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The study evaluates the heavy metals, geo-accumulation index and contamination factor in soil around dumpsites in Uyo, Akwa Ibom State, Nigeria. Soil samples were collected, during rainy season, at depth of 0-15cm and 15-30cm from two... more
The study evaluates the heavy metals, geo-accumulation index and contamination factor in soil around dumpsites in Uyo, Akwa Ibom State, Nigeria. Soil samples were collected, during rainy season, at depth of 0-15cm and 15-30cm from two study sites (A, B) and a control site (C). Soil samples were all analyzed for heavy metals (Pb, Ni, Cd and Cu) using Atomic Absorption Spectroscopy (AAS). The concentration of Lead at site A for depth 0-15 cm ranged from 13.71 -14.90 mg/kg with a mean value of 14.38 ± 0.61 mg/kg; Nickel varied from 2.35 – 3.22 mg/kg (2.74 ± 0.44 mg/kg); Cadmium ranged from 3.78 – 4.13 mg/kg (3.93 ± 1.18 mg/kg); Copper ranged from 27.84 – 28.34 mg/kg (28.14 ± 0.27 mg/kg). The heavy metals concentration in soil at sites A and B followed the sequence, Cu > Pb > Cd > Ni while at the control site; Cu > Cd > Ni > Pb. The calculated geo-accumulation index (Igeo) showed that the soil samples from sites A and B for Pb, Ni and Cu belong to class 2, which implie...
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Coating porosity is an important property that supports solid-gas and solid-liquid exchange that can either enhance various science and technological applications or promote damage if not properly controlled. However, non-destructive... more
Coating porosity is an important property that supports solid-gas and solid-liquid exchange that can either enhance various science and technological applications or promote damage if not properly controlled. However, non-destructive instrumental techniques for the measurement of porosity on coated walls or surfaces can be quite challenging. Here, a seamless capillary rise technique has been used to determine both the thickness and porosity of a thin silica coating. Uniform coatings were prepared from 5 wt% hydrophobic fumed silica in absolute ethanol and spin-coated at 500–8000 rpm on glass slides. Capillary imbibition of squalane was then controlled into known areas of the resulted hydrophobic nano-porous coatings. The mass of the solid (silica) and the infiltrated oil (squalane) were gravimetrically measured. The porosity of the material was calculated as the percentage fraction of the pore volume while the film thickness was determined as the ratio of the total volume to the are...
Nanoremediation approaches have been applied to remove oil from surface and ground water as oil spills have been found to have long-term negative consequences for the ecosystem. Nanoremediation via the nanosorption mechanism of different... more
Nanoremediation approaches have been applied to remove oil from surface and ground water as oil spills have been found to have long-term negative consequences for the ecosystem. Nanoremediation via the nanosorption mechanism of different environmental matrices in the world at large is at its formative stages despite the alarming and extensive prevalence of petroleum related environmental pollution. Over 9 million barrels of oil have been leaked in the last five decades, making that ecosystem one of the most deteriorated by oil exploration and extraction activities. The goal of this research is to assess the current status, trends, and future prospects of the nanosorption of surface and ground water in oil spill regions. High surface area of nanomaterials, wide spectrum of treatable contaminants, non-generation of intermediate or secondary products, as well as speed and extent of contaminant destruction give nanoremediation a superior comparative edge over other treatment technologie...
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Analysis of physicochemical properties of Eucalyptus citriodora gum revealed that the gum is mildly acidic, brownish in colour, ionic and has the potentials to swell four times its original volume. GCMS analysis of the gum indicated the... more
Analysis of physicochemical properties of Eucalyptus citriodora gum revealed that the gum is mildly acidic, brownish in colour, ionic and has the potentials to swell four times its original volume. GCMS analysis of the gum indicated the presence of some carboxylic acids, pyran-4-one, 1,3-dioxolane, benzofuran and 1,2-ethanediyl acetate while analysis of its FTIR spectrum revealed functional groups that are common to polysaccharides. Scanning electron micrograph of the gum also revealed the existence of particle aggregations with some internal bridges within the system. Rheological properties of the gum were found to be affected by pH, concentration, temperature and by the presence of some electrolytes (KCl, CaCl2, AlCl3 and urea). Average value of intrinsic viscosity deduced from Huggins and Kraemer plots was 3.51 dL/g while the sum of their constants was 0.36 (i,e< 0.5 and suggested the absence of molecular association). Calculated value of the Power law constant was (b = 0.812)...
Phenol degradation in aqueous solutions using chitosan prepared from Crassostrea gigas (Sea oyster) shells as adsorbent was investigated using photocatalysis and adsorption processes at ambient temperature. Photolysis was carried out to... more
Phenol degradation in aqueous solutions using chitosan prepared from Crassostrea gigas (Sea oyster) shells as adsorbent was investigated using photocatalysis and adsorption processes at ambient temperature. Photolysis was carried out to study the effect of light on the degradation of phenol at ambient temperature while adsorption process was carried out without utilizing solar illumination. Effect of initial concentrations of phenol (50, 75, 100 and 150 mg/l), TiO 2 loading (4, 8, 16 and 20 %), and composite mass (adsorbent + TiO 2 ) (1, 3, 5 and 8 g) were investigated using UV-Visible spectrophotometric technique. The results obtained indicate that phenol removal increases with time and concentration of the catalyst (TiO 2 ) and decreases with increase in initial concentration of phenol and composite mass. Combination of UV irradiation with TiO 2 loading gave a degradation efficiency ranging from 98.13 - 98.92 % while UV irradiation with composite mass gave a degradation efficiency...
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The use of environmentally benign materials as adsorbent for bleaching palm oil has been revitalize due to loss of significant amount of oil associated with commercial bleaching earth. This paper examined the performance of inactivated... more
The use of environmentally benign materials as adsorbent for bleaching palm oil has been revitalize due to loss of significant amount of oil associated with commercial bleaching earth. This paper examined the performance of inactivated shell samples from snail, mussel, periwinkle and the corresponding acid activated samples as an alternative bleaching material for palm oil. Effectiveness of the bleaching process was examined by determining critical process parameters such as degree of bleaching (%), adsorbent dosage (%), and oil retention capacity of the adsorbent. Maximum bleaching performance of 98.70%–96.60% for inactivated samples and 97.79%–95.52% for 0.5 M hydrochloric acid activated samples were obtained at low adsorbent dosage of 9.09 wt.%. The weight percentage of residual oil (1.38–20.08 wt.%) in the spent adsorbent was extremely low for all the samples. Inactivated samples could be a better alternative for commercial adsorbent.
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Indoor air quality parameters were investigated in an occupied air–conditioned office and unoccupied air–conditioned office located in the Faculty of Natural and Applied Sciences Complex in Akwa Ibom State University – Nigeria, during the... more
Indoor air quality parameters were investigated in an occupied air–conditioned office and unoccupied air–conditioned office located in the Faculty of Natural and Applied Sciences Complex in Akwa Ibom State University – Nigeria, during the rainy (June – July) and dry (November – December) seasons of 2016. Particulate matter (PM 1 , PM 2 , PM 5 , PM 10), temperature, relative humidity, carbon monoxide (CO) and carbon dioxide (CO 2) levels were simultaneously measured in fourteen (14) sampling days using Fluke 985 Particle Counter and Fluke 975 AirMeter. The concentrations of particulate matter in the occupied air–conditioned office during the rainy season ranged from 5152 – 5984 μg/m 3 for PM 1 ; 2744 – 3015 μg/m 3 for PM 2 ; 137 – 149 μg/m 3 for PM 5 and 36 – 50 μg/m 3 for PM 10 and in the unoccupied air–conditioned office, the concentrations of particulate matter ranged from 1898 – 2556 μg/m 3 for PM 1 ; 987 – 1311 μg/m 3 for PM 2 ; 38 – 59 μg/m 3 for PM 5 and 15 – 24 μg/m 3 for PM 10. During the dry season, the concentrations of particulate matter in the occupied air–conditioned office ranged from 5852 – 6510 μg/m 3 for PM 1 ; 4490 – 4992 μg/m 3 for PM 2 ; 335 – 362 μg/m 3 for PM 5 and 59 – 69 μg/m 3 for PM 10 and in the unoccupied air–conditioned office, the concentrations of particulate matter ranged from 2598 – 3112 μg/m 3 for PM 1 ; 1168 – 1694 μg/m 3 for PM 2 ; 153 – 257 μg/m 3 for PM 5 and 29 – 42 μg/m 3 for PM 10. This study has revealed that the particulate matter (PM 1 , PM 2 , PM 5 , PM 10) concentrations in an occupied air–conditioned office were significantly (P < 0.001) higher than those obtained in unoccupied air–conditioned office during both rainy and dry seasons. However, the concentrations of PM 10 obtained in the present study were found to be much lower than the ambient maximum contaminant level for airborne PM 10 standard promulgated by the United States Environmental Protection Agency (USEPA) (150 μg/m 3 daily average and 50 μg/m 3 annual average) and World Health Organization (WHO) PM 10 guidelines values (50 μg/m 3 daily average and 20 μg/m 3 annual average). Although there were no significant relationships among PM 1 , PM 2 , PM 5 , and PM 10 in occupied air-conditioned office, correlation analysis indicated that PM 1 , PM 2 and PM 5 were significantly correlated at P < 0.01 in unoccupied air-conditioned office and correlation coefficients were different. Apart from suspended atmospheric dust and settling dust, human activities in the occupied air–conditioned office significantly influenced the particulate matter concentrations obtained compared to those obtained in unoccupied air–conditioned office in both rainy and dry seasons. Although the concentrations of CO and CO 2 were below detection limit (BDL), they indicated adequate air exchange at the time of the assessment in the air–conditioned office during the sampling period. The results obtained have revealed important contributions towards the understanding of particulate matter distribution patterns and provided baseline data that can be used for potential identification of human health risks associated with airborne particulate matter in air–conditioned offices in Akwa Ibom State University – Nigeria.