Microplastic pollutants in water: A comprehensive review on their remediation by adsorption using various adsorbents.

Microplastics (MPs), as emerging pollutants, have attracted the attention of environmentalists, statespersons, and the scientific community over the last few decades. To address the spread of MPs in the environment, it is imperative to develop various removal techniques and materials that are effective, scalable, and ecologically benign. However, to the best of our knowledge, no review has systematically examined the removal of MPs using adsorption or provided an in-depth discussion on various adsorbents. Adsorption is an inexpensive and effective technology for wastewater treatment. Recently, many researchers have conducted studies on MP remediation using diverse adsorbent materials, such as biochar, activated carbon, sponges, carbon nanotubes, metal-layered oxides, metal-organic frameworks (MOFs), and zeolites. Each adsorbent has advantages and disadvantages. To overcome their disadvantages, researchers have been designing and developing hybrid adsorbents for MP remediation. This review provides insights into these individual adsorbents and also discusses hybrid adsorbents for MP removal. Finally, the review elaborates on future possibilities and ways to enable more efficient, scalable, and environmentally friendly MP cleanup. Overall, this review bridges the gap between contemporary MP remediation using adsorption techniques and adsorbent development.

DDoS attack detection in smart grid network using reconstructive machine learning models.

Network attacks pose a significant challenge for smart grid networks, mainly due to the existence of several multi-directional communication devices coupling consumers to the grid. One of the network attacks that can affect the smart grid is the distributed denial of service (DDoS), where numerous compromised communication devices/nodes of the grid flood the smart grid network with false data and requests, leading to disruptions in smart meters, data servers, and the state estimator, ultimately effecting the services for end-users. Machine learning-based strategies show distinctive benefits in resolving the challenge of securing the network from DDoS attacks. Regardless, a notable hindrance in deploying machine learning-based techniques is the requirement of model retraining whenever new attack classes arise. Practically, disrupting the normal operations of smart grid is really discouraged. To handle this challenge effectively and detect DDoS attacks without major disruptions, we propose the deployment of reconstructive deep learning techniques. A primary benefit of our proposed technique is the minimum disruption during the introduction of a new attack class, even after complete deployment. We trained several deep and shallow reconstructive models to get representations for each attack type separately, and we performed attack detection by class-specific reconstruction error-based classification. Our technique experienced rigid evaluation via multiple experiments using two well-acknowledged standard databases exclusively for DDoS attacks, including their subsets. Later, we performed a comparative estimation of our outcomes against six methods prevalent within the same domain. Our outcomes reveal that our technique attained higher accuracy, and notably eliminates the requirement of a complete model retraining in the event of the introduction of new attack classes. This method will not only boost the security of smart grid networks but also ensure the stability and reliability of normal operations, protecting the critical infrastructure from ever-evolving network attacks. As smart grid is advancing rapidly, our approach proposes a robust and adaptive way to overcome the continuous challenges posed by network attacks.

A proceeding to numerical study of mathematical model of bioconvective Maxwell nanofluid flow through a porous stretching surface with nield/convective boundary constraints.

Nanofluids become significant in the mass and heat transfer models, especially in engineering problems. Current proceedings focused on the bioconvective Maxwell nanofluid flow passing through the permeable stretchable sheet contingent to nield boundary conditions involving effects of activation energy and thermal radiation. Various physical quantities are involved in this mechanism like magnetic field, thermophoresis, and Brownian motion. The main objective of the study is to report the heat and mass transport in the existence of motile microorganisms. In a mathematical perspective, this structured physical model is going to govern with the help of partial differential equations (PDEs). These governing PDEs are then converted into dimensionless ordinary differential equations form by utilizing appropriate similarity transformations. For numerical results, the shooting technique with 'bvp4c' built-in package of MATLAB was implemented. Computed results are then visualized graphically and discussed effects of involving physical variables on the nano-fluid flow profiles are comprehensively. From results, it has been concluded that the fluid flow velocity, temperature, concentration, and microorganism density profiles show escalation on increasing the numeric values of porosity, thermophoresis, buoyancy ratio, bioconvection Rayleigh, Peclet number parameters and decrement reported due to increasing the counts of Prandtl number, magnetic field, radiation, Brownian motion, Lewis number as evident from figures. The numerical outcomes observed by fixing the physical parameters as [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text]. Magnetic field and Brownian motion create retardation impact due to the liquid momentum. In tables, the numerical values of Skin friction, Nusselt number, Sherwood number, and microorganisms density number are presented and also comparison table of our computed results and already published results is included for the validation.

Synthesis of CaCO3 supported nano zero-valent iron-nickel nanocomposite (nZVI-Ni@CaCO3) and its application for trichloroethylene removal in persulfate activated system.

Nano zero-valent (nZVI) based composite have been widely utilized in environmental remediation. However, the rapid agglomeration and quick deactivation of nZVI limited its application on large scale. In this work, CaCO3 supported nZVI-Ni catalyst, namely nZVI-Ni@CaCO3 was prepared and used for the efficient removal of trichloroethylene (TCE) in PS oxidation process. The successful disbursement of nZVI-Ni on CaCO3 support material not only increased the surface area of nZVI-Ni@CaCO3 (69.45 m2/g) with respect to CaCO3 (5.92 m2/g) and bare nZVI (13.29 m2/g) but also improved the catalytic activity. XRD, XPS and FTIR analysis confirmed the successful formation of nZVI-Ni@CaCO3 nanoparticles. The nZVI-Ni@CaCO3 nanoparticles combined with PS had achieved complete removal of TCE (99.8%) with dosage of 36 mg/L and 1.34 mM respectively. These results showed that the use of CaCO3 as support material for nZVI-Ni could have significant influence on contaminant removal process. Scavenging and EPR tests validated the existence of SO4•-, OH• and O2•- radicals in PS/nZVI-Ni@CaCO3 system and highlighted the dominant role of SO4•- radicals in TCE removal process. HCO3- ions and humic acid have shown adverse effect on TCE removal due to radical scavenging and buffering effect. Owing to improved catalytic activity and easy preparation, the nZVI-Ni@CaCO3 nanoparticles could be served as an alternative strategy for environmental remediation.

Estimation of heat transfer coefficient and friction factor with showering of aluminum nitride and alumina water based hybrid nanofluid in a tube with twisted tape insert.

Twisted tape is one of the active thermal proficiency boosting technology which has been deeply examined because to consistent efficiency findings and easy implementations. Thermo-hydraulic effectiveness of tubes fitted with twisted tapes is becoming highly significant. Although twisted tapes can cause swirls and disturb boundary layers, this is the most widely used method for improving convection. In the present attempt, to enhance the heat transfer twisted tape is inserted in tube. In the current modern research, the effect of twisted tape, on the enhancement of thermal transport, Nusselt number and friction factor performance of AIN-Al2O3/water hybrid nanofluid is evaluating utilizing CFD and ANSYS-FLUENT software. the consequence of twisted pitch 44 mm, 66 mm, 88 mm, 100 mm and Reynolds numbers 800, 1200, 1600 and 2000 on Nusselt number, heat transfer coefficient and friction coefficient have been computed numerically with 0.01 to 0.04 volume friction of nanopowders. The commercial ANSYS-FLUENT code was used in this analysis utilizing the SIMPLE method for pressure-velocity coupling. The [Formula: see text] model and Navier Stokes equations are integrating utilizing finite volume method in ANSYS-FLUENT. It was observed that inserting the twisted tape in tube significantly improves the thermal conductivity as well as friction factor compared with the simple tube without turbulator.

Degradation of trichloroethylene in aqueous solution by FeS2 catalyst under innovative oxic environments.

Rapid growth and industrialization have become a major threat to water contamination with carcinogenic chlorinated hydrocarbons such as trichloroethylene (TCE). Therefore, this study aims to assess the TCE degradation performance through advanced oxidation process (AOP) using catalyst FeS2 in combination with oxidants persulfate (PS), peroxymonosulfate (PMS), and hydrogen peroxide (H2O2) in PS/FeS2, PMS/FeS2, and H2O2/FeS2 systems, respectively. TCE concentration was analyzed using gas chromatography (GC). The results found the trend for TCE degradation by the systems was PMS/FeS2>PS/FeS2>H2O2/FeS2 (99.84, 99.63, and 98.47%, respectively). Degradation of TCE was analyzed at different pH ranges (3-11) and maximum degradation at a wide pH range was observed for PMS/FeS2. The analysis using electron paramagnetic resonance (EPR) and scavenging tests explored responsible reactive oxygen species (ROS) for TCE degradation and found that HO• and SO4-• played the most effective role. The results of catalyst stability showed PMS/FeS2 system the most promising with the stability of 99, 96 and 50% for the first, second and third runs, respectively. The system was also found efficient in the presence of surfactants (TW-80, TX-100, and Brij-35) in ultra-pure water (89.41, 34.11, 96.61%, respectively), and actual groundwater (94.37, 33.72, and 73.48%, respectively), but at higher reagents dosages (5X for ultra-pure water and 10X actual ground water). Furthermore, it is demonstrated that the oxic systems have degradation capability for other TCE-like pollutants. In conclusion, due to its high stability, reactivity, and cost-effectiveness, PMS/FeS2 system could be a better choice for the treatment of TCE contaminated water and can be beneficial for field application.

Partial differential equations modeling of bio-convective sutterby nanofluid flow through paraboloid surface.

In this research article, the behavior of 2D non-Newtonian Sutterby nanofluid flow over the parabolic surface is discussed. In boundary region of surface buoyancy-driven flow occurred due to considerable temperature differences produced by the reaction happen between Sutterby nanofluid and catalyst at the surface. Free convection which is sighted easily on the parabolic surface is initiated by reaction on the catalyst surface modeled the 1st order activation energy. Applications of parabolic surfaces are upper cover of bullet, car bonnet, and air crafts. Under discussion flow is modelled mathematically by implementing law of conservation of microorganism's concentration, momentum, mass and heat. The governing equations of the system is of the form of non-linear PDE's. By the use of similarity transform, the governing PDE`s transformed as non-dimensional ODE's. The resultant system of non-dimensional ODE's are numerically solved by built-in function MATLAB package named as 'bvp4c'. Graphical representation shows the influence of different parameters in the concentration, velocity, microorganisms and temperature profiles of the system. In temperature profile, we examined the impact of thermophoresis coefficient Nt (0.1, 0.5, 1.0), Prandtl number Pr (2.0, 3.0, 4.0), and Brownian motion variable Nb (0.1, 0.3, 0.5). Velocity profile depends on the non-dimensional parameters i.e. (Deborah number De & Hartmann number Ha) and found that these numbers (De, Ha) cause downfall in profile. Furthermore, mass transfer, skin friction, and heat transfer rates are numerically computed. The purpose of the study is to enumerate the significance of parabolic surfaces for the transport of heat and mass through the flow of bio-convective Sutterby nanofluid.

Thermal transport analysis of six circular microchannel heat sink using nanofluid.

Electronics devices growth in the last decade of the twentieth century ushered in a revolution inside the electronics segment. Continuous micro-sizes and operation cause these devices to heat up, resulting in a reduction in their performance or damage to their parts. Because heat can decrease device performance and life span while also wasting energy, offering an incorporated and effective cooling system has become a significant part of the design of device equipment. One of the key challenges of modern generation technology is the cooling of electronic devices. Nanofluids have attracted attention in a broad range of engineering implementations due to their great properties, which may be used to effectively cool devices while also improving energy efficiency. In view of the above defects, this numerical research object to examine the chip surface temperature, heat transfer rate, thermal resistance, Darcy friction factor and reliability of microelectronic chips in minichannel heat sinks is scrutinized by utilizing a [Formula: see text]/water nanofluid as a coolant and comparing the nanoliquid outcomes with the outcomes of water. [Formula: see text]/Water nanofluids at 1%, 2% and 3% volume concentrations are employed for this scrutinization. Here, a commercial CFD ANSYS (R19.2) FLUENT software package is used to analyze the electronic chip performance. The CFD ANSYS (R19.2) FLUENT software package is used for modeling, meshing and simulation of the current study.

Recent progress in melting heat phenomenon for bioconvection transport of nanofluid through a lubricated surface with swimming microorganisms.

The cooling of numerous microelectronic devices has become a need in today's world. Nanofluids, a novel type of heat transport fluid containing nano-sized particles embedded in a host liquid, were developed a few years ago. Impact of ultra-fine nanoparticles with oil, water, or ethylene glycol produces these fluids. Nano-liquids have a variety of applications, including engine cooling, electronic devices, biomedicine, and the manufacture of thermal exchangers. The main objective of current research article is to scrutinizes theoretically, the effects of axisymmetric magnetohydrodynamic flow of bio-convective nanoliquid through a moving surface in the occurrence of swimming microorganisms. The idea of the envisaged model is improved by considering the consequence of thermal radiation, activation energy with generalized slip effects under convective boundaries. The present analysis is developed in the form of mathematical formulation and then solved numerically. The governing flow equations are transmuted into dimensionless nonlinear ODEs system by compatible similarity transformations and then integrated this so-formulated highly nonlinear problem numerically via bvp4c built-in scheme in MATLAB. The significance of influential parameters versus velocity field, temperature profile, concentration field and motile density of microorganism's profile are examined with the aid of graphs and tabular data. The physical interpretation of outcomes highlight that the velocity receives increment for amplified mixed convection parameter. The thermal profile is found to be reducing with a greater Prandtl number. The concentration profile of nanoparticle boosts up for greater activation energy parameter. The microorganism's profile is reduced via bioconvection Lewis number. This investigation contains the significance of bioconvection phenomenon, thermal radiation, slip effects and activation energy under convective boundary conditions. These impacts are used in axisymmetric, stagnation point flow of bioconvective magnetized nanofluid containing swimming gyrotactic motile microorganisms over a lubricated surface. The present analysis is not yet published.

Mechanism of trichloroethylene degradation in Fe(II)-activated peroxymonosulfate coupled with citric acid system in the presence of surfactants.

This study demonstrated that peroxymonosulfate (PMS) activated by Fe(II)/citric acid (CA) could effectively degrade trichloroethylene (TCE) in the presence of Tween-80 (TW-80) or sodium dodecyl sulfate (SDS). Significant TCE removal of 91.6% (90.1%) with 1.3 g L-1 TW-80 (2.3 g L-1 SDS) were achieved at the PMS/Fe(II)/CA/TCE molar ratio of 4/4/4/1 (20/20/20/1). TCE degradation could be greatly elevated by Fe(II) and CA addition, while the existence of surfactants restrained TCE removal and the inhibitory effect increased with the higher surfactant concentration. The tests of the electron paramagnetic resonance (EPR) and reactive radicals scavenging experiments proved that sulfate radical (SO4-•), hydroxyl radical (HO•), and superoxide radical (O2-•) were responsible for TCE degradation and SO4-• acted as the major one. The influences of initial solution pH and inorganic anions k(Cl- and HCO3-) on TCE removal were also investigated. Eventually, TCE removal in actual groundwater tests with surfactants confirmed that the PMS/Fe(II)/CA process has a huge potential of practical application in remediating the groundwater contaminated by TCE after the pretreatment by solubilization using surfactants.

Computational Analysis of Nanoparticle Shapes on Hybrid Nanofluid Flow Due to Flat Horizontal Plate via Solar Collector.

The present work discusses the 2D unsteady flow of second grade hybrid nanofluid in terms of heat transfer and MHD effects over a stretchable moving flat horizontal porous plate. The entropy of system is taken into account. The magnetic field and the Joule heating effects are also considered. Tiny-sized nanoparticles of silicon carbide and titanium oxide dispersed in a base fluid, kerosene oil. Furthermore, the shape factors of tiny-sized particles (sphere, bricks, tetrahedron, and platelets) are explored and discussed in detail. The mathematical representation in expressions of PDEs is built by considering the heat transfer mechanism owing to the effects of Joule heating and viscous dissipation. The present set of PDEs (partial differential equations) are converted into ODEs (ordinary differential equations) by introducing suitable transformations, which are then resolved with the bvp4c (shooting) scheme in MATLAB. Graphical expressions and numerical data are obtained to scrutinize the variations of momentum and temperature fields versus different physical constraints.

Case report: Pulmonary artery thrombosis in cyanotic congenital heart disease.

Cyanotic congenital cardiac anomalies increase the risk of thrombosis. In pediatric congenital heart disease, the diagnosis of pulmonary artery thrombosis is rare. We reported an 11-year-old male child who developed progressive shortness of breath over six months. He was subsequently referred to the National Institute of Cardiovascular Diseases, Karachi, Pakistan. The child was diagnosed as a case of double outlet left ventricle, levo-transposition of the great arteries, pulmonary stenosis, ventricular septal defect and thrombus in the main pulmonary artery with extension into the branch pulmonary arteries. He underwent thromboendarterectomy with a Glenn shunt and made an uneventful postoperative recovery.

Unveiling the catalytic ability of carbonaceous materials in Fenton-like reaction by controlled-release CaO2 nanoparticles for trichloroethylene degradation.

Carbonaceous materials (CMs) have been applied extensively for enhancing the catalytic performance of environmental catalysts, however, the self-catalytic mechanism of CMs for groundwater remediation is rarely investigated. Herein, we unveiled the catalytic ability of various CMs via Fe(III) reduction through polyvinyl alcohol-coated calcium peroxide nanoparticles (PVA@nCP) for trichloroethylene (TCE) removal. Among selected CMs (graphite (G), biochar (BC) and activated carbon (AC)), BC and AC showed enhancement of TCE removal of 89% and 98% via both adsorption and catalytic degradation. BET and SEM analyses showed a higher adsorption capacity of AC (27.8%) than others. The generation of solution-Fe(II) and surface-Fe(II) revealed the reduction of Fe(III) on CMs-surface. The role of O-containing groups was investigated by the FTIR technique and XPS quantified the 52% and 57% surface-Fe(II) in BC and AC systems, respectively. EPR and quenching tests confirmed that both solution and surface-bound species (HO•, O2-• and 1O2) contributed to TCE degradation. Acidic pH condition encouraged TCE removal and the presence of HCO3- negatively affected TCE removal than other inorganic ions. Both schemes (PVA@nCP/Fe(III)/BC and PVA@nCP/Fe(III)/AC) exhibited promising results in the actual groundwater, surfactant-amended solution, and removal of other chlorinated-pollutants, opening a new direction towards green environmental remediation for prolonged benefits.

Enhancement in reactivity via sulfidation of FeNi@BC for efficient removal of trichloroethylene: Insight mechanism and the role of reactive oxygen species.

A novel catalyst of sulfidated iron-nickel supported on biochar (S-FeNi@BC) was synthesized to activate persulfate (PS) for the removal of trichloroethylene (TCE). A number of techniques including XRD, SEM, TEM, FTIR, BET and EDS were employed to characterize S-FeNi@BC. The influence of sulfur to iron ratio (S/F) on TCE removal was investigated by batch experiments and a higher TCE removal (98.4%) was achieved at 0.22/1 ratio of S/F in the PS/S-FeNi@BC oxidation system. A dominant role in iron species conversion was noticed by the addition of sulfur in FeNi@BC system. Significant enhancement in recycling of the dissolved and surface Fe(II) was confirmed which contributed to the generation of free and surface-bound active radical species (OH, O2-, 1O2, SO4-). Further, the presence and contribution of these radicals were validated by the electron paramagnetic resonance (EPR) and quenching study. In addition, XPS results demonstrated the dominant role of S(-II) with the increase of Fe(II) from 36.3% to 58.6% and decrease of Fe(III) from 52.1% to 39.8% in the PS/S-FeNi@BC system. In crux, the influence of initial pH, catalyst dosage, oxidant dosage, and inorganic ions (HCO3-, Cl-, NO3- and SO42-) on TCE removal was also investigated. The findings obtained from this study suggest that S-FeNi@BC is an appropriate catalyst to activate PS for TCE contaminated groundwater remediation.

Mechanism of surfactant in trichloroethene degradation in aqueous solution by sodium persulfate activated with chelated-Fe(II).

The mechanism of surfactants in surfactant-in situ chemical oxidation (S-ISCO) coupled process for trichloroethene (TCE) degradation was firstly reported. The performance of TCE solubilization and inhibition of TCE degradation in three nonionic surfactants (TW-80, Brij-35, TX-100) in PS/Fe(II)/citric acid (CA) system was compared and TW-80 was evaluated to be the optimal surfactant in S-ISCO coupled process due to the best TCE solubilizing ability and minimal inhibition for TCE degradation (only 31.8% TCE inhibition in the presence of 1 g L-1 TW-80 surfactant). The inhibition mechanism in TCE degradation was also demonstrated by comparing the strength of ROSs and PS utilization. In the presence of TW-80 (1 g L-1), over 97.5% TCE was removed at the PS/Fe(II)/CA/TCE molar ratio of 30/4/4/1, in which more than 86.7% TCE was dechlorinated. The result of scavenger experiments revealed that the dominant radicals were HO• and SO4-• in PS/Fe(II)/CA system in TW-80 containing aqueous solution, among which SO4-• performed a greater role in TCE removal. Moreover, over 85.3% TCE degradation in actual groundwater revealed the potential of PS/Fe(II)/CA process for actual groundwater remediation in containing TW-80 of TCE contaminant. This research provided a novel alternative technology for groundwater remediation with TCE contaminant when containing surfactants.

Trichloroethylene degradation by PVA-coated calcium peroxide nanoparticles in Fe(II)-based catalytic systems: enhanced performance by citric acid and nanoscale iron sulfide.

In this study, the enhanced trichloroethylene (TCE) degradation performance was investigated by polyvinyl alcohol coated calcium peroxide nanoparticles (PVA@nCP) as an oxidant in Fe(II)-based catalytic systems. The nanoscale iron sulfide (nFeS), having an average particle size of 115.4 nm, was synthesized in the laboratory and characterized by SEM, TEM, HR-TEM along with EDS elemental mapping, XRD, FTIR, ICP-OES, and XPS techniques. In only ferrous iron catalyzed system (PVA@nCP/Fe(II)), TCE degradation was recorded at 58.9% in 6 h. In comparison, this value was increased to 97.5% or 99.7% with the addition of citric acid (CA) or nFeS in PVA@nCP/Fe(II) system, respectively. A comparative study was performed with optimum usages of chemical reagents in both PVA@nCP/Fe(II)/CA and PVA@nCP/Fe(II)/nFeS systems. Further, the probe compounds tests and electron paramagnetic resonance (EPR) analysis confirmed the generation of reactive oxygen species. The scavenging experiments elucidated the dominant role of HO• to TCE degradation, particularly in PVA@nCP/Fe(II)/nFeS system. Both CA and nFeS strengthened PVA@nCP/Fe(II) system, but displayed completely different mechanisms in the enhancement of active radicals generation; hence, their different contribution to TCE degradation. The acidic environment was favorable for TCE degradation, and a high concentration of HCO3- inhibited TCE removal in both systems. Conclusively, compared to PVA@nCP/Fe(II)/nFeS system, PVA@nCP/Fe(II)/CA system resulted in encouraging TCE degradation outcomes in actual groundwater, showing great potential for prolonged benefits in the remediation of TCE polluted groundwater. Graphical abstract.

Preventing the preventable: role of transamine in total knee arthroplasty.

OBJECTIVE: To assess the efficacy and safety of perioperative intravenous Tranexamic Acid in reducing blood loss and transfusion requirements in patients undergoing Total Knee Arthroplasty. METHODS: The prospectivedouble-blind randomised control trial was conducted from March to July 2014 at the Combined Military Hospital, Rawalpindi, and comprised patients below 85 years of age undergoing unilateral or bilateral cemented Total Knee Arthroplasty. The patients were divided into control or Transaminegroups. Two doses of 15mg/kg of Transamine were given to the latter group. All patients were operated under spinal or combined spinal-epidural anaesthesiausing pneumatic tourniquet and similar cemented implant. Primary outcome was postoperative blood loss in drains. Secondary outcomes were the number of blood units transfused, change in haemoglobin level and adverse events. RESULTS: Of the 62 patients on the study, there were 34(55%) patents in the Transaminegroup with a mean age of 64±8.4 years, and28(45%)in the control group with a mean age of 60.8±10.3. The two groups were matched for demographic and blood indices.Mean blood loss via intra-articular drain in the control group was 619±243ml per knee, and 402±169ml per knee in the Transaminegroup. Blood transfusions were required by 14(50%)patients in the control groupand 6(17.6%)in the Transaminegroup. CONCLUSIONS: Perioperative intravenous transamine significantly reduced blood loss as well as blood transfusion requirements.