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Amalu Titus Oko Ugwu Igwe Izuchukwu Ehugbo Uchenna Okeh Benedette Duluora Emmanuel 《GeoJournal》2021,86(4):1691-1703
GeoJournal - The tourism industry has been touted to have huge significant impact on the social and economic growth of local people across the world. This study is carried out to examine the role... 相似文献
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Adsorption kinetics and intraparticulate diffusivities of Hg, As and Pb ions on unmodified and thiolated coconut fiber 总被引：9，自引：9，他引：0
J. C. Igwe M.Sc. D.CHE M.Eng. Ph.D. A. A. Abia M.Sc. Ph.D. C. A. Ibeh B.Sc. 《International Journal of Environmental Science and Technology》2008,5(1):83-92
As, Hg and Pb are examples of heavy metals which are present in different types of industrial effluents responsible for environmental pollution. Their removal is traditionally made by chemical precipitation, ion-exchange and so on. However, this is expensive and not completely feasible to reduce their concentrations to the levels as low as required by the environmental legislation. Biosorption is a process in which solids of natural origin are employed for binding the heavy metal. It is a promising alternative method to treat industrial effluents, mainly because of its low cost and high metal binding capacity. The kinetics was studied for biosorption experiments using coconut fiber for As (III), Hg (II) and Pb (II) ions adsorption. The specific surface area and surface charge density of the coconut fiber are 1.186×1025 (m2/g) and 5.39 ×1024 (meq/m2), respectively. The maximum adsorption capacity was found to be the highest for Pb (II) followed by Hg (II) and As (III). The modification of the adsorbent by thiolation affected the adsorption capacity. Equilibrium sorption was reached for the metal ions at about 60 min. The equilibrium constant and free energy of the adsorption at 30 °C were calculated. The mechanism of sorption was found to obey the particle-diffusion model. The kinetic studies showed that the sorption rates could be described by both pseudo first-order and pseudo second-order models. The pseudo second-order model showed a better fit with a rate constant value of 1.16 × 10?4/min. for all three metal ions. Therefore, the results of this study show that coconut fiber, both modified and unmodified, is an efficient adsorbent for the removal of toxic and valuable metals from industrial effluents. 相似文献
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Ogbonnaya Igwe 《Journal of the Geological Society of India》2018,91(2):227-231
Jharkhand is well known for the largest iron deposits in India. Noamundi is the main deposit, which is associated with shale, keolinite. The rock succession exposed in the southern Singbhum and Keonjhar and lying unconformably over the older metamorphics are known as Iron Ore Series (Ravindrakumar, 1986). This paper relates the assessment of grades of iron ore of the area. The study involves with pre-processing, FLAASH (Fast Line-of-Sight Atmospheric Analysis of Spectral Hypercubes) Atmospheric correction algorithms of EO-1 Hyperion data and evaluating the spectral characteristic by using ENVI 4.7 software package. The position of peak reflectance and absorption trough, continuums removal and absorption band depth are considered for assessment the spectral characters. The strong absorption observed is between the 860 to 900nm wavelength region and peak reflectance is observed in the 750 to 780nm wavelength region of the image spectra. The position of the NIR absorption trough shift to the direction of the longer wavelengths is due to decrease of iron content. Higher values of band depth indicate a better possibility of the iron occurrence. As a result, this spectral study enables the possibility to differentiate the grades of iron ores from hyperspectral satellite images. 相似文献
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Variations in soils derived from an erodible sandstone formation and factors controlling their susceptibility to erosion and landslide 总被引：4，自引：0，他引：4
Environmental degradations caused by erosion and landslide within an area in the South-eastern part of Nigeria were assessed, and also an attempt to characterize the underlying soils based on their degree of susceptibility to erosion and landslide. Factors affecting soil erodibility such as physical and chemical properties of soil, as well as vegetation density and slope gradient was determined in 20 different areas. Simple linear regression and principal component analysis were employed to relate the factors controlling erosion and landslide to the erosion and slide densities, and to determine the pattern that exists in the data and as well express the data in such a way as to highlight their similarities and differences. Four vertical horizons and two horizontal zones of soil were distinguished based on their degree of weathering as well as their chemical and mineralogical composition; hence the soils were classified into six different types based on their degree of susceptibility to erosion and landslide. Variations in their degree of susceptibility to erosion and landslide were majorly controlled by its chemical and mineralogical composition rather than its particle size distribution. 相似文献
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Ogbonnaya Igwe 《Landslides》2014,11(2):319-326
A catastrophic rock debris avalanche on one of the highlands demarcating Cameroon and Nigeria, 3 days after a transient period of heavy rainfall in November 2010, killed two people and damaged economic trees, plants and farmlands. Detailed field investigation and sampling were undertaken by a team from the International Programme on Landslide to analyse the slope movement. The investigation was in two phases—5 days and then 7 months after the event to study the effect of alternating dry and rainy seasons on the geotechnical properties of the materials associated with the slope failures. It was also aimed at assessing the effect of time on the morphology of the slip plane as a new approach to understanding the development of potential failure planes and reactivated landslides. Available evidence showed that present failure planes form mini-deposition axes which may become future slip zones as they are still steep enough to accelerate instability. The research also traced the pattern of rock weathering and joints evolution in the area and found that the systematic weathering of feldspar in the basement aggravated slope instability by creating zones of weakness characterized by structures that aid fragmentation. Soils were thin (<1 m) in some slopes and deep (>2 m) in others and may represent the differential effect of weathering and erosion on the mountains which are important in analyzing the mechanism and mobility of the failed masses. Samples collected were subjected to various geotechnical laboratory tests such as unconsolidated undrained triaxial, consistency, particle size and permeability tests. 相似文献
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Detailed studies on the micromorphology and mineralogy of two guillied soils in Anambra State of Nigeria were carried out. Thin sections were prepared and point counting technique used in investigating the pedological features. Micromorphological analysis indicates that the S-matrix of the soil have mainly sepic and inundulic with few asepic plasmic fabric. Distribution patterns are agglomeroplasmic to porphyroskelic and granular.Clay mineralogy was determined by x-ray diffractometry and the result reveals that the soils are mostly dominated by kaolinite and quartz.Macromorphologically, the soils are very deep, well drained and coarse to medium textured with granular and medium subangular structures.The occurrence of ferriargillans in the B-horizon is a strong indication of pedotranslocation. Other contemporary processes or regrouping phenomena are pedotranslocation, pedoturbation, pedocompaction and pedotransformation of minerals. The role of clay mineralogy type in soil erosion problems is discussed. 相似文献
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The influence of grading on the shear strength of loose sands in stress-controlled ring shear tests 总被引：1，自引：1，他引：1
Three silica sand samples—well graded, intermediately graded, and narrowly graded—having different uniformity coefficients,
were constituted to allow the investigation of the influence of particle size distribution on their mechanical behavior. Using
a ring shear apparatus, samples were tested under a wide range of laboratory conditions. Results of the tests clearly indicate
that, for specimens confined under identical stress conditions, well-graded specimens have higher values of peak and steady
state strengths than the rest of the specimens. A relationship between uniformity coefficient and shear strengths shows that
the higher the uniformity coefficient, the higher the shear strength. On account of these, well-graded specimens have higher
static liquefaction resistance than the poorly graded specimens. Within the range of normal stresses employed in the tests,
results reveal that not only are poorly graded sands more likely to suffer higher postfailure strength reduction, but that
their steady-state strengths are easily reduced to zero, the magnitude of the confining stress notwithstanding. This reduction
of shear resistance to zero has been described as complete liquefaction in this paper. While almost all of the narrowly graded
specimens suffered complete liquefaction, widely graded ones did not; an observation that seem to highlight the influence
of grading on the mechanical behavior of the sands. 相似文献