Browsing by Author "Olasehinde, Emmanuel Folorunso"

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    Adsorption of Methylene Blue onto Acid Modified Raphia Taedigera Seed Activated Carbon
    (Advanced Journal of Chemistry, 2020-04-19) Olasehinde, Emmanuel Folorunso; Abegunde, Segun Michael
    In this work, the possibility of using Raphia taedigera seed as a low-cost adsorbent to remove methylene blue (MB) dye from aqueous solutions was investigated. The activated carbon was prepared by carbonization and chemical treatment of the seed with sulphuric acid to produce acidmodified Raphia taedigera seed activated carbon (RTAC). The surface morphology and bond arrangement of the RTAC were evaluated using the scanning electron microscopy (SEM) and Fourier transforms infrared spectroscopy (FTIR), respectively. The SEM analysis results revealed that the prepared adsorbent had aggregated and rough surface structure with pores and FTIR revealed the presence of several functional groups such as –C=O, –OH, –C=C–, –N=O and –C=N–. The adsorption efficiency of the RTAC for the removal of the MB dye was assessed under different experimental conditions including, contact time, temperature, pH, adsorbent dosage, and dye initial concentration. The results gave the performances of 99.611% after 15 min, 99.635% at 303 K, 99.894% at pH 9, 99.256% with 0.9 g, and 99.743% for 40 mg/L for evaluating the effect of the contact time, temperature, pH, adsorbent dosage, and dye solutions initial concentration, respectively. The adsorption of the MB dye onto the RTAC conformed to Langmuir isotherm and fit best to pseudo-second-order kinetic models. Thermodynamic studies indicated a spontaneous, endothermic, feasible, and physisorption nature of the RTAC and MB dye interactions. The present study found the acid-modified Raphia taedigera seed activated carbon to be a promising low-cost adsorbent for the removal of MB dye from aqueous solution.
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    Effect of Drying Method on Phytochemical Compositions and Inhibition Efficiency of Alchornea Laxiflora and Mucuna Flagellepes Leaves Extracts in Corrosion Prevention
    (Science Publishing Group, 2019-08-13) Adebayo, Oluwafemi Lawrence; Olasehinde, Emmanuel Folorunso; Lajide, Labunmi; Oloruntoba, Daniel
    : This study was aimed at investigating the influence of different drying methods on the photochemical composition and inhibition efficiency of Alchornea laxiflora and Muccuna flagellepes leaves extracts in corrosion prevention. The fresh samples of the leaves were collected, sorted, dried using two different drying methods viz; air drying and sun drying methods. The dried plant samples were ground separately sieved using 0.25µm and then extracted with ethanol using maceration method and then concentrated the filtrate in a water bath at 600C to obtained air dried Alchornea laxiflora leaves (AALL), air dried Mucunna flagellepes leaves (AMFL), sun dried Alchornea laxiflora leaves (SALL) and sun dried Muccuna flagellepes leaves (SMFL) extracts. The extract of each sample was analyzed separately for their phytochemical constituents using appropriate methods. From the results, there was variation in the composition in respect of the phytochemical of interest but it could be concluded that the drying methods have little effect on the phytochemical composition of the studied plant but air drying methods could be adopted as it gave highest content (AALL: Sapolin 45.55 mg/g, tannin 10.58mg/g, flavnoid 7.49mg/g, Terpenoid 7.06 mg/g, Alkaloid 35.61mg/g, phytobalatin 2.43mg/g and cardiac glycoside 4.72mg/g; AMFL: Sapolin 28.55mg/g, Tannin 5.39 mg/g, Flavnoid 6.42 mg/g, Terpenoid 5.94 mg/g, Alkaloid 4.53mg/g, Cardiac glycoside 6.33 mg/g; SALL: Saponin 20.00mg/g, Tannin 4.04 mg/g, Flavnoid 1.91 mg/g, Terpenoid 6.03 mg/g, Alkaloid 12.56 mg/g, Phytobalatin 2.57 mg/g, Cardiac glycoside 3.86mg/g: SMFL: Sapolin 15.00 mg/g, Tannin 3.82 mg/g, Terpenoid 4.82 mg/g, Alkaloid 6.25 mg/g and cardiac glycoside 4.93 mg/g. The corrosion inhibition efficiency of the samples extract on mild steel in 1.0M HCl solution was investigated using weight loss measurements. The weight loss measurement indicates an increase in corrosion inhibition efficiencies that reach 90.02% and 84.92% in AALL and AMFL extract and 79.74% and 72.12 in the SALL and SMFL extract respectively. The weight loss data established that the inhibition efficiency on mild steel increases with increase in the concentration of the plant extracts but decreased with increase in temperature. Thermodynamic parameters such as enthalpy change, entropy change, and activation energy were evaluated. Kinetics of the reaction in the presence of the extracts revealed that it follows a first order reaction and the half-life increased as the concentration of the extract increases.
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    Preparation and characterisation of biochars from elephant grass and their utilisation for aqueous nitrate removal: Effect of pyrolysis temperature
    (Elsevier, 2020-09-21) Adesemuyi, Mibinuola Florence; Adebayo, Matthew Ayorinde; Akinola, Adebisi Olayinka; Olasehinde, Emmanuel Folorunso; Adewole, Kehinde Abiodun
    Biochar is a solid material obtainable from biomass pyrolysis and useful for pollution alleviation and soil amendment. In this study, Biochars A and B were produced from elephant grass at pyrolytic temperatures of 400 ◦C and 600 ◦C, respectively, for removal of nitrate ion from aqueous solution. The physicochemical characteristics of the biochars were evaluated. The biochars were also characterised using Fourier Transform Infrared (FTIR) spectroscopy, Scanning Electron Microscopy (SEM), Energy Dispersive X-ray (EDX), and X-ray Diffraction (XRD). Operational variables such as pH, contact time, and concentration of nitrate ion were varied and optimum variables were obtained. Kinetic and equilibrium data were subjected to kinetic (pseudo-first order, pseudosecond order, Avrami fractional order, Elovich and intraparticle diffusion) and equilibrium (Langmuir, Freundlich, Liu, and Redlich-Peterson) models, respectively, to elucidate the interaction between the nitrate ion and biochars. The yields of Biochars A and B were 41.40 % and 32.25 %, respectively. The two biochars possessed good cation exchange capacity, water-holding capacity, carbon stability, and porosity. Avrami fractional kinetic order was the best model that explained the kinetic data. Maximum adsorption capacities obtained from Liu model (the best equilibrium model) are 140.7 and 237.5 mg g− 1 for Biochars A and B, respectively. Adsorption process was spontaneous and exothermic. There was a decrease in the disorderliness in the nitratebiochar system. Biochar B performed better than Biochar A for removal of nitrate ion from water. In summary, the biochars produced from elephant grass excellently removed nitrate ion from solution and could be utilised for water decontamination.
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    Preparation and characterization of a new adsorbent from raphia taedigera seed
    (Research Group Publishers, 2019-09-16) Olasehinde, Emmanuel Folorunso; Abegunde, Segun Michael
    There has been widespread research and engagement in recent years on the use of plant material in preparing porous carbon for wastewater treatment. In this study, new biochars (BCs) impregnated with 0.1 M sulphuric acid (RTA) and 0.1 M sodium hydroxide (RTB) were prepared. The BCs and raw seed [RTR] were characterized using scanning electron microscopy (SEM), Four ier - transform infrared (FTIR) spectrophotometer, and thermogravimetric/Differential thermal analyser. [TGA/DTA) to determine their morphology, spectral bands and thermal behaviour respectively. RTR showed a scattered aggregated surface microstructure, while both RTA and RTB gave aggregated rough surfaces with high number of pores. The FTIR analysis showed significant changes in term of band shift, bands disappearances, and new band formations due to pyrolysis and activation of the BCs. The results of the TGA/DTA revealed that RTA and RTB have better thermal stability than RTR, with the maximum degradation temperature of RTR, RTA, and RTB occurred at 3800C, 4250C and 4100C respectively. Adsorption efficiencies ranged from 81.671 to 99.743% for performance evaluation on the BCs using different adsorbent dosages and the initial concentrations of methylene blue solutions. These preliminary investigations suggest that biochars prepared from Raphia taedigera seed can be used for methylene blue removal from wastewater
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    Studies on Thermal Stability, Shelf Life and Electrochemical Measurement of Methanol Extract of Air Dried Alchornea Laxiflora Leaves in Corrosion Prevention
    (Science Publishing Group, 2019-11-22) Adebayo, Oluwafemi Lawrence; Olasehinde, Emmanuel Folorunso; Lajide, Labunmi; Oloruntoba, Daniel; Ajayi, Morenike Grace
    The aim of this study was to determine the thermal stability and shelf life of the extract together with the influence of extract concentration, temperature and pH variation of the acidic medium on the inhibition efficiency using 1.0 M Sodium hydroxide. The dried plant samples were ground, sieved using 0.25µm and then extracted with methanol using maceration method. The phytochemical constituents were analyzed using appropriate methods. The phytochemicals detected were: Alkaloid, saponin, flavnoid, tannin, terpenoid, steroid and cardiac glycoside. Weight loss experiment was performed to ascertain the stability and shelf life of the extract at different storage temperature and time respectively while polarization experiment was used to study the behaviour of the extract on mild steel corrosion at varying concentration of the extract, pH and temperature of the acidic media. It was found that the stability of the extract inhibition efficiency was affected by the mode of storage and the inhibition efficiency decreases with increase in storage temperature of the extract. The life span of the extract was found to be 60 days from its production stage, after this, there was reduction in the inhibition efficiency of the extract. Moreso, the corrosion rate of the mild steel in 1.0 M HCl, monitored by electrochemical measurement revealed that the corrosion rate decreases with increase in the pH, decrease in temperature and increase in concentration of the extract in the acidic solution.