Globally, environmental challenges have been recognised as a matter of concern. Among these challenges are the reduced availability and quality of drinking water, and greenhouse gases that give rise to change in climate by entrapping heat, which result in respirational illness from smog and air pollution. Globally, the rate of demand for the use of freshwater has outgrown the rate of population increase; as the rapid growth in town and cities place a huge pressure on neighbouring water resources. Besides, the rapid growth in anthropogenic activities, such as the generation of energy and its conveyance, release carbon dioxide and other greenhouse gases, warming the planet. Polymer nanocomposite has played a significant role in finding solutions to current environmental problems. It has found interest due to its high potential for the reduction of gas emission, and elimination of pollutants, heavy metals, dyes, and oil in wastewater. The revolution of integrating developed novel nanomaterials such as nanoparticles, carbon nanotubes, nanofibers and activated carbon, in polymers, have instigated revitalizing and favourable inventive nanotechnologies for the treatment of wastewater and gas separation. This review discusses the effective employment of polymer nanocomposites for environmental utilizations. Polymer nanocomposite membranes for wastewater treatment and gas separation were reviewed together with their mechanisms. The use of polymer nanocomposites as an adsorbent for toxic metals ions removal and an adsorbent for dye removal were also discussed, together with the mechanism of the adsorption process. Patents in the utilization of innovative polymeric nanocomposite membranes for environmental utilizations were discussed.
A concern over the toxicity of chemicals used during the activation stage in the preparation of activated carbon is beginning to gain attention. The study therefore looked into the possibility of using bio-activators (lemon juice and potash leached from the peel of unripe plantain) as activating chemicals, for environmentally friendly activated carbon. Coconut shell and the peel from unripe plantain were used as feedstock and pyrolyzed at 400 and 450 °c. An impregnation ratio of 0.25:1 was used while laboratory grade potassium hydroxide was used as a base activating agent as a control setup. Characterization of the activated carbon was carried out using parameters like bulk density and yield which were obtained using standard procedures. Results showed that activating carbon using bio-activators as activating agents had very good characteristics when compared with the control. Bio-activators are therefore recommended for the production of bio based activated carbon especially in the fields of medicine, food and pharmaceuticals. The effect of carbonization temperature on adsorption efficiency and pore structure were investigated using methylene blue as adsorbate and SEM respectively
Introduction: Cardiovascular diseases are a known health threat with no respect for age. The need to understand the initiation and progress of the disease is expedient in proper diagnosis and management of the disease. Objective: The work is targeted at simulating the effect of elevated blood pressure on the initiation and development of plaque over time concerning wall shear stress, WSS and plaque wall stress, and PWS. Methods: Conditions such as blood velocity, pressure, and arterial wall conditions associated with blood flow in arteries, as well as patient-specific characterization related to these variables and conditions, were plugged into modified models in the COMSOL multiphysics software. The artery was modeled as an idealized 2-D carotid artery model. Results: Results showed that the WSS distribution with respect to changes with a blood pressure of 500 Pa gave the highest WSS value at the plaque neck and 1500 Pa gave the highest WSS value in the regions close to the plaque root. It was also observed that as the plaque size increased, the region experiencing severely high values for WSS also expanded. Conclusion: It can be recommended that blood pressure monitoring is necessary to curb the attendant cardiovascular diseases associated with high blood pressure.
This study exploited the solvent extraction and mechanical agitation techniques for the remediation of soils contaminated with polycyclic aromatic hydrocarbons (PAHs). The removal of pollutants from diesel contaminated site through ethanol, hexane, and ethanol-hexane mixtures was evaluated. 50 g dried contaminated soil was placed in a Soxhlet extractor and 250 ml solvent (ethanol, or hexane, or ethanol-hexane mixture) was added with extraction occurring at different temperatures of 30, 35, 45, 50, and 60 °C for 16 h. Mechanically agitated method was carried out by weighing out an equal amount of 50 g of the contaminated soil, thoroughly washing with 250 ml of ethanol, hexane, and equal ratio of ethanol to hexane. Qualitative analysis recovered PAHs was done by Agilent series gas chromatography equipped with flame ionization detector. The chromatographic evaluations of the solvent extraction of the contaminated soil showed that more of the polluted compounds were removed when hexane was the solvent. The maximum yield of extracted diesel by the solvent hexane was 11.84% at 60 °C. Extracted diesel removal was also directly proportional to periods of extraction.
The use of Moringa oleifera seed in water purification has reduced the use of chemical-based coagulants which is detrimental to both human and livestock. This project aimed at testing the microbial properties of M. oleifera seed oil extract on some selected pathogens (Bacterial and fungi). The oil was extracted using Soxhlet apparatus with ethanol as solvents. Gas-chromatography-mass spectrometry (GCMS) analyses were carried out for the identification of active components in the oil extract. The zone of inhibition test carried out showed that this particular plant seed oil extract has antifungal property with Candida albicans and Rizopus stolonifera with highest zone of inhibition. The raffinate was used for water purification and the oil for the production of an antifungal soap.
Agricultural wastes are potential sources for the commercial production of biofuels because of their availability and low market price. In the present study, the viability of producing bioethanol from three varieties of cassava pulp and peel (CPP) was studied. Acid hydrolysis was performed by dispersing 20% w/v CPP in 100 mL of hydrochloric acid. Biological hydrolysis was performed by inoculating gelatinized CPP paste with Aspergillus niger. A set of un-gelatinized control samples was used to investigate the effect of heat pretreatment on the reducing sugar yield. The hydrolyzed samples were fermented with Saccharomyces cerevisiae, and the ethanol yield was determined. The reducing sugar yield was 110.7 g/L, 100.4 g/L, and 96.7 g/L from acid hydrolysis of three cassava varieties, while a yield of 98.9 g/L was obtained from cassava peel at 0.7 M and 50 min. The gelatinized pulp from the samples hydrolyzed with A. niger consistently produced more reducing sugar than the control samples. The highest ethanol yields were 54.8% and 33.1% obtained, respectively, from a heat-pretreated variety and cassava peel. Results from the conversion of cassava peel readily bring to light a more useful way of managing cassava wastes in the environment.
Water borne diseases have continued to linger and has remained a major challenge facing most developing nations today. This has been caused mainly by lack of access to clean water. The rapid industrialization has led to the discharge of effluents loaded with pollutants into our water bodies that have greatly affected humans, aquatic life and the environment. This work looks into the possibility of improving the quality water through the elimination of (i) inherent contaminants in water using filters made from cheap locally available red clay and biomass (300 microns sawdust) materials and (ii) chemical treatment of industrial and domestic effluents which in itself is a source of environmental pollution. The sawdust-clay materials were first thoroughly dry mixed in four different weight ratios, 6/80 (sample A), 5/80 (sample B) 4/80 (sample C) and 2/80 (sample D) before water was then added gradually and mixed until the clay clumped together completely, softened and workable. It was then wedged by pressing firmly in order to remove bubbles from the inside of the clay and molded into cup--like shape. It was first sun dried then oven dried at 110 °C and then fired in a Muffle furnace at 850 °C to burnout the sawdust biomass and thus create fine pores within the clay matrix. Performance of the sawdust-clay filters for the purification of waste water obtained from two different sources, industrial and kitchen effluents, was investigated. Results obtained from the study showed that the four filters (A, B, C and D) proved to be moderately effective for the treatment of the two effluents. All the filters reduced the total dissolved solids (TDS) to 120 and 110 mg/L of the industrial and kitchen waste water respectively, to acceptable levels which is less than 500mg/L, set by the World Health Organization (WHO). Conductivity values obtained after the treatment of the water samples were lower than the 1000 µs/cm limit set by WHO. And with the exception of filter D, others greatly reduced the turbidity of water samples as values less than 5 NTU as set by WHO were obtained. The pH values or acidity reduced for the industrial waste water from 4.5 to 7.02 and for kitchen waste water from 5.1 to 7.02 which met the specification set by WHO. Some of the heavy metals detected in the water samples were effectively reduced to acceptable levels. The filtration rates were 140, 100, 50 and 20 ml/min for filters B, A, C and D respectively. The rates rapidly reduced to about 2.7, 1.7, 1.0 and 0.7 ml/min for A, B, C and D respectively after 30 minutes of filtration. This implies that the filters were effective and should thus be developed for industrial and domestic waste water treatment applications.
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