Browsing by Author "Labena, Ahmed"

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Antibacterial and Anti-Fungal Biological Activities for Acrylonitrile, Acrylamide and 2-Acrylamido-2-Methylpropane Sulphonic Acid Crosslinked Terpolymers
(MDPI, 10/30/2020) Farag, Reem K.; Atta, Ayman M.; Labena, Ahmed; AlHawari, Salma H.; Safwat, Gehan; Diab, Ayman A
There is a pressing demand to synthesize polymers that have antibacterial and antifungal properties. The aim of this study was to synthesize a crosslinked hydrophilic terpolymer with acrylamide, acrylonitrile, acrylic acid, acrylamido-2-methylpropane sulphonic acid and ethylene glycol dimethacrylate as a crosslinker. The chemical structure and thermal stability of the prepared cross-linked terpolymers were confirmed by spectroscopic and thermal analyses. Moreover, the swelling experiments were performed to investigate their swelling capacity. Furthermore, the efficiency of the synthesized cross-linked polymer gels was assessed as an antimicrobial agent against Gram-positive, Gram-negative bacteria and fungal strains. The synthesized polymers showed broad inhibition effect, with more antibacterial activity by the AM4 polymer sample containing high percentage of acrylonitrile monomer in the prepared terpolymers (4 mol ratio of acrylic acid: 1 mol ratio of acrylamide: 16 mole ratio of acrylonitrile against Gram negative bacterial strain), while sample M3 terpolymer (1 mol ratio of acrylamide: 1 mole ratio acrylonitrile: 3 mole ratio of acrylamido-2-methylpropane sulphonic acid) showed a promising anti-fungal activity.
Chapter 13 - Biological souring and mitigation strategies in oil reservoirs Author links open overlay panel
(Elsevier, 2023-03) Labena, Ahmed; Husien, Shimaa; Elhady, Reem
Biological souring is one of the major problems facing the oil and gas sector as a result of biogenic sulfide generation in the reservoirs. Sulfidogenic microorganism and particularly sulfate-reducing bacteria are the main generator of the biogenic sulfide. In consequence, souring has a plethora of economic and environmental problems. It has a negative impact on the petroleum industry, where the generated sulfide lowers air quality and causes adverse health problems due to its toxicity and carcinogenicity. Furthermore, it affects the whole industry by reducing the product quality and enhancing metal corrosion. Therefore, different physical, chemical, and biological mitigation strategies have been developed for biological souring inhibition. In this chapter, the biological souring definition, mechanism, factors affecting the souring process, and the mitigation strategies and the methods used to assay the souring will be discussed. © 2023 Elsevier Inc. All rights reserved.
Grafting of Acrylic Membrane Prepared from Fibers Waste for Dyes Removal: Methylene Blue and Congo Red
(MDPI, 2021-04) Labena, Ahmed; Abdelhamid, Ahmed E; Husien, Shimaa; Youssef, Tarek; Azab, Ehab; Gobouri, Adil A; Safwat, Gehan
Dyes are a type of pollutant that have been discharged into water streams by various industries and had harmful effects on the environment and human health. Therefore, present work was directed to recycle acrylic fibers waste to be used as an adsorbent to exclude dyes such as methylene blue (MB) and Congo red (CR) from dyes-polluted wastewater. Acrylic fibers waste was converted into membrane followed by chemical grafting with p-phenylenediamine monomer to form functional modified membranes. Afterwards, some characterization analyses; Fourier transform- infrared, scanning electron microscope, swelling behavior, and porosity properties were performed for the acrylic fiber grafted membrane (AFGM). For obtaining the best conditions that permit the highest adsorption capacity of the AFGM, some preliminary experiments followed by general full factorial design experiments were displayed. Langmuir, Freundlich isotherms and kinetic studies evaluations were applied. Results revealed that, the adsorption capacities of the AFGM were 61% for Methylene blue and 86% for Congo red that stated the high affinity of the AFGM to the anionic dyes. The reusability of the AFGM membranes in different cycles for 3Rs processes “Removal, Recovery, and Re-use” indicated the efficiency of the AFGM to be used in wastewater treatment.