The key process parameters for the hydrolysis and fermentation of Colocynthis vulgaris Shrad seeds shell (CVSSS) were optimized using the Box-Behnken Design (BBD) of Response Surface Methodology ...(RSM). Kinetic study was also carried out. The proximate analysis of the CVSSS was done by the method of the Association of Organic and Applied Chemistry (AOAC). Enzymatic hydrolysis was experimented by using Aspergillus Niger as a crude enzyme isolated from soil at sawdust dump site and screened for cellulosic activities. Factors that affected the hydrolysis of the CVSSS were screened by using the Greco-Latin square design of experiment. However, for Saccharomyces cerevisiae, factors that affected the fermentation of the CVSSS were screened by using the same Greco-Latin square design of experiment. Meanwhile, the result of the proximate analysis revealed that the CVSSS had 73.54% cellulose which could be converted to bioethanol. It was established that temperature, pH and time had significant effect on hydrolysis, while the optimum results were obtained at 46.8 °C, 3.32 d, 5.68 and 59.87% for temperature, time, pH and glucose yield, respectively. Temperature, yeast dosage, pH and time had significant effect on fermentation, while the optimum results from optimization were found to be 33.58 °C, 7.0, 3.55 d, 1.65 g per 50 mL and 25.6% for temperature, pH, time, yeast dosage and ethanol yield, respectively. The kinetics of both the enzymatic hydrolysis and fermentation agreed with the Michealis-Menten kinetic model with the correlation coefficients (R2) of 0.9708 and 0.8773, respectively. However, from the error analysis, the experimental and predicted values had a very good relationship as described by Michaelis-Menten model.
•Biofertilizer was produced by aerobic composting method.•Actinomycetes isolated was found to be good agents for biofertilizer synthesis.•Organic matter and Carbon content of the composts was found ...to be decreasing.•Nitrogen contents increased significantly with time.•Leaf area index revealed 10th week as the optimum growth period for Maize and Okra.
In this work, biofertilizer was synthesized by mixing sawdust and other nitrogenous agricultural wastes into composites in the following ways: S1 (sawdust + chicken litter + vegetable waste), S2 (sawdust + sewage sludge + vegetable waste) and S3 (sawdust only as the control) respectively using actinomycetes as the microbial inoculums. In-vessel method of composting was employed with 120 L capacity polyethylene (PET) container as the bioreactor for the pilot scale study. Microorganisms were isolated from landfill extracts. Aeration was accomplished through turning of the compost twice weekly. Nitrogen, Carbon, Organic Matter and pH were determined at 5days intervals till the end of composting exercise. Flame Atomic Absorption Spectrometer (FAAS), was used for determination of the mineral composition of the raw materials and end products. American Society for Testing and Materials was used in the Analysis of Nitrogen, Carbon, and Organic Matter contents. Biofertilizer was analyzed more for activeness as organic fertilizer in the field studies using two crops (Maize and Okra). Biochemical test revealed that six genera of Actinomycetes were isolated. Inorganic salt starch agar medium was noticed to be effective isolation media for Actinomycetes. Actinomycetes were found to be good agents for biofertilizer synthesis due to their ability to mineralize nitrogen during composting. Preliminary investigation revealed that Rothia spp gave the highest percentage degradation of cellulose (21.6 %) as well as highest percentage mineralization of nitrogen (6.87 %) after 21days of incubation. Dosage ratio of 2:1:1 w: w, moisture content of 50–60 % and 25 days was found to be the optimum condition for nitrogen mineralization. Organic matter content of composts S1 and S2 decreased significantly with time while total kjeldahl nitrogen (TkN) content of the composts increased except compost S3 which on the contrary, reduced. The maximum temperature achieved at the end of 25 days compositing of substrate S2 was 64.6 ℃. Analysis of the leaf area index (LAI) revealed 10th week after transplant to be the period of optimum growth for both crops. In addition to, all the analysis conducted pointed to the fact that influence of biofertilizer on Okra and Maize growth performance is equivalent to the growth performance of chemical fertilizer on the same crops, affirming that organic fertilizer can comfortably replace chemical fertilizer in future.
•An adsorbent was produced using plantain peels.•The plantain peel adsorbent was found to be very effective in removing crude oil from water effectively.•The highest adsorption capacity was found to ...be 50.1g/mg.•Regeneration studies proved that the peels adsorbent can be reused after regeneration.•Temkin isotherm model was the model of the best fit.
In this work, acetylated plantain peels as a novel composite with high surface area and well-ordered framework of porosity was prepared. Kinetic and isotherm modelling of crude oil removal was considered as well. Batch adsorption studies were carried out with the function of oil water ratio, pH and temperature. Characterization of activated carbon was carried out to ascertain the nature of the composite prepared and its affinity to oil sorption. Surface morphology was investigated with scan electron microscope (SEM). Chemical composition of compounds was investigated using X-ray fluorescent machine while the X-ray diffraction machine (XRD) examined the crystallographic nature of the plantain peels. Salt addition techniques was employed for point zero charge analysis at ionic strengths 0.05 and 0.1 mol/dm3. The influence of pH, temperature and oil/water ratio was found to be highly significant and strongly influenced oil removal by the composite. SEM analysis showed several changes on the surface of the composite after acid treatment. XRF and XRD revealed that the raw plantain peels were highly composed of quartz. The point zero charge revealed that the surface of acetylated plantain peels was predominately positive charge at pH ranging between 4.05±0.1 and 4.07±0.1. However, the composite exhibited high adsorption efficiency at a very low pH of 5 with 90.9% of crude oil removal. Isotherm modelling revealed that the composite material was highly matched to Temkin isotherm model with maximum adsorption capacity of 50.1mg/g. The kinetic data fitted well with Bahattacharya-Venkobachor model. The regenerated biomass exhibited high performance and functionality and used successively in different adsorption activities. Therefore, acetylated plantain peel composite is an efficient, economic viable and sustainable adsorbent materials suitable in remediation of crude oil polluted water.
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The viscosity of oil-based drilling mud was optimized and modeled in this study. Imported bentonite and local clay additives, and diesel oil (base fluid) were used to prepare two muds; oil-based mud ...with bentonite (OBMB) and oil-based mud with clay (OBMC). The local clay was beneficiated with hydrochloric acid (HCl) and then characterized using an x-ray fluorescence (XRF) spectrometer. The result of the characterization revealed that the local clay is more silica (SiO2) than kaolin. The interactive effects of three operating conditions, temperature, aging time, and bentonite/clay dosage, respectively, on the viscosity of each mud were determined. The Response surface methodology (RSM) of the central composite design tool of Design Expert software (version 12) was employed to optimize the viscosity of each mud. The RSM carried out revealed the interaction between the three operating variables of temperature, time, and dosage of bentonite/clay and their impact on the viscosity of each mud. Optimum viscosity of 19.3 cP for OBMB and 25.9 for OBMC were obtained at temperature of 313K, aging time of 30 minutes and bentonite/clay dosage of 9 wt%. Analysis of variants (ANOVA), mathematical modeling, and graphical plots further established the actual interaction between the response-viscosity of each mud and the considered process factors. The generated models revealed linear, interactive, and quadratic equations which adequately described the relationship between the viscosity of each mud and the considered factors of temperature, time, and dosage. The experimental data and the predicted results were compared, and the model predicted values are in good agreement with the experimental results. Doi: 10.28991/HEF-2021-02-04-09 Full Text: PDF
This work is targeted towards addressing the crude oil pollution menace in Nigeria and other OPEC member countries where exploration and exploitation of crude oil causes oil spill in our environment. ...In order to achieve this, equilibrium, thermodynamics modelling and optimization of oil layer removal by activated plantain pseudo stem fiber has been demonstrated in this work. Plantain pseudo stem fiber adsorbent with well-ordered framework of porosity on the surface was prepared by esterification method of activation using organic acid. Effect of oil water ratio, pH and temperature were examined using batch adsorption studies. Scanning Electron Microscope and Fourier Transform Infrared spectrometer was used to ascertain the surface morphology and functional groups of the raw and treated plantain pseudo stem fiber. Thermodynamics and isotherm analysis of crude oil removal was studied using established equations. Optimization and modeling of the process parameters was done using response surface methodology and artificial neural network. Batch experiments revealed that the optimum removal of oil occurred at oil water ratio of 0.2g/100cm3 with 94.7% of oil removed. Scanning electron microscope analysis revealed the extent of changes on the surface of the composite after acid treatment. Disappearances of some functional groups occasioned by acid treatments were revealed by Fourier transform infrared spectrum analysis. Meanwhile, the activated plantain pseudo stem fiber exhibited high potential at a very low pH of 5 with 96.7% of crude oil removal. Thermodynamic studies revealed activation energy, change in enthalpy and change in entropy for irreversible pseudo-first order and pseudo-second order model as (20.51, 21.15, -0.121 KJ/mols) and (45.78, 33.59, -0.163 KJ/mols) indicating non-spontaneous process. Equilibrium modeling revealed that the composite material was highly matched to Temkin isotherm model with maximum adsorption capacity of 54.35mg/g. The adsorption capacity of 54.35mg/g is very close to 55.30mg/g reported in literature for standard adsorbent (commercial zeolite). Optimization of the process revealed the optimum conditions as 50 mins, 90 °C and 0.2 g. At this point, the theoretical oil removal was 98.61% which was experimentally validated as 98.56%. Response Surface Methodology and Artificial Neural Network adequately predicted the oil removal with correlation coefficient >0.97. Therefore, results obtained from this investigation has shown that esterified plantain pseudo stem fiber composite is an efficient, economic viable and sustainable adsorbent and suggested the production of the adsorbent in commercial quantity since the process of adsorption highly matched with the standard models.
This work focuses on the recycling of waste groundnut oil as a potential feedstock for biodiesel production using activated coconut husk as a regenerating agent. The coconut husk was functionalized ...using organic acid. The properties of the functionalized coconut husk were investigated via instrumental analysis. Non-parametric modeling involving 2-degree isotherm models were used. The regeneration/recycling of the waste oil were done in batch mode examining key factors of temperature, time, concentration and dosage. Biodiesel was synthesized from recycled waste groundnut oil using transesterification reaction. The properties of biodiesel were examined using ASTM and AOAC official standards. Brunauer-Emmett-Teller surface analysis revealed the surface area of the adsorbent as 371.88 m2/g and a porosity distribution of 0.567 η on the surface at a pH of 6.1. Batch mode analysis revealed that 97.5% of impurities was removed from waste groundnut oil under one batch process at 80 °C after 4 h with 6 g of the activated coconut husk. Langmuir isotherm model provided the best fit to the experimental data with adsorption capacity of 33.5 mg/g at R2 of 0.996. Adsorption of waste groundnut oil impurities onto activated coconut husk was endothermic, as evidenced by the calculated ΔH of +2.7914 kJ/mol. A high cetane number of 48.4 obtained after transesterification is an indication of the good ignition quality of the obtained recycled waste groundnut oil methyl ester. Kinematic viscosity and acid value were revealed to be 4.65 mm2 S−1 and 0.31 mg KOH/g, while the calorific value stood at 38,053 kJ/kg. GC-MS analysis revealed a complex mixture of fatty acid methyl esters dominated by unsaturated fatty acids (58.78%). Recycling of waste cooking oil in this work using activated coconut husk demonstrated good quality as a regenerating agent. The properties of biodiesel obtained showed that it has all the good qualities comparable to other existing biodiesel based on the ASTM and AOAC official standards. More work on the recycling of other waste cooking oils for green energy synthesis to protect our environment from pollution emanating from the use of conventional petro-diesel and promote energy transition is highly recommended.
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•Recycling of waste groundnut oil (WGO) as a potential feedstock for biodiesel production was investigated.•The regeneration/recycling of the waste oil were done in batch mode under key factors of temperature, time, concentration and dosage.•Acid Functionalized Coconut Husk proved to be a good recycling agent.•Biodiesel was synthesized from recycled waste groundnut oil (RWGO) using transesterification reaction.•Batch mode analysis revealed that 97.5% of impurities was removed from waste groundnut oil under one batch process at 80 °C after 4 h.
This work focuses on the treatment of crude oil polluted water using indigenous adsorbent prepared using mango seed shell. Esterification of mango seed shell (MSS) as a novel composite with high ...surface area and well-ordered framework of porosity was prepared and kinetic and isotherm modelling of crude oil removal considered. Batch adsorption studies were carried out with the function of oil water ratio, pH and temperature. Material characterization was carried out to ascertain the nature of the composite prepared and its affinity to oil sorption. Surface morphology was investigated with scan electron microscope (SEM). Chemical composition of compounds was investigated using X-ray fluorescent machine while the X-ray diffraction machine (XRD) examined the crystallographic nature of the pretreated mango seed shell (MSS). Salt addition techniques was employed for point zero charge analysis at ionic strengths 0.05 and 0.1 mol/dm3. The influence of pH, temperature and oil/water ratio was found to be highly significant and strongly influences oil removal by the composite. SEM analysis showed several changes on the surface of the composite after acid treatment. XRF and XRD revealed that the raw MSS were highly composed of quartz. The point zero charge revealed that the surface of esterified MSS was predominately positive charge at pH ranging between 4.06±0.1 and 4.04±0.1. However, the composite exhibited high adsorption efficiency at a very low pH of 5 with 90.69% of crude oil removal. Isotherm modelling revealed that the composite material was highly matched to Temkin isotherm model with maximum adsorption capacity of 50.80 mg/g. The kinetic data fitted well with Bahattacharya-Venkobachor model. The regenerated biomass exhibited high performance and functionality and used successively in different adsorption activities. Therefore, esterified MSS composite is an efficient, economic viable and sustainable adsorbent materials suitable in remediation of crude oil polluted water.
•An adsorbent was produced using mango seed shell.•The mango seed shell adsorbent was found to be very effective in removing crude oil from water effectively.•The highest adsorption capacity was found to be 50.1 g/mg.•Regeneration studies proved that plantain peels adsorbent can be reused after regeneration.•Temkin isotherm model was the model of the best fit.
Starch was extracted (isolated) from cocoyam with the aid of water solution of oxalic acid and ammonium oxalate in 8 samples of ratios, 1:3, 1:1, 3:1, 2:3, 2:1, 1:2 and 0:0 respectively. The ...physiochemical properties were investigated in order to unveil its characteristics and unravel the potentials for industrial applications of the cocoyam starch. The physiochemical properties investigated includes; Amylose and Amylopectin contents, water binding capacity, particle size distribution, swelling power and solubility. The results obtained showed that swelling power and solubility of the starch were temperature dependent. The solubility was found to increase with temperature increase as the cocoyam starch showed highest solubility within the 70-90
°
C temperature range. The swelling power was found fluctuating between the temperatures of 25-90
°
C. The swelling power starch sample isolated with blending ratios of 2:1 and 1:2 were temperature dependent. The Amylose content ranges from 3.06 to 31.21%.
The key process parameters for the filtration loss of water-based drilling fluid (WBDF), using Arachishypogaea shells cellulose (AHSC) were optimized using the two-level-two factor full factorial ...design of Response Surface Methodology (RSM). This research reveals the key outcomes of investigations, carried out on the formulation of a sustainable drilling fluid system, where AHSC is used as a fluid loss additive having no toxicity and high biodegradability. The characterization and pre-treatment of the AHSC used were carried out. Meanwhile, the result of the proximate analysis revealed that the AHSC had 70.40% cellulose, which is a good additive for drilling mud formulation that displays related functions as some of the foreign fluid loss polymers like polyanionic cellulose used in producing drilling muds. It was established that, additive concentration and filtration time had significant effects on WBDF formulation and performance while the optimum results were obtained as: 6g, 15 minutes and 11.58ml for additive concentration, filtration time and filtration loss, respectively. This investigation showed the suitability of AHSC as fluid loss additive that is cost-effective and eco-friendly alternative in this challenging phase of the hydrocarbon exploration industry.
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