Decrease In Permeability Research Articles

Axisymmetric Slow Rotation of Coaxial Soft/Porous Spheres.

The steady low-Reynolds-number rotation of a chain of coaxial soft spheres (each with an impermeable hard core covered by a permeable porous layer) about the axis in a viscous fluid is analyzed. The particles may be unequally spaced, and may differ in the permeability and inner and outer radii of the porous surface layer as well as angular velocity. By using a method of boundary collocation, the Stokes and Brinkman equations for the external fluid flow and flow within the surface layers, respectively, are solved semi-analytically. The particle interaction effect increases as the relative gap thickness between adjacent particles or their permeability decreases, which can be significant as the gap thickness approaches zero. A particle's hydrodynamic torque is reduced (its rotation is enhanced) when other particles rotate in the same direction at equivalent or greater angular velocities, but increases (its rotation is hindered) when other particles rotate in the opposite direction at arbitrary angular velocities. For particles with different radii or permeabilities, the particle interaction has a greater effect on smaller or more permeable particles than on larger or less permeable particles. For the rotation of three particles, the presence of the third particle can significantly affect the hydrodynamic torques acting on the other two particles. For the rotation of numerous particles, shielding effects between particles can be substantial. When the permeability of porous layers is low, relative fluid motion is barely felt by the hard cores of the soft particles. The insights gained from this analysis on the effects of interactions among rotating soft particles may be of great importance in many physicochemical applications of colloidal suspensions.

Chitosan Extracted from the Biomass of Tenebrio molitor Larvae as a Sustainable Packaging Film.

Waste from non-degradable packaging materials poses a serious environmental risk and has led to interest in developing sustainable bio-based packaging materials. Sustainable packaging materials have been made from diverse naturally derived materials such as bamboo, sugarcane, and corn starch. In this study, we made a sustainable packaging film using chitosan extracted from the biomass of yellow mealworm (Tenebrio molitor) shell waste. The extracted chitosan was used to create films, cross-linked with citric acid (CA) and with the addition of glycerol to impart flexibility, using the solvent casting method. The successful cross-linking was evaluated using Fourier-Transform Infrared (FTIR) analysis. The CA cross-linked mealworm chitosan (CAMC) films exhibited improved water resistance with moisture content reduced from 19.9 to 14.5%. Improved barrier properties were also noted, with a 28.7% and 10.2% decrease in vapor permeability and vapor transmission rate, respectively. Bananas were selected for food preservation, and significant changes were observed over a duration of 10 days. Compared to the control sample, bananas packaged in CAMC pouches exhibited a lesser loss in weight because of excellent barrier properties against water vapor. Moreover, the quality and texture of bananas packaged in CAMC pouch remained intact over the duration of the experiment. This indicates that adding citric acid and glycerol to the chitosan structure holds promise for effective food wrapping and contributes to the enhancement of banana shelf life. Through this study, we concluded that chitosan film derived from mealworm biomass has potential as a valuable resource for sustainable packaging solutions, promoting the adoption of environmentally friendly practices in the food industry.

Accounting for the effect of pressure on the permeability of gases through polymer membranes

The calculation scheme is proposed for analyzing the effect of pressure on the permeability of various gases through polymeric membranes. The calculation scheme is based on the proposed equation, in which the activation energy of the permeability process decreases under the action of pressure according to a power law. The adequacy of the calculation scheme was verified on the example of CO2 permeability through polyimide-based membranes. A good agreement was found between the calculated and experimental data on the increase in permeability with increasing pressure. The performance of the scheme was also tested using the example of three polyimides for two cases-growth and non-monotonic change in permeability. The decrease in permeability and the absence of dependence on pressure are analyzed.

Investigating temperature-dependent gas permeation in PIM-1: Hysteresis, annealing effects, and thermal history impact

This study investigates the gas permeability, diffusion coefficients, and solubility coefficients of CO2 and N2 in PIM-1 over the temperature range of 35 °C–135 °C. During the first heating-cooling cycle, both gases' permeability exhibited hysteresis, which diminished during the second cycle. Thermal mechanical analysis confirmed volume relaxation occurring at temperatures above 95 °C, indicating physical aging. By calculating the relaxation time associated with volume relaxation, the influence of physical aging was minimized through measurements on samples annealed at 135 °C for 15 h. This approach enabled a successful evaluation of the temperature dependence of gas permeability under conditions where the impact of physical aging could be disregarded. The results revealed that the permeability of CO2 decreased, and that of N2 increased with increasing temperature. The diffusion coefficients showed positive temperature dependence, while the solubility coefficients decreased. Physical aging significantly affected the diffusion coefficients but had minimal impact on the solubility coefficients. Heat of sorption and activation energies for gas permeability and diffusion estimated, and it was found that the decrease in CO2 permeability with temperature was mainly attributed to the large heat of sorption for CO2.

Effect of permeability on displacement efficiency and dominant oil–displacement mechanism in surfactant flooding

Interfacial tension (IFT) reduction and emulsification are two important mechanisms of surfactant flooding. However, for light oil reservoirs with different permeabilities, whether which mechanism is more important in improving displacement efficiency remains unclear. In this study, surfactants with strong emulsifying properties and ultralow IFT were screened using an interfacial tensiometer and a self-developed emulsification performance tester. The ability of the two surfactants to improve displacement efficiency was compared through a series of core flooding experiments. Experimental results showed that the surfactant with ultralow IFT did not have strong emulsifying properties. With the decrease in permeability, the oil displacement efficiency improved by emulsification increased first and then decreased, whilst that improved by IFT reduction declined. Moreover, IFT reduction was the dominant mechanism to improve oil displacement efficiency in medium-high and ultralow permeability reservoirs, whilst emulsification was dominant in low permeability reservoirs. The comprehensive utilization of multiple mechanisms and the combination of technologies should be considered when surfactant flooding is used in reservoirs with ultralow permeability. This work advances our current understanding of surfactant flooding and provides a reference for the formulation of plans to enhance oil recovery in light oil reservoirs.

Insights into the Injectivity and Propagation Behavior of Preformed Particle Gel (PPG) in a Low-Medium-Permeability Reservoir.

Heterogeneous phase combined flooding (HPCF) has been a promising technology used for enhancing oil recovery in heterogeneous mature reservoirs. However, the injectivity and propagation behavior of preformed particle gel (PPG) in low-medium-permeability reservoir porous media is crucial for HPCF treatment in a low-medium-permeability reservoir. Thus, the injectivity and propagation behavior of preformed particle gel in a low-medium-permeability reservoir were systematically studied by conducting a series of sand pack flooding experiments. The matching factor (δ) was defined as the ratio of the average size of PPG particles to the mean size of pore throats and the pressure difference ratio (β) was proposed to characterize the injectivity and propagation ability of PPG. The results show that with the increase in particle size and the decrease in permeability, the resistance factor and residual resistance factor increase. With the increase in the matching factor, the resistance factor and residual resistance factor increase. The higher the resistance factor and residual resistance factor are, the worse the injectivity of particles is. By fitting the relationship curve, PPG injection and propagation standards were established: when the matching coefficient is less than 55 and β is less than 3.4, PPG can be injected; when the matching coefficient is 55-72 and β is 3.4-6.5, PPG injection is difficult; when the matching coefficient is greater than 72 and β is greater than 6.5, PPG cannot be injected Thus, the matching relationship between PPG particle size and reservoir permeability was obtained. This research will provide theoretical support for further EOR research and field application of heterogeneous phase combined flooding.

Improvement of microbial alkalinity resistance in self-healing cementitious materials by means of gradient domestication

The harsh environment of high alkalinity inhibits the effective induction of calcium carbonate precipitation by microorganisms within concrete. In this study, a gradient domestication method was employed to enhance the alkali tolerance of Sporosarcina pasteurii, and various activity parameters (OD600, conductivity, urease activity, and calcium carbonate content) were assessed in an alkaline cultivation setting. Subsequently, a comprehensive evaluation was conducted to compare the impact of domesticated microorganisms on the mechanical properties, impermeability, and self-healing capacity of concrete. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques were employed to characterize the morphology and composition of mineralization products. The results demonstrate that gradient domestication techniques effectively enhance the activity of microorganisms in highly alkaline environments and confirmed that enhanced alkalinity tolerance possesses the potential for multigenerational retention. In comparison to the undomesticated microbial samples at 28 d, concrete incorporating domesticated microorganisms exhibited a 16.59 % increase in compressive strength, a 37.74 % reduction in sorption, and a 23.08 % decrease in permeability. Additionally, the maximum closed crack width measured 0.57 mm, exceeding the 0.44 mm observed in the non-domesticated bacterial group. This study offers a promising strategy for improving the efficiency of microbial-induced calcium carbonate precipitation in concrete.

Pectin film fortified with zein nanoparticles and Fe3+-Encapsulated propolis extract for enhanced fruit preservation

In this study, pectin served as the film matrix while propolis extract (PPE) acted as both an antibacterial agent and antioxidant. Utilizing the encapsulation of zein nanoparticles and cross-linking of Fe3+ with pectin molecules, a dual encapsulation system of PPE in the pectin film was successfully achieved, resulting in antibacterial and antioxidant pectin films. The effects of incorporating PPE, zein, and Fe3+ on various properties of the pectin films were investigated. Additionally, the impact of zein nanoparticle encapsulation and Fe3+ dual encapsulation systems on the release characteristics of PPE in the pectin films was examined. Characterization techniques including FTIR, SEM, XRD crystal diffraction, and thermogravimetric analysis were employed to analyze the interactions, microstructure, crystal structure, and thermal stability of the films. The results showed that the double cross-linking of zein and Fe3+ led to a reduction in the moisture content of the pectin film by approximately 46%, a decrease in water vapor permeability by about 19%, an almost doubling of tensile strength and antioxidant activity, and a significant improvement in antibacterial properties. Additionally, the incorporation of zein and Fe3+ enhanced the release characteristics of PPE in the pectin films. Notably, the developed composite coating demonstrated improved preservation properties during the storage of strawberry fruits.

TECHNOLOGICAL COMPLICATIONS (FORMATION DAMAGE) DURING CO2 INJECTION FOR ENHANCED OIL RECOVERY. Part 1. GEOCHEMICAL PROCESSES INVOLVING ROCK MINERALS, CHANGE OF PETROPHYSICAL AND GEOMECHANICAL ROCK PROPERTIES

Decrease in permeability, porosity, change in wettability of oil-bearing formations during field development are defined by a general term - formation damage, which occur at various stages of field development, including drilling, production, application of enhanced oil recovery methods, well stimulation technologies with acid compositions, hydraulic fracturing and well workover. Reservoir damage leads to a reduction in the oil and gas content of reservoirs and in the economic efficiency of operation. In this regard, it is important to understand and prevent formation damage based on experimental and analytical methods, the applicationof which will minimize damage to the oil and gas bearing reservoir. The review considers anthropogenic processes that cause damage to oil and gas reservoir when CO2 is injected by various methods to enhance oil recovery. The processes of interaction of CO2 with formation rock are considered in detail. The main geochemical transformations of rock minerals are given, which lead to changes in the structure of pore space, permeability and porosity, decrease of geomechanical properties. Secondary sedimentation processes and risks of rock particles removal into the borehole are discussed.

AN EXPERIMENTAL STUDY ON THE USE OF SEDIMENTATION COMPOSITIONS DURING STEAM INJECTION

At present time, many oil fields, especially in historically developed areas of The experience of developing deposits of high-viscosity oils (HVO) and natural bitumen has shown that thermal methods are the most promising technologies. Of the entire arsenal of thermal methods, areal steam injection and cyclic-steam stimulation have become the most widespread.When choosing an effective thermal impact technology, it is necessary to take into account the peculiarities of the geological and physical parameters of deposits and the factors involved in oil recovery. An effective technology should be based on the use of the main most important factors that increase oil recovery.One example of areal steam injection is the underground-surface method of developing the Yarega area of the Yaregskoef ield. With this technology, steam is pumped from the surface through vertical wells. Oil production is carried out in the underground galleries of the oil sheds.Twenty years of practice and geophysical studies of steam injection wells have revealed a number of factors that prevent uniform heating of the reservoir over the entire thickness and efficient use of coolant energy. It turned out that the injected steam is mainly concentrated in the bed zone of the formation. In this case, the formation does not warm up evenly in thickness. The heterogeneity of the reservoir (tectonic disturbances, cracks every 20-25 m) does not allow the creation of steam pressure up to 1,6 MPa along the contour of the developed areas in order to involve the inclined block. At design pressures, steam breaks into mine workings and gently descending production wells are observed.The experimental studies described in this work are aimed at finding alignment of the intake profile of steam injection wells and redistribution of coolant in a remote reservoir zone. The results of the application of sedimentation compositions in bulk reservoir models under various thermobaric conditions of steam injection are presented. As a result of injection of solutions of iron sulfate, sodium carbonate and calcium chloride, insoluble sediments were formed in the rock, which led to a decrease in permeability during water vapor filtration. The experimental study was performed on a bulk reservoir model using natural core grinding, as well as drilled and extracted core samples from wells of the Yaregskoe field. The use of sedimentation compositions in steam injection wells in the future may contribute to the involvement of rock sections in the development by redistributing the steam flow, which in turn will increase the oil recovery coefficient and reduce the steam-oil ratio.

On the role of the porous support membrane in seawater reverse osmosis membrane synthesis, properties and performance

In this study, we explore the role of the polysulfone (PSU) support membrane skin-layer and whole-body pore morphology on the physical-chemical properties and separation performance of hand-cast polyamide-PSU (PA-PSU) composite seawater reverse osmosis (SWRO) membranes. We tailor the support membrane pore morphology by varying the PSU concentration and the coagulation bath temperature. In order to isolate the impacts of the PSU support, all of the porous supports are coated using identical m-phenylene diamine (MPD) and trimesoyl chloride (TMC) solution compositions, reaction conditions, and post-treatments. As PSU concentration increases, PSU support membrane pore size, surface and body porosity, water permeability, MPD mass uptake (by the PSU support), and PA-PSU composite membrane water permeability decrease, while MPD and TMC conversion, PA film mass and thickness, crosslinking degree (XD), and PA-PSU composite membrane NaCl rejection increase. As PSU support membrane coagulation bath temperature increases, support membrane pore size, surface and body porosity, MPD uptake, PA film mass, thickness and XD, MPD and TMC conversion, and NaCl rejection increase, while composite PA-PSU membrane water and NaCl permeability decrease. Composite membrane permeabilities were 70–90 percent of the (theoretical) unsupported PA film permeabilities due to the high XD and low PA coating film thickness. Composite PA-PSU membrane water/salt permeabilities both correlate most strongly with PA coating film mass/thickness and XD, which in turn correlate most strongly with TMC conversion. The key to increasing water permeability is lower PA film mass/thickness and XD with higher support membrane surface pore size and porosity. In contrast, the key to increasing NaCl rejection is higher PA film mass/thickness and XD with lower support membrane surface pore size and porosity.

Maximizing N-Nitrosamine Rejection via RO Membrane Plugging with Hexylamine and Hexamethylenediamine.

The rapid expansion of urban areas and the increasing demand for water resources necessitate substantial investments in technologies that enable the reuse of municipal wastewater for various purposes. Nonetheless, numerous challenges remain, particularly regarding disinfection by-products (DBPs), especially carcinogenic compounds such as N-nitrosamines (NTRs). To tackle the ongoing issues associated with reverse osmosis (RO) membranes, this study investigated the rejection of NTRs across a range of commercially available RO membranes. In addition, the research aimed to improve rejection rates by integrating molecular plugs into the nanopores of the polyamide (PA) layer. Hexylamine (HEX) and hexamethylenediamine (HDMA), both linear chain amines, have proven to be effective as molecular plugs for enhancing the removal of NTRs. Given the environmental and human health concerns associated with linear amines, the study also aimed to assess the feasibility of diamine molecules as potential alternatives. The application of molecular plugs led to changes in pore size distribution (PSD) and effective pore number, resulting in a decrease in membrane permeability (from 5 to 33%), while maintaining levels suitable for RO processes. HEX and HDMA exhibited a positive effect on NTR rejection with ACM1, ACM5 and BW30LE membranes. In particular, NDMA rejection, the smallest molecule of the tested NTRs, with ACM1 was improved by 65.5% and 70.6% after treatment with HEX and HDMA, respectively.

The roles of different migration mechanisms in the transport of H2O–CH4 gas mixture in shales

Studying the roles of different migration mechanisms in shale matrix gas transport is beneficial for shale gas extraction and CO2 sequestration. The roles of different transport mechanisms in shale H2O–CH4 gas mixture transport were investigated considering their contributions to fluid flux. A permeability model coupling multiple gas migration mechanisms was developed by combining the pore network-related effective medium approximation, which was validated using process data from simultaneous H2O–CH4 transport in shales. The results showed that the gas transport mechanisms dominating methane and water vapor migration in shale differed. Slip flow and Knudsen diffusion contributed approximately 99% to methane migration. Water vapor surface diffusion as well as slip flow and Knudsen diffusion primarily contributed to the water vapor permeability before and after a time point, respectively. Water vapor and methane permeability generally decreased with time. The equilibrium water vapor and methane permeabilities ranged from 2.7699×10−22–12.312×10−22 m2 and 0.2640×10−21–4.9036×10−21 m2, respectively. The methane surface diffusion permeability increased slowly with time before approaching methane monolayer adsorption (before ∼100 s). An increase in relative humidity (approximately 300–3600 s) can promote the transport of water vapor. Water vapor and methane adsorption, especially the condensation of adsorbed water, could largely explain the decrease in shale gas permeability.

Experimental study on the mass transfer permeability of hollow fiber membranes for a humidifier in a proton exchange membrane fuel cell

A membrane humidifier is a device used to increase proton conductivity in a fuel cell system, enhancing the performance and longevity of the fuel cell. In this study, a hollow fiber membrane is tested under various operating conditions to determine the membrane humidifier performance by estimating the amount of water vapor through the membrane. The results show that the mass transfer rate increases with increasing temperature, flow rate, and relative humidity while it decreases with pressure and membrane thickness. Particularly, temperature affects the mass transfer rate the most. When the temperature is increased from 50°C to 80°C, the performance improves by approximately 4.5 times. In contrast, the flow rate affects it the least; an approximately 2.5 times increase in the flow rate results in a 16% improvement in performance. Furthermore, the counterflow consistently exhibits greater efficiency than the co-flow. Moreover, the water vapor permeability through the membrane is assessed. The membrane permeability increases with decreasing membrane thickness and pressure and increasing temperature and inlet relative humidity. The findings indicate that 1°C rise in temperature leads to an increase of approximately 5% in permeability and approximately 19% increase in pressure, resulting in an approximately 15% decrease in permeability.

Experimental study on the dynamic evolution of rock pore structure in real-time monitoring based on nuclear magnetic resonance

The rock structure determines the stability and reliability of underground engineering. Great achievements have been made in the study of rock structural damage, but there are few studies on real-time monitoring of rock structural changes under different increasing and unloading decreasing pressures. In this paper, the dynamic evolution rule of pore structure in rock under the combined action of water pressure and different confining pressure of increasing and decreasing is monitored by NMR technique. The porosity and permeability of rock under different confining pressures are consistent. The increase of confining pressure leads to the closure of pores, which leads to the decrease of porosity and permeability, but the amplitude and time of change are different. During the process of decreasing confining pressure, the T2 spectral curve, porosity and permeability of the rock did not fully recover due to the reduction of confining pressure, indicating that plastic deformation occurs inside the rock at this time. The mathematical relationship between porosity and permeability is established, and the permeability of rock is not only related to the size of porosity, but also closely related to the pore structure of rock.

Carboxymethyl hemicellulose/sorbitol/gallic acid green composite films for fresh fruit preservation

Fruits are prone to deterioration during transportation and preservation, while conventional packaging materials generally pose a persistent threat to the environment. In the present study, a multifunctional green composite film was developed using solution casting method through the interactions of hydrogen bonds among carboxymethyl hemicellulose, sorbitol, and gallic acid, which was subsequently employed as functional materials for fresh fruit preservation application. In particular, the influence of the degree of substitution (DS) of carboxymethyl hemicellulose on the properties of the composite films was investigated. The results indicated that as the DS increased, the carboxymethyl hemicellulose/sorbitol/gallic acid composite film demonstrated a notable improvement in transmittance, air barrier property, and antibacterial activity. Specifically, the composite film (DS = 0.59) showed a 42.54 % increase in transmittance and a 48.31 % decrease in air permeability compared to the composite film containing hemicellulose (control sample). Furthermore, the composite film (DS = 0.59) displayed a desired inhibition effect against Staphylococcus aureus. Based on the 9-day blueberry preservation test, the composite film (DS = 0.59) exhibited a weight loss rate of 15.36 %, whereas the blank group retained a value up to 20.34 %. In addition, the increased DS was found to lead to the decreased tensile strength but improved elongation at break. Overall, the carboxymethyl hemicellulose/sorbitol/gallic acid green composite films, derived from natural bio-materials and free of environmental concerns, could hold great promise as a novel packaging material for fresh fruit preservation.

Experimental investigation on methane hydrate-bearing sediment permeability under a wide range of conditions

Depressurization exploitation of hydrate in methane hydrate-bearing sediments (MHBS) causes changes in sediment effective stress, deformation, and hydrate content, often resulting in decreased permeability which reduces gas production efficiency. To investigate the evolution of MHBS permeability subjected to these changing conditions, permeability tests on MHBS of different methane hydrate saturation level were performed during isotropic compression and drained triaxial shearing under a wide range of effective stress conditions. The results obtained from compression tests indicate that with increasing effective stress, MHBS permeability first decreases rapidly and then tends to stabilize, and the influence of hydrate saturation on permeability gradually reduces. The permeability during the triaxial shear process is closely related to volumetric deformation, with shear-contraction specimen exhibiting continuous decrease in permeability and shear-dilation specimens experiencing an increase in permeability. Unique correlation between permeability with effective void ratio (affected by hydrate saturation) was observed at low confining pressure and early stage of shear. However, this relationship becomes nonunique under increased pressure and shear strain. Thus, a unified MHBS permeability model for a range of conditions is established based on the observed relationship between MHBS permeability and effective void ratio, considering the influence of confining stress, shear strain, and the breakage of sediment particles.

Spermidine mitigates salt stress in grapevine with alterations in physicochemical properties and nutrient composition

AbstractBackgroundPolyamines are plant growth regulators that exert a pivotal role in salt tolerance.AimsThis research focused on investigating the effect of spermidine on morphological and physicochemical characteristics and ion accumulation of two grapevine cultivars under NaCl stress.MethodsA greenhouse experiment was conducted with three factors, including two grapevine cultivars (Vitis vinifera L. cv. Bidaneh‐Sefid and cv. Siah‐Sardasht), four levels of NaCl (together with the nutrient solution, including 0 [control], 20, 40, and 80 mM), and four spermidine levels ([foliar spray], 0 [control], 0.25, 0.5, and 1 mM). The experiment was performed in a factorial trial in accordance with a randomized complete design with three replicates.ResultsVegetative growth indices, including leaf number, fresh and dry weight of shoot, and root, were decreased by NaCl treatments. The application of spermidine positively reduced the effects of NaCl on morphological characteristics. Moreover, NaCl and/or spermidine significantly (p ≤ 0.05) improved antioxidant enzyme activities associated with rising total protein accumulation. NaCl stress significantly decreased ion percentage (calcium, magnesium, phosphate, potassium, iron, and zinc) in the leaves of both cultivars. Based on the results, increasing salinity levels significantly boosted plant Na+ and Cl− percentage, along with increased membrane permeability and malondialdehyde (MDA) concentration. Interestingly, cv. Bidaneh‐Sefid leaves accumulated less Na+ and Cl− compared to the other cultivar. On the other hand, applying spermidine reduced the levels of Na+ and Cl− in both cultivars, and this reduction was associated with a decrease in membrane permeability and MDA concentration.ConclusionsThe findings confirmed the role of spermidine in reducing the negative effects of NaCl, although more investigations with different grapevine cultivars under NaCl stress are required.

Mechanistic analysis of membrane fouling by microplastics in a gravity-driven ceramic membrane reactor for roofing rainwater reuse

The presence of microplastics (MPs) in aquatic environments is a direct consequence of human activities and social development. Consequently, the removal of MPs is essential in water treatment processes, including the membrane filtration of roofing rainwater. Additionally, MPs carried by roofing rainwater pose potential risks to both the ecosystem and human health. However, the fouling behavior of MPs and their impact on the performance of gravity-driven ceramic membranes (GDCMs) remains largely unexplored. In this study, we investigated the effects of the coexisted MPs in rainwater, specifically granulate and fiber MPs, on the formation of fouling layers. We examined their physical and biological characteristics, such as components and microbial community structure. The results demonstrated a positive correlation between the formation of the biological functional layer and the diverse morphology of MPs, which led to a significant decrease in membrane permeability and exacerbated membrane fouling, while having no remarkable influence on permeate quality. Furthermore, different shapes of MPs exhibited varying characteristics: the cake layer of the granulate-MPs group exhibited superior compressibility, while the fiber-MPs group formed and matured more rapidly. MPs not only directly combined with organic matter but also induced metabolic products of microorganisms. Therefore, understanding the primary mechanisms of membrane fouling by MPs in GDCMs for roofing rainwater reuse is of utmost importance. Our study presents novel insights into the mechanisms of membrane fouling in the presence of coexisting MPs in roofing rainwater reuse and provides guidance for improving the performance of GDCMs in the presence of MPs.

Development of PBS/Nano Composite PHB-Based Multilayer Blown Films with Enhanced Properties for Food Packaging Applications.

Biobased and biodegradable plastics have emerged as promising alternatives to conventional plastics offering the potential to reduce environmental impacts while promoting sustainability. This study focuses on the production of multilayer blown films with enhanced functional properties suitable for food packaging applications. Films were developed through co-extrusion in a three-layer film configuration, with Polybutylene Succinate (PBS) and Polybutylene Succinate Adipate (PBSA) as the external and internal layers, respectively. The functional layer consisted of Polyhydroxybutyrate (PHB) enhanced with nanoclays Cloisite® 30B at varying weight ratios. Films were also processed by manipulating the extruder screw speed of the functional layer to investigate its impact on the functional properties. Rheology, mechanical strength, and barrier performance were characterised to establish correlations between processing conditions and functional layer blends (Cloisite® 30B/PHB) on the properties of the resultant films. Rheological test results indicated that the system with 5% Cloisite® had the best polymer/nanofiller matrix dispersion. Mechanical and permeability tests showed that by varying the process conditions (the alteration of the thickness of the functionalized layer) resulted in an improvement in mechanical and barrier properties. Furthermore, the addition of the nanofiller resulted in a stiffening of the film with a subsequent decrease in permeability to oxygen and water vapour.