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Volume 4, Problème 5 (2021)

article de recherche

Investigating Invalidity of Air Dispersion Gaussian Plume models using Three Dimensional Finite Element Model

Youssef Hafez*

Although deficiencies in air dispersion Gaussian plume models have been well known, yet quantification of their negligence of some mechanisms like the longitudinal diffusion has not been yet made. This is done in this study using a three dimensional unsteady finite element model, Suite-3D (Solving Unsteady Incompressible Transport Equation in Three Dimensions, 3D). The model is developed to solve the advection-diffusion transport equation with decay and source terms. Suite-3D uses the standard Galerkin’s method without upwinding. Difference schemes are used (central, backward, forward) for the time integration. The elements are 8-node cubic brick elements (hexahedrons). Eight Gaussian quadrature points are used for the numerical integration of the element matrices. Suite-3D is validated against exact solutions of two problems; one has only advection and diffusion terms while the other has advection-diffusion-decay-source terms. The total percentage relative error for the first case was less than 0.61% while it reached 1.0% in the second case. The model is applied to study air pollution dispersion due to a point source. Special treatment is applied to allow comparing Suite-3D with the steady Gaussian
plume model. It is noted that neglecting the x-diffusion term in Gaussian plume model under calm wind conditions (velocity=0.2 m/s) results in discrepancies up to 81% at 180 m downstream of the source compared to prediction by the Gaussian plume model. In this zone Gaussian plume models can be considered to be not valid.

article de recherche

Comparative Assessment of Some Heavy Metals Bioaccumulation in Juvenile African Catfish (Clarias Gariepinus) Exposed to Detergent and Spent Oil Pollutants

Abidemi Iromini, Atilola O

Head, trunk and tail of juvenile Clarias gariepinus exposed to pollutants; Detergent, Spent Oil and Detergent & Spent Oil in the volume 20 mg/L, 4 mg/L and 20 mg/L & 4 mg/L respectively, and were observed for the uptake of some selected heavy metals (Cu, Pb, Fe, Mn, and Zn). The study reveals the contamination of fish samples with heavy metals. The uptake of heavy metals in Fish samples were in the order of Fe> Zn> Cu> Mn> Pb in all pollutants, in the trend of Head>Trunk>Tail. The highest mean concentration was observed in Fe 48.33 ± 0.88(mg/kg) in the head of samples treated with detergent and Spent Oil, with uptake levels higher than the maximum permissible limits prescribed by WHO/ FAO. Whereas the concentration of heavy metals Cu, Pb, Mn and Zn were below the maximum permissible limits. The lowest mean concentration was observed in the tail.

Commentaire

Charcoal briquettes; clean energy for cooking in Uganda

Godfrey Korinako Atuheire*

Charcoal briquettes are a solid and convenient fuel source made from densification of agricultural waste. A briquette is a compressed block of coal dust or other combustible biomass material (e.g. charcoal, sawdust, wood chips, [peat, or paper) used for fuel and kindling to start a fire. The term derives from the French word break, meaning brick. Densification involves conversion of combustible, low density materials and compressing them into solid fuel of a convenient shape. As such, briquettes have a high bulk density compared to fire wood and loose biomass, giving a longer burning time and thus cost savings for the user. In addition, briquettes offer other advantages such as burning with negligible smoke and no odor, producing less residual ash, being dust free and can be formed into uniform sizes and shapes which eases packing and are easy to use.

article de recherche

Incidence of the genus Aspergillus and its species in the atmosphere of Sao Paulo, Brazil and its relations with the environment

Dulcilena De Matos Castro E Silva

Bioaerosols are biological materials suspended in the air, and they also include fungi. The fungal genus Aspergillus is relevant in the
respiratory infection of critical patients, and Aspergillus fumigatus is the most frequent species in the Metropolitan Region of Sao Paulo
(MRSP), Brazil.

Article de révision

The Effect of Environmental Pollution on Life Expectancy in the U.S

Shivam Jha*

This paper studies the effect of environmental pollution on life expectancy across US counties. Controlling for the effect of
socioeconomic factors such as income and smoking habits. I find that air pollution shortens life expectancy by approximately one year for every
extra ten micro grams of fine particulate matters (PM2.5) per cubic meter of air, and chemical disposal shortens life expectancy by about 1
month for each standard deviation increase in pounds of chemicals disposed. The effects are stronger on males compared to females.

Article de révision

India at A Turning Point: Coal or Renewables-At Stake the Future of the Nation

Wangchuk Chungyalpa

Under the “Atmanirbhar Bharat Abhiyan”, the self-reliant India Scheme, the current BJP government wants to make India completely
self-sufficient concerning energy requirements. To meet the growing energy needs of the nation, they plan to exploit coal deposits of India.
This has major environmental implications as coal is one of the most pollutant forms of fossil fuel. This commentary article examines the
pros and cons of such a decision. It considers all arguments and highlights why such a decision is short sighted and disastrous for the
environment-nationally as well as globally.

Article de révision

Characteristics of Methyl Ter-Butyl Ether (MTBE), a Pollutant, in Drinking water: A Review

Shumaila Javed

As MTBE is another safer possible substitute of diethyl ether, MTBE is extensively used in industry as the Tert-Butyl group avoids MTBE
from forming potentially explosive peroxides. In the methodology of contact dissolution therapy, MTBE is injected directly into the gallbladder
to dissolve gallstones. Certain bacterial strains have been degenerated MTBE under strongly toxic conditions, particularly at the aerobic
fringes of petroleum hydrocarbon plumes which can describe that large MTBE groundwater plumes are generally not experienced. Acute
exposure of humans to high concentrations of MTBE can result in nausea, vomiting, dizziness, and sleepiness. Animal studies have shown
that MTBE is rapidly absorbed following oral or inhalation exposures. Animal studies indicate that MTBE is rapidly distributed in the blood to
all parts of the body including the brain. Animal studies have shown that MTBE is rapidly excreted following oral or inhalation exposures.
Animal morbidity knowledge indicate that MTBE is low in acute toxicity. Information on the developmental or reproductive toxicity of MTBE in
humans was not found in the available secondary sources. In animal studies, high concentrations of MTBE produced developmental and
reproductive toxicity in mice and rats. Treatment of alkyl group Tert-Butyl Ether from contaminated surface and groundwater provides presents
specific challenges thanks to the chemical science properties of MTBE that rely powerfully on its hydrophilic nature. Separation Methyl-tert-butyl
ether is one of the most challenging processes in the chemical industry.

Article de révision

Impact of Ozone Layer Depletion on Enviroment

Fareeha Shahid

The presence of ozone in stratosphere has play very important role in existence and survival of human beings and all other kind of life. It is
very important factor for all kind of biological and global phenomenon. It is very important because it act as a barrier against the harmful
ultraviolet radiations and balance the life in biosphere. But unfortunately, different anthropogenic activities such as emissions of CFCs,
HCFCs, methyl chloride, methyl bromide and other halogens lead to the depletion of ozone. The ozone depletion resulted in production
of an ozone layer in troposphere near the ground which act as a pollutant and it is responsible for adverse effects on plants, humans
and aquatic environment and it has increased different kinds of diseases in humans. The mutations caused by UV rays result in variation
in different traits of plants which ultimately decrease in production of crops. However, UV radiation is required in optimum intensity for both
plants and animals. The wide-ranging effects of ozone depletion with most of them being detrimental for all kinds of system are being assessed.
The adverse effects of ozone depletion can be minimized by adopting some measures including preferring public transport, minimizing the
use of harmful nitrogenous compounds, planting trees and most important is the use of less harmful alternatives of ozone depletion
substances.

Article de révision

Impact of Ozone Layer Depletion on Enviroment

Fareeha Shahid

The presence of ozone in stratosphere has play very important role in existence and survival of human beings and all other kind of life. It is
very important factor for all kind of biological and global phenomenon. It is very important because it act as a barrier against the harmful
ultraviolet radiations and balance the life in biosphere. But unfortunately, different anthropogenic activities such as emissions of CFCs,
HCFCs, methyl chloride, methyl bromide and other halogens lead to the depletion of ozone. The ozone depletion resulted in production
of an ozone layer in troposphere near the ground which act as a pollutant and it is responsible for adverse effects on plants, humans
and aquatic environment and it has increased different kinds of diseases in humans. The mutations caused by UV rays result in variation
in different traits of plants which ultimately decrease in production of crops. However, UV radiation is required in optimum intensity for both
plants and animals. The wide-ranging effects of ozone depletion with most of them being detrimental for all kinds of system are being assessed.
The adverse effects of ozone depletion can be minimized by adopting some measures including preferring public transport, minimizing the
use of harmful nitrogenous compounds, planting trees and most important is the use of less harmful alternatives of ozone depletion
substances.

Article de révision

Heavy Elements in Soil of West Qurna-1 Oil Field in Basrah Governorate, Southern Iraq

Hamid T Al-Saad, Hamzah A Kadhim, Makia M Al-Hejuje

Soil samples were collected seasonally from ten locations in west Qurna-1 oil field from January-December, 2018 to determine the
concentrations of some heavy elements (lead (Pb), nickel (Ni), Copper (Cu), Cadmium (Cd), Manganese (Mn) and Iron (Fe) in exchangeable
and residual phases of soil. The results of seasonal mean concentrations in exchangeable phase of (pb, Ni, Cu, Cd, Mn and, Fe) showed
that, the highest concentration were (16.85, 39.47, 21.21, 5.60, 358.42, and 641.44) μg/g dry weight respectively, while the lowest
concentration were (14.50, 31.37, 18.39, 3.90, 340.41 and 619.48) μg/g dry weight respectively . The result of seasonal mean
concentrations in residual phase of (pb, Ni, Cu, Cd, Mn and, Fe) showed that, the highest concentration were (27.04, 84.82, 28.75,
7.73, 259.83, and 649.30) μg/g dry weight respectively, while the lowest concentration were (24.95 , 81.38, 26.74, 6.71, 228.46, 641.44) μg/g
dry weight respectively. Heavy elements indices (Geo-accumulation index (I-geo), Contamination Factor (CF) and Enrichment Factor (EF) were
calculated for soil, according to I-geo Index, the soil in the study area was practically unpolluted with Ni, Cu, Mn, Fe, while the soil was
unpolluted to moderately polluted with Pb, and for Cd the soil was strongly polluted to extremely polluted.

Recherche

Assessment of Solid Waste Management Practices among Residents of Buari Ishola Isibo in Ede North Local Government Area, Osun State, Nigeria

Omoge Adeyemi O, Abraham Frank U, Adekale Temitope A, Adesegun Mobolaji M, Coursin Oluwapelumi O, Odide and Clement E

Background: Waste management is of crucial concern for public health. Inadequate solid waste management heightens the morbidity and mortality in various ways. In many developing countries, the development of waste management has not kept up with the rapid urbanization and growing consumption and has therefore grown to a big problem. The increasing difficulty in managing wastes in Nigeria has become one of the most intractable environmental issues.

Objective: This study seeks to evaluate the solid waste management practices among residents Buari Ishola Isibo in Ede North Local Government Area, Osun State, Nigeria.

Methodology: A descriptive cross – sectional study was used and multi-stage random sampling method was employ in selecting 60 households of Buari Ishola Isibo in Ede North Local Government Area, Osun State, Nigeria. Questionnaire was used for data collection and data was analyzed using SPSS version 21.

Results: The age of the respondents were between 15 – 60 years and above. 29 (48.3%) were between 31 – 60 years old, 31 (52.0%) were males, 40 (66.7%) were married, 57 (95.0%) were Islam and Yoruba. 29 (48.3%) earned 10,000 – 30,000 monthly, 23 (38.3%) had secondary school education, 39 (65.0%) were traders and 27 (45.0%) have 6 – 10 households respectively. Of the 60 respondents, 28 (46.7%) collect their refuse in an open dustbin, 35 (58.3%) empty their dustbin into river/stream, 24 (40.0%) empty their dustbin twice a week. 47 (78.3%) had no communal refuse depot in their community, 35 (58.3%) uses river/stream as their predominant community refuse depot and 44 (73.3%) make use of open dumping as their main refuse disposal methods.

Conclusion: Inadequate solid waste management heightens the morbidity and mortality in various ways. Right solid waste management is prerequisite to aesthetic living conditions in any environment. Maintaining effective solid waste management practices in any community will help curbing the spread of infectious diseases causing organisms, environmental hazards and improve the standard of living.

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