Textile wastewater accommodates many toxic organic contaminants that could potentially threaten the ecosystem if left untreated. Methylene blue is a toxic, non-biodegradable, cationic dye that is reportedly observed in significant amounts in the textile effluent stream as it is widely used to dye silk and cotton fabrics. Congo red is a carcinogenic anionic dye commonly used in the textile industry. This study reports an investigation of methylene blue and Congo red removal using a chitosan-graphene oxide dip-coated electrospun nanofiber membrane. The fabricated nanocomposite was characterized using Scanning Electron Microscopy (SEM), FT-IR Spectroscopy, Raman Spectroscopy, UV-vis Spectroscopy, Drop Shape Analyzer, and X-ray Diffraction. The isotherm modeling confirmed a maximum adsorptive capacity of 201 mg/g for methylene blue and 152 mg/g for Congo red, which were well fitted with a Langmuir isotherm model indicating homogenous monolayer adsorption.
Untreated textile effluent may contain toxic organic pollutants that can have negative impacts on the ecosystem. Among the harmful chemicals present in dyeing wastewater, there are two frequently used organic dyes: methylene blue (cationic) and congo red (anionic). The current study presents investigations on a novel two-tier nanocomposite membrane, i.e., a top layer formed of electrosprayed chitosan–graphene oxide and a bottom layer consisting of an ethylene diamine functionalized polyacrylonitrile electrospun nanofiber for the simultaneous removal of the congo red and methylene blue dyes. The fabricated nanocomposite was characterized using FT-IR spectroscopy, scanning electron microscopy, UV-visible spectroscopy, and Drop Shape Analyzer. Isotherm modeling was used to determine the efficiency of dye adsorption for the electrosprayed nanocomposite membrane and the confirmed maximum adsorptive capacities of 182.5 mg/g for congo red and 219.3 mg/g for methylene blue, which fits with the Langmuir isotherm model, suggesting uniform single-layer adsorption. It was also discovered that the adsorbent preferred an acidic pH level for the removal of congo red and a basic pH level for the removal of methylene blue. The gained results can be a first step for the development of new wastewater cleaning techniques.
The aim of the publication is to report the accuracy, repeatability and the linearity of three commercially available interface pressure measurement systems employed in the treatment of venous disease. The advances in the treatment and management of chronic venous disease by compression therapy have led to considerable research interest in interface pressure measurement systems capable of measuring low-pressure ranges (10–60 mmHg). The application of a graduated pressure profile is key for the treatment of chronic venous disease which is achieved by using compression bandages or stockings; the required pressure profiles are defined in standards (BSI, RAL-GZ, or AFNOR) for different conditions. However, achieving the recommended pressure levels and its accuracy is still deemed to be a challenge. Thus, it is vital to choose a suitable pressure measurement system with high accuracy of interface pressure. The authors investigated the sensing performance of three commercially available different pressure sensors: two pneumatic based (AMI and PicoPress®) and one piezoresistive (FlexiForce®) pressure sensors, with extensive experimental work on their performance in terms of linearity, repeatability, and accuracy. Both pneumatic based pressure measurement systems have shown higher accuracy in comparison to the flexible piezoresistive pressure sensors.
This paper presents the fundamental research of design, development, and evaluation of an active compression system consisting of silicone based inflatable mini-bladders, which could be used in applying radial pressure for the treatment of venous disease. The use of mini-bladders will nullify the effect of radius of curvature and provide a higher resolution to the pressure distribution. They are designed with two elastomeric layers and inflation is limited only to one side. The mini-bladders apply a radial force onto the treated surface when inflated, and the pressure inside mini-bladders could be measured using the concept of back pressure, which provides the flexibility to inflate mini-bladders to a predefined pressure. The 3-D deformation profile of the mini-bladders was analysed using finite element method (FEM) and FEM simulations were validated with experimental data, which showed good agreement within pressure region required for the treatment of venous disease. Finally, the pressure transmission characteristics of mini-bladders were evaluated on a biofidellic lower leg surrogate and the results have shown that the mini-bladders could apply a uniform pressure irrespective of the location on the leg with a 60%–70% of inlet pressure successfully transmitted onto the leg surface, while 40%–50% was available after the fat layers.
This research aimed to investigate the use of microencapsulated sodium fusidate to impart antibacterial properties into conventional cotton gauze used to treat traumatic wounds. The microcapsules were prepared with sodium fusidate dissolved in ethanol as the active substance (core) and calcium alginate as the wall material (shell) using an electrospraying method. The microcapsules were then loaded into a 1% solution of chitosan, and conventional sterile cotton gauze fabric was impregnated in this suspension and dried at room temperature. The microcapsules obtained were examined with Fourier transform infrared spectroscopy to confirm the constituents, and by scanning electron microscopy to examine the size and distribution of the microcapsules. The results showed that microcapsules with sodium fusidate as the core material were produced in a size range of 50–200µm. The antibacterial properties of these gauze samples were tested for resistance to both Gram-positive and Gram-negative bacteria. The samples showed antibacterial properties against Gram-positive bacteria (Staphylococcus aureus) only, with an average inhibition zone of 31.67±2.89mm in diameter. The antibacterial effect of the treated gauze samples was tested after washing to investigate the strength of the binding agent, to find out whether the samples maintained antibacterial properties after two hand-rubbed washes. Its absorption capacity, rate of absorbency and air permeability values were 555±4.51%, 1.25±0.04 seconds and 408±2.65cm3/cm2/seconds, respectively. The research findings have established the possibility of imparting antibacterial properties into sterile cotton gauze using microencapsulation of sodium fusidate.