Dye removal with magnetic graphene nanocomposite through micro reactors

Contaminated waste water treatment and clean water scarcity are current challenges acutely in the Asian and African continents. This paper bestows applied co-precipitation technique for the fabrication of Magnetic Graphene Nano-Composites (MGNCs) for water treatment purposes. In this paper, characterization procedures were applied to delineate numerous physical and chemical properties of the synthetic MGNCs and mixing performance for several designed microreactors were determined using the Dushman’s method in comparison to two parallel reactions. The mixing timings for different microreactors at flow rates between 100 and 300 ml/hr were determined. MCNCs were utilised to remove an Acid Blue 25 dye as a pollutant from water at diverse types of microreactors. The comparison between the various microreactors’ performance and mixing time was accomplished. The maximum instantaneous removal capacity of graphene-based nanomaterial was recorded using K.M micro mixer about 68% for 10 ppm dye concentration

Characterization of atypical polyaniline nano-structures prepared via advanced techniques

Conductive polymers had been the topic of a vast number of investigations during the last decades, so, the synthesis of conducting polymers and study of their physical properties has been of prime importance. One of these conductive polymers is polyaniline. The current work is to prepare polyaniline (PANI) nanostructured material via four different preparation techniques which were sol-gel, rapid mixing, sonochemical and supercritical carbon dioxide (SC-CO2) assisted polymerization. The morphology of the prepared PANI samples was determined using Transmission electron microscopy (TEM) and Scanning Electron Microscope (SEM). The molecular structure of prepared PANI samples was characterized by Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). The electrical conductivity of the synthesized samples was assessed by using the four-probe method at room temperature. The surface area of the prepared samples was determined using Brunauer Emmett Teller (BET). The characterization results of the prepared PANI confirm that the morphology, chemical composition, crystallinity, conductivity and surface area were altered significantly as a consequence of its synthesis via atypical techniques. Keywords: Polyaniline nano-structures, Nanoparticles, Nanorods, Nanofibers, Sonochemical, Sol gel, Rapid mixing polymerization, Supercritical carbon dioxide assisted polymerization, Polyaniline characterizatio

Hybridized high concentration photovoltaic unit with enhanced performance air gap membrane distillation unit via depositing reduced graphene oxide layer upon the condensation plate using electrophoretic deposition technique

Amongst the membrane distillation techniques, the air gap configurations showed an outstanding thermal efficiency, while a decline in productivity was recorded due to the additional thermal and mass resistances. The current study proposes minimizing the additional thermal and mass resistances by altering the condensation process to dropwise condensation. Depositing a layer of reduced graphene oxide using the electrophoretic deposition technique on the copper condensation plate was investigated to obtain a hydrophobic nature and attain dropwise condensation. Moreover, different operating conditions were examined for the optimum conditions, which were 45 V, 30 s, 1 cm, and 0.5 mg/ml, for the applied voltage, deposition time, distance between electrodes, and concentration, respectively. This modified condensation plate was investigated experimentally on the lab-scale test rig and showed an improvement in the productivity of 12.5% and 28.5% at the minimum and maximum feed temperatures, respectively. On the other hand, solar energy was utilized to eliminate the heating source required for the membrane distillation unit. A high concentration photovoltaic (HCPV) unit was introduced numerically in the current work with 36 multijunction cells. Furthermore, a microchannel heat sink was successfully designed to keep the cells from thermal degradation. The numerical results showed that the HCPV system could supply hot water up to 55 °C and produce electric power up to 230 W

Photocatalytic decolorization of methylene blue using TiO2/UV system enhanced by air sparging

In this work, the photocatalytic degradation of wastewater containing an organic dye (Methylene Blue) was investigated in a slurry-type reactor enhanced by air sparging. Commercial TiO2 was used as the photocatalyst which was activated using ultraviolet irradiation. The effects of initial dye concentration, photocatalyst loading, solution pH and air’s superficial velocity on the degradation efficiency were evaluated. The degradation efficiency of the dye increased with increasing the pH of the solution and decreasing the initial dye concentration. Moreover, increasing the catalyst loading up to 1 g/l showed an improvement in the degradation efficiency. However, the efficiency deteriorated with a further increase in the catalyst loading. Introducing air into the reaction medium in the form of micro-bubbles significantly improved the degradation efficiency by providing oxygen molecules required for the oxidation reaction. Furthermore, these air bubbles created turbulence in the reaction medium, which resulted in the enhancement of the mass transfer rate of dye molecules from the solution bulk to the catalyst surface with a subsequent increase in the degradation efficiency. A complete decolorization of 10 ppm dye solution was achieved in the neutral solution (pH = 7) with a catalyst loading of 1 g/l and an air superficial velocity around 2 cm/s. The effect of the air superficial velocity on the degradation reaction kinetics was investigated and the reaction was found to follow the pseudo second order rate law. Keywords: Photocatalysis, TiO2, Air sparging, Methylene blue, Ultraviole

Improving the rate of Cu+2 recovery from industrial wastewater using a vertical array of reciprocating perforated zinc discs

AbstractThis work investigates the possibility of improving the rate of Cu+2 recovery and/or removal from industrial wastewater by cementation technique using an array of pulsating horizontal perforated zinc discs. The results show that the rate of cementation was found to increase by increasing frequency and amplitude of oscillation (vibrating velocity); disc diameter; copper ion concentration and solution temperature while decreasing by increasing the disc separation. Under certain conditions using pulsating array of perforated zinc discs was found to increase the rate of mass transfer by a factor of 17 times the stagnant discs. The activation energy of the reaction was found to be 8.948kcal/mol which indicates that under the present conditions cementation takes place under mixed control, i.e. the reaction is partially diffusion control. As such no overall mass transfer correlation could be obtained

Influence of encapsulation materials on the thermal performance of concentrator photovoltaic cells

The Ethylene-Vinyl Acetate (EVA) layer in the polycrystalline solar cells suffers from lower thermal conductivity. Therefore, this work presents a numerical study for a possible way to enhance the thermal conductivity of the lower encapsulant layer. A comprehensive three-dimensional (3D) model is proposed to evaluate the conventional and modified solar cell performance. The ongoing research study can be achieved by doping three different nanoparticles of Boron Nitride (BN), Zinc Oxide (ZnO), and Silicon Carbide (SiC) with loading ratios of 10%, 20%, and 30% to the lower EVA matrix layer. The present numerical work was conducted under 20 suns concentration ratio and variable coolant flowrates. The findings reveal that a significant reduction in local and average solar cell temperature is achieved for all studied cases, especially at a 30% loading ratio of n-SiC. Moreover, it is observed that the net gained electrical power was enhanced by 7.16% at the same SiC loading ratio. However, ZnO and BN fillers reported a slight percentage increase of 6.77% and 5.95%, respectively. The thermal and electrical efficiency has been improved with the new EVA-nanoparticle layer due to lower average cell temperature. Therefore, at 1200 ml/h, the thermal and electrical efficiency achieved the highest value in SiC than BN and ZnO; the maximum value was reported 70.02% for thermal efficiency and 16.94% for electrical one