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The efficiency of sand filtration was investigated in terms of the behavior of the nanoplastics (NPLs) with different surface functionalities. The initial condition concentrations of NPLs were varied, and their effects on retention and transport were investigated under a constant flow rate in saturated porous media. The behavior of NPLs in this porous system was discussed by considering Z- average size and zeta (ζ) potential measurements of each effluent. The retention efficiencies of NPLs were ranked as functionalized with amidine [A-PS]+ > with sulfate [S-PS]− > with surfactant-coated amidine [SDS-A-PS]−. The reversibility of the adsorption process was revealed by introducing surfactant into the sand filter system containing adsorbed [A-PS]+ at three different initial state concentration conditions. The deposition behavior on sand grain showed that positively charged NPLs were attached to the quartz surface, and negatively charged NPLs were attached to the edge of the clay minerals, which can be caused by electrical heterogeneities. The homoaggregates made of positively charged NPLs were more compact than those made of negatively charged NPLs and surfactant-coated NPLs. An anti-correlation was revealed, suggesting a connection between the fractal dimension (Df) of NPL aggregates and retention efficiencies. Increased Df values are associated with decreased retention efficiencies.The findings underscore the crucial influence of NPL surface properties in terms of retention efficiency and reversible adsorption in the presence of surfactants in sand filtration systems. [ABSTRACT FROM AUTHOR]

Thermal diodes are a novel method to rectify the heat transfer mechanism and help reduce heat losses in solar thermal collectors during non-collection periods. The current study introduces and analyzes a new planar thermal diode integrated collector storage (ICS) solar water heating system using an experimental approach. This thermal diode ICS system has a simple, affordable structure composed of two parallel plates. Water serves as a phase change material to transfer heat through evaporation and condensation inside the diode. Three scenarios were considered to assess the dynamics of the thermal diode ICS: atmospheric pressure, depressurized thermal diodes, and Ppartial = 0, − 0.2, and − 0.4 bar. The water temperature reached 40 °C, 46 °C, and 42 °C in Ppartial = 0, − 0.2, and − 0.4 bar, respectively. The heat gain coefficients are 38.61, 40.65, and 39.26 W/K, while the heat loss coefficients are 9.56, 5.16, and 7.03 W/K in Ppartial = 0, − 0.2, and − 0.4 bar, respectively. The optimum heat collection and retention efficiencies are 45.3% and 33.5% in Ppartial = − 0.2 bar. Hence, there is an optimum partial pressure to achieve the best performance, equal to − 0.2 bar. The acquired results illustrate the robustness of the planar thermal diode in reducing heat losses and rectifying the heat transfer mechanism. Furthermore, despite the simple structure of the planar thermal diode, its efficiency is as high as that of other types of thermal diodes analyzed in recent studies. [ABSTRACT FROM AUTHOR]

Thermal diodes are novel mechanisms with high thermal resistance in one direction and low thermal resistance in the other. The current study introduces a new planar thermal diode integrated collector storage (ICSs) system and analyzes its transient dynamics and performance under field conditions in several scenarios, including operating at atmospheric pressure and partial vacuums: P total = 0.7 atm and 0.5 atm. The acquired data illustrate that the collector has approximately the same transient dynamics during the collection period, while differences pronounce during the retention period. Utilizing partial vacuums is tricky and may cause to decrease in performance; however, the best retention and collection efficiencies were obtained at 16.97% and 29.33% when P total = 0.7 atm was utilized. Increasing the partial vacuums to P total = 0.5 atm decreases the retention efficiency significantly to nearly 3.26%. The heat gain (forward mode) coefficient was not affected significantly by partial vacuums. However, the heat loss (reverse mode) coefficient was reduced by nearly 17.63% at P total = 0.7 atm compared to atmospheric pressure. The calculated heat gain and heat loss coefficients are 9.28 W/k and 19.65 W/k at P total = 0.7 atm; hence, the constructed thermal diode successfully serves as a unidirectional heat transfer mechanism. [ABSTRACT FROM AUTHOR]

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The efficiency of sand filtration was investigated in terms of the behavior of the nanoplastics (NPLs) with different surface functionalities. The initial condition concentrations of NPLs were varied, and their effects on retention and transport were investigated under a constant flow rate in saturated porous media. The behavior of NPLs in this porous system was discussed by considering Z- average size and zeta (ζ) potential measurements of each effluent. The retention efficiencies of NPLs were ranked as functionalized with amidine [A-PS]+ > with sulfate [S-PS]− > with surfactant-coated amidine [SDS-A-PS]−. The reversibility of the adsorption process was revealed by introducing surfactant into the sand filter system containing adsorbed [A-PS]+ at three different initial state concentration conditions. The deposition behavior on sand grain showed that positively charged NPLs were attached to the quartz surface, and negatively charged NPLs were attached to the edge of the clay minerals, which can be caused by electrical heterogeneities. The homoaggregates made of positively charged NPLs were more compact than those made of negatively charged NPLs and surfactant-coated NPLs. An anti-correlation was revealed, suggesting a connection between the fractal dimension (Df) of NPL aggregates and retention efficiencies. Increased Df values are associated with decreased retention efficiencies.The findings underscore the crucial influence of NPL surface properties in terms of retention efficiency and reversible adsorption in the presence of surfactants in sand filtration systems.

The numerical modeling of transverse laminar flow past a new type of hollow-fiber membranes with external profiling has been performed. A model system of parallel fibers with symmetrical parallel protrusion obstacles or grooves is considered. The absorption of point particles (solute or gas molecules) from a laminar transverse flow of a viscous incompressible liquid (gas) is calculated for a row of fibers, and the dependences of the efficiency of retention of particles by fibers on the Peclet (Pe), Reynolds (Re), and Schmidt (Sc) numbers and on the distance between neighbor fibers in a row are determined. The flow velocity and concentration fields are calculated by numerical solution of the Navier–Stokes equations and the convective diffusion equation in a wide range of Peclet numbers Pe = 0.1 − 105 for Sc = 1, 10, 1000 and Re ≤ 100. [ABSTRACT FROM AUTHOR]

Ascidians are considered as filter-feeder biofouling pests that negatively affect aquaculture facilities. However, they can also be recognized as a potential co-cultured/extractive species for integrated multi-trophic aquaculture (IMTA) with potential added value as bioresources. A systematic review aiming to understand the ecological importance of ascidians as efficient filter-feeders [What?]; their potential contribution as extractive species [How?]; and to set the benchmark for their nutritional value and potential added value to the aquaculture industry [For what?] is a timely contribution to advance the state of the art on these largely overlooked bioresources. In the last two decades, there has been an overall increase in publications addressing ascidians in aquaculture, namely, their negative impacts through biofouling, as well as their role in IMTA, environmental status, and microbiology. While Ciona intestinalis, a solitary ascidian, has been the most studied species, overall, most ascidians present high filtration and fast-growth rates. As ascidians perform well under IMTA, competition for resources and space with other filter-feeders might occur, which may require additional management actions to optimize production. Studies addressing their bioactive products show that ascidians hold great potential as premium ingredients for aquafeed formulations, as well as dietary supplements (e.g., amino acids, fatty acids). Further research on the potential use of ascidians in IMTA frameworks should focus on systems carrying capacity.

The numerical modeling of transverse laminar flow past a new type of hollow-fiber membranes with external profiling has been performed. A model system of parallel fibers with symmetrical parallel protrusion obstacles or grooves is considered. The absorption of point particles (solute or gas molecules) from a laminar transverse flow of a viscous incompressible liquid (gas) is calculated for a row of fibers, and the dependences of the efficiency of retention of particles by fibers on the Peclet (Pe), Reynolds (Re), and Schmidt (Sc) numbers and on the distance between neighbor fibers in a row are determined. The flow velocity and concentration fields are calculated by numerical solution of the Navier–Stokes equations and the convective diffusion equation in a wide range of Peclet numbers Pe = 0.1 − 105 for Sc = 1, 10, 1000 and Re ≤ 100.

[Display omitted] Microencapsulation helps to improve bioavailability of a functional whey protein, lactoferrin (Lf), in adults. Herein, we report the Lf loading capacity (LC) and retention efficiency (RE) in the microparticles of surface-reacted calcium carbonate (SRCC) of different types and compare them to those of widely used vaterite microparticles. The LCs and REs are analyzed in connection to the total surface area and the volume of intraparticle pores. The best performing SRCC3 demonstrates Lf LC of 11.00 wt% achieved in a single absorption step and 74% RE after two cycles of washing with deionized water. A much larger surface area of SRCC templates and a lower pH required to release Lf do not affect its antitumor activity in MCF-7 assay. Layer-by-Layer assembly of pepsin-tannic acid multilayer shell around Lf-loaded microparticles followed by acidic decomposition of the inorganic core produces microencapsulated Lf with a yield ~36 times higher than from vaterite templates reported earlier, while the scale of encapsulated Lf production is ~12,000 times larger. In vitro digestion tests demonstrate the protection of ~65% of encapsulated Lf from gastric digestion. The developed capsules are prospective candidates for functional foods fortified with Lf. [ABSTRACT FROM AUTHOR]

Retention behavior of a flexible barrier in mitigating a granular flow is still an open problem not fully understood, especially due to the complexity of the granular material and the flexible barrier. Understanding the retention mechanism and quantifying the influencing factors of retention efficiency are desirable for optimizing the design and minimizing the maintenance cost of a debris-resisting flexible barrier. In this paper, a numerical model, based on the discrete element method, is presented, calibrated, and validated to analyze the interaction between a granular flow and a flexible net. A full-scale numerical simulation is first performed to compare with a large-scale physical modeling test in the literature and validate the applied parameters in the simulation. The interaction and deposition characteristics of the granular flow interacting with a flexible net are revealed. Afterward, parametric study is performed to investigate the effects of the internal friction angle (φ) of debris material and the relative mesh size of flexible net on the retention efficiency and clogging mechanism of a flexible barrier. The simulation results illustrate that the particle passing ratio (P) increases with increment of the friction angle of particles and enlargement of the mesh size of a flexible net. Both parameters have critical effects on the retention efficiency of a flexible barrier in intercepting a granular flow. Therefore, the friction angle and the particle size distribution characteristics of the debris material are suggested being used for optimization of the mesh size and more efficient design of debris-resisting flexible barriers. [ABSTRACT FROM AUTHOR]

Around the world, there is growing interest in the use of rainwater retention, and in particular channel retention, as part of urban drainage systems. This is made possible by means of intentional damming of rainwater in the existing sewer collectors in order to maximise the use of gravitational spaces in the channels. This approach is particularly favourable for drainage types related to high levels of urban development, where construction of a building is difficult due to the low amount of space available. This article explains the results of a study concerning the efficiency assessment of three retention devices characterised by different hydraulic systems, one of which uses channel retention in its operation. The analysis conducted within the simulation study has demonstrated that the use of standard single-chamber reservoirs is the least efficient solution. A comparison of the functions of different hydraulic systems of retention reservoirs under equal conditions has shown that the necessary retention capacity of a single-chamber reservoir is many times greater in comparison to highly efficient solutions and it may constitute up to 582% of the reservoir’s capacity and works in conjunction with the channel retention system. At the same time, it has been demonstrated that the application of channel retention is not the most efficient solution for all hydraulic conditions for a drainage system or for all hydrological conditions. In addition, the article proposes a set of retention efficiency indices that may be used in the future assessment of individual rainwater storage solutions. Estimation of the necessary capacity of the retention facilities operating in specific hydraulic conditions was made on the basis of model tests—hydrodynamic modelling with the use of SWMM 5.0 software. The course of the research was planned using the theory of experiment planning (DOE) with the use of Statistica software, whereas efficiency indices were developed with the use of artificial neural networks (ANNs). The study results include practical and cognitive aspects. These may constitute guidelines for the designers and potential investors, as well as a tool with the aim of promoting the most efficient rainwater retention solutions in urban drainage systems.

Atmospheric particulate matter (PM) has been of concern owing to its negative effects on human health and its role in environmental degradation. For mitigation purposes, it is important to select the most efficient plant species in urban greening. Here, a fast, cost-saving methodology was first added to the conventional method to investigate the size-resolved PM retention capacity and efficiency of twenty plant species. Surface PM (SPM), which can be removed by water and brushing, accounted for 44.9–66.9% of total PM, in which the water-soluble PM (DPM) accounted for 12.9–22.1% of total PM. A large mass proportion of in-wax PM (14.1–31.7%) was also observed. Platycladus orientalis, Eriobotrya japonica, Viburnum odoratissimum, Magnolia grandiflora had the highest AEleaf (retention efficiency on per unit leaf area) to retain SPM within different diameter classes (DPM, PM0.1–2.5, PM2.5–10, PM>10). AEplant (retention efficiency of individual tree) varied greatly among different plant species, mainly due to the dependence on the total area of a tree. AEland (retention efficiency on per unit green area) is a suitable index for PM retention ability and efficiency. In general, P. orientalis, V. odoratissimum, Pittosporum tobira, Photinia serrulate, M. grandiflora, E. japonica were the efficient species in retaining PM at different scales (i.e., leaf, individual tree, green area). The species like Trifolium repens, Phyllostachys viridis, were the least efficient plant species. The investigated species are all evergreen species, which will remove PM throughout the whole year, even in winter. So, we recommended that the plant species with the highest PM retention efficiency can be used in urban greening. Meanwhile, horticulture practices should also be considered to improve the leaf area index to improve their PM retention and air purification abilities.

Wound filters are quite popular in the domestic water purification systems. The performance of these filters is based on the distinctive yarn and winding variables. Yarn used for filtration application is normally produced on DREF spinning system. Several researchers have reported the influence of DREF spinning variables on yarn properties. However none of them are in context of filtration application. Since elucidation of influence of winding parameters on the filter performance has already been reported; it thus becomes intriguing to explore the influence of spinning suction pressure on filtration behavior. Yarn spun at different suction pressures was used to produce wound filter cartridges, keeping winding variables unchanged. Filters wound using yarn spun at higher spinning suction pressure resulted in greater pressure drop but showed better micron rating. However the pressure drop encountered also affects the retention capacity of the wound filter. The outcome of this study helps in establishing the relation between spinning suction pressure and performance parameters of wound filters. Design expert® software was used to develop regression equations to predict performance of wound filter for the given spinning suction pressure which is of practical significance for yarn and filter manufacturers, without performing filter test.

The efficiency of sand filtration was investigated in terms of the behavior of the nanoplastics (NPLs) with different surface functionalities. The initial condition concentrations of NPLs were varied, and their effects on retention and transport were investigated under a constant flow rate in saturated porous media. The behavior of NPLs in this porous system was discussed by considering Z- average size and zeta (ζ) potential measurements of each effluent. The retention efficiencies of NPLs were ranked as functionalized with amidine [A-PS]+ > with sulfate [S-PS]- > with surfactant-coated amidine [SDS-A-PS]-. The reversibility of the adsorption process was revealed by introducing surfactant into the sand filter system containing adsorbed [A-PS]+ at three different initial state concentration conditions. The deposition behavior on sand grain showed that positively charged NPLs were attached to the quartz surface, and negatively charged NPLs were attached to the edge of the clay minerals, which can be caused by electrical heterogeneities. The homoaggregates made of positively charged NPLs were more compact than those made of negatively charged NPLs and surfactant-coated NPLs. An anti-correlation was revealed, suggesting a connection between the fractal dimension (D f ) of NPL aggregates and retention efficiencies. Increased D f values are associated with decreased retention efficiencies.The findings underscore the crucial influence of NPL surface properties in terms of retention efficiency and reversible adsorption in the presence of surfactants in sand filtration systems.

To investigate the retention efficiency and mechanism of nitrogen of Vegetative filter strips (VFSs) in the Danjiangkou Reservoir area, simulated runoff discharging experiments were carried out in a new-established Bermuda VFS. The results showed that the Bermuda VFS reduced 73.1-86.1 % of surface runoff through infiltration. The outflow rate of runoff increased first and then became stable with time. The concentration reduction rates (CRRs) and load reduction rates (LRRs) of NH3-N increased initially and then decreased with the increase of inflow concentration. The average CRRs and LRRs of NH3-N in three treatments ranged 66.1-90.3 % and 90.0-96.7 %, respectively. The concentration reduction of NH3-N was primarily achieved by soil adsorption. The optimal inflow concentration of NH3-N for the optimum CRR was between 0.65 and 3.52 mg/dm3. The CRRs and LRRs of NO3-N fluctuated between 6.8-14.0 % and 72.0-77.9 % in three treatments. The concentration reduction of NO3-N was primarily achieved by plant uptake and soil microbe assimilation. The optimal inflow concentration of NO3-N for optimum CRR exceeded 6.78 mg/dm3. The CRRs and LRRs of TN increased with the increase of inflow concentrations. The average CRRs in the low, moderate and high treatments reached 9.7, 14.8 and 27.4 %, respectively, and the average LRRs reached 72.1, 74.3 and 81.2 %, respectively. The optimal inflow concentration of TN for optimum CRR exceeded 10.21 mg/dm3. The study showed that Bermuda grass can retain nitrogen in runoff efficiently and should be promoted around the Danjiangkou reservoir. [ABSTRACT FROM AUTHOR]

Stormwater ponds can serve as retention hotspots for phosphorus (P) moving out of the urban environment. This retention may be reduced by P speciation that reduces the bioavailability of P to primary producers and alters its mobility in sediments. Here we examined the mobility and fate of dissolved P in urban stormwater ponds with a set of complementary field measurements and short‐term laboratory and field experiments. We measured the types and amount of P in water column and sediments of urban stormwater ponds. We further assessed the mobility of different P types in pond sediments in the field and rates of P release from sediment cores maintained under laboratory conditions. Finally, we assessed P uptake rates by pond algal communities using short‐term bioassay experiments. We found that dissolved organic P was highly prevalent in urban pond water and sediments and that this type of P was mobile within sediments and could be released under high or low O2 conditions. We also found highly variable P demand by algae among stormwater ponds and that algal growth responses to P was correlated to water column N:P ratios. Altogether, our results indicate an important role for organic phosphorus cycling in urban stormwater ponds, which likely constrains the overall retention efficiency in these aquatic ecosystems. Key Points: Phosphorus (P) retention in stormwater ponds may be constrained by the generation of nonbioavailable but highly mobile dissolved organic PDissolved organic phosphorus was especially prevalent and mobile in urban pond sediments and released regardless of oxygen concentrationsWhile high P demand was evident, algal growth was limited in ponds with especially low dissolved N:P ratios [ABSTRACT FROM AUTHOR]

Sponges are an important constituent of filter-feeder benthic communities, characterized by high ecological plasticity and abundance. Free bacteria constitute an important quota of their diet, making them excellent candidates in aquaculture microbial bioremediation, where bacteria can be a serious problem. Although there are studies on this topic, certain promising species are still under investigation. Here we report applied microbiological research on the filtering activity of Sarcotragus spinosulus on two different concentrations of the pathogenic bacterium Vibrio parahaemolyticus in a laboratory experiment. To evaluate the effects of the filtration on the surrounding nutrient load, the release of ammonium, nitrate, and phosphate was also measured. The results obtained showed the efficient filtration capability of S. spinosulus as able to reduce the Vibrio load with a maximum retention efficiency of 99.72% and 99.35% at higher and lower Vibrio concentrations, respectively, and remarkable values of clearance rates (average maximum value 45.0 ± 4.1 mL h−1 g DW−1) at the highest Vibrio concentration tested. The nutrient release measured showed low values for each considered nutrient category at less than 1 mg L−1 for ammonium and phosphate and less than 5 mg L−1 for nitrate. The filtering activity and nutrient release by S. spinosulus suggest that this species represents a promising candidate in microbial bioremediation, showing an efficient capability in removing V. parahaemolyticus from seawater with a contribution to the nutrient load.

[Display omitted] • Cs doped resins treated by pre-pyrolysis increase the sulfate content in carbonate. • Carbonate transfers anion exchange resins into nitrate for oxidizing sulfur species. • Pre-pyrolysis with anion exchange resin turns Cs doped resin into Cs 2 SO 4. Molten salt oxidation (MSO), a viable alternative treatment process for spent resins, has the ability to capture sulfur and radioactive nuclides contained within spent resins. S and Cs in Cs doped cation exchange resins are absorbed by MSO to produce unstable compounds when the -SO 3 H is removed. This study particularly suggests a novel technique for introducing anion exchange resins with the aid of pre-pyrolysis to carry out an adequate adsorption of Cs and S in Li 2 CO 3 -Na 2 CO 3 -K 2 CO 3 melt system in order to significantly boost the adsorption of Cs and S in MSO. In addition, XRD, SEM-EDS, and ICP-MS test findings support the idea that this technique encourages the production of thermally stable cesium doped sulfate, which successfully preserves 99.99% and 92.09% Cs in waste salt after MSO at 800 °C for 0.5 h and 2.5 h, respectively. This study provides fresh insight into the prospective MSO applications. [ABSTRACT FROM AUTHOR]

Urban trees have the potential to reduce air pollution, but the retention capacity and efficiency of different tree species for atmospheric particulate matter (PM) accumulation and the underlying mechanism hasn't been well understood. To select tree species with high air purification abilities, the supplementing ultrasonic cleaning (UC) procedure was first introduced into the conventional leaf cleaning methods [single water cleaning (WC) or plus brush cleaning (BC)] for eluting the leaf-retained PM. Further updates to the methodology were applied to investigate the retention capacity, efficiency, and mechanism for PM of five typical greening tree species in Beijing, China. Meanwhile, the particle size distribution of PM on the leaves, the PM retention efficiencies of easily removable (ERP), difficult-to-remove (DRP) and totally removable (TRP) particles on the leaf ( AE leaf ), and the individual tree scales were estimated. The experimental leaf samples were collected from trees with similar sizes 4 (SDR) and 14 days (LDR) after rainfall. When the leaves were cleaned by WC + BC, there was, on average, 29%–46% of the PM remaining on the leaves of different species, which could be removed almost completely if UC was supplemented. From SDR to LDR, the mass of the leaf-retained PM increased greatly, and the particle size distribution changed markedly for all species except for Sophora japonica . Pinus tabuliformis retains particles with the largest average diameter (34.2 μm), followed by Ginkgo biloba (20.5 μm), Sabina chinensis (16.4 μm), Salix babylonica (16.0 μm), and S. japonica (13.1 μm). S . japonica and S . chinensis had the highest AE leaf to retain the TRP and ERP of both PM 1 and PM 1 − 2.5 , respectively. Conversely, S . babylonica and P . tabuliformis could retain both TRP and ERP of PM 2.5–5 and PM 5–10 , and PM > 10 and TSP with the highest AE leaf , respectively. In conclusion, our results could be useful in selecting greening tree species with high air purification abilities. [ABSTRACT FROM AUTHOR]

The objectives were estimate the balance of N and P, the retention of K, Ca, Mg, Cu, Fe, Mn, Zn, Cd, Pb and Cr, and the economic viability in a culture system of Nile tilapia subjected to the addition of B. subtilis and B. cereus in the diet. The analysis of nutrients in the diet and in the fish were carry out for the calculations of the rate of nutrient retention efficiency (RNRE), protein efficiency ratio (PER) and efficiency of nitrogen retention (NER). The experimental design for the content of nutrients in the soil on collection times and collection site at the end of cultivation was in factorial 4 x 2 with five replications and to the NER, and PER in fish RNRE was completely randomized with four treatments and five replicates. The analyses of variance were employed, followed by Tukey test (p

Industrial processing of fruit and vegetables can have detrimental effects on health-promoting phytochemicals. Here, a novel pilot-scale process using an innovative spiral-filter press followed by a thermal treatment was evaluated for the production of tomato juice. Three-month storage of the resulting juice was also evaluated. The process impact of the different unit processes, with emphasis on the novel spiral-filter pressing, was investigated for the three major compound classes present in tomato (ascorbic acid, phenolic compounds and carotenoids). The spiral-filter press processing did not seem to cause degradation of ascorbic acid, phenolic compounds or carotenoids, which can be ascribed to the fast processing in a low-oxygen atmosphere. Maintaining the native constitution of tomato to a great extent, the spiral-filter press thus offers potential for processing tomatoes and other vegetables into juices, smoothies and purees. [ABSTRACT FROM AUTHOR]

The low-impact development (LID) Editor rain barrel option of release 5.5 of the EPA storm water management model (SWMM) software does not allow the consideration of demand-driven behaviour of domestic rain water harvesting (RWH) systems to evaluate their runoff retention potential. This paper compares the results of the LID Editor with those obtained by a detailed demand-driven tank model scheme – used as a benchmark – and developed using basic functions of SWMM. The comparison showed the LID Editor-based model to generally overestimate the benchmark model in the evaluation of both volumetric and peak retention efficiency. The high variability of the results of the comparison suggests the use of the LID Editor rain barrel option for long-term simulation but not for single event analysis. A sensitivity analysis revealed that the overestimation provided by the rain barrel option is significant for tanks smaller than 2 m3, tank sizes of major diffusion for domestic RWH. [ABSTRACT FROM AUTHOR]

Encapsulation is an established technique to protect sensitive materials from environmental stress. In order to understand the physical protection mechanism against oxidation, knowledge about the powder microstructure is required. Time domain-nuclear magnetic resonance (TD-NMR) has the potential to determine the surface oil (SO) and droplet size distribution by relaxation and restricted self-diffusion, respectively. The amount of SO, the retention and encapsulation efficiency are determined based on a lipid balance. The oil load of the initial powder and after SO removal is measured by TD-NMR. The results correlate with gravimetric and photometric references. The oil droplet size obtained by TD-NMR correlates well with static light scattering. The diameter of droplets in emulsions and dried powder both measured by TD-NMR, correlates (r = 0.998), implying that oil droplets embedded in a solid matrix can be measured. Summarising, TD-NMR allows analysis of the microstructure of encapsulated lipid powders, in a rapid, simple and non-destructive way. [ABSTRACT FROM PUBLISHER]

Wound filters are quite popular in the domestic water purification systems. The performance of these filters is based on the distinctive yarn and winding variables. Yarn used for filtration application is normally produced on DREF spinning system. Several researchers have reported the influence of DREF spinning variables on yarn properties. However none of them are in context of filtration application. Since elucidation of influence of winding parameters on the filter performance has already been reported; it thus becomes intriguing to explore the influence of spinning suction pressure on filtration behavior. Yarn spun at different suction pressures was used to produce wound filter cartridges, keeping winding variables unchanged. Filters wound using yarn spun at higher spinning suction pressure resulted in greater pressure drop but showed better micron rating. However the pressure drop encountered also affects the retention capacity of the wound filter. The outcome of this study helps in establishing the relation between spinning suction pressure and performance parameters of wound filters. Design expert® software was used to develop regression equations to predict performance of wound filter for the given spinning suction pressure which is of practical significance for yarn and filter manufacturers, without performing filter test. [ABSTRACT FROM AUTHOR]

A growth trial was conducted to examine the effect of dietary digestible energy ( DE) content on methionine (Met) utilization and requirement in juvenile Nile tilapia ( Oreochromis niloticus). Ten iso-nitrogenous (288 g kg−1 protein) practical diets, with two DE levels (10.9 MJ kg−1; 12.4 MJ kg−1) and five methionine supplementation levels (0, 1, 2, 4 and 6 g kg−1), were hand-fed twice daily to triplicate groups of Nile tilapia (initial body weight 8.95 ± 0.06 g) for 8 weeks. Weight gain ( WG) and specific growth rate ( SGR) increased significantly with increasing dietary methionine concentration at the same DE content ( P < 0.001). At the same dietary methionine level, WG and SGR of fish fed high- DE diets were significantly higher than that of fish fed low- DE diets ( P = 0.0001), although no interaction was found between dietary DE and methionine supplementation. Based on quadratic regression analysis between dietary methionine concentration and weight gain, optimal methionine requirement for maximum growth, expressed as g Met required kg−1 diet (low- versus high- DE diets), increased as diet DE concentration increased (7.34 versus 9.90 g kg−1 diet, respectively; with cysteine 4.70 g kg−1 diet). The results indicated that diet DE content affects methionine utilization and requirement in juvenile Nile tilapia, fish fed high- DE diets required more methionine for maximum growth. [ABSTRACT FROM AUTHOR]

Effective removal of small colloidal nanoparticles (NPs, e.g., <20 nm), including rigid particles, macromolecules, organics, viruses, antibiotics, hormones, etc., by dead-end filtration, is very important in drinking water, chemical, biopharmaceutical, and semiconductor factories. Most existing operations focused on sieving mechanism-based filtration with small-pore membranes (e.g., <20 nm) to capture these tiny NPs, which unfortunately leads to high energy consumption. This study proposed an emerging method that is to use large pore membranes (i.e., ∼100 nm) to capture NPs down to 2.8 nm. The ultimate goal is to address the grand challenge presented in the United Nations Sustainable Development Goal 12 on energy saving. To capture (or adhere) small NPs by large-pore membranes, the surface electrostatic interactions between NP and membrane should be considered in addition to the sieving mechanism. To examine the feasibility of the proposed method, the retention efficiency of ∼100 nm rated polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), and polycarbonate track-etched (PCTE, as a model filter) membranes against 2.8 nm ZnS quantum dot (QD), 5 and 10 nm Au and 100 nm PSL in water and isopropanol (IPA, a representative organic solvent) were studied experimentally and theoretically. In the experiments, the electrospray-scanning mobility particle sizer (ES-SMPS) was used to measure the size distribution of these nanosized colloids before and after the membrane to determine the retention efficiency. In the theory, we combined the hydrodynamic particle transport, extended Derjaguin-Landau-Verwey-Overbeek (xDLVO), and Maxwell models to calculate the NP retention. Results showed that the data agreed with the theoretical model very well, and the NP retentions in IPA were higher than that in water due to a significant change of acid-base interaction from repulsion to attraction. The retention of the 10 nm Au NPs and the 2.8 nm NPs could be attained by ∼80 and 35%, respecively, in IPA by the PTFE. This study was the first to show the combined theoretical model can accurately predict the retention of sub-10 nm NPs by different membranes in an organic solvent and water. The model predicts the retention of 5 nm Au NPs can be increased to higher than 99% by increasing the zeta potential of the PTFE about 5 times, thus a sustainable UF cutting significant carbon footprint is foreseeable in near future. [Display omitted] • A method proposed to address United Nations grand challenge of cutting carbon footprint. • UF substitutes NF in biopharmaceutical and semiconductor factories for energy saving. • Removal of sub-10 nm NPs by 3 UF membranes was studied experimentally and theoretically. • Effects of NP size, filter material, and solutions on NP retention were uncovered. • Retention of 2.8 and 5 nm NPs can reach >99% by increasing membrane charge. [ABSTRACT FROM AUTHOR]

We investigated and compared, by laboratory experiments, the filter-feeding activity on bacteria by the solitary ascidian Styela plicata and the colonial ascidian Polyandrocarpa zorritensis . Clearance rates and retention efficiencies were estimated by using, as only food source, the bacterial species Vibrio alginolyticus selected on account of its importance in aquaculture pathogenicity. The Cmax was 1.4 ± 0.17 L h − 1 g − 1 DW for S. plicata and 1.745 L h − 1 g − 1 DW for P. zorritensis . The highest retention efficiency was 41% corresponding to a removed bacterial biomass of 16.34 + 1.71 μgCL − 1 g − 1 DW for P. zorritensis and 81% corresponding to a bacterial biomass of 32.28 + 2.15 μgCL − 1 g − 1 DW for S. plicata . Styela plicata resulted higher efficient than P. zorritensis in removing V. alginolyticus from seawater in experimental tanks, thus representing a more suitable biofilter to restore the quality of microbiologically contaminated waters including those where aquaculture is practiced. Present laboratory experiments represent the first contribution to the comparison of the filtration activity of the two ascidians, as well as to characterize the filtration process on bacterioplankton and pone the basis for future field works aimed to restore bacteriological polluted seawater. [ABSTRACT FROM AUTHOR]

The emergency exhaust system of the Pakistan Research Reactor-1 (PARR-1) in corporates charcoal bed filters for the removal of radioiodine from exhaust gases in case of an emergency involving the release of radioiodine. The filters adsorb radioiodine. Testing of the filters is necessary so as to assess their iodine retention efficiency, if they are to meet regulatory requirements. The retention efficiency of our filters has been measured and found to be 99.1%. This value is higher than the value of the activated charcoal filter efficiency (99%) employed to determine the source term for release through emergency exhaust with filtration, for dose calculations. In this paper, the procedure for testing the efficiency of charcoal filters has been discussed and results obtained presented.

Vegetative filter strips can effectively reduce nitrogen and phosphorus load or concentration from agricultural land to surface water. However, the efficiency of vegetative filter strips vary with soil, hydrology and vegetation condition in different rainfall-runoff cases through long-term monitoring, so it is important to assess retention efficiency of vegetative filter strips under single rainfall-runoff condition. Mathematical model is an important tool for the planning and design of vegetative filter strips. Thus, an ease-to-use assessment model is presented to better assess nitrogen and phosphorus retention effect by vegetative filter strips under single runoff condition in the northwest area of China with serious soil erosion. The simplified model proposed involves 3 parts: coupling sub-model, linear correlation sub-model and mixing zone conceptual sub-model. The coupling sub-model of the vegetative filter strips model (VFSMOD) and the modified universal soil loss equation (MUSLE) is made to simulate purification effect of suspended solids (mainly means sediments), because sediment retention efficiency is the combined effect of the sediments entrapped process and the soil erosion or sediments yield process in vegetative filter strips itself. According to significant correlation with sediments and those particle pollutants on runoff, the linear correlation method is used to calculate removal effect of particle nitrogen and particle phosphorus by vegetative filter strips. Infiltration is regarded as the only mechanism to remove dissolved pollutants, namely vegetative filter strips reduce dissolved nitrogen and phosphorus volume by diffusion and infiltration into soil. Therefore, based on mechanism research of the interaction of dissolved pollutants in topsoil and surface runoff, and through simplifying pollutant transport in deep soil, the mixing zone conceptual sub-model is utilized to assess the effect of vegetative filter strips on dissolved nitrogen and phosphorus. Furthermore, the mass dynamic balance equilibrium within overland flow and soil mixing zone is considered accordingly; in overland flow, mass balance includes diffusion, infiltration and soil losses, and in soil mixing zone, it is regarded as uniform mixing and its change covers diffusion and infiltration from runoff, denitrification, leaching, soil losses and adsorption etc. Among them, the coupling model can predict hydrology and suspended solids transport well by considering runoff sluicing impact on sediments from vegetative filter strips in surface soil, and the results show that the relative deviations between simulated and measured concentrations of suspended solids are within ±20%, and the determination coefficients between simulated and measured values is 0.98. The simplified particle nitrogen and phosphorus transport algorithm is presented by the linear correlation method based on field plot experiment data, and the good prediction in runoff and sediments also resulted in good prediction of particle nitrogen and phosphorus transport by vegetative filter strips, since adsorbed nitrogen and phosphorus are the main components of nitrogen and phosphorus in the areas with serious soil erosion. Similarly, the results also show that the relative deviations between simulated and measured concentrations of particle pollutants are within ±20%. It is obvious that a good prediction of dissolved nitrogen and phosphorus is obtained by the mixing zone conceptual model, the input and output of the mass balance system of vegetative filter strips consider biological and chemical processes of dissolved nitrogen and phosphorus in soil mixing zone, and furthermore the detailed analysis and proper simplification for vegetative filter strips system are presented. The relative deviations are within ±20% between simulated and measured concentrations of dissolved nitrogen and phosphorus. Thus, the combined nitrogen or phosphorus modeling approach successfully predicts runoff, sediment, nitrogen and phosphorus transport in the areas with serious soil erosion, which provides the reference for controlling runoff and pollutants transport using vegetative filter strips. [ABSTRACT FROM AUTHOR]

We sampled zooplankton and fecal pellets in the upper 200 m of Monterey Bay and nearby coastal regions in California, USA. On several occasions, we observed high concentrations of large pellets that appeared to be produced during night-time by dielly migrating euphausiids. High concentrations of pellets were found in near-surface waters only when euphausiids co-occurred with high concentrations of large (>10 μm) phytoplankton. Peak concentrations of pellets at mid-depth (100 or 150 m) during the day were consistent with the calculated sinking speeds of pellets produced near the surface at night. At these high flux locations (HI group), pellet concentrations declined below mid-depth. In contrast, at locations where the phytoplankton assemblage was dominated by small phytoplankton cells (<10 μm), pellet production and flux were low (LO group) whether or not euphausiid populations were high. Protozooplankton concentrations did not affect this pattern. We concluded that the day and night differences in pellet concentration and flux in the HI profiles were mostly due to sinking of dielly-pulsed inputs in the surface layer, and that small zooplankton ( Oithona , Oncaea ), heterotrophic dinoflagellates, and bacterial activity probably caused some pellet degradation or consumption below 100 m. We estimated that consumption of sinking pellets by large copepods was insignificant. High fluxes of pellets were episodic because they required both high concentrations of large phytoplankton and large stocks of euphausiids. Under these conditions, flux events overwhelmed retention mechanisms, resulting in large exports of organic matter from the upper 200 m. [ABSTRACT FROM AUTHOR]