Industrial dyes are major pollutants in wastewater and river water with an initial visible concentration of 1 mg/L. Recent studies have shown the possibility of using polyphenol oxidase in catalytic biological treatment due to its ability to oxidize a large number of dyes and pollutants in wastewater and the flexibility to work in wide ranges of temperature, pH and salinity. It is easy availability as well as the low economic cost resulting from its use in biological treatments, this enzyme polyphenol oxidase was used. The findings in this study showed that the extraction of polyphenol oxidase (PPO) from potato peel was homogenized with potassium phosphate buffer (0.1 M, pH 7) at a ratio of 1:10 (weight: volume) for two min. The result of enzyme purification by ion exchange chromatography showed that the yield of this step was 64 % and the specific activity was 6541.67 U/mg. The polyphenol oxidase was immobilized covalently on the functionalized pumice stone (25.2 U/gm) compared with other methods. The characterization results demonstrated that the optimum pH for immobilized and free enzyme activity was 6.0 while the pH range of free and immobilized polyphenol oxidase stability was from 4.5 -7.0 and 3.5 - 8.5 respectively. The better temperature for free and immobilized polyphenol oxidase activity was 25 ºC, whereas the free and immobilized polyphenol oxidase was stable at 15-35 and 15-50 °C respectively. The outcomes showed that the decolorization efficiency of blue textile dye employing immobilized polyphenol oxidase reached 99.85 % after 24 hr. for 100 mg/L concentration while for other concentrations 200, 300, 400, 500 and 1000 mg/L the decolorization efficiencies were 85.96, 76.15, 72.54, 66.94 and 63.5 % respectively. Based on the results, the immobilized polyphenol oxidase on pumice stone is highly efficient in removing textile dyes at large concentrations and in different environmental conditions.
The main aim of this paper is studied the punching shear and behavior of reinforced concrete slabs exposed to fires, the possibility of punching shear failure occurred as a result of the fires and their inability to withstand the loads. Simulation by finite element analysis is made to predict the type of failure, distribution temperature through the thickness of the slabs, deformation and punching strength. Nonlinear finite element transient thermal-structural analysis at fire conditions are analyzed by ANSYS package. The validity of the modeling is performed for the mechanical and thermal properties of materials from earlier works from literature to decrea
... Show MoreNatural frequency under initial stresses for simply supported cross-ply composite laminated plates (E glass- fiber) are obtained using Refind theory (RPT). This theory accounts for parabolic distribution of the transverse shear strain through the plate thickness and satisfies the zero traction boundary conditions on the surfaces of the plate without using shear correction factors. The governing equations for Eigen value problem under initial stress are derived using Hamilton’s principle and solved using Navier solution for simply supported cross-ply symmetric and antisymmetric laminated plates. The effect of many design factors such as modulus ratio, thickness ratio and number of laminates on the Natural frequency and buckling stresses
... Show MoreTwo field experimسents were conducted in one of the fields of the Agriculture Division of Ain Al-Tamr /Holy Karbala Governorate at two sites of different textures during the agricultural season 2020/2021. The first site has sandy loam texture (gypsum soils). The second site has loamy sand texture (calcareous soils). The factors of the study included: The first factor included two types of soil, gypsum and calcareous soil. The second factor is the tillage systems (no-tillage, spring spike harrows, disc harrows, and mold board plow). The experiment was designed in the two study sites according to the RCBD with three replications. The Valley type center pivot irrigation system was evaluated before planting, three speeds, 30, 50 and 100% of th
... Show MoreMassive multiple-input multiple-output (massive-MIMO) is considered as the key technology to meet the huge demands of data rates in the future wireless communications networks. However, for massive-MIMO systems to realize their maximum potential gain, sufficiently accurate downlink (DL) channel state information (CSI) with low overhead to meet the short coherence time (CT) is required. Therefore, this article aims to overcome the technical challenge of DL CSI estimation in a frequency-division-duplex (FDD) massive-MIMO with short CT considering five different physical correlation models. To this end, the statistical structure of the massive-MIMO channel, which is captured by the physical correlation is exploited to find sufficiently
... Show MoreWastewater discharge containing organic dyes may pose a hazard to the environment, which necessitates that dye removal must occur prior to wastewater release into water bodies. Herein, copper oxide nanoparticles (CuO NPs) were prepared by a green precipitation method to enable decolorization of a cationic dye (methyl violet; MV) from aqueous media. Complementary tools were employed to characterize the CuO NPs adsorbent: spectroscopy (FTIR and UV-VIS), microscopy (FESEM and TEM), XRD, BET surface area analysis, and point of zero charge (pHPZC) via potentiometry. The FTIR bands at 722, 663, 569, and 465 cm−1 correspond to the vibrational modes of CuO NPs, along with the optical absorbance band at 275 nm that supports the formation of Cu
... Show MoreWastewater discharge containing organic dyes may pose a hazard to the environment, which necessitates that dye removal must occur prior to wastewater release into water bodies. Herein, copper oxide nanoparticles (CuO NPs) were prepared by a green precipitation method to enable decolorization of a cationic dye (methyl violet; MV) from aqueous media. Complementary tools were employed to characterize the CuO NPs adsorbent: spectroscopy (FTIR and UV-VIS), microscopy (FESEM and TEM), XRD, BET surface area analysis, and point of zero charge (pHPZC) via potentiometry. The FTIR bands at 722, 663, 569, and 465 cm1 correspond to the vibrational modes of CuO NPs, along with the optical absorbance band at 275 nm that supports the formation of CuO NPs.
... Show MoreBackground:sThe aims of this study were to evaluate and compare the ability of three different techniques to obdurate simulated lateral canals, evaluate the effect of the main canal curvature on obturation of lateral canals and compare the gutta-percha penetration between coronal and apical lateral canals. Materials and methods: Resin blocks with 30 straight and 30 curved were used in this study. Each canal has two parallel lateral canals. The main canal has 0.3 mm apical diameter and 0.04 taper. The canals were divided into six groups according to canal curvature and obturation techniques used (n=10): Groups C1 and C2: straight and curved canals obturated with continuous wave technique using E&Q masterTM system. Groups O1 and O2: straight
... Show MoreVarious industrial applications include the dyeing of textiles, paper, leather, and food products, as well as the cosmetics industry. Physic-chemical methods are required to breakdown dyes because they are known to be harmful and persistent in the environment. Many companies' treated effluents contain small amounts of dyes. When it comes to removing dye from wastewater, adsorption has verified to be aneconomical alternative to more traditional treatment procedures. It's important to degrade color impurities in industrial effluents since they constitute a serious health and environmental concern. One way that's been tried is using clay minerals as an adsorbent. Using adsorption for removing
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