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Mathematical and Kinetic Modelling of the Adsorption of Crude Oil Spill Using Coconut Coir Activated Carbon
Ukpong Anwana Abel,
Gumus Rhoda Habor,
Oboh Innocent Oseribho
Issue:
Volume 6, Issue 1, March 2021
Pages:
1-9
Received:
9 October 2020
Accepted:
26 October 2020
Published:
12 January 2021
Abstract: Crude oil spills have tremendous effects on our environment and poses severe pollution problems around the world as hazardous chemicals such as polycyclic aromatic hydrocarbons are released into the ecosystem. The clean-up of these spills using natural adsorbent is considered as an eco-friendly and cost effective method of handling the oil spills due to its high oil sorption capacity and biodegradability. Coconut coir predominantly found in the Niger Delta area of Nigeria was carbonized and chemically activated using Potassium Hydroxide (KOH) for the removal of crude oil spill. The kinetic data were fitted into various kinetic models with Pseudo-second order model showing best fit with a correlation coefficient R2=0.999 and the Boyd model revealed that the adsorption was controlled by internal transport mechanism and film-diffusion was the major mode of adsorption. Thus, Coconut Coir Activated Carbon (CCAC) showed significant capability to be used as a low-cost, re-generable and eco-friendly adsorbent in oil spill clean-up. A mathematical model was also developed using multivariate numerical optimization method and was validated by fitting it into the experimental data which gave a correlation coefficient R2=0.997. Hence, the empirical model developed using multivariate numerical optimization method can be used for the design of industrial treatment plant.
Abstract: Crude oil spills have tremendous effects on our environment and poses severe pollution problems around the world as hazardous chemicals such as polycyclic aromatic hydrocarbons are released into the ecosystem. The clean-up of these spills using natural adsorbent is considered as an eco-friendly and cost effective method of handling the oil spills d...
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Effect of Reducing Nitrogen and Applying Organic Fertilizer on Nitrogen Use Efficiency and Rice Yield in Red Soil Regions of the Southern China
Qihong Tu,
Zhenjiang Zhang,
Min Liu
Issue:
Volume 6, Issue 1, March 2021
Pages:
10-15
Received:
26 November 2020
Accepted:
22 December 2020
Published:
12 January 2021
Abstract: To explore the amount of reducing N fertilizer, a 2-year field experiment was conducted to investigate the effects of reducing N fertilizer and applying organic fertilizer on nitrogen use efficiency (NUE) and rice yield in red soil regions of the Southern China. On the basis of applying 4500 kg/ha organic fertilizer and local custom fertilization with 204 kg/ha urea application, five treatments including no nitrogen fertilization (CK), local customary nitrogen application (N100), and nitrogen reduction of 10% (N90), 20% (N80), and 30% (N70) were conducted. The results showed that nitrogen agronomic efficiency (NAE), nitrogen recovery efficiency (NRE), nitrogen physiological efficiency (NPE) and nitrogen partial factor productivity (NPFP) of N90 treatment were significantly higher than those of other treatments, and the yield was as high as 9.33 t/ha, which showed a significant differences compared with CK and N100. The output value, benefit, and benefit-cost ratio of N90 were significantly higher than those of N100, which increased by 6.38%, 6.42%, 8.35%, and 8.20%, respectively. In addition, while applying the same amount of organic fertilizer, the rate of nitrogen reduction has little effect on the soil organic matter content, meaning that N90 can achieve high NUE and high yield in rice. It is good to provide the theory basis for fertilizer decision-making in practice.
Abstract: To explore the amount of reducing N fertilizer, a 2-year field experiment was conducted to investigate the effects of reducing N fertilizer and applying organic fertilizer on nitrogen use efficiency (NUE) and rice yield in red soil regions of the Southern China. On the basis of applying 4500 kg/ha organic fertilizer and local custom fertilization w...
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The Initiators of the Appearance of Organic Compounds on Earth, the Distribution of Natural Radionuclides in the Plant Mass
Issue:
Volume 6, Issue 1, March 2021
Pages:
16-23
Received:
24 December 2020
Accepted:
6 January 2021
Published:
18 January 2021
Abstract: An experiment was performed on the synthesis of organic substances from a mixture of carbon monoxide and hydrogen on the surface of iron and cobalt, coated with carbide clusters, formed during processing at 573 K in an atmosphere of carbon monoxide. The obtained results indicate that the most likely direction of the formation of organic substances from mixtures of molecular hydrogen and carbon oxides is the thermal hydrogenation (radiation-thermal hydrogenation has a higher speed) at 300-573 K of carbide clusters covering the surface of metals. A significant fraction of organic matter on the Earth is formed during the solidification and cooling of the surface of a “hot” planet from 600 K to 300 K. Initiation by ionizing radiation creates the real condition for the highly endothermic processes of dissociation of water and carbon dioxide molecules, synthesis of new organic molecules and molecular oxygen. On a completely cooling up to 300 K planet this process continued by the vital activity of living organisms and during photosynthesis. The energy of quanta of visible light is much less than the energy of C=O bonds in the CO2 molecule and the dissociation energy of the H-O bond in the H2O molecules. The value of the energy of gamma quanta emitted by the K40 isotope is many times higher than the value of the dissociation energy of the H-O and C=O bonds. The analysis of numerous samples of water, soil, vegetation, livestock products showed the presence of K40 radioisotopes in all samples. The role of gamma radiation of K40 radioisotope should be taken into account at comprehensive analysis of initial stage of photosynthesis. This conclusion is consistent with the revealed facts of increased plant yields on soils with relatively high concentrations of natural radioisotopes, observation of photosynthesis under thick layers of water in the presence of only long-wave infrared rays or in the absence of chlorophyll and oxygen.
Abstract: An experiment was performed on the synthesis of organic substances from a mixture of carbon monoxide and hydrogen on the surface of iron and cobalt, coated with carbide clusters, formed during processing at 573 K in an atmosphere of carbon monoxide. The obtained results indicate that the most likely direction of the formation of organic substances ...
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Enzymatic and Dilute Acid Hydrolyses of Maize Stalk Substrate in Bio-ethanol Production
Issue:
Volume 6, Issue 1, March 2021
Pages:
24-30
Received:
1 February 2021
Accepted:
9 February 2021
Published:
23 February 2021
Abstract: Biofuels have been identified as suitable in combating climate change as a result of green gas emissions from fossil fuels. Bioethanol is a biofuel from lignocellulosic biomass is considered a viable renewable energy alternative to fossil fuels. However, the recalcitrance of biomass feedstocks due to the presence of lignin, creates a barrier to glucose fermentation. This study compares enzymatic and dilute acid hydrolyses of cellulose substrates obtained from pretreated maize stalk. The cellulose substrates were hydrolysed into glucose using dilute H2SO4, dilute HCl and Cellulase enzyme. The glucose obtained was fermented using an active yeast strain (Saccaromyces cerevisae) and then distilled in accordance with ASTM D1078 to obtain bio-ethanol. High Performance Liquid Chromatography (HPLC) was used in quantitative analyses of the bio-ethanol produced while qualitative tests were done based on ASTM D7795-12 for physical tests (density, boiling point, miscibility, non-volatile residues, colour, flammability and distillation range) and chemical tests (Acidity, Alkalinity, Fusel oil, Readily carbonizable substances and readily oxidizable substances). Enzymatic hydrolysis gave a higher glucose yield, while there was no significant difference between hydrolysis using dilute acids. There was significant difference in extraction efficiencies between acid and enzymatic hydrolysis methods. The bio-ethanol produced has similar purity levels with qualitative properties to that of an industrial grade ethanol.
Abstract: Biofuels have been identified as suitable in combating climate change as a result of green gas emissions from fossil fuels. Bioethanol is a biofuel from lignocellulosic biomass is considered a viable renewable energy alternative to fossil fuels. However, the recalcitrance of biomass feedstocks due to the presence of lignin, creates a barrier to glu...
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