 times that of the pristine electrospun fibrous membranes. Moreover, this study demonstrated that transparent and conductive membranes can be fabricated based on TFMs using vacuum-assisted filtration of silver nanowires followed by mechanical pressing. Compared with indium tin oxide films, conductive TFMs exhibited good electrical conductivities (9 Ω per square (Ω·sq−1), 78% transmittance at 550 nm) and notable mechanical performance (to bear abundant bending stresses).

Drilling muds play an important role in drilling and production operations so that the degree of success in such operations is determined by the proper design of these fluids. To optimize drilling operations and avoid excessive expenditure, it is essential to prepare a drilling mud that is both cheap and efficient. Fluid additives are typically used in drilling systems to improve these fluids' capabilities in terms of hole cleaning capacity, filtration control, viscosity, yield point, heat transfer, etc. However, environmental concerns, cost of production, and availability are always considered challenging factors. This study introduces an eco-friendly herbal fiber in powder and regular forms as a potential alternative to other chemical additives. To do so, Alyssum homolocarpum seed mucilage was added with different concentrations to the water-based drilling muds, and its rheological behavior, filtration control, and the induced formation damage were examined and the optimum concentration was introduced. The results of this study revealed the advantages of the drilling muds formulated with Alyssum in terms of filtration control, rheology, formation damage, and greenness.

Well killing remains to be the critical technological stage before proceeding with workover operations. Well killing using Visco-Elastic Gel (VEG) has been found to preserve and reinstate the filtration characteristics of bottom-hole formation zone efficiently. Since, these methods exclude the possibility of penetration of well-killing fluids into the reservoirs, the natural permeability of the reservoir retained. In this article, the authors have reported for the first time about a new VEG with controlled fracture times that remains appropriate for killing oil wells associated with both terrigenous carbonate reservoir operations. A distinctive feature of the proposed technology using a VEG with adjustable degradation times (can vary from 3 to 120 h) is that it requires a relatively smaller volumes of the composition in comparison with that of the conventional technologies. As a result, a significant reduction in the negative impact on the reservoir is achieved resulting from a relatively low penetrating ability of the proposed VEG. High structural properties of the VEG make it possible to reliably block the overlapped reservoir interval and it excludes the penetration of process fluid into the reservoir. In addition, it also eliminates the flow of formation fluid from the reservoir, which is absolutely necessary for trouble-free repairing work. It was found from the present study that the use of a breaker of a particular, single type does not provide the desired results and in the present study, the authors have deduced a relatively complex breaker based on peroxyhydrate and citric acid with a 1:1 ratio. The introduction of the encapsulated peroxyhydrate at the stage of preparation of the VEG ensures monodispersity of its dispersion characteristics. The developed VEG was successfully tested in 32 wells of oil fields in the Perm Krai fields in Russia. The well killing technology developed and described in this article using a VEG with adjustable destruction times has successfully been applied in the fields of the Perm Krai. The economic effect from the application of this technology was found to be $6.000 per well.

In this paper, the manufacturing of macro-porous tubular ceramic supports for membranes is described. The novel supports are fabricated from natural diatomite and alumina raw materials using the extrusion method. The structure was analyzed by X-ray diffraction (XRD) and mercury porosimetry techniques; the presence of possible defects was investigated by scanning electron microscopy (SEM). The permeability has been measured from water flux in standard experiments. Experimental results show that the open porosity, the average pore size (APS), the pore size distribution, the strength, and the permeability of sintered supports, have been found to depend, mainly on the concentration of alumina (Al2O3) additive. Supports prepared with the addition of 10 wt.% of alumina and sintered at 1200 °C, can be considered as the most optimized; they have a porosity ratio of about 46%, an APS is around 7.7 μm, a flexural strength value of about 28 MPa, and water permeability of around 15 m3 h−1 m−2 bar−1. Such materials could be of great interest in the supports fabrication for membrane application, for instance, water filtration.

There is a direct link between the extent of formation damage and the filtration volume of the drilling fluids in hydrocarbon reservoirs. The filtration volume could be diminished by adding different additives to the drilling fluids. Recently, nanoparticles have been extensively used for enhancing the filtration characteristics of the drilling fluids. However, there is no reliable model for investigating the influence of this class of additives on the performance of drilling fluids. Hence in this study, two powerful tools ELM (Extreme Learning Machine) and PSO-LSSVM (Particle Swarm Optimization-Least Square Support Vector Machine) are applied to determine the effect of various nanoparticles on the filtration volume. The assessment of the models is carried out by computing the statistical parameters and it was found that ELM has a greater ability to predict the filtration volumes, while PSO-LSSVM performs satisfactorily too. The model predictions and experimental results are in excellent agreement as suggested by the values of root mean squared error (RMSE = 0.2459), coefficient of determination (R2 = 0.999), and mean relative error (MRE = 2.028%) for the dataset. The statistical analysis showed that the suggested model can predict the filtration volume with great accuracy. Moreover, through sensitivity analysis of the input parameters, it was found that for a specified nanoparticle, the filtration volume is highly influenced by nanoparticle concentration and it is the essential variable for the optimization process.

The analysis of microplastics (MP) becomes more difficult for smaller sizes, especially in complex matrices such as sediment of natural waters. In this work, we analyzed MPs in sediment using laser direct infrared (LDIR) imaging, a relatively new technique in environmental MP studies. Sediment samples were spiked with analytical surrogates (polyethylene spheres), and subjected to density separation, wet peroxide oxidation, calcite removal, and filtration. The extracted particles were coated on to a low-emissivity glass slide which was first examined on a stereomicroscope. Six slides (two sediment samples and four different blanks) were further analyzed using an Agilent LDIR system. Approximately 520 and 430 MP/g were found in the two samples, with diameter ranging 20–3384 μm and 84% being smaller than 100 μm. The increase in particle count with decreasing particle sizes followed a power law curve, suggesting that a large portion of the smaller MPs was generated by the breakdown of larger plastic pieces. Major polymers found in this work included polyamide, polyester, polytetrafluoroethylene, and polyacetal. Most MPs were fragments, while beads and fiber were also found. In the two sediment samples, 14% and 46% of the total particles, respectively, were composed of non-plastic micro-sized particles, including natural polyamide, cellulose, chitin, rubber, and “unknown”. Challenges, potential biases, and uncertainties are discussed. This work is the first application of LDIR imaging on MPs in natural sediment.

Hollow fiber microfiltration (MF) and ultrafiltration (UF) membrane processes have been extensively used in water purification and biotechnology. However, complicated filtration hydrodynamics wield a negative influence on fouling mitigation and stability of hollow fiber MF/UF membrane processes. Thus, establishing a mathematical model to understand the membrane processes is essential to guide the optimization of module configurations and to alleviate membrane fouling. Here, we present a comprehensive overview of the hollow fiber MF/UF membrane filtration models developed from different theories. The existing models primarily focus on membrane fouling but rarely on the interactions between the membrane fouling and local filtration hydrodynamics. Therefore, more simplified conceptual models and integrated reduced models need to be built to represent the real filtration behaviors of hollow fiber membranes. Future analyses considering practical requirements including complicated local hydrodynamics and nonuniform membrane properties are suggested to meet the accurate prediction of membrane filtration performance in practical application. This review will inspire the development of high-efficiency hollow fiber membrane modules.

During the past four decades the use of nonwoven geotextiles as filter materials in geotechnical works has experienced a marked increase. In this study, the water permeability coefficient of nonwoven geotextiles after 23 years of exploitation in drainage system was determined to evaluate the influence of physical clogging on filtration performance of geotextiles. The obtained results showed that the geotextiles were clogged by soil particles. What is more, the objective in this study was to establish a gradient ratio test method for estimating a clogging phenomenon of geotextile filter adequately. A series of gradient ratio tests on three kinds of needle-punched nonwoven geotextile filters whose number of constrictions differs was performed. A geotextile filter was put under a silty sand layer. Based on the test results, it was confirmed that the water permeability coefficient became small as the gradient ratio increased, depending on the number of constrictions of the geotextile. It was also found that the modified gradient ratio GR4 is more sensitive than GR8 and GR25. Based on interpretation of the experimental results, the authors recommend the acceptance limit of GR8 equal to 3.7 and of GR4 equal to 4.8.

Massive quantities of sludge are being generated with the rise in populace and increase of wastewater produced. Ordinary sand and paved drying beds are still designed within the conventional way. This research focused on creating modern procedures to reduce the drying up duration for the combined sludge produced. This included the use of direct thermal solar heated water pipes, wick vertical drain, and horizontal filtration combined with bottom drainage for three built tanks utilizing freshly combined primary and secondary sludge with initial concentrations ranging from 0.42%−3% for the different filling cycles performed over two stages under changing climatic conditions. In-situ measurements of solid content, temperature and sludge height were taken. For stage one, the solids content reached 8.53% for solar tank, 7.42% for wick vertical drain tank and 17.4% for the conventional paved dry tank after 105 days of operation. For stage two, solids content reached 6.9% and 6.6% for solar and wick vertical drain tanks respectively and 7.93% in the conventional PDB combined with horizontal flow after 35 days of operation. Results are promising and could lead to better operational performance of PDB while decreasing the required time required; hence maximizing and upgrading the existing facilities.

Rock bolts are commonly used to stabilise slopes and underground excavations but their installation can sometimes be difficult in challenging grounds due to excessive leakage or washout of the grout. To manage these problems, tubular geotextile socks have been adopted in the industry but there has been a lack of research on their properties. To advance the understanding of sock behaviour, the water permittivity and filtration properties of two types of grout sock have been investigated in their unstretched state. From the permittivity tests, it is shown that water flow through these socks will be laminar and that using more than one layer in a setup can effectively reduce the flow velocity. Moreover, it has been shown that the effect of the tester should be considered in the analysis or else the permittivity of the geotextile could be underestimated. From the filtration tests, it is shown that both types of grout sock tested are effective in minimising grout loss and that the permittivity of the filter cake will be many orders of magnitude lower than that of the socks. The results also show that the water–cement ratio of the grout will be reduced as a result of the dewatering process.

In the vacuum treatment of dredged slurries via prefabricated vertical drains (PVDs), both filtration and consolidation may happen to dredged slurries when subjected to the vacuum gradient. Similar to the consolidation, the filtration may provide equally useful information on interpreting the constitutive behavior of the slurry. In this paper, a new approach utilizing the filtration process is devised to evaluate the constitutive behaviors of dredged slurries. The approach is composed of a vacuum filtration device and an iterative curve fitting algorithm. Two types of tests, namely step-vacuum filtration and constant-vacuum filtration followed by compression test, must be conducted on the slurry specimens, and only the time variations of the filtrate discharge should be recorded. On the basis of the recorded data, the curve fitting algorithm is adopted for determining the parameters of the constitutive equations. The effectiveness of the proposed approach is verified through comparing the obtained compressibility and permeability of the slurries with the data provided by the oedometer test and with the empirical relationships from different sources. The comparisons demonstrate that the constitutive relationships determined by the present approach can predict the compressibility and permeability characteristics of dredged slurries with an acceptable degree of accuracy.

Background During shortages of filtering face pieces (FFP) in a pandemic, it is necessary to implement a method for safe reuse or extended use. Our aim was to develop a simple, inexpensive and ecological method for decontamination of disposable FFPs that preserves filtration efficiency and material integrity. Material and methods Contamination of FFPs (3M Aura 9320+) with SARS-CoV-2 (1.15 × 104 PFUs), Enterococcus faecium (>106 CFUs), and physiological nasopharyngeal flora was performed prior to decontamination by submersion in a solution of 6 % acetic acid and 6 % hydrogen peroxide (6%AA/6%HP solution) over 30 minutes. Material integrity was assessed by testing the filtering efficiency, loss of fit and employing electron microscopy. Results and Discussion Decontamination with the 6%AA/6%HP solution resulted in the complete elimination of SARS-CoV-2, E. faecium and physiological nasopharyngeal flora. Material characterization post-treatment showed neither critical material degradation, loss of fit or reduction of filtration efficiency. Electron microscopy revealed no damage to the fibers, and the rubber bands’ elasticity was not affected by the decontamination procedure. No concerning residuals of the decontamination procedure were found. Conclusion The simple application and widespread availability of 6%AA/6%HP solution for decontaminating disposable FFPs make this solution globally viable, including developing and third world countries.

Drilling fluids face failure during drilling deep reservoir with high temperature and high salt. The experimental results show that high temperature and salinity reduce the negative charge on the surface of bentonite in the drilling fluid and cause the coalescence of bentonite particles. As a result, the particles coalesce, the grid structure is destroyed, and the rheological properties, rock-carrying capacity and filtration properties are lost. To resolve the foregoing, in this study, 0.05-wt% carbon nanotubes are introduced into a 4% bentonite drilling fluid under conditions where the temperature and concentration of added NaCl reach 180 °C and 10 wt%, respectively. The carbon nanotubes adsorb on the bentonite surface and increase the space among bentonite particles. The steric hindrance prevents the coalescence of bentonite in high temperature and high salt environment. Thus bentonite maintains the small size distribution of bentonite and supports the bentonite grid structure in the drilling fluid. As a result, the rock-carrying capacity of the drilling fluid increases by 85.1%. Moreover, the mud cake formed by the accumulation of small-sized bentonite particles is dense; consequently, the filtration of bentonite drilling fluid reduced by 30.2%.

Geotextile tube dewatering is a pre-treatment method utilized in the remediation of high-water content materials (i.e. sediments and slurries). However, given the association some contaminants (e.g. dioxins and furans, (i.e. PCDD/F)) have with particulate matter in these contaminated sediments, understanding the fate and transport of this particle matter in the dewatered effluent is essential. In this paper, pressure filtration tests (PFTs) were conducted to investigate the effect of pressure and filter cake formation on both geotextile filtration efficiency and effluent quality. Transport tests were then performed to evaluate the particle transport through the developed filter cake, as well as the hydraulic characteristics of the medium during dewatering. HYDRUS, a one-dimensional model contaminant transport model was then employed to simulate the experimental particle transport test results. Three different mechanisms of particle transport (i.e. attachment only, detachment only, both attachment and detachment) through saturated porous media were examined to identify the possible mechanisms of observed effluent particle concentration. HYDRUS modeling outputs suggest that both attachment and detachment mechanisms are involved in a given particle's fate and transport during geotextile dewatering. In addition, parameters such as confining pressure and filter cake properties affect the particle concentration in the effluent.

The study of environmental DNA released by aquatic organisms in their habitat offers a fast, non-invasive and sensitive approach to monitor their presence. Common eDNA sampling methods such as filtration and precipitation are time consuming, require human intervention and are not applicable to a wide range of habitats such as turbid waters and poorly-accessible environments. To circumvent these limitations, we propose to use the binding properties of minerals to create a passive eDNA sampler.We have designed 3D-printed samplers made of hydroxyapatite (HAp samplers), a mineral known for its high binding affinity with DNA. The shape and the geometry of the samplers have been designed to facilitate their handling in laboratory and field. Here we describe and test the ability of HAp samplers to recover artificial DNA and eDNA.We show that HAp samplers efficiently recover DNA and are effective even on small amounts of eDNA (By better understanding the physico-chemical interactions between DNA and the HAp sampler surface, one could improve the repeatability of the sampling process and provide an easy-to-use eDNA sampling tool for aquatic environments.

Filtration control is important to ensure safe and high efficient drilling. The aim of the current research is to explore the feasibility of using basil seed powders (BSPs) to reduce filtration loss in water-based drilling fluid. The effect of BSP concentration, thermal aging temperature, inorganic salts (NaCl and CaCl2) on the filtration properties of bentonite/basil suspensions was investigated. The filtration control mechanism of BSP was probed via water absorbency test, zeta potential measurement, particle size distribution measurement, and filter cake morphologies observation by scanning electron microscope. The incorporation of BSPs into the bentonite suspension generated acceptable rheology below 1.0 w/v%. The BSPs exhibited effective filtration control after thermal aging at 120 °C, but less efficiency at 150 °C. After thermal aging at 120 °C, the bentonite suspension containing 1.0 w/v% BSPs could resist NaCl and CaCl2 pollution of 5.0 w/v% and 0.3 w/v% respectively. Besides general filtration control behaviors, the exceptional water retaining capability formed by numerous nanoscale 3D networks in the basil seed gum and considerable insoluble small particles in BSPs might further contribute to the filtration control. The excellent filtration properties bring basil seed a suitable and green candidate for the establishment of high-performance drilling fluids.

At present, the cyanide gold extraction process is still the main technology for gold production. Generated cyanide tailings containing highly toxic substances exhibit potential environmental risks. These tailings are in urgent need of purification treatment, especially after being classified as hazardous waste. In this study, the impacts of elution methods, operating time, tailings/water ratios, reagent types on the elution rates of cyanide were investigated. Furthermore, the composite elution method developed in this research was extended for engineering. Results showed that the optimum elution conditions were determined to be: stirring elution, tailings/water ratio (M/V; 1:1) and operating time (10-20 min). Besides, 4 reagents (sodium dodecyl benzene sulfonate, cyclodextrin, sodium silicate and calcium hydroxide) were selected from four categories of 21 reagents for further composite elution. The cyanide elution rate was the highest (90.7%±0.1%) while the molar ratio of these 4 reagents was 5:2:2:1. Moreover, the combination of reagent elution and positive pressure filtration improved the elution efficiency of cyanide (92.6%±0.8%). And the cyanide content in the toxic leaching solution was lower than the standard value (5.0 mg/L). Furthermore, the composite elution method developed in this study was also extended for engineering. The concentration of cyanide in the leachate was5.0 mg/L, and was stable during 189 days of detection. Notably, the effluent can be reused directly, or reused after further treatment. The zero discharge of effluents and solid wastes was realized in the processes. The above results provided supports for the engineering treatment of cyanide tailings.

The coronavirus disease 2019 (COVID-19) pandemic has caused a surge in demand for face masks, with the massive consumption of masks leading to an increase in resource-related and environmental concerns. In this work, we fabricated meltblown polypropylene (mb-PP)-based high-performance planar face masks and investigated the effects of six commonly used disinfection methods and various mask-wearing periods on the reusability of these masks. The results show that, after three cycles of treatment using hot water at 70 °C for 30 min, which is one of the most scalable, user-friendly methods for viral disinfection, the particle filtration efficiency (PFE) of the mask remained almost unchanged. After mask wearing for 24 h and subsequent disinfection using the same treatment procedures, the PFE decreased to 91.3%; the average number of bacterial and fungal colonies was assessed to be 9.2 and 51.6 CFU∙g−1, respectively; and coliform and pyogenic bacteria were not detected. Both the PFE and the microbial indicators are well above the standard for reusable masks after disinfection. Schlieren photography was then used to assess the capabilities of used and disinfected masks during use; it showed that the masks exhibit a high performance in suppressing the spread of breathed air.

Polymer (anionic polyacrylamide, APAM) flooding produced wastewater has a relatively high degree of mineralization and abundant ionic species. A comprehensive and systematic investigation of the influence of ion identity on APAM-induced membrane fouling is extremely necessary but has not been conducted to date. A comparative investigation was performed herein to reveal the underlying mechanisms of the influence of Na+ and Ca2+ (1000 mg/L) on APAM-induced membrane fouling in the adsorption and microfiltration (MF) processes. Na+ and Ca2+ exhibited contrasting influences on the filtration efficiency, cleaning efficiency, and fouling resistance. Compared to Na+, Ca2+ promoted reversible fouling and the formation of a loose cake layer; moreover, a higher removal rate and flux recovery were achieved. Additionally, simulations based on adsorption kinetic and membrane fouling models, and a series of microscopic analyses were performed to validate the contradictory influences. During the APAM-based MF process, the membrane fouling was effectively mitigated at the applied ionic strength because of the stronger hydration repulsive force generated by hydrated Ca2+ compared to that by Na+. This study provides vital guidance for membrane fouling control in the microfiltration of polymer flooding produced wastewater.

An affinity membrane was prepared by coaxial electrospinning and amidoxime (AONFA), and it was applied to selectively recovery Au (III) from an aqueous solution. The static adsorption results showed that, when pH at 5, the maximum adsorption capacity of AONFA membrane for Au (III) was 509.3 mg·g-1. AONFA membrane exhibit much higher affinity and selectivity towards Au (III) than other metal cations. The membrane could be regenerated effectively by mixture solution of thiourea and HCl, and the desorption ratio reached almost 100% after 4 hours desorption. The dead-end filtration results showed that, the membrane utilization efficiency and adsorption capacity can be improved by increasing the flow rate, while increasing the concentration shorted the breakthrough process and had little impact to adsorption capacity. We can flexibly adjust the flow rate and concentration according to the situation to obtain the maximum utilization efficiency of the membrane in filtration process. The dynamic adsorption capacity is higher than the static adsorption capacity. The adsorption mechanism for Au (III) is electrostatic adsorption and reduction. Thus, AONFA membrane filtration was demonstrated to be a promising method for continuous recover Au (III) from wastewater.

Coupling membrane filtration with peroxymonosulfate (PMS) activation is promising to overcome the selectivity-permeability trade-off in membrane-based water treatment. However, the PMS catalytic efficiency of membrane still needs improvement to offset the insufficient reaction time during filtration process. Herein, an oxidized carbon nanotube intercalated nitrogen doped reduced graphene oxide (NRGO-OCNT) membrane with PMS activation function was firstly designed and prepared, which confined PMS activation in membrane interlayer for enhanced water treatment. The influence of confinement scale on membrane performance was studied through changing the OCNT intercalation ratio. Under the optimal confinement condition, the NRGO-OCNT membrane filtration integrated with PMS activation (MFPA) could realize 100% 4-chlorophenol removal at a high permeate flux of 290.2 L m−2 h−1 bar−1 (retention time of only 0.36 s), whose performance was 2.8, 1.7 and 5.0 times higher than that of filtration alone, NRGO MFPA (excessive confinement) and NRGO-OCNT powder-based batch reaction (no confinement), respectively. Moreover, NRGO-OCNT MFPA preferentially removed smaller-sized organics which easily entered and diffused in confined interlayer. The outstanding performance of NRGO-OCNT MFPA was owing to the nanoconfinement effect in appropriate confined interspacing, where the mass transfer rate of reactants was greatly boosted for enhanced generation of SO4 − and OH towards pollutant.

The presence of newly emerging pollutants in the aquatic environment poses great challenges for drinking water treatment plants. Due to their low concentrations and unknown characteristics, emerging pollutants cannot be efficiently removed by conventional water treatment processes, making technically, economically, and environmentally friendly water purification technologies increasingly important. This article introduces a one-step reverse osmosis (OSRO) concept consisting of riverbank filtration (RBF) and reverse osmosis (RO) for drinking water treatment. The OSRO concept combines the relatively low-cost natural pretreatment of river water with an advanced engineered purification system. RBF provides a continuous natural source of water with stable water quality and a robust barrier for contaminants. With the pre-removal of particles, organic matter, organic micro-pollutants (OMPs), and microbes, RBF becomes an ideal source for a purification system based on RO membranes, in comparison with the direct intake of surface water. OSRO treatment removes almost 99.9% of the particles, pathogens, viruses, and OMPs, as well as the vast majority of nutrients, and thus meets the requirements for the chlorine-free delivery of drinking water with high biostability. The OSRO treatment is cost effective compared with the standard conventional series of purification steps involving sprinkling filters, softening, and activated carbon. Artificial bank filtration (ABF), which functions as an artificial recharge in combination with a sand filtration system, is proposed as an alternative for RBF in the OSRO concept to supply drinking water from locally available resources. It is also suggested that the OSRO concept be implemented with wind power as an alternative energy source in order to be more sustainable and renewable. An OSRO-based decentralized water system is proposed for water reclaiming and reuse. It is suggested that future water treatment focus on the combination of natural and engineered systems to provide drinking water through technically efficient, financially feasible, resource reusable, and environmentally relevant means.

Sterilizing filtration is a common unit operation for the manufacture of parenteral drug products. However, filter performance can be impacted by properties of both the membrane material and the solution being filtered, requiring extensive multi-factor studies to optimize the filtration process for a given drug product. Here, we report the use of a modified bundle of capillaries approximation to predict filter performance. The model is directly applicable for both Newtonian and non-Newtonian solutions and does not require assumptions of steady state. Using a hydrophilic polyvinylidene difluoride (PVDF) filter as a test case, we show that the model fitting parameters align with expected values and both flux and shear are well predicted. Moreover, two case studies are presented to demonstrate the model's utility for filtration process optimization: 1) protein adsorption of an antibody formulation and 2) filter fouling of a 1% (w/v) carboxymethylcellulose (CMC) solution. In both cases, the model was able to accurately identify optimal filtration parameters to reduce the amount of adsorption or improve the filter capacity, respectively. This methodology can be easily extended to alternate filter types and provides an additional predictive tool to speed process development and minimize trial and error during filtration process design.

At the University office, a special area or room is provided for smoking, at  University the smoking room or smoking area still uses air vents and fans to neutralize cigarette smoke. As a result, the smoke that is hit by the fan in the smoking room spreads out and disturbs the surrounding health or interferes with the activities of employees at University. This smoking area needs to be handled, namely making a tool that can filter cigarette smoke and monitor the condition or level of air quality in the room so that cigarette smoke does not spread out of the room and interfere with health. To help the filtration system in the smoking room, it is necessary to have an automatic system that is able to work when the cigarette smoke in the room is at a certain level. The sensors used to detect levels of CO (carbon monoxide), CO2 (carbon dioxide) in cigarette smoke are MQ-7 and MQ-135. How this tool works, if the cigarette smoke in the room reaches the gas threshold level in the room, the fan will suck into the filtration room after which it will be exhaled back into the smoking room and will notify the condition of the room on the LCD monitor display.

In the context of workplace safety, activated carbon in the fiber form (i.e., activated carbon fiber, ACF) represents an alternative adsorbent to granular activated carbon (GAC) for use in organic vapor respiratory protection devices. ACFs are high surface area carbonaceous materials that are often available in a self-supporting non-woven form. The physical form of ACF suggests the potential for a filtration medium that is capable of supporting both organic vapor adsorption and particulate filtration.To study the application of these materials in respiratory protection devices, ACFs (ACFF 1200 m2/g, ACFF 1800 m2/g, and ACFF 2000 m2/g) were challenged with representative organic vapors (toluene, hexane, and methyl ethyl ketone (MEK)) at an occupationally relevant concentration (200 ppm). Breakthrough curves were generated for at least three different bed weights of adsorbent. Pressure drop (i.e., the resistance across the filtration media) was also measured to determine maximum ACF bed depths for use in respiratory protection devices.Breakthrough experiments indicate that ACFF 2000 has the highest adsorption capacity for toluene (381 mg/g), followed by ACFF 1800 and ACFF 1200 (344 mg/g and 239 mg/g, respectively). A similar trend was observed for hexane: 221 mg/g, 196 mg/g, and 146 mg/g for ACFF 2000, ACFF 1800, and ACFF 1200, respectively. ACFF 1200 showed the highest adsorption capacity for the polar adsorbate MEK (168 mg/g), followed by ACFF 1800 and ACFF 2000 (166 mg/g and 147 mg/g, respectively). Based on the constraints of pressure drop, it seems unlikely the exclusive use of ACF in a filtering facepiece respirator can provide an adsorbent mass sufficient for full shift protection against organic vapor contaminants at or above the legally enforceable permissible exposure level (PEL). Nevertheless, the incorporation of ACF into a facepiece respirator appears promising for "nuisance odor" applications; i.e., the further reduction of organic vapor concentrations when workplace exposures are already below PEL concentrations. Implication StatementThis research brings innovation to the field of occupational health and air pollution control technology by investigating the adsorption performance of activated carbon fiber (ACF) media in the context of worker respiratory protection. ACF properties such as high specific surface area (m2/g), high permeability to airflow, and rapid adsorption kinetics make it ideal for use in thin, N95-style respirators for organic vapors. Respiratory protection is an exciting and relevant application for ACF media. A lightweight adsorbent such as ACF, if incorporated into an N95-style respirator, could potentially provide nuisance-level VOC protection in a physical form that is accessible to workers and consistent with OSHA's voluntary use provisions for facepiece respirators. The research presented in this manuscript represents one of several steps planned in the characterization of ACF media for this particular application.

The northern part of Lamongan Regency is an area that is geologically and geographically vulnerable to freshwater. The condition of the existing water sources is not suitable for use as a source of clean water, because the water is brackish and green in color. The eutrophication process occurs due to excessive use of fertilizers for pond business, so that the nitrogen and phosphate content is high. The community in Karanggeneng village uses water from the Bengawan Solo River for daily use. The water condition of Bengawan Solo in the rainy season is dark brown in color because it contains a lot of soil, while in the dry season it is green because it contains a lot of pesticide or fertilizer residues discarded by farmers. From the problems above, it is necessary to socialize the water purification of Bengawan Solo by using the filtration method. Socialization activities are carried out directly to the Karanggeneng village community. This activity is carried out in two stages, the first is the preparation of tools and materials, the second stage is socialization to the community. In the first stage, chemical and physical water quality parameters were tested. In the second stage, the community was very enthusiastic about the implementation of this activity. The use of filtration methods is easy and inexpensive to be applied on a household scale. Suggestions, it is necessary to disseminate information to the wider community so that all people can access clean water for their daily needs. the second stage is socialization to the community. In the first stage, chemical and physical water quality parameters were tested. In the second stage, the community was very enthusiastic about the implementation of this activity. The use of filtration methods is easy and inexpensive to be applied on a household scale. Suggestions, it is necessary to disseminate information to the wider community so that all people can access clean water for their daily needs. the second stage is socialization to the community. In the first stage, chemical and physical water quality parameters were tested. In the second stage, the community was very enthusiastic about the implementation of this activity. The use of filtration methods is easy and inexpensive to be applied on a household scale. Suggestions, it is necessary to disseminate information to the wider community so that all people can access clean water for their daily needs.

Filtration by the fibrous medias is recognized as one of the most effective methods to control particulate pollution. A type of 3-D mesh spacer filter (3-D filter) proposed is effective for filtrating the large particles with low pressure drop. This study described the flow characteristics of dust-containing gas within the 3-D filter by means of CFD-DEM model. The influences of air velocity, particle concentration and restitution coefficient of particle on the filtration performance as well as the particles deposition process were simulated. The results showed that the particles capturing efficiency of 3-D filter was increased with the air velocity and particle concentration while the particles rebound made the filtration efficiency decreased when the air speed was increased more than 3.0 m/s. For the particle properties, the smaller restitution coefficient, the higher filtration efficiency. When the quality of particle deposition was increased to 70 g/m2, the filtration efficiency almost remained unchanged.

This paper focuses on the performance assessment of the green filtration system that incorporated with evaporative cooling that used to enhance indoor air quality. This system was invented in an attempt to thrive in a clean environment that becomes a solution for certain places. Indoor air quality (IAQ) and public health risk related to each other, it is due to the percentage of the city population that stays indoors rather than go outdoors. Indoor air contamination is originated from mixed origins such as volatile organic compounds (VOCs) and indoor airborne particulate matter (PM). The results show that the green filtration system manages to filter PM and VOCs in the air but not as efficient as modern air filters in the market. Furthermore, the evaporative cooling system possesses a huge deal in energy-saving within hot and arid climatic regions.

Graphene is novel & invigorating nanocarbon material that has drawn in both scholastic and industrial interest in last 10–15 years. It is by and large widely investigated as a result of its extraordinary properties including, superior mechanical and non-corrosive property, amazingly high surface area, great optical translucency, outstanding electrical and heat carrying properties and so forth. More importantly, these properties can be tailored to some extent by developing different grades of derivatives of Graphene. In this report, a various routes used to produce Graphene & Graphene-based materials are reviewed, detailed review of recent progress in application of these materials for desalination of water and purification of air is presented. Various attributes of Graphene & its derivatives which can revolutionise the air filtration & water desalination processes are underlined. Graphene Aerogels and doped sheets prove to be efficient alternates for air filtration & pollutant removal applications with relatively high specific surface area of around 1300 m2/g [24]. These doped derivatives show improved adsorption efficiency around 55–65% [25], which is studied to be rising with energy inputs like potential difference. Graphene and its derivatives-based water filtration is proving to be extremely efficient than the conventional water filtration & desalination mechanisms. Reverse Osmosis (RO), one of the widely used conventional methods of desalination comes with a large expense of money and energy but yields low volumes of filtered water. About 85–95% of input water gets wasted in the RO mechanism, yielding only 5–15% of usable water. The conventional Solar desalination is more efficient as compared to RO, but even that can be improved by 70–90% [45-47] by incorporating Graphene and its derivatives as part of a volumetric system, light absorbing layer and filtration layer in Solar Desalination process. The graphene-based membranes because of their high permeability and excellent ion repellency can be used for desalination applications with a removal efficiency of 33–100% [61] depending on the pore size and the applied pressure. Capacitive Deionization method of desalination can also be a very efficient alternative to the RO due to its minimal energy requirement of only 0.1–2.03 kWh/m3 [52].

Pickering emulsion is a heterogeneous system consisting of at least two immiscible liquids, which are stabilized by solid particles, in which organic solvent or water is dispersed into other phase in form of micrometre-sized droplets. Compared to traditional emulsions stabilized by surfactant, solids are cheap and can be easily separated and recycled by centrifugation or filtration after use. Moreover, the properties of Pickering emulsions can be adjusted by using different types of solid particles. Up to now, Pickering emulsions have been applied in a wide range of areas such as material science and catalysis. Here we review recent studies on Pickering emulsions stabilized by metal-organic framework, graphitic carbon nitride and graphene oxide.

Filter media made of expanded polytetrafluoroethylene filters are known to be incompatible with poly-alpha-olefin or any oil-based challenge particles, and thus, filters made of expanded polytetrafluoroethylene had limited use in pharmaceutical applications. The benefits of expanded polytetrafluoroethylene filters, e.g. intrinsic durability, more energy-efficient, chemical inertness, etc., are therefore not being fully utilized. A new expanded polytetrafluoroethylene filter media compatible with poly-alpha-olefin particles was then developed by a filter manufacturer. The goal of this study is to investigate the filtration performance and characteristics of the new expanded polytetrafluoroethylene media and to compare it with the conventional expanded polytetrafluoroethylene media. In this study, four pleated high-efficiency particulate air filters made of either the conventional or the new expanded polytetrafluoroethylene media, and either of the two variants of pleat depths (36 mm and 31 mm) were tested under two different challenge tests, one using potassium chloride (KCl) salt particles and the other using poly-alpha-olefin particles. Both challenge particles are submicron and polydisperse. The collection efficiency, pressure drop, and dust holding capacity were measured in both tests. Due to the sensitivity of KCl particle release to environmental factors, a repeatability test was also performed for the KCl test. poly-alpha-olefin test results show that the new expanded polytetrafluoroethylene filter performed remarkably better than the conventional expanded polytetrafluoroethylene filter, achieving a high amount of dust retention at the same preset final pressure drop.

Filtration membranes are widely applied in medical fields. However, these membranes are challenged by bacterial contamination in hospitals, which increases the risk of nosocomial infections. Thus, it is significant to develop antibacterial filtration membranes. In this work, an oxidated dextran (ODex)-based antibacterial coating was designed and constructed on microfiltration (MF) membranes and melt-blown fabrics. Polyhexamethylene guanidine (PHMG) was synthesized as an antibacterial agent, and was fixed by ODex onto filtration membranes. The functionalized MF membranes increased the filtration efficiency for E. coli from 20.9% to 99.9%, and improved the absorption ratio for endotoxin by 59.1%, while the water flow rate still remained as high as 5255 L (h m2)−1. Furthermore, the trapped bacteria were inactivated by the antibacterial coating. For the melt-blown fabrics, the aerosol filtration efficiency was increased from 74.6% to 81.0%, and the antibacterial efficiency was promoted to 92.0%. The present work developed a facile and universal antibacterial functionalization strategy for filtration membranes, which provided a new method for the design and development of various novel antibacterial filtration materials in the medical field.

In this study, the behavior of a filter bed of stratified sedimentary rocks was evaluated through the analysis of turbidity removal efficiency and head losses. Two types of sands were used as materials, fine and medium, as well as crushed limestone. The materials were characterized to determine the average particle diameter, porosity, and permeability coefficient, obtaining respectively 0.17 mm, 0.39, and 1 × 10−3 cm/s for fine sand, 0.33 mm, 0.41, and 3 × 10−3 cm/s for medium sand, and 1.26 mm, 0.45, and 1 × 10−2 cm/s for crushed limestone. Hydrodynamic analyses of the clean filter under conditions of rapid filtration were carried out, by which the different rates of filtration to be used in each experiment were determined, establishing a direct correlation between the rate of filtration and the thickness of the bed; in this way, it was possible to determine the maximum bed thickness that could be used to maintain a rate of rapid filtration higher than 120 m/day. A hydrodynamic study with synthetic turbid water prepared at 8 NTU using tap water and bentonite was also carried out. Total head losses and turbidity removal were studied for each material at a rate of 153 m/day with removal efficiencies of 93.7% for medium sand with a loss of 23 cm and 67.8% for limestone with a loss of 4.5 cm and a rate of 389 m/day. It is recommended to use the medium sand and limestone type material for use in surface water filtration processes.

In this study, the macro-structure of quartz flocs was assessed from X-ray computed tomography images. An image segmentation workflow was established to identify the floc sub-units that comprised each macro-floc, which permitted the macro-structure to be defined in terms of the number, size, and connectivity of the sub-units. A simplified structural model of non-penetrating spheres was used to understand the scaling relationships of the macro-floc properties. It was found that although sub-unit size varied widely, there was a limiting volume (2.8 × 106μm3), above which floc growth occurs only by sub-unit aggregation. This approach permits the quantification of macro-floc structure and composition in 3D on the scale of tens of μm to the mm scale. Knowledge of macro-floc structure allows a deeper understanding of the role of macro-floc breakage and re-arrangement in subsequent dewatering treatments such as thickening or filtration.

Attack and filtration play an important role in industrial wet phosphoric acid production processes and its main challenge is to produce an aqueous solution of phosphoric acid of the highest yield and purity possible. The main objective of this work is to conduct a sensitivity analysis of command and control parameters to optimize P2O5 losses within attack and maturation tank. The industrial data obtained by following the operation of the process have undergone an amendment by eliminating missing values and outliers and a response surface model has been used to link operating parameters of attack and filtration unit to co-crystallized P2O5 losses, unattacked P2O5 losses, and water soluble P2O5 losses, for line A and B, separately. All of the postulated models have given satisfactory results basing on statistical analysis. Those models have been used to perform a multi-objective optimization, using a desirability function, in order to minimize P2O5 losses. The achieved values of P2O5 losses have been checked by testing their effect on yield. The yield value obtained was 95.45%, which corresponds to a gain of 1.47% over the current average yield.

Filter cartridges are widely applied in the industrial dust removal system, and pleat structure plays a major role in expanding the filter area in limited space. In this study, the effect of pleat ratio (the ratio of pleat height to pleat pitch) on the effective filtration area (EFA) during polydisperse dust loading was analyzed. The results indicate that the dead zone formed by pleating will increase the structural resistance and reduce the EFA. When pleat ratio is 0.74–1.48, the EFA percentage varies slightly with the dust deposition per unit area (DDPUA). When pleat ratio is 2.22–3.70, the EFA percentage decreases with the increase in DDPUA. The threshold friction velocity surges with the decrease of dust particle size, and the larger the pleat ratio, the more easily for larger dust particles to deposit at the pleat corners, leading to the reduction of the EFA percentage decreasing rate.

Dyes are the substances that are used to impart color to textiles, fabrics, leather, or other materials. These are such colored substances that bond chemically to any substrate to which they are being applied. Any fabric’s attraction is its color. Regardless of how great its development is, if not colored as expected to be, it will fall flat as a business material. Therefore, the turn of events and utilization of manufactured colors for texture coloring has formed into a multibillion-dollar industry. In actual, humanity has known about the specialty of adding color to texture since 3500 BCE. They look attractive after coloring but their waste is toxic to the environment. Scientists, then again, are worried about their toxic nature. Engineered colors adversely affect all parts of life. Dyes have harmful effects upon water bodies as much waste from industries goes to rivers, lakes, etc. which ultimately causes water pollution. So, quick prevention measures need to be taken for saving the environment from dye waste. This paper likewise tells the classification and toxicity of some synthetic dyes and provides a brief idea about present methods for the removal of dyes from the environment which includes adsorption, chemical precipitation, inorganic materials usage, membrane filtration, and ion exchange. It also provides aspects affecting adsorption of color like arrangement pH, adsorbent portion, and temperature.

Rapid, efficient, and selective separation of tumor cells from complex body fluids is urgently needed for clinical application of tumor-cell-based liquid biopsy. Herein, a size-selective affinity filtration system, named Selective, User-friendly, highly Porous, Efficient, and Rapid filter (SUPER Filter), was developed for high-performance tumor cell isolation and analysis. SUPER Filter enabled selective interaction of tumor cells with size-optimized and antibody-coated micropore walls during filtration, achieving high efficiency of 91.0 ± 6.1% in PBS and 83.7 ± 6.4% in whole blood. Meanwhile, its larger micropore size than traditional filtration devices greatly reduced nonspecific capture of background cells (55-126 cells/mL blood) with enrichment factors of 1.1 × 104 - 1.0 × 105 and purity of 52.7 ± 4.2%. Moreover, its high porosity enabled ultra-fast (< 5 s for 1 mL of blood or 10 mL of buffer samples) and user-friendly gravity-driven filtration. Finally, SUPER Filter demonstrated rapid, efficient, and selective separation of tumor cells from blood and large-volume pleural and ascetic fluid samples of cancer patients for morphological and molecular analysis. We expect that this size-selective affinity filtration strategy facilitates clinical application of tumor-cell-based liquid biopsy.

Alternating crossflow filtration is an emerging technology to mitigate fouling in crossflow microfiltration of cell-protein mixtures by periodically reversing the direction of flow. So far, it is understood that the anti-fouling effects are mostly related to the pressure fluctuations upon changing from forward to reversed flow direction and to a smaller extent to the flow reversal along the membrane as such. However, it is not yet clear how pressure fluctuations and flow reversal influence the axial distribution of fouling and the prevailing types of fouling. We conducted alternating crossflow filtrations of a model suspension containing yeast cells (4.2% dry matter) and bovine serum albumin (0.8 g l−1), where the duration and crossflow velocity of the forward and the backwards phase were varied independently. We found that the material, which deposits in the forward phase, can be better removed or loosened during the backwards phase, and vice versa, if forward and backwards flow conditions are equal in terms of time, crossflow velocity and overall transmembrane pressure. This leads to a detectable overall lower resistance due to deposit layer formation. Despite the positive effects of alternating crossflow filtration on filtration resistance, flux, and solute transmission, the less compact deposit layer also allows for an easier penetration of solutes and small particles into the membrane pores, which was detectable in terms of an increased ratio of irreversible fouling resistance.

High humidity and high dust concentration in deep coal mines may severely challenge the performance of respirators worn by coal miners. This paper aims at quantitatively evaluating the respirators used in deep coal mines and providing scientific guidance for the respiratory protection of miners. Based on the self-designed in-situ PM2.5 collector, controllable PM2.5 generator, human breathing simulator, and respirator simulation testing system, under the simulated deep mine working condition, this study investigated the effects of dust loading, wearing time, and dust concentration on the filtration efficiency, breathing resistance, and quality factor of N95 elastomeric respirators. With the increase of dust loading, the respirator filtration efficiency firstly decreased, then increased (minimum value 97.5%). The breathing resistance increased exponentially from 120 to 180 to 1020–1530 Pa, and the quality factor decreased logarithmically from 0.051 to 0.076 to 0.0058–0.0085 Pa−1. As the PM2.5 coal dust concentration increased from 5 to 50 mg/m3, the wearing time for the respirator breathing resistance to exceed 300 Pa reduced from 7 h to less than 1 h. One N95 elastomeric respirator is not able to perform an 8-h work shift. To avoid the excessive breathing resistance caused by dust loading, more filter cartridges are needed for coal miners.

Liquid aerosols are found in many industrial sectors, particularly in the mechanical industry (oil mists). Granular bed (GB) filtration could be an interesting means for the removal of these liquid aerosols, due to their high storage capacity, robustness and low maintenance requirements. The aim of the study was to establish the filtration performance (filtration efficiency, pressure drop) of a fixed granular bed during filtration and its clogging by a liquid aerosol. Three grades of sand, obtained by sieving 100–200, 200–355 and 355–500 μm and glass beads of 140 μm diameter were used as the granular medium. The evolution of filtration efficiency and pressure drop of the GB was monitored during clogging with a DEHS aerosol of MMAD = 0.7 μm. Our measurements show that the filtration performance of granular beds during clogging was very similar to that observed for fibrous media. The fraction of the GB pore volume occupied by liquid when the drainage plateau is reached was between 28 and 33%. The GB reaches a drainage stage whose pressure drop can be correctly predicted using a model described for fibrous media.

Proteoform-resolved information, obtained by top-down (TD) “intact protein” proteomics, is expected to contribute substantially to the understanding of molecular pathogenic mechanisms and in turn, identify novel therapeutic and diagnostic targets. However, the robustness of mass spectrometry (MS) analysis of intact proteins in complex biological samples is hindered by high dynamic range in protein concentration and mass, protein instability, and buffer complexity. Here, we describe an evolutionary step for intact protein investigations through the online implementation of tandem microflow size exclusion chromatography with nanoflow reversed-phase liquid chromatography and MS (μSEC2-nRPLC-MS). Online serial high-/low-pass SEC filtration overcomes the aforementioned hurdles to intact proteomic analysis through automated sample desalting/cleanup and enrichment of target mass ranges (5-155 kDa) prior to nRPLC-MS. The coupling of μSEC to nRPLC is achieved through a novel injection volume control (IVC) strategy of inserting protein trap columns pre- and post-μSEC columns to enable injection of dilute samples in high volumes without loss of sensitivity or resolution. Critical characteristics of the approach are tested via rigorous investigations on samples of varied complexity and chemical background. Application of the platform to cerebrospinal fluid (CSF) pre-fractionated by OFFGEL isoelectric focusing drastically increases the number of intact mass tags (IMTs) detected within the target mass range (5-30 kDa) in comparison to one-dimensional nRPLC-MS with approximately 100x less CSF than previous OFFGEL studies. Furthermore, the modular design of the μSEC2-nRPLC-MS platform is robust and promises significant flexibility for large-scale TDMS analysis of diverse samples either directly or in concert with other multidimensional fractionation steps.

Carbon nanomaterials have proven their wide applicability in molecular separation and water purification techniques. Here, an unzipped carbon nanotubes (CNT) embedded graphene oxide (GO) membrane (uCNTm) is reported. The multiwalled CNTs were longitudinally cut into multilayer graphene oxide nanoribbons by a modified Hummer method. To investigate the varying effects of different bandwidths of unzipped CNTs on their properties, four uCNTms were prepared by a vacuum-assisted filtration process. Unzipped-CNTs with different bandwidths were made by unzipping multiwalled CNTs with outer diameters of 0-10, 10-20, 20-30, and 30-50 nm and named uCNTm-1, uCNTm-2, uCNTm-3, and uCNTm-4, respectively. The uCNTms exhibited good stability in different pH solutions, and the water permeability of the composite membranes showed an increasing trend with the increase of the inserted uCNTm's bandwidth up to 107 L·m-2·h-1·bar-1, which was more than 10 times greater than that of pure GO membranes. The composite membranes showed decent dye screening performance with the rejection rate of methylene blue and rhodamine B both greater than 99%.

Microfibers-weaved ceramic filters are in increasing demand due to their high filtration efficiency, stable structure and remarkable ceramic properties in water and gas treatment. To date, it remains a challenge to find an effective way to weave ceramic microfibers. This work demonstrates a novel strategy that combines gel-casting and in situ cross-flow microfluidic molding to fabricate highly flexible and shape-retentive green microfibers and then weaves them before sintering. By tailoring the curing temperature and flow rate, the diameter and surface morphology of the microfiber is accordingly tuned. Besides mesh structure, the microfibers can also be weaved into more complex three-dimensional structures such as dragonfly knot, Chinese knot, etc. Benefitting from the widely used solution system and microfluidic method, this system can serve as a general and stable platform for preparing microfibers-weaved ceramic filters made from different materials, thus holds great potential in a wide range of working conditions.

In this research, the modification of emulsion polyvinyl chloride (EPVC) filtration membranes was evaluated by incorporating tungsten trioxide (WO3) nanosheets. The WO3 nanosheets at five different percentages were blended with the polymeric casting solution to prepare flat sheet membranes via the phase separation method. The prepared nanocomposite membranes were characterized by SEM, AFM, ATR, mean pore radius, porosity, and contact angle measurements. The investigated parameters were water flux, rejecting protein and three dyes, antifouling ability, long-term test and reuse ability. The obtained results showed that adding an optimal amount of WO3 (1 wt%) enhanced water flux and dye rejection. The nanocomposite membranes presented a lower contact angle due to the hydrophilicity of inserted WO3 nanosheets. The water permeability increased from 191 L/m2h.bar for the bare membrane to 238.8 L/m2h.bar for 1 wt% WO3 EPVC membrane with 96.6, 95.4 and 57.5% rejection rates for Reactive Green 19, Reactive Red 195 and Reactive Yellow 39 solutions with molecular weights of 1419, 1136.31 and 699.2 g/mole, respectively. The long-term test and reuse ability performance showed that the dye rejection did not change sensibly and good resistance was observed against the flux reduction. In conclusion, WO3 can be applied as a suitable nanosheet to modify PVC membranes.

Oil spill is a catastrophic accident to environment and human beings, requiring a rapid response to reduce the damage. The conventional oil collecting techniques based on adsorption or filtration, however, are not suitable for rapid response because of their performance dependence on oil types. Here we show that an oil collection technique based on gravity, unlike the conventional schemes based on adsorption or filtration, enables collection of light as well as heavy oils regardless of the viscosity. A solid sheet, which is lighter than water but heavier than oil, would be placed by gravity between oil and water, thereby physically separating oil from water. This fact is utilized to devise a simple and yet efficient oil recovery scheme. The oil on the sheet, over 10 cm in diameter and 0.18 mm in thickness, is drawn into a reservoir by gravity through a 4 mm tube connected to a hole in the center of the sheet. The sheet floating on water can recover oil at a rate of ~1,150,000 L m-2 h-1 that is an order of magnitude higher than that obtainable from filtration methods. We expect this nature-provided oil recovery scheme, which is autonomous, inexpensive, and fast, would provide a quick oil spill remediation regardless of the oil type, thereby minimizing the damage to environment and human beings.