Dahiru Ajiya - Academia.edu (original) (raw)

Papers by Dahiru Ajiya

European journal of advanced chemistry research, Jun 5, 2022

Mining environment is known for a high level of heavy metals due to the activities which cause ad... more Mining environment is known for a high level of heavy metals due to the activities which cause adverse alteration of the ecological system. This research study the partitioning of heavy metals in artisanal mining sites in RiminZayan, Toro Local Government Area Bauchi state, Nigeria. The concentration of heavy metals like lead, Cadmium, Iron, Zinc, Cobalt (Co), Copper , Chromium, Manganes and Nickel, were determined using the sequential extraction method recommended by Community Bureau of Reference (BCR) and physic-chemical properties such as the pH, cation exchange capacity, total organic carbon, total organic matter, electrical conductivity and soil particle size. The result show that the soil in the area has a clayey texture with the percentage of clay, slit and sand ranging from 9.29-27.10, 6.31-13.41 and 59.32-84.39 %, respectively. The pH levels of the soil ranged from 6.04 to 6.45 indicating that the soil in thee study is slightly acidic in nature. The observed electrical conductivity (EC) obtained in this study for the samples of soil sediments taken from around the mining site were 26.76, 31,30 and 42.66 µs/cm respectively. The percentages of organic matter of the soil in the same location are 0.423, 0.061 and 0.452 %. Cation exchange capacity (CEC) of the soil in the same vanity were respectively found to be 4.003, 7.385 and 3.994 cmol/kg. The metals were fractionated into six fractions and determined using Atomic Absorption Spectrophotometric techniques (AAS). The results of the soil analysed indicated that there was high abundance of heavy metals such as cadmium, chromium, copper, iron, lead, nickel, and zinc in the residual fraction, pointing to their lithogenic origins, and therefore primarily inherited from the parent material. Cobalt and manganese are bound to other fractions (exchangeable, carbonate, manganese oxide, ironmanganes oxide, organic matter-sulphide, and residual metals which shows their anthropogenic origin. The ratio of bioavailability factor (BF) ranged from 27.47 to 89.66, Contamination factor showed values ranging from 0.001 to 16.299 which suggests that some soils were not contaminated while some were moderately contaminated metals investigated. The degree of contamination (DC) showed that the highest recorded were from nonmining area (19.517) while active mining sites and abandoned mining sites values are: 5.985 and 3.843, respectively. This trend could be owing to the bioavailability and mobility of the metals from the mining sites to nonmining locations. The data generated were subjected to one-way ANOVA. The least significant difference test (p ≤ 0.05).

I am grateful to Allah Subhanahu Wata'ala (SWT) that gave me the rare opportunity, sustained life... more I am grateful to Allah Subhanahu Wata'ala (SWT) that gave me the rare opportunity, sustained life and health to carry out this research. My special thanks go to my supervisor, Dr Suzi Salwah Binti Jikan who contributed immensely in guidance and all the assistance required for the progress of the research work. My gratitude goes to Dr Nur Azam Bin Badarulzaman who assisted with technical advice and fabricated the tape casting machine with which TPTS films were made. The contribution of my cosupervisor, Dr Balkis Binti A. Talip is also noted with gratitude. Likewise my second co-supervisor, Dr Darfizzi Derawi who facilitated some of my research work in his laboratory at The University Kebangsaan Malaysia (UKM), his contribution is appreciated. I would like also to acknowledge the contribution of Dr Hazel Monica Mathias-Peralta who provided funds to procure some of the most necessary chemicals for the research at the initial stage. Most importantly, I would like to express my profound gratitude to all the Academic and non-academic staff of the Faculty of Applied Sciences and Technology who shared their experience with us in exhibitions, workshops and symposiums which eventually shape the research work significantly. My special appreciation to the laboratory technicians who reserved their time to be with us in the laboratory especially

International Journal of Integrated Engineering, 2020

The effect of water (as a primary plasticiser) content on the chemical structure and mechanical p... more The effect of water (as a primary plasticiser) content on the chemical structure and mechanical properties of thermoplastic tapioca starch (TPTS) film was evaluated. The TPTS films were produced by tape casting technique through mixtures of fixed amount of glycerol and varied contents of tapioca starch and water. The water content used in the films formulation were 30, 45, and 60 wt %. There was observed increase in hydrogen bonding interaction between starch and water molecules depicted by the downward shift between 3303-3281 cm-1. The excessive amount of water loading portrayed increase in crystallinity due to free volume movement of the starch particles. The changes in water loading also showed variation in the tensile strength and elongation at break of the TPTS films. This observation is because of the dependence of mobility of polysaccharide plastics on the water content in the premix. Therefore, starch forms entanglements with the plasticisers to form a flexible film.

Journal of Science and Technology, 2017

Thermoplastic tapioca starch (TPTS) film was made by tape casting. The viscoelastic behaviour, th... more Thermoplastic tapioca starch (TPTS) film was made by tape casting. The viscoelastic behaviour, thermal degradation and surface morphology were investigated using Dynamic mechanical analysis (DMA), Thermogravimetric analysis (TGA) and Scanning electron microscope (SEM) respectively. The DMA result shows that the storage modulus as well as loss modulus of the TPTS films with 0, 5, 10, 15 and 20% glycerol appears to reduce with increase in glycerol content due to phase relaxation as a result of molecular interaction of the starch molecules with glycerol molecules. Whereas, tan δ shows the effect of temperature is higher on the TPTS film with low glycerol content. The thermal degradation of the TPTS is more susceptible to heat as shown by curve 2(e) for film sample with 20% glycerol, showing that higher glycerol content reduces thermal stability of the film. Even though, lowering of glass transition temperature of the TPTS films took effect with the higher concentration of glycerol whic...

The aim of this work is to study the influence of different proportions of glycerol on the proper... more The aim of this work is to study the influence of different proportions of glycerol on the properties of tapioca starch films. The films were characterized to determine crystallinity by using X-ray diffraction (XRD), thermal property by differential scanning calorimetry (DSC) and mechanical property by tensile test. The DSC thermograms show a decrease in the melting temperature (TPeak) with increase in the glycerol content. According to XRD diffractograms, pure starch exhibits crystallinity, but gelatinisation converts the starch film with 0 (w/w) % glycerol to amorphous, it gains back its crystallinity with the increase in the glycerol concentration. Mechanical properties were also influenced by variation of the percentage ratio of glycerol. The tensile strength was observed to decrease with increase in glycerol concentration whereas the elongation at break sharply increase with increase in glycerol concentration.

Science Forum (Journal of Pure and Applied Sciences)

European journal of advanced chemistry research, Jun 5, 2022

Mining environment is known for a high level of heavy metals due to the activities which cause ad... more Mining environment is known for a high level of heavy metals due to the activities which cause adverse alteration of the ecological system. This research study the partitioning of heavy metals in artisanal mining sites in RiminZayan, Toro Local Government Area Bauchi state, Nigeria. The concentration of heavy metals like lead, Cadmium, Iron, Zinc, Cobalt (Co), Copper , Chromium, Manganes and Nickel, were determined using the sequential extraction method recommended by Community Bureau of Reference (BCR) and physic-chemical properties such as the pH, cation exchange capacity, total organic carbon, total organic matter, electrical conductivity and soil particle size. The result show that the soil in the area has a clayey texture with the percentage of clay, slit and sand ranging from 9.29-27.10, 6.31-13.41 and 59.32-84.39 %, respectively. The pH levels of the soil ranged from 6.04 to 6.45 indicating that the soil in thee study is slightly acidic in nature. The observed electrical conductivity (EC) obtained in this study for the samples of soil sediments taken from around the mining site were 26.76, 31,30 and 42.66 µs/cm respectively. The percentages of organic matter of the soil in the same location are 0.423, 0.061 and 0.452 %. Cation exchange capacity (CEC) of the soil in the same vanity were respectively found to be 4.003, 7.385 and 3.994 cmol/kg. The metals were fractionated into six fractions and determined using Atomic Absorption Spectrophotometric techniques (AAS). The results of the soil analysed indicated that there was high abundance of heavy metals such as cadmium, chromium, copper, iron, lead, nickel, and zinc in the residual fraction, pointing to their lithogenic origins, and therefore primarily inherited from the parent material. Cobalt and manganese are bound to other fractions (exchangeable, carbonate, manganese oxide, ironmanganes oxide, organic matter-sulphide, and residual metals which shows their anthropogenic origin. The ratio of bioavailability factor (BF) ranged from 27.47 to 89.66, Contamination factor showed values ranging from 0.001 to 16.299 which suggests that some soils were not contaminated while some were moderately contaminated metals investigated. The degree of contamination (DC) showed that the highest recorded were from nonmining area (19.517) while active mining sites and abandoned mining sites values are: 5.985 and 3.843, respectively. This trend could be owing to the bioavailability and mobility of the metals from the mining sites to nonmining locations. The data generated were subjected to one-way ANOVA. The least significant difference test (p ≤ 0.05).

I am grateful to Allah Subhanahu Wata'ala (SWT) that gave me the rare opportunity, sustained life... more I am grateful to Allah Subhanahu Wata'ala (SWT) that gave me the rare opportunity, sustained life and health to carry out this research. My special thanks go to my supervisor, Dr Suzi Salwah Binti Jikan who contributed immensely in guidance and all the assistance required for the progress of the research work. My gratitude goes to Dr Nur Azam Bin Badarulzaman who assisted with technical advice and fabricated the tape casting machine with which TPTS films were made. The contribution of my cosupervisor, Dr Balkis Binti A. Talip is also noted with gratitude. Likewise my second co-supervisor, Dr Darfizzi Derawi who facilitated some of my research work in his laboratory at The University Kebangsaan Malaysia (UKM), his contribution is appreciated. I would like also to acknowledge the contribution of Dr Hazel Monica Mathias-Peralta who provided funds to procure some of the most necessary chemicals for the research at the initial stage. Most importantly, I would like to express my profound gratitude to all the Academic and non-academic staff of the Faculty of Applied Sciences and Technology who shared their experience with us in exhibitions, workshops and symposiums which eventually shape the research work significantly. My special appreciation to the laboratory technicians who reserved their time to be with us in the laboratory especially

International Journal of Integrated Engineering, 2020

The effect of water (as a primary plasticiser) content on the chemical structure and mechanical p... more The effect of water (as a primary plasticiser) content on the chemical structure and mechanical properties of thermoplastic tapioca starch (TPTS) film was evaluated. The TPTS films were produced by tape casting technique through mixtures of fixed amount of glycerol and varied contents of tapioca starch and water. The water content used in the films formulation were 30, 45, and 60 wt %. There was observed increase in hydrogen bonding interaction between starch and water molecules depicted by the downward shift between 3303-3281 cm-1. The excessive amount of water loading portrayed increase in crystallinity due to free volume movement of the starch particles. The changes in water loading also showed variation in the tensile strength and elongation at break of the TPTS films. This observation is because of the dependence of mobility of polysaccharide plastics on the water content in the premix. Therefore, starch forms entanglements with the plasticisers to form a flexible film.

Journal of Science and Technology, 2017

Thermoplastic tapioca starch (TPTS) film was made by tape casting. The viscoelastic behaviour, th... more Thermoplastic tapioca starch (TPTS) film was made by tape casting. The viscoelastic behaviour, thermal degradation and surface morphology were investigated using Dynamic mechanical analysis (DMA), Thermogravimetric analysis (TGA) and Scanning electron microscope (SEM) respectively. The DMA result shows that the storage modulus as well as loss modulus of the TPTS films with 0, 5, 10, 15 and 20% glycerol appears to reduce with increase in glycerol content due to phase relaxation as a result of molecular interaction of the starch molecules with glycerol molecules. Whereas, tan δ shows the effect of temperature is higher on the TPTS film with low glycerol content. The thermal degradation of the TPTS is more susceptible to heat as shown by curve 2(e) for film sample with 20% glycerol, showing that higher glycerol content reduces thermal stability of the film. Even though, lowering of glass transition temperature of the TPTS films took effect with the higher concentration of glycerol whic...

The aim of this work is to study the influence of different proportions of glycerol on the proper... more The aim of this work is to study the influence of different proportions of glycerol on the properties of tapioca starch films. The films were characterized to determine crystallinity by using X-ray diffraction (XRD), thermal property by differential scanning calorimetry (DSC) and mechanical property by tensile test. The DSC thermograms show a decrease in the melting temperature (TPeak) with increase in the glycerol content. According to XRD diffractograms, pure starch exhibits crystallinity, but gelatinisation converts the starch film with 0 (w/w) % glycerol to amorphous, it gains back its crystallinity with the increase in the glycerol concentration. Mechanical properties were also influenced by variation of the percentage ratio of glycerol. The tensile strength was observed to decrease with increase in glycerol concentration whereas the elongation at break sharply increase with increase in glycerol concentration.

Science Forum (Journal of Pure and Applied Sciences)