Health and Environment

Oil Spill Cleanup with Raw Luffa Aegyptiaca Sponge: Modification Effects, Sorption Isotherm, Kinetics and Thermodynamics

Adaku Chinonyerem Ajiwe — 2025-09-25

Oil spill can be extremely hazardous and environmentally threatening, and therefore needs to be contained and cleaned up as soon as possible. These serious environmental consequences have long been recognized and considerable research and technological development has been carried out to develop appropriate remediation techniques. Most of the sorbents in use for cleanup technologies are synthetic, non-biodegradable and imported. There is need to develop natural sorbents which are biodegradable, cost effective and readily available in line with agricultural wastes Luffa aegyptiaca sponge were functionalized by acetylation to increase their hydrophobic properties and oil sorption capacities. Structural modification from acetylation of Luffa aegyptiaca sponge was analyzed using Fourier Transform Infrared Spectroscopy (FTIR). The effect of time and catalysts (KBr and KI) on the acetylation process was examined to optimize conditions. Sorption behaviours was studied using kinetic models, including first, Hill second, Pseudo-second and Intra-particle diffusion models. Isotherm models such as Langmuir, Freundlich and Temkin isotherm model were also used to analyze the crude oil sorption behaviour. The results reveal that the acetylation significantly enhanced the hydrophobic properties of the materials. The kinetic studies of all the samples demonstrated that acetylation process adhered to pseudo-second order kinetics model with high R²values. In the crude oil sorption analysis, the values of the coefficient of determination indicated that the Freundlich isotherm model has a better correlation, by implying that the adsorption from acetylation is heterogeneous and multi-layered. The FTIR spectra confirmed successful acetylation through the presence of characteristic functional groups. The SEM analysis of the acetylated sample revealed significant changes in surface morphology, with increased porosity and roughness compared to the raw samples. The findings demonstrated that the acetylated materials could serve as effective, natural sorbents for oil spill remediation, offering a sustainable and cost effective alternatives to synthetic sorbents.

Comparative Evaluation of the Structural and Adsorptive Properties of Modified and Unmodified Cucurbita moschata Seed Husk for Crude Oil Spill Clean-up

Adaku Chinonyerem Ajiwe — 2025-08-19

This study investigates the structural and adsorption properties of modified and unmodified Cucurbita moschata seed husk with a view to evaluating its potential as a low-cost bio-sorbent for crude oil clean-up. The raw seed husk was subjected to chemical modification through acetylation, aiming to enhance its surface characteristics and functional group availability. Comprehensive characterizations were conducted using Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and surface area analysis to determine changes in morphology and functional groups. Batch adsorption experiments were carried out to assess the sorption efficiency of both modified and unmodified Cucurbita moschata seed husk in removing crude oil from aqueous solutions under varying conditions of contact time, catalyst usage. Adsorption kinetics and isotherm models, including first-order, pseudo-second-order, Intra diffusion, Freundlich, Langmuir and Temkin were applied to interpret the experimental data. The results revealed that acetylation significantly improved the surface roughness, porosity and active binding sites of the sample, leading to enhanced oil uptake capacity. The modified Cucurbita moschata seed husk exhibited superior adsorption efficiency, with equilibrium data fitting well to the Freundlich isotherm and Pseudo-second order kinetic model, indicating multilayer adsorption on a heterogeneous surface. These findings suggest that modified Cucurbita moschata seed husk, holds promising potential as a sustainable, ecofriendly, and effective adsorbent for treating oil spill clean-up in our environment

Correlation between precipitation over the Andralanitra landfill and PM2.5 and PM10 concentrations in the City of Antananarivo, Madagascar

NËL Andriaseta — 2025-04-03

This study examines the correlation between particulate matter (PM2.5 and PM10) concentrations in the city of Antananarivo and precipitation over the constantly burning open landfill (Andralanitra), located 12 km from the city. Statistical analysis was conducted using daily PM2.5 and PM10 concentration data from air quality monitoring stations (November 2023 to October 2024) and daily precipitation data from the Andralanitra landfill. The results indicate a weak negative correlation between the daily concentrations of PM2.5 and PM10 and the daily precipitation levels. The correlation is stronger for PM10 than for PM2.5, likely due to the differences in particle size: PM10 particles are more affected by precipitation. Additionally, monthly precipitation levels at Andralanitra show a moderate negative correlation with the monthly concentrations of PM2.5 and PM10. Seasonal variations also influence the overall concentrations of PM, and an increase in precipitation intensity at Andralanitra leads to a reduction in the number of days considered polluted. These findings emphasize that air pollution caused by particulate matter (PM2.5 and PM10) is directly influenced by precipitation levels at Andralanitra.

The role of infectious disease in the loss of biodiversity

Merrill Singer — 2024-09-16

Discussion of the relationship of infectious disease and biodiversity loss most commonly is framed in terms of the impact of diminishing biodiversity on zoonotic diseases among humans. Less examined is the role of infectious disease as a direct driver of biodiversity loss through species declines, local extirpations, and global extinctions. Recent studies, however, suggest that infectious diseases in wildlife populations are emerging at notably high rates. The diversity of emerging infectious diseases, magnified by the likelihood that there will be an increased frequency of outbreaks over time, have raised concern that infectious disease may play a strong role in wildlife species extinctions. The purpose of this Commentary is to draw attention to the growing role infectious pathogens are having in wild animal biodiversity loss and ecosystem disruption, changes which, in turn, rebound on human health and wellbeing.

Environmental and chemical determinants of contamination and survival of Vibrio cholerae in water sources in Bukavu in the Democratic Republic of the Congo

Albert M. Mumbumbu — 2024-07-22

Introduction: Cholera is endemo-epidemic in Bukavu. The aim of the study was to assess the environmental determinants of permanent contamination of spring and well water and to evaluate some of the chemical factors responsible for the persistence of Vibrio cholerae in water consumed by cholera patients.
Methods: Conducted in the Bukavu health district from September 2020 to September 2021, this was a cross-sectional. The potential of hydrogen (pH) of the water was evaluated before comparing it with the survival of Vibrio cholerae. A total of 641 latrines, 92 water sources, and wells were surveyed, with 298 samples analyzed in the laboratory.
Results: Out of the 641 latrines surveyed, 367 (57%) were found to be unsanitary; 54 (59%) of the water sources and wells were also deemed unsanitary. In total, 57% of the water samples were found to contain Vibrio cholerae, with 90% exhibiting an alkaline pH, of which 54% tested positive for the bacteria. Conversely, 10% of the samples had an acidic pH, with 80% of those containing Vibrio cholerae. The pH levels of the water remained alkaline both during the epidemic (95%) and post-epidemic (84%), thereby favoring the survival of Vibrio cholerae serotypes Ogawa and Inaba in these water sources. An acidic pH was observed to increase the likelihood of Vibrio cholerae survival in these waters by a factor of 3.39.
Conclusion: Spring and well water are consistently contaminated with Vibrio cholerae due to the unsanitary conditions of nearby latrines. The presence of Vibrio cholerae serotypes Inaba and Ogawa in these water sources is further influenced by the alkaline and acidic pH levels.

Study of thermal comfort in some standard school buildings: A case of Madagascar island

Sinta Rivel — 2024-07-11

This study focuses on thermal comfort in some classroom school buildings of the Malagasy Ministry of National Education, located in the city of Diego-Suarez, characterized by a warm tropical climate throughout the year. This study was carried out in December 2023, then between January and February 2024. The analysis is based on the adaptive approach, using questionnaires and taking measurements of thermal parameters via weather sensor. During study hours from 7:30 a.m. to 11:30 a.m. in the morning and 2:30 p.m. to 5:30 p.m. in the afternoon, the questionnaires are completed at the same time as in-situ measurements are taken. In total, 223 questionnaires were completed by the occupants including (students and teachers), distributed in four classrooms of two different primary schools. The results reveal that the percentage of thermal acceptance inside the old school reaches 35%, compared to only 15% for the modern school. The majority of respondents believe that the air flow speed is more favorable in the old building, with a perception of comfort at 60%, compared to 40% for the modern building.

Determination of some heavy metals and physicochemical properties in contaminated soils of open waste dumpsite in Awka, Anambra State

Ogochukwu J. Okakpu — 2024-01-15

The current study was designed for the assessment of cadmium, chromium, lead, nickel, zinc and manganese and some physicochemical properties of soils collected from an open dumpsite in Awka, Nigeria. Soil samples at the depth (0-20 cm) were randomly collected at the dump field and were analyzed for physicochemical parameters and heavy metals using standard analytical methods. The results show that the main dumpsite had a high sand content (91.48% ± 0.26%) with a low silt 4.07% ± 0.03% and clay 4.65% ± 0.00%. The pH of the dumpsite soils was 6.07 ± 0.04 which is an acidic pH. Organic matter (%) and organic carbon (%) were 3.84 ± 0.06 and 2.23 ± 0.04 respectively. The EC (µS cm^-1) was 476.9 ± 0.00 while the ECEC (cmol/kg) 18.93 ± 0.04. The bulk density (g cm^-3) was 1.32 ± 0.00 and the porosity (%) of the dump soil was 41.40 ± 0.00. Total metal concentrations of Cd, Cr, Pb, Ni, Zn and Mn were also analyzed and the concentrations of the heavy metals at dumpsitewas obtained (28.35 ± 0.21 to 149.10 ± 0.01 mg/kg). Metal contamination at dumpsite was in the order of Mn ˃ Zn ˃ Pb ˃ Cd ˃ Cr ˃ Ni. The study evidently indicates the presence of heavy metal contamination in the dumpsite even though some of them fell below the critical permissible concentration level. However, it is their accumulation and persistence in the soils of the dump site that may be a cause of concern for their surrounding environment and organisms.

Modeling and simulation of absorption solar air conditioning to reduce energy consumption: A case of some cities in tropical region

Modeste Kameni Nematchoua — 2024-01-08

Buildings are one of the most important infrastructure sectors in today’s society. However, in Madagascar, most hotels, malls, hospitals use fossil fuels to meet energy needs, especially in the traditional air conditioning system. they consume a considerable amount of energy that has negative effects on the environment. The emergence of solar cooling systems is a very interesting solution to this problem because the use of renewable energies in this sector contributes to a significant reduction of greenhouse gas emissions in the environment. Madagascar is one of the countries with high renewable energy potential, notably solar energy estimated at 2000kWh/m².an.At present, the rate of exploitation of this potential for the operation of the solar absorption cooling system coupled with the building is still non-existent. This energy is clean, sustainable, profitable and environmentally friendly. This is the main objective of this work which uses this energy source to ensure thermal comfort in a building in Madagascar and contributes to the development of this system. The TRNSYS software helped us to model and simulate this system. To do this, first we will select 4 big cities of the big island, a building of total surface 80 m² was used. Then, the hourly thermal loads of this building for the whole year were simulated using the TRNbuild sub-program using meteorological data for a typical year of the selected cities. The dimensions of the components of the solar absorption air conditioning system were obtained using the maximum loads of the building. The results of the simulations show, the system meets the cooling load needs of the building with the climatic conditions of each selected city.

Evaluation of selected physicochemical properties of River Otamiri, Imo State

Victor C. Eze — 2024-01-04

Surface water monitoring is essential, especially when the water is normally used for industrial, agricultural, and domestic purposes. The study determined the physicochemical properties of the River Otamiri using the American Public Health Association standard methods for water analysis. In this study, river water samples were collected five times during the dry season from four sampling points (WSP-1, WSP-2, WSP-3 and WSP-4) along the watercourse of the river in Owerri West Local Government Area of Imo State. The levels of the selected physicochemical parameters were compared with the National Standard for Drinking Water Quality (NSDWQ) guidelines. The findings showed that the pH (4.99±0.11 – 6.30±0.08), dissolved oxygen (4.16±0.01 – 6.45±0.03), total hardness (17.10±1.78 – 27.80±2.54), chloride (68.30±0.58 – 91.90±0.64), and sulphate (39.55±3.32 – 51.21±2.11) were below the acceptable limit of the National Standard for Drinking Water Quality (NSDWQ). However, electrical conductivity (1116±29.75 – 1419±28.54), turbidity (18.90±2.81 – 31.70±8.13) and nitrate (45.50±3.06 – 69.90±2.11, except in water sample point-4) were above the recommended limit according to the NSDWQ guideline, while temperature levels (26.90±0.04 – 28.40±0.02) were within the acceptable limit. The study concludes that the River Otamiri is contaminated. It is therefore advisable to purify water from the river before use for domestic and industrial purposes.

A qualitative study on the morbidity experiences of under-five children in oil spill communities

Pearl Abereton — 2023-05-02

Introduction: Under-five years old (U5) children that reside in oil spill communities are exposed to various pollutants, and therefore are prone to respiratory symptoms and diseases. This study aimed to develop a deeper understanding on the lived experiences of U5 children residing in these communities.
Methods: The study was done in August, 2022 , on eleven caregivers/parents of U5 children, aged 26-45 years old via purposive sampling. This study utilized a phenomenological research design through in-depth interviews and audio recordings.
Results: Findings revealed that numerous oil spills have occurred, and are still occurring. According to the respondents, these spills are caused majorly by poor maintenance of old, rusted pipelines of oil companies; and pipeline vandalism, leading to land, water and air pollution. Results also showed that these spills have led to several adverse respiratory health (RH) experiences in U5, including cough, catarrh, chest pain and other health emergencies that have resulted in frequent hospital visitations and admissions like difficulty/fast breathing, pneumonia, hemoptysis, exacerbation of previously existing conditions, asthma development, etc. The destruction of their source of livelihood, have contributed to worsening these symptoms.
Conclusion: U5 children living in crude oil polluted areas are burdened with a high prevalence of respiratory symptoms and diseases. Implementation of already existing regulatory laws on oil pollution, prompt clean-up of oil spills, provision of standard health facilities, and trained health personnels, were some of the measures recommended to curb the menace of crude oil spills and its RH effects.