scholarly journals Safe Mining Assessment of Artisanal Barite Mining Activities in Nigeria

Mining ◽  
2021 ◽  
Vol 1 (2) ◽  
pp. 224-240
Author(s):  
David Oluwasegun Afolayan ◽  
Azikiwe Peter Onwualu ◽  
Carrick McAfee Eggleston ◽  
Adelana Rasak Adetunji ◽  
Mingjiang Tao ◽  
...  
Keyword(s):  
Water Samples ◽  
Illicit Drugs ◽  
Heavy Metal Contamination ◽  
Daily Intake ◽  
Contamination Factor ◽  
Initial Section ◽  
Small Scale ◽  
Contamination Assessment ◽  
Long Time ◽  
Safe Mining

Barite, used in mud formulation, is mined in several places to support the industry. However, there is insufficient literature on the downside of mining and associated hazards, especially in the artisanal barite mining sector. This paper contains three parts. The initial section reviews major causes of mining accidents and health hazards in Nigeria. The second section examines existing but weak institutional frameworks and policies for artisanal and small-scale mining (ASM) in Nigeria. In the third part, data from questionnaires and heavy metal contamination assessment are compared with health and environmental standards to identify and characterize hazards. It was observed that 54% had health challenges traceable to illicit drugs, and 54% were ignorant about the use of safety kits. The UV-Vis, AAS, and ICP-MS analyses confirmed lead, barium, zinc, copper, and iron in the water samples. Index of geoaccumulation (Igeo) and contamination factor (CF) show that water samples are moderate to highly polluted by Pb2+, Ba2+, and highly contaminated. The chronic daily intake assessment and health quotient analysis revealed that the accumulation of lead and barium is possible and can initiate chronic diseases in humans over a long time. Certain safe mining protocols and controls are recommended.

scholarly journals Trace and Heavy Metal Contamination Status of Soil and Water in Artisanal and Small Scale Gold Mining Vicinity in Kuchiko-Hausa, Gurara LGA, Niger State, Nigeria

2020 ◽  
pp. 207-219
Author(s):  
Sani Aliyu Haruna ◽  
Amanabo Musa ◽  
Gbodi Timothy Ayinla
Keyword(s):  
Trace Metals ◽  
Water Samples ◽  
Gold Mining ◽  
Heavy Metal Contamination ◽  
Soil Surface ◽  
Soil Samples ◽  
Small Scale ◽  
Water Stream ◽  
Water And Soil Samples

Mining activities have long been recognized as a major source of environmental contamination associated with heavy metals. In this study, ten (10) trace metals namely As, Cd, Co, Cr, Cu, Fe, Hg, Ni, Pb and Zn were analysed from water (stream, river and borehole) and soil (surface and sub-soil) samples collected from around the artisanal and small scale gold mining site within the vicinity in Kuchiko-Hausa, Gurara LGA, Niger State, Nigeria using Atomic Absorption Spectroscopy. The result from the water and soil samples showed the while all the investigated trace metals were absent from all the water samples, Hg was only found with concentration of 0.006 and 0.0053 mg/mL for the stream and river water samples, the soil samples showed the presence of all the trace metals except Cd and Co with As and Cr found only in the surface soil. All detected trace metals in the samples were all lower than the WHO permissible limits. Periodic and systematic study of the investigated and other metals concentrations is therefore recommended since long-term exposure of these metals poses significant health risk for human, animals and plants.

scholarly journals Physicochemical Studies for Risk Identification, Assessment, and Characterization of Artisanal Barite Mining in Nigeria

2021 ◽  
Vol 13 (23) ◽  
pp. 12982
Author(s):  
David Oluwasegun Afolayan ◽  
Carrick McAfee Eggleston ◽  
Azikiwe Peter Onwualu ◽  
Adelana Rasak Adetunji ◽  
Mingjiang Tao ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Drinking Water ◽  
Heavy Metal Contamination ◽  
Contamination Factor ◽  
Risk Identification ◽  
Carcinogenic Risk ◽  
Small Scale ◽  
Exposure Level ◽  
Mining Activities ◽  
Mining Sites

Over 90% of barite mining activities in Nigeria are carried out by artisanal and small-scale miners (ASMs), and up to 75% of these miners operate informally, without mining license and rights. Such mining activities endanger human lives through the uncontrolled release of toxic heavy metals and other pollutants which are major causes and consequences of severe health hazards in children and adults living close to the mining sites. This paper is in two parts. The first section assesses the extent of heavy metal contamination of Cd, Cu, Fe, Pb, Ba, and Zn in drinking water by the mine water and tailing effluents. The second section estimates heavy metals’ toxicity and exposure level and analyzes and characterizes other human health risks in tailing effluents selected from three barite mining sites in Nigeria. Inductively coupled plasma mass spectroscopy (ICP-MS) results show that the concentrations of Ba and Pb among other heavy metals are above the allowable limits for drinking water. Index of geo-accumulation (Igeo) and contamination factor (CF) for Ba, Fe, and Pb were classified as moderately to extremely polluted (based on the Igeo) and highly contaminated (based on the CF). The calculated non-carcinogenic risk for Ba is 0.87 and 0.99 for Pb. HQ/HI (health quotient/health index) for Zn, Cu, and Fe is ≤0.005. The results indicate that some precautionary measures should be taken to avert the non-carcinogenic risk of Ba and Pb. It is important that barite mining is carried out in a responsible manner, respecting local and national mining laws and global environmental standards.

Non-Gaussian probability distributions of solar wind fluctuations

1994 ◽  
Vol 12 (12) ◽  
pp. 1127-1138 ◽  
Author(s):  
E. Marsch ◽  
C. Y. Tu
Keyword(s):  
Solar Wind ◽  
Probability Distributions ◽  
Time Lag ◽  
Small Scale ◽  
Time Lags ◽  
Mhd Turbulence ◽  
Theoretical Concepts ◽  
Fluid Turbulence ◽  
Long Time ◽  
Non Gaussian

Abstract. The probability distributions of field differences ∆x(τ)=x(t+τ)-x(t), where the variable x(t) may denote any solar wind scalar field or vector field component at time t, have been calculated from time series of Helios data obtained in 1976 at heliocentric distances near 0.3 AU. It is found that for comparatively long time lag τ, ranging from a few hours to 1 day, the differences are normally distributed according to a Gaussian. For shorter time lags, of less than ten minutes, significant changes in shape are observed. The distributions are often spikier and narrower than the equivalent Gaussian distribution with the same standard deviation, and they are enhanced for large, reduced for intermediate and enhanced for very small values of ∆x. This result is in accordance with fluid observations and numerical simulations. Hence statistical properties are dominated at small scale τ by large fluctuation amplitudes that are sparsely distributed, which is direct evidence for spatial intermittency of the fluctuations. This is in agreement with results from earlier analyses of the structure functions of ∆x. The non-Gaussian features are differently developed for the various types of fluctuations. The relevance of these observations to the interpretation and understanding of the nature of solar wind magnetohydrodynamic (MHD) turbulence is pointed out, and contact is made with existing theoretical concepts of intermittency in fluid turbulence.

scholarly journals Evaluation of Minerals Content of Drinking Water in Malaysia

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Azrina Azlan ◽  
Hock Eng Khoo ◽  
Mohd Aizat Idris ◽  
Amin Ismail ◽  
Muhammad Rizal Razman
Keyword(s):  
Drinking Water ◽  
Water Samples ◽  
Mineral Water ◽  
Tap Water ◽  
Fluoride Concentration ◽  
Daily Intake ◽  
Peninsular Malaysia ◽  
Mineral Water Sample ◽  
Geographical Locations ◽  
Iron And Manganese

The drinking and mineral water samples obtained from different geographical locations had concentrations of the selected minerals lower than the standard limits, except for manganese, arsenic, and fluoride. The concentrations of manganese and arsenic in two mineral water samples were slightly higher than the standard international recommended limits. One mineral water sample had a fluoride concentration higher than the standard limits, whereas manganese was not detected in nine drinking and mineral water samples. Most of the selected minerals found in the tap water samples were below the international standard limits, except for iron and manganese. The concentrations of iron and manganese in the tap water samples were higher than the standard limits, which were obtained from one and three of the studied locations, respectively. The potable water obtained from various manufacturers and locations in Peninsular Malaysia is safe for consumption, as the minerals concentrations were below the standard limits prescribed by the Malaysian Food Regulations of 1985. The data obtained may also provide important information related to daily intake of these minerals from drinking water.

scholarly journals Long-term investigation of phosphorus removal by iron electrocoagulation in small-scale wastewater treatment plants

2018 ◽  
Vol 78 (6) ◽  
pp. 1304-1311 ◽  
Author(s):  
I. Mishima ◽  
M. Hama ◽  
Y. Tabata ◽  
J. Nakajima
Keyword(s):  
Wastewater Treatment ◽  
Phosphorus Removal ◽  
Wastewater Treatment Plants ◽  
Phosphorus Release ◽  
Small Scale ◽  
Operational Conditions ◽  
Long Time ◽  
Negative Effect ◽  
Iron Electrolysis

Abstract Small-scale wastewater treatment plants (SWTPs), called Johkasou, are widely used as decentralized and individual wastewater treatment systems in sparsely populated areas in Japan. Even in SWTPs, nutrients should be removed to control eutrophication. An iron electrolysis method is effective to remove phosphorus chemically in SWTPs. However, it is necessary to determine the precise conditions under which phosphorus can be effectively and stably removed in full scale SWTPs for a long period. Therefore, long-term phosphorus removal from SWTPs was investigated and optimum operational conditions for phosphorus removal by iron electrolysis were analyzed in this study. Efficient phosphorus removal can be achieved for a long time by adjusting the amount of iron against the actual population equivalent. The change of the recirculation ratio had no negative effect on overall phosphorus removal. Phosphorus release to the bulk phase was prevented by the accumulated iron, which was supplied by iron electrolysis, resulting in stable phosphorus removal. The effect of environmental load reduction due to phosphorus removal by iron electrolysis was greater than the cost of power consumption for iron electrolysis.

scholarly journals A theoretical verification of the integral fluctuation theorem for accelerated colloidal systems in the long-time limit

2021 ◽  
Author(s):  
Yash Lokare
Keyword(s):  
Steady State ◽  
Time Scales ◽  
Numerical Study ◽  
Quantitative Description ◽  
Experimental Studies ◽  
Fluctuation Theorem ◽  
Nonequilibrium Steady States ◽  
Small Scale ◽  
Colloidal Systems ◽  
Long Time

A quantitative description of the violation of the second law of thermodynamics in relatively small classical systems and over short time scales comes from the fluctuation-dissipation theorem. It has been well established both theoretically and experimentally, the validity of the fluctuation theorem to small scale systems that are disturbed from their initial equilibrium states. Some experimental studies in the past have also explored the validity of the fluctuation theorem to nonequilibrium steady states at long time scales in the asymptotic limit. To this end, a theoretical and/or purely numerical model of the integral fluctuation theorem has been presented. An approximate general expression for the dissipation function has been derived for accelerated colloidal systems trapped/confined in power-law traps. Thereafter, a colloidal particle trapped in a harmonic potential (generated by an accelerating one-dimensional optical trap) and undergoing Brownian motion has been considered for the numerical study. A toy model of a quartic potential trap in addition to the harmonic trap has also been considered for the numerical study. The results presented herein show that the integral fluctuation theorem applies not only to equilibrium steady state distributions but also to nonequilibrium steady state distributions of colloidal systems in accelerated frames of reference over long time scales.

On the analysis of the integral fluctuation theorem for accelerated colloidal systems in the long-time limit

2021 ◽  
Author(s):  
Yash Lokare
Keyword(s):  
Steady State ◽  
Time Scales ◽  
Numerical Study ◽  
Quantitative Description ◽  
Experimental Studies ◽  
Fluctuation Theorem ◽  
Nonequilibrium Steady States ◽  
Small Scale ◽  
Colloidal Systems ◽  
Long Time

Abstract A quantitative description of the violation of the second law of thermodynamics in relatively small classical systems and over short time scales comes from the fluctuation-dissipation theorem. It has been well established both theoretically and experimentally, the validity of the fluctuation theorem to small scale systems that are disturbed from their initial equilibrium states. Some experimental studies in the past have also explored the validity of the fluctuation theorem to nonequilibrium steady states at long time scales in the asymptotic limit. To this end, a theoretical and/or purely numerical model of the integral fluctuation theorem has been presented. An approximate general expression for the dissipation function has been derived for accelerated colloidal systems trapped/confined in power-law traps. Thereafter, a colloidal particle trapped in a harmonic potential (generated by an accelerating one-dimensional optical trap) and undergoing Brownian motion has been considered for the numerical study. A toy model of a quartic potential trap in addition to the harmonic trap has also been considered for the numerical study. The results presented herein show that the integral fluctuation theorem applies not only to equilibrium steady state distributions but also to nonequilibrium steady state distributions of colloidal systems in accelerated frames of reference over long time scales.

Community Replacement Pathways: What Do Fossil Sequences Reveal About Marine Ecosystem Transitions?

1990 ◽  
Vol 5 ◽  
pp. 262-272
Author(s):  
William Miller
Keyword(s):  
Fossil Record ◽  
Large Scale ◽  
Marine Ecosystem ◽  
Small Scale ◽  
Data Sets ◽  
Mass Extinctions ◽  
Ultimate Cause ◽  
Long Time ◽  
History Of ◽  
Time And Energy

Paleontologists have lavished much time and energy on description and explanation of large-scale patterns in the fossil record (e.g., mass extinctions, histories of monophyletic taxa, deployment of major biogeographic units), while paying comparatively little attention to biologic patterns preserved only in local stratigraphic sequences. Interpretation of the large-scale patterns will always be seen as the chief justification for the science of paleontology, but solving problems framed by long time spans and large areas is rife with tenuous inference and patterns are prone to varied interpretation by different investigators using virtually the same data sets (as in the controversy over ultimate cause of the terminal Cretaceous extinctions). In other words, the large-scale patterns in the history of life are the true philosophical property of paleontology, but there will always be serious problems in attempting to resolve processes that transpired over millions to hundreds-of-millions of years and encompassed vast areas of seafloor or landscape. By contrast, less spectacular and more commonplace changes in local habitats (often related to larger-scale events and cycles) and attendant biologic responses are closer to our direct experience of the living world and should be easier to interpret unequivocally. These small-scale responses are reflected in the fossil record at the scale of local outcrops.

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