Browsing by Author "Ajayi, O.A"

Now showing 1 - 4 of 4
  • Item
    Adsorption of cyanide from aqueous solution using calcinated eggshell: equilibrium and optimisation studies
    (Elsevier, 2016) Eletta, O.A; Ajayi, O.A; Ogunleye, O.O; Akpan, I.C
    Eggshells were calcined and used to adsorb cyanide from its aqueous solution. X-ray diffraction (XRD), X-ray fluorescence (XRF), Fourier Transform Infra-red (FTIR) and Scanning Electron Microscope (SEM) were used to characterize both raw and calcined eggshell (CE) while UV spectrophotometer was used to monitor the cyanide concentration. The XRD and FTIR showed the conversion of CaCO3 to CaO. Batch adsorption experiments were carried out using 10 ml each of 0.01 mol/L to 0.05 mol/L cyanide solutions at different contact times, and adsorbent dosages. To establish optimum adsorption conditions, Central Composite Design (CCD) in Response Surface Methodology (RSM) was employed using the time, concentration and adsorbent dosages as variables at a fixed pH of 7. Adsorption efficiency of 84.53% was obtained with 0.01 mol/L, 8.98 g of calcined eggshell at 26.58 min contact time using RSM. Pseudo second order kinetic model best fitted the experiment. The coefficients of determination of Langmuir and Freundlich isotherms were 0.988 and 0.650 respectively, with Langmuir isotherm giving a better fit for the adsorption. The maximum monolayer adsorption capacity from Langmuir isotherm was 3.27 mg/g at pH 7 and a temperature of 30 °C
  • Item
    Identification and Characterisation of Major Hydrocarbons in Thermally Degraded Low Density Polyethylene Films
    (University of Port Harcourt, 2017-10) Eletta, O.A; Ajayi, O.A; Ogunleye, O.O; Tijani, I.A; Adeniyi, A.G; Agbana, A.S
    The vast application of Low Density Polyethylene (LDPE) in packaging, greenhouses, homes etc has led to its huge accumulation as a municipal solid waste with monumental health, economic and environmental consequences. Since these are non-biodegradable and their photodegradation occurs only over a very long period, their economic conversion to energy products through pyrolysis is the thrust of this study. LDPE sample collected from the University of Ilorin Community was thermally degraded in a pyrolyser at temperatures ranging from 203 – 400 oC. The products of pyrolysis were in three (3) states of matter and both the liquid and solid products were analysed using FTIR to determine the functional groups and GC- MS for the hydrocarbons present in the products. For the GC-MS analysis, the peaks that had 90% above quality when compared with the compounds in the installed NIST11 library were reported. There were alkanes, alkenes, halogenated alkanes, and very few aromatics in the liquid product and, the hydrocarbons were observed to range between C10 - C27. The FTIR and GC-MS results show the potential of the oil obtained as renewable source of energy while that for residue shows its inherent energy content. The liquid product was refluxed over molecular sieve catalyst (US 2882244A) and the calorific value was found to increase from 13,974 kJ/kg to 15,815.52 kJ/kg and this is found to be comparable to the range for lignite and dry wood.
  • Item
    Optimization of Dye Removal from Textile Wastewater using Activated Carbon from Sawdust
    (Faculty of Engineering and Technology, University of Ilorin, Kwara State, 2018-03) Eletta, O.A.A; Mustapha, S.I; Ajayi, O.A; Ahmed, A.T
    This study is aimed at developing an adsorbent from sawdust for optimum removal of dye from textile wastewater. The adsorbent was developed, characterised and, the adsorptive capability for the removal of dye was determined by optimizing the process parameters (adsorbent dosage, contact time and agitation speed) using Response Surface Methodology. The physical and chemical characterization of the effluent was carried out before and after the adsorption studies. From the results, a maximum adsorption capacity of 98.5 % was obtained at the optimized conditions of 1.5 g, 90 min and 275 rpm for adsorbent dose, contact time and agitation speed respectively. The ANOVA of the regression model showed that the model is highly significant with R2 of 0.98. Further analysis carried out revealed that, in addition to dye removal, trace metals were also adsorbed in the process. This fact was established when the concentration of copper in the wastewater was found to decrease from 0.09 ppm to 0.03 ppm corresponding to 66.7 % removal at the end of the process.
  • Item
    Optimization of dye removal from textile wastewater using activated carbon from sawdust as adsorbent
    (Faculty of Engineering and Technology, University of Ilorin, 2018-03) Eletta, O.A; Mustapha, S.I; Ajayi, O.A; Ahmed, A.T
    This study is aimed at developing an adsorbent from sawdust for optimum removal of dye from textile wastewater. The adsorbent was developed, characterised and, the adsorptive capability for the removal of dye was determined by optimizing the process parameters (adsorbent dosage, contact time and agitation speed) using Response Surface Methodology. The physical and chemical characterization of the effluent was carried out before and after the adsorption studies. From the results, a maximum adsorption capacity of 98.5 % was obtained at the optimized conditions of 1.5 g, 90 min and 275 rpm for adsorbent dose, contact time and agitation speed respectively. The ANOVA of the regression model showed that the model is highly significant with R2 of 0.98. Further analysis carried out revealed that, in addition to dye removal, trace metals were also adsorbed in the process. This fact was established when the concentration of copper in the wastewater was found to decrease from 0.09 ppm to 0.03 ppm corresponding to 66.7 % removal at the end of the process.