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Evaluation of novel Mg/Al/Ni-BaFe ternary layered hydroxides uptake of methyl orange dye from water
Nuhu Dalhat Mu’azu,Nabeel Jarrah,Mukarram Zubair,Mohammad Saood Manzar,Taye Saheed Kazeem,Mamdouh Al-Harthi 한국화학공학회 2019 Korean Journal of Chemical Engineering Vol.36 No.12
MgAlNi-BaFe ternary layered hydroxide (UMLDH) and its calcined (CMLDH) form were synthesized and tested as adsorbents for methyl orange dye (MO) uptake from water. The adsorptive performances of the new magnetic nanocomposites were modeled, evaluated and optimized via response surface methodology (RSM). The UMLDH and CMLDH maximum removal efficiency and adsorption capacities data were fitted into RSM models with insignificant lack of fit (p-values<0.05) and high R2=0.991-0.997. The UMLDH and CMLDH MO adsorption capacities increased with decrease in both pH and initial MO concentration and decreased when the temperature was increased. Under optimal operating conditions, pseudo-second-order described kinetics of MO sorption on the nanocomposites, while the Freundlich isotherm gave the best fits for both the two adsorbents. The MO uptake simultaneously incorporated both mono and multi-layer surface adsorption involving strong electrostatic attraction and chemical interactions between MO and the adsorbents surface functional groups. Respectively, the obtained maximum Langmuir theoretical sorption capacity of 715.44 and 708mg/g, indicated profoundly improved MO sorption capacities compared with many other magnetic-LDHs. These results demonstrate the potential of MgAlNi-BaFe as excellent adsorbents for effective remediation of dyes wastewater effluents.
Taye Saheed Kazeem,Mukarram Zubair,Muhammad Daud,Nuhu Dalhat Mu’azu,Mamdouh Ahmed Al-Harthi 한국화학공학회 2019 Korean Journal of Chemical Engineering Vol.36 No.7
Ternary layered double hydroxide, MgCoAl (MCA) and its graphene-based composite (G/MCA) were fabricated via a simple co-precipitation technique. The composites along with their calcined products (MCA-C) and (G/ MCA-C) were used as adsorbents for the removal of an anionic dye, methyl orange (MO), from aqueous phase. The characterization results (scanning electron microscopy and transmission electron microscopy) revealed homogeneous dispersion of graphene onto the MCA. Calcination of G/MCA resulted in a rough and heterogeneous surface with significant improvement in oxygen functionalities and surface area, which plays a crucial role in improved dye adsorption performance. Adsorptive equilibrium was established at 240 min for MCA and G/MCA and 180min for MCA-C and G/MCA-C respectively at pH 3 and optimum dosage of 10mg. The Redlich-Peterson and Langmuir isotherm models closely describe the adsorption process with maximum adsorption capacities of 357.14, 384.62, 400.12 and 434.78mg/g for MCA, G/MCA, MCA-C, and G/MCA-C respectively. Kinetics modeling indicates the adequacy and fitness of the pseudo-second-order model. A thermodynamics evaluation substantiates the exothermic nature of the adsorption processes. The MO-graphene ternary LDH composite adsorption process is controlled by several mechanisms including hydrogen bonding, surface adsorption, chemical and electrostatic interactions with surface reconstruction. The high removal efficiency of the MO coupled with high recovery and reusability of these nanomaterials showcases their potential for deployment in wastewater treatment.
Nasir, Muhammad,Johari, Megat Azmi Megat,Yusuf, Moruf Olalekan,Maslehuddin, Mohammed,Al-Harthi, Mamdouh A. Techno-Press 2020 Advances in concrete construction Vol.10 No.5
This study investigated the effect of alkaline activators - NaOH<sub>aq</sub> (NH) (NH: 0-16 M) and Na<sub>2</sub>SiO<sub>3aq</sub> (NS) (NS/NH: 0-3.5) in the synthesis of silico-manganese fume (SMF) and ground blast furnace slag (BFS) blended alkali-activated mortar (AASB). The use of individual activator was ineffective in producing AASB of sufficient fresh and hardened properties, compared to the synergy of both activators. This may be attributed to incomplete dissolution and condensation of oligomers required for gelation of the binder. An inverse relationship was noted among the fresh properties and the NH concentration or NS/NH ratio. This was influenced by the dissolution and condensation of silicate monomers under polymerization process. The maximum 28-day strength of ~45 MPa, setting time of 60 min and flow of 182 mm was obtained with the use of combined activators (10M-NH and NS/NH=2.5). The combined activators at NS/10M-NH=2.5 constituted SiO<sub>2</sub>/Na<sub>2</sub>O, H<sub>2</sub>O/Na<sub>2</sub>O and H<sub>2</sub>O/SiO<sub>2</sub> molar ratio of 1.61, 17.33 and 10.77, respectively. This facilitated the formation of C-S-H, C/K-A-S-H and C-Mn-S-H in the framework together with an increase in the crystallinity due to more silicate re-organization within the aluminosilicate chain. On comparison of the high concentrated with mild alkali synthesized product, it revealed that the concentration of OH<sup>-</sup> and Si monomers together with alkali metals influenced the dissolution of precursors and embedment of the constituent elements in the polymeric matrix. These factors eventually contributed to the microstructural densification of the mortar prepared with NS/10M-NH=2.5 thereby enhancing the compressive strength.
S.H. Abdul Kaleel,Bijal Kottukkal Bahuleyan,S.K. De,Masihullah Jabarulla Khan,Rachid Sougrat,Mamdouh A. Al-Harthi 한국공업화학회 2012 Journal of Industrial and Engineering Chemistry Vol.18 No.5
Ethylene polymerization was carried out using highly active metallocene catalysts (Cp2ZrCl2 and Cp2TiCl2) in combination with methylalumoxane. Titanium(IV) oxide containing 1% Mn as dopant was used as nanofillers. The influence of filler concentration, reaction temperature and pressure on the catalytic activity and polymer properties was investigated. There was a fourfold increase in the activity of zirconocene catalyst by addition of doped-titania. The morphology indicates that the doped-titania nanoparticles have a nucleus effect on the polymerization and caused a homogeneous PE shell around them. The optimum condition for polymerization was found to be 30 8C.