PaperID: AJERD0302-01; Pages: 1-11
Author(s): Modestus Chidera UWAZIE, Okechukwu Dominic ONUKWULI, Akinpelu Kamoru BABAYEMI, Jonah Chukwudi UMEUZUEGBU
Abstract: This study was on the risk management analysis of labour and equipment for effective production output in quarries, in Ondo, Oyo and Ogun States of Nigeria with aim of identifying the work hazards encountered by quarry workers, assessing the level of risk faced by quarry worker’s, examining the likelihood of occurrence of hazards at quarry workplace and precautionary measures put in place. Sixty quarry workers were randomly selected across both skilled and unskilled division and were administered with a structured questionnaire to know the various hazards and hazard management during their operations in quarry. Data collected were analysed using descriptive statistics, frequency tables and charts. Potential Hazards faced by respondents according to the analysis are electric shocks (69.23%), noise pollution (86.15%), dusts impact (86.15%), fly rocks during blasting (52.31%), excessive workload (73.85%), long hours of work (80.00%), slips and trips (93.85%) and wet floors/road (50.77%). Victims include the community people (64.62%), operators (69.23%), visitors (56.92%) and new workers (63.08%). Risk control measure mostly used was first aid facilities and this was adequate. Workers are also likely to experience fly rocks (26.2%), long hours of work (49.2%), wet floors/road (33.8%), hydrocarbon fuel spillage (52.3%), runoff from sites (33.8%) and soil erosion to farmlands (32.3%), dust impact on visuals (55.4%). Quarry workers (64.6%) attest they do not attend safety seminars because they are not given by the management. A proportion of 24.6% of the quarry workers has not been involved as causalities of any hazard despite the regular (always) breakdown of workers (40.0%) at the workplace. The results of the water analysis revealed the level of heavy metals like Lead (Pb), Cadmium (Cd), Magnesium (Mg) and Chromium (Cr) are higher than the permissible limit recommended by WHO; hence the water sources pose a great threat to the health of the people and workers.
PaperID: AJERD0302-02; Pages: 12-18
Dynamics of Polyaromatic Hydrocarbon Degradation Under Monitored Bioattenuation System
Author(s): Chioma Bertha EHIS-ERIAKHA, Vincent Aizebeoje BALOGUN
Abstract: Bioattenuation encompasses processes that lead to reduction of the mass, toxicity, mobility, or volume of contaminants without human intervention. This study was designed to determine the dynamics of polyaromatic hydrocarbon degradation under a monitored bioattenuation bioremediation system. Preliminary analysis was conducted to determine the extent of pollution by chemical analysis and to enumerate the microbiological population in the sample by standard microbiological methods. The identities of the hydrocarbon degrading bacteria population were ascertained using 16SrRNA molecular typing algorithm. The experimental duration was 35 days and the microcosm was monitored at weekly interval under a controlled system. A 4% spike in crude oil level was conducted to increase the concentration of PAH in the sample to 989.1 mg/kg. Total viable heterotrophic and hydrocarbon degrading bacteria populations were CFU X 108g and the dominant class of microbes was Grammaproteobacteria and genus Pseudomonas. The overall degradation rate was recorded at 52%. Anthracene was 100% degraded while benzo(b)fluoranthene, fluorine and pyrene had above 50% removal. All other PAHs present in the sample experienced some level of degradation except acenaphthylene, dibenz (a,h)anthracene and chrysene which increased slightly in concentration. The natural attenuation process was effective in degradation of the pollutant within the experimental period.
PaperID: AJERD0302-03; Pages: 19-26
Author(s): Eugenia Obiageli OBIDIEGWU, Ezenwanyi Fidelia OCHULOR, Henry Ekene MGBEMERE
Abstract: Due to scanty or lack of good insulating refractory materials in commercial quantity, most of the manufacturing and processing industries in developing countries such as Nigeria depend mainly on imported insulating refractory bricks to line their furnaces. This is to improve energy efficiency and reduction in energy loss. Despite the abundant resources of fireclay in the country for the production of insulating refractory bricks, these industries depend mainly on the imported refractory bricks. This leads to the high cost of the final product. This work studied the characteristics of insulating refractory bricks from Nigerian clay and Gmelina seed shell particulate. The chemical composition of the raw materials were analysed using Atomic Absorption Spectrometer. The samples were obtained by mixing both clay and Gmelina seed shells such that the composition of the Gmelina seed were 0 %, 20%, 25 %, and 30 %. The compressed bricks were dried and sintered at a heating rate of 2.5oC/min to temperatures ranging from 950oC to 1100oC at 50oC intervals, The results of the physical, thermal and mechanical characterisation showed that when Gmelina content were between 25-30 wt% at temperatures between 1000oC to 1100oC, the porosity increased from 26.1 – 72.4%, bulk density decreased from 3.4 – 1.5 g/cm3, Cold crushing strength increased from 126 – 1162 kN/m2 and thermal conductivity decreased from 0.28 – 0.12 W/mK. These results indicate that Gmelina particles helped to produce bricks with enhanced insulating properties. In conclusion, this work discovered a new refractory material (Gmelina seed shells which are in abundance in Nigeria). This can increase the physical, thermal and mechanical characteristics of a refractory brick. Also, this work could benefit the manufacturing and pottery industries, and in the production of refractory materials.
PaperID: AJERD0302-04; Pages: 27-34
Author(s): Stephen Adeyemi ALABI, Tolulope Abidemi ALABI
Abstract: Sandcrete blocks are the primary material used in Nigeria as partition walls and sometimes as load-bearing walls. The quality of the constituent materials, the curing methods, and the mixing methods are known to influence quality. However, the quality of blocks is usually evaluated using the compressive strength, fB. However, different studies have shown that there is no unique fB value for block due to high inherent variability. The uncertainty associated with fB is reportedly evaluated using a traditional statistical method that requires a significant amount of test results. Extensive data are usually not available due to the practical challenges in the preparation of the compression test sample. This study, therefore, utilizes the Markov chain Monte Carlo (MCMC) Bayesian probabilistic approach to solve the challenges of restricted testing data as well as the uncertainty inherent in the test results to ensure the quality of the block produced. The framework begins with the development of a general probability model called the likelihood function to evaluate the marginal posterior probability based on a limited number of fB data. The mean and coefficient of variation (COV) values of the MCMC generated sample and the direct measurement of fB were 0.94 N/mm2 and 13.10%, and 1.03 N/mm2 and 19.20% respectively. The difference between the average values of the samples from the MCMC approach and the direct measurement is 0.09 N/mm2, representing a relative difference of 8.77%. On the other hand, the COV difference is 6.10%, showing a considerable variation of 31.80%. The slight difference between the average values shows that the mean values are in good agreement with each other, inferring that the probabilistic MCMC-based method performs excellently. It can be concluded that integrating prior knowledge, limited compression test data, and Bayesian inference methods into the design process can contribute to a more reliable structure even with higher permissible stress. Factors such as the degree of uncertainty in the design of walls and the consequences of the collapse of walls or structures can be logically integrated into the design specifications.
PaperID: AJERD0302-05; Pages: 35-42
Author(s): Zamani Donald ISHAYA, Gyang Yakubu PAM, Dangana Mallam KULLA, Abubakar Ishaq JUMARE
Abstract: World environmental degradation and energy supplies insecurities occasioned by climate change, air pollution and coronary diseases has contributed to the increased interest in new energy sources. This study focused on the production and characterization of the methyl esters fatty acid (MEFA) of African Mahogany (AM) at varied oil to methanol molar ratios (MR) of 1:6, 1:9 and 1:12, while other key parameters of 0.50 % NaOH catalyst concentration at 60 o C, for 1-hour were kept constant. The oil from the African mahogany seed kernel was extracted using a Mechanical expeller and a yield of 44.88% – by weight was obtained. AM percent free fatty acid was reduced from 17.39 to 0.46 mg (KOH)/ g (of the oil) by 4-runs of H2SO4 acid esterification. This was followed by alkaline (NaOH) transesterification conducted and the biodiesels were produced at the varied oil to methanol molar ratios. The chemical composition cum profile of the produced biodiesels were determined using the gas chromatograph and mass spectrometer (GCMS). The results indicated increasing yields of MEFA from AM at molar ratio (MR) of 1:6 was 55.99 %, then AM. at MR of 1:9 was 65.97 %, and AM. at MR of 1:12 to 79.48 %. Similarly, the principal composition of Octadecenoic acid methyl ester increased from 16.55% in crude AM oil to 30.22 %, 39.89 % and 46.62 % in the biodiesel produced as the molar ratios were increased from 1:6 to 1:12. Thus, a mathematical model y = 1.763×2 + 1.167x + 46.604 (MR = 1 < x < 5) having the predictability R² = 1 for AM feedstock was established.
PaperID: AJERD0302-06; Pages: 43-53
Author(s): Ajibola Ibrahim QUADRI, Mubaarak ABDULHAMEED
Abstract: Previous works of research have indicated that quality standards are being ignored by actors in Nigerian Construction industry. This paper investigated and reported the strength properties of sandcrete blocks produced in Akinyele Local Government Area of Oyo State, Nigeria. A total of 30 blocks were acquired, three (3) blocks each of 6″ (450 mm × 150 mm × 225 mm) and 9″ (450 mm × 225 mm × 225 mm) were collected from five (5) industries randomly. Soil samples were also collected and tested. The tests carried out were, sieve analysis, specific gravity, compressive strength, and water absorption rate. The compressive strength of all the blocks was below standard requirement as their values range between 0.22 N/mm2 and 0.46 N/mm2 for the (9″) blocks, 0.3 N/mm2, and 0.6 N/mm2 for the (6″) blocks. It could be concluded that sandcrete blocks from the selected industries in the Local Government Area did not meet 2.1 N/mm2, the minimum strength required for non-load bearing walls. Therefore, they should not be used as non-load bearing units. It is recommended that professional bodies and government agencies responsible for quality assurance of building units should enforce compliance of block industries with the minimum required specifications.
PaperID: AJERD0302-07; Pages: 54-65
Author(s): Michael Sunday OLAKUNLE, Olusegun Ayoola AJAYI, Francisca Unoma NWAFULUGO
Abstract: Cyanide poisoning in water bodies often results from human activities via cassava processing, which is highly undesirable in water bodies. This work describes the preparation of palm kernel fibre ash (PKFA) adsorbent via wet beneficiation, calcination and impregnation with Iron (II) nitrate for cyanide adsorption from its aqueous solution. The raw palm kernel fibre (PKF), calcined PKFA and Fe2+ impregnated PKFA (Fe-PKFA) were characterized using a scanning electron microscope (SEM) and Fourier Transform Infrared (FTIR), whereas UV spectrophotometer was used to monitor the cyanide concentration. Box-Behnken experimental design method of the response surface methodology (RSM) was employed to study the effect of temperature, contact time, adsorbent dosages, and initial concentration on the adsorption efficiency of the adsorbents at fixed pH 7. Optimal adsorption efficiency of 85.43% was obtained with 60 ppm initial concentration, 3 g of calcined Fe-impregnated adsorbent dosage at 42 minutes contact time and temperature of 35 oC. The developed model for the adsorption process gave R2 value of 0.9985 which shows that the model is significantly high, and there was good agreement between the experimental and simulated values. The adsorption process was best described by the pseudo-second order and intra particle diffusion kinetic models. The Temkin adsorption isotherm gave the highest regression coefficient and the variation of adsorption energy was 14.47kJ/mol which indicated an exothermic process. The results revealed that the Fe2+ impregnated PKFA adsorbent can serve as a good and sustainable adsorbent for cyanide biosorption from wastewater.
PaperID: AJERD0302-08; Pages: 66-76
Development of Mathematical Modelling for Predicting Spray Mass Flux on Tree Canopies
Author(s): Buba Baba SHANI
Abstract: This study is to develop a mathematical model that could theoretically estimate spray mass flux of spray materials of a selected sprayer at different operating conditions in an orchard farm. Investigation were conducted and data were collected on randomly selected orchard tree of population of (n)100. A paired t-test was conducted and the result revealed that the calculated t- values (0.769) is less than the table value (3.25) at 0.01 level of significance, with (r 2) of 0.98, the Root mean Square Error (RMSE), the standard deviation (S d) 0.059 and 0.0065 respectively. All the inputs variables of the model developed indicate high degree of precision with which the treatment values were compared and are a good index of reliability of the experimental results and the sensitivity of developed predicted models to change in the constituent independent variables is negligible and not significant.
PaperID: AJERD0302-09; Pages: 77-85
Development of Model Systems Using Aspen Plus for Syngas Production from Waste via Gasification
Author(s): Henry Ikechukwu ILEHOMON, Patience Oshuare SEDEMOGUN
Abstract: The need for Energy is paramount to human existence. Biomass Gasification utilizes the process of synthesis gas “Syngas” production which can be used as an alternate to conventional means of energy generation. This Research encompasses the development of model systems using ASPEN Plus for syngas production from waste via gasification. The feed stock proximate and ultimate analysis used was obtained from previous authors whose research was done within Minna, Niger state. These obtained data were used to develop a model system using ASPEN PLUS simulation software and the Syngas composition H2, N2, CO, CO2, CH4. From table 5, model 3 and 4 of the Syngas composition where compared with the effective Syngas range of values, H2– 2-5%, CO- 35-40%, H2– 20-40%, CO2– 25-35%, CH4– 0-15%, which was within the range for effective Syngas. The obtained simulated Results show that the waste generated from these locations can generate an effective amount of Syngas that can be used for Energy Generation.
PaperID: AJERD0302-10; Pages: 86-93
Author(s): Thomas Ndyar GUMA, Habeeb Alabi ABDULSALAM
Abstract: Artisanal green sand casting of aluminium pots is a highly profitable avenue for small to medium scale self-employment as well as technological and economic development in Kaduna metropolis. The casting process was nevertheless observed to be often characterized with reruns before attaining defect-free castings. This was seen to be capable of increasing the unit casting cost and lowering productivity and profitability and morale of the involved shop floor personnel. The aim herein is to statistically provide basic insight into the total defects level of artisanal cast aluminium pots at Panteka Tudunwada, the main area of aluminium pot casting activities in Kaduna metropolis. The statistical analysis was conducted with Microsoft Excel tools using 10-week collated number of defect-free and defective castings produced from the 10 most productive foundry shops in the area. Collated information indicates that within the 10-week period, 25611 defect-free and 9639 defective pot castings were produced in the area. Analyses of the information indicated that the number of defective pot castings varied from shop to shop to overall level of 27.3%. This defect level was seen to be rather high compared to what is obtainable from foundries with Research and Development (R&D) units where better control of casting variables are achieved through research efforts, and defects levels are usually kept in 3 to 15% range. The analyses also showed that the skills used in controlling foundry variables were not the same among the artisans; and there is high correlation between the number of defective and defect-free pot castings within the foundry shops. The identified common types of defects that resulted in the defective castings included open blow holes, burnt skin, cracks, and hard spots. The information is hereby posited for any improvement strategy in the pot-casting business and for relevant research interests.
PaperID: AJERD0302-11; Pages: 94-104
Author(s): Ezenwanyi Fidelia OCHULOR, Eugenia Obiageli OBIDIEGWU, Sunday Chukwujekwu ANAH, John Obioma UGBOAJA
Abstract: Melt treatment via introduction of magnesium (Mg) master alloy during casting of thin wall ductile iron (TWDI), is plagued with a number of challenges such as excessive oxidation, fume and slag formation, carbide precipitation, shrinkage tendency as well as its fading tendency arising from peculiar properties of Mg with respect to molten iron. In this study, variation of the weight percent of master alloy was investigated to determine effects on magnesium recovered and consequently, on nodularity, nodule count and mechanical properties of the cast TWDI. Samples were produced using sandwich method by treating melt of suitable composition with Mg master alloy varied in proportion from 0, 1, 2, 3, 4 and 5 wt.%, two stage inoculation process was carried out. Microstructure examination was carried out according to ASTM E407 and 247 specifications: nodularity and matrix type present within the cast TWDI samples. Magnesium content prior to casting was determined via spectrometric analysis, hardness test was carried out according to ASTM E10 using the brinell scale. The Ultimate tensile strength (UTS) was obtained in accordance with ASTM E8 standards. Results obtained from the microstructure examination, showed presence of ferrite and pearlite matrix within the microstructure of all the samples, 3 wt. % Mg master alloy treated TWDI sample possessed pearlitic phase dominated microstructure. Percent nodularity and nodule counts showed optimum values of 94.1%, 821 and 92.6%, 735 nodules/mm2 for 2% and 3% alloy treated samples respectively. Matrix type consisted of ferrite and pearlite phases observed for MA2 and MA3 samples, whereas carbide precipitations were included in all other samples. The control sample (MA0) which was not magnesium treated showed graphite flakes. This study has shown that increased proportions of magnesium master alloy did not lead to better nodule characteristics instead carbide precipitates and decline of mechanical properties were observed.
PaperID: AJERD0302-12; Pages: 105-114
Development of a Low-Cost Polyurethane (Foam) Waste Shredding Machine
Author(s): Arinola Bola AJAYI, Samuel Olabode AFOLABI, Tosin Emmanuel FOLARIN, Habeeb Akorede MUSTAPHA, Abiodun Felix POPOOLA
Abstract: In this paper, a low-cost, small size polyurethane (foam) shredding machine was designed, developed and tested for the purpose of shredding of foam for waste recovery and processing. It has been observed that the wastes generated from various Foam Industries can be recycled. This is to reduce wastages, and encourage clean environment, however, most of the recycling are done on a large scale and only done by large industries that can afford heavy equipment needed for this operation, which does not allow for evaluation of the viability of the process before embarking on such project, and also allow small scale industries venture into this business of recycling of foam materials. For the small-scale industries to be involved so that these polyurethane waste materials from Foam Industries are effectively utilized, there is need for small scale machines that can be used by any industry either large or small and is pocket friendly. Hence, this reason necessitated the need for a small-scale foam shredding machine that can shred foam on a small scale thereby causing a reduction in the operation cost. The shredding machine can be utilized by both small and large business outfits. Standard mechanical design practice was used to design the parts. Factors considered during the selection of materials included: material properties, material cost and availability, processing and environment. The shredder was designed to be operated with one horsepower (single phase) electric motor. The machine has a hopper with a cover, a gear inserted into a roller which has spike rods (6mm thick) made of mild steel, systematically welded on it to shear the fed foam scrap. Screen was fixed into the machine at the bottom side of the hopper to control the size of the shredded materials. Different screen sizes can be fixed depending on the need. During performance test of the machine, 10kg of waste foam of different densities were fed into the machine gradually at different times. It was observed that the average shredding times reduces as densities increases, efficiencies and shredding rates increases with densities. It is concluded from the design, development, testing, evaluation and observation of this machine that this machine will serve the purpose of shredding waste foam on a small scale as intended.
PaperID: AJERD0302-13; Pages: 115-125
Treatment of Synthetic Dairy Waste Water Using Tamarind Tree Branch as Coagulant
Author(s): Saidat Olanipekun GIWA, Musa ADAMU, Abdulwahab GIWA
Abstract: Studies have shown that Alzheimer’s disease can be linked to residual aluminium in treated water as most of the water treatment plants make use of aluminium salt flash mixing unit. Also, in developing countries, chemical coagulants are usually imported which contribute to high cost of acquisition. Use of natural coagulants have been identified as potential solution to these problems because these substances are not only readily available at low or no cost, they are also presumably safe. In this work, coagulation/flocculation efficiency of tamarind branch coagulant (Tambrant) in the treatment of synthesized dairy wastewater was investigated. In order to achieve the aim of the study, experiments were carried out at varying coagulant dosage and time without adjusting the pH of the synthetic wastewater under treatment. The effect of these factors on the removal of turbidity and chemical oxygen demand (COD); and the dynamic of pH during the treatment were studied. Kinetic and isothermic studies were also carried out. The results obtained showed that Tambrant was effective in treating turbidity and COD in the wastewater. However, the pollutant removal efficiency of the coagulant was affected by variation of coagulant dosage and/or treatment time. Also, pH variation during the treatment was not significantly affected by these factors. COD removal was best explained by both first and second order kinetic models (irreversible). Freundlich model was found to best fit turbidity data. More works need to be done to improve the effectiveness of the coagulant for wastewater treatment.
PaperID: AJERD0302-14; Pages: 126-132
Influence of Some Climatic Variables on Runoff in Ajali River Nigeria
Author(s): Andy Obinna IBEJE
Abstract: The linearity of hydro-climatic relations is required to analyse the dependence of streamflow on some climatic variables. This study is focused on evaluating the relationship and significance of average annual climatic variables in estimating annual runoff in Ajali River located in Enugu State, Nigeria. 1983-2006 records of annual climatic and runoff data are used to develop multiple linear regression (MLR) model, expressing the annual runoff as a function of the annual climatic variables. In addition, hypotheses are tested using t-test and one-way ANOVA. At 0.05 level of significance, the results revealed that the model was not statistically significant in predicting runoff in Ajali River basin. MLR model evaluated as Q = 2.81I0.024 S-0.037 H-0.055 W-0.028 R0.096 Ts0.172 E-0.111 P 0.016, revealed a non-linear relationship between runoff and the climatic system while the multiple coefficient of determination, R2 is estimated as 0. 228, meaning that climatic variables account for 22.8% of the variation in runoff. Also, the significant test revealed that none of the climate variables is a significant predictor of annual runoff (p ˃ 0.05) in Ajali watershed. Based on the findings, it can be deduced that non-climatic factors such as human activities, account for 77.2% of the annual runoff variation in the watershed. To ensure sustainable water supply in the study area, efforts should be geared towards the control of human activities in the river basin.
PaperID: AJERD0302-15; Pages: 133-141
Evaluation of Selected Software Packages for Structural Engineering Works
Author(s): Samson Olalekan ODEYEMI, Mutiu Adelodun AKINPELU, Rasheed ABDULWAHAB, Biliyamin Adeoye IBITOYE, Afusat Idowu AMOO
Abstract: There are confusions on the software to be used in the analysis and design of building structures as there are hundreds of Structural Engineering software applications in the world today. Majority of these software applications operate on certain criteria which makes them suitable for some projects and unsuitable for some. There is a need to research the strength and weakness of some of these software tools to help structural engineers in the selection of the best application in their daily tasks. In this paper, 17 different Structural Engineering software tools were evaluated based on their functional strengths. From the study, it was observed that different software applications have different functions and therefore, it is impossible to say one is better than the other. However, some software application can execute general structural engineering works which makes them versatile but at the same time, quite complex to handle when compared with others.
PaperID: AJERD0302-16; Pages: 142-151
Reactive Power and Voltage Control of Nigerian Grid System Based on Artificial Bee Colony Algorithm
Author(s): Ganiyu Ayinde BAKARE, Lauratu Abubakar LAWAL, Okpo Uchechukwu OKEREKE
Abstract: Reactive power and voltage control in electrical power system leads to simultaneous minimization of the real power losses and enhancement of voltage profiles at affected customers’ buses. To achieve these goals available generating units’ excitation systems, discrete tap positions of on-load tap changer of transformers are adjusted as well as switching of discrete doses of inductors and capacitors etc. at load buses. This is mixed integer non-linear optimization problem with the existence of multiple optimum solutions. Thus, there is a need to develop intelligent technology to achieve the global optimum solution. This paper presents the application of Artificial Bee Colony (ABC) Algorithm to solve the optimization problem using the above-mentioned control devices. The effectiveness of the developed algorithm has been demonstrated on standard IEEE 30 bus network and real 54-bus Nigeria 330kV grid system modelled in MATPOWER under three different loading scenarios. Simulation results on IEEE 30 bus revealed that the algorithm was able to achieve real power loss reduction of 0.9646%, 0.6384% and 6.01% while for 54-bus Nigeria 330kV grid system real power loss reduction of 9.497%, 7.45% and 10.12% was procured for 80%, 100% and 120% loading conditions respectively. For both system studies, the algorithm was able to eliminate the voltage limits violations. The approach was able to procure significant power loss reduction and eliminate the voltage limits violations by restoring them within limits. This thus leads to reduction in the cost of energy to the consumers and voltage profiles enhancement; hence improvement in the network power quality and voltage stability.
