Federal University of Technology Minna

Shaba E.Y., Jacob J.O., Tijani J.O., Suleiman M.A.

In this era, nanotechnology is gaining enormous popularity due to its ability to reduce metals, metalloids and metal oxides into their nanosize, which essentially alter their physical, chemical, and optical properties. Zinc oxide nanoparticle is one of the most important semiconductor metal oxides with diverse applications in the field of material science. However, several factors, such as pH of the reaction mixture, calcination temperature, reaction time, stirring speed, nature of capping agents, and concentration of metal precursors, greatly affect the properties of the zinc oxide nanoparticles and their applications. This review focuses on the influence of the synthesis parameters on the morphology, mineralogical phase, textural properties, microstructures, and size of the zinc oxide nanoparticles. In addition, the review also examined the application of zinc oxides as nanoadsorbent for the removal of heavy metals from wastewater.

Iwuozor K.O., Ighalo J.O., Emenike E.C., Ogunfowora L.A., Igwegbe C.A.

Adsorption as a technique is preferred to these other methods in the mitigation of methyl orange (MO) because of its simplicity in design and operation, indifferent sensitivity towards toxicants and low operational cost. This study is aimed at evaluating the performance of various adsorbent groups in the mitigation of MO from aqueous solutions. It will help reduce the arbitrary choice of adsorbent types for MO adsorption leading to a reduction in the amount of published literature with little/incremental contributions to the field. The study was based on an analysis of over 240 published works of literature on the subject within the last 5 years. The adsorbents were classified into the following seven groups based on their chemical composition; biosorbents, activated carbon, biochar, clays and minerals, polymers and resins, nanoparticles, and composites. In terms of frequency of utilisation of adsorbent group, composites were the most frequently used (>40%). It was observed that nanoparticles and polymers were the most frequently used constituents in the manufacture of composite adsorbents for MO. The choice of nanoparticles in composite adsorbents could be due to their flexibility in going into the matrices of other material types due to their small sizes. Polymers also act as good matrices for immobilising other composite constituents. Nanoparticles was the best adsorbent group for MO uptake. Clays and minerals had the greatest proportion of adsorbents with MO uptake capacity greater than the 1000 ​mg/g threshold. • The performance of various adsorbent groups for MO adsorption was reviewed. • Composites were the most frequently used (>40%) adsorbent group for MO adsorption. • Nanoparticles and polymers were the most frequently used constituents in the composite. • Nanoparticles were the best adsorbents for MO uptake. • Clays and minerals had the greatest proportion of adsorbents with >1000 ​mg/g capacity.

Alshahrani B., Olarinoye I.O., Mutuwong C., Sriwunkum C., Yakout H.A., Tekin H.O., Al-Buriahi M.S.

In this research article, the radiation shielding properties of newly developed high Fe content amorphous alloys were reported. The chemical compositions of these alloys were Fe 83 B 9 C 3 Si 4 P 1 , Fe 84 B 10 C 2 Si 2 P, Fe 85 B 8 C 3 Si 3 P 1 , and Fe 86 B 5 C 8 P 1 . Monte Carlo simulation method was successfully used to study the problem of radiation propagation through theses alloys under suitable boundary conditions of vacuum. Our results indicate that MAC value decays as photon energy grows varying from 0.0997 to 0.0387, 0.0997–0.0387, 0.0998–0.0387, and 0.0998–0.0387 cm 2 /g for FBCSP1, FBCSP2, FBCSP3, and FBCSP4 respectively. However, gradual increase was observed in both parameters of mean free path (MFP) and half value layer (HVL) as energy increases. The maximum and minimum value of the effective atomic number (Z eff ) was 23.09 and 22.97, 23.29 and 23.17, 23.41 and 23.30, and 23.4 and 23.29 for FBCSP1– FBCSP4 respectively. FNRC (Fast Neutron Removal Cross-section) values were: 0.1538, 0.1538, 0.1536, and 0.1561cm-1 for FBCSP1– FBCSP4 respectively. Moreover, an extensive comparison was reported between the radiation shielding proficiency of the studied alloys and that of the traditional materials. It can be concluded that, FBCSP alloys can conveniently replace the traditional materials in photon shielding application especially when space is a constraint. • High Fe content amorphous alloys were reported for radiation shielding applications. • Simulations were successfully applied in the design of vacuum system for radiation propagation. • The optimum thickness for narrow beam transmission geometry is less than 1 MFP. • FBCSP alloys can conveniently replace the traditional materials.

Egbosiuba T.C., Abdulkareem A.S., Kovo A.S., Afolabi E.A., Tijani J.O., Roos W.D.

The presence of As(V) and Mn(VII) in water beyond the permissible concentration allowed by World Health Organization (WHO) standard affects human beings, animals and the environment adversely. Hence, there is need for an efficient material to remove these potentially toxic elements from wastewater prior to discharge into water bodies. This research focused on the application of response surface method (RSM) assisted optimization of Fe-Ni/Activated carbon (AC) catalyst for the synthesis of MWCNTs. Also, the MWCNTs was carboxylated and the adsorption behaviors of both nano-adsorbents in the removal of As(V) and Mn(VII) from industrial wastewater was investigated through experimental and computational techniques. The prepared Fe-Ni/AC, MWCNTs and MWCNTs-OCH2CO2H were characterized using BET, TGA, FTIR, HRSEM, HRTEM, XRD and XPS. The result showed the BET surface area of Fe-Ni/AC, MWCNTs and MWCNTs-OCH2CO2H were obtained as 1100, 1250 and 1172 m2/g, respectively. Due to the enhanced impact of carboxylation, the adsorption capacity of As(V) and Mn(VII) removal increased from 200 to 192 mg/g for MWCNTs to 250 and 298 mg/g for MWCNTs-OCH2CO2H. The isotherm and kinetic models were best fitted by Langmuir and pseudo-second order kinetics, while the thermodynamic investigation found that the adsorption process was endothermic, spontaneous and chemisorptions controlled. The regeneration potential of MWCNTs and MWCNTs-OCH2CO2H after six repeated applications revealed good stability of adsorption efficiency. The study demonstrated optimization importance of Fe-Ni/AC catalyst design for MWCNTs adsorbents and the potentials of utilizing both MWCNTs and MWCNTs-OCH2CO2H in the removal of selected heavy metals from water and soil.

Peter O.J., Kumar S., Kumari N., Oguntolu F.A., Oshinubi K., Musa R.

Monkeypox (MPX), similar to both smallpox and cowpox, is caused by the monkeypox virus (MPXV). It occurs mostly in remote Central and West African communities, close to tropical rain forests. It is caused by the monkeypox virus in the Poxviridae family, which belongs to the genus Orthopoxvirus. We develop and analyse a deterministic mathematical model for the monkeypox virus. Both local and global asymptotic stability conditions for disease-free and endemic equilibria are determined. It is shown that the model undergo backward bifurcation, where the locally stable disease-free equilibrium co-exists with an endemic equilibrium. Furthermore, we determine conditions under which the disease-free equilibrium of the model is globally asymptotically stable. Finally, numerical simulations to demonstrate our findings and brief discussions are provided. The findings indicate that isolation of infected individuals in the human population helps to reduce disease transmission.

Egbosiuba T.C., Egwunyenga M.C., Tijani J.O., Mustapha S., Abdulkareem A.S., Kovo A.S., Krikstolaityte V., Veksha A., Wagner M., Lisak G.

Nickel nanoparticles (NiNPs) supported on activated multi-walled carbon nanotubes (MWCNTs) were used as an adsorbent applied towards Pb(II), As(V) and Cd(II) remediation from industrial wastewater. The result revealed the hydrophilic surface of MWCNTs-KOH was enhanced with the incorporation of NiNPs enabling higher surface area, functional groups and pore distribution. Comparatively, the removal of Pb(II), As(V) and Cd(II) on the various adsorbents was reported as NiNPs (58.6 ± 4.1, 46.8 ± 3.7 and 40.5 ± 2.5%), MWCNTs-KOH (68.4 ± 5.0, 65.5 ± 4.2 and 50.7 ± 3.4%) and MWCNTs-KOH@NiNPs (91.2 ± 8.7, 88.5 ± 6.5 and 80.6 ± 5.8%). Using MWCNTs-KOH@NiNPs, the maximum adsorption capacities of 481.0, 440.9 and 415.8 mg/g were obtained for Pb(II), As(V) and Cd(II), respectively. The experimental data were best suited to the Langmuir isotherm and pseudo-second order kinetic model. The fitness of experimental data to the kinetic models in a fixed-bed showed better fitness to Thomas model. The mechanism of metal ion adsorption onto MWCNTs-KOH@NiNPs show a proposed electrostatic attraction, surface adsorption, ion exchange, and pore diffusion due to the incorporated NiNPs. The nanocomposite was highly efficient for 8 adsorption cycles. The results of this study indicate that the synthesized nanocomposite is highly active with capacity for extended use in wastewater treatment.

Ochedi F.O., Liu Y., Hussain A.

Emissions of mercury and arsenic from flue gas and water have become a great public concern due to their hazards to human health and the ecosystem. Many removal methods have been developed to capture mercury and arsenic from flue gas and water. Adsorption is the most potential one based on simple equipment, low energy consumption, and low corrosiveness. However, due to huge demand, inactivation or consumption, the cost of adsorbents is quite high, limiting the large-scale applications of adsorption technologies. Coal fly ash (CFA) is a kind of solid waste generated from coal combustion. Its emissions and accumulation have resulted in severe environmental consequences and disposal challenges. Recently, CFA has been identified as a suitable adsorbent to capture mercury and arsenic from water and flue gas due to its abundant supply, good pore structure, and low cost. Hence, the use of CFA as adsorbents/precursors to prepare mercury and arsenic adsorbents has great practical significance as it cannot only reduce their capture cost but also ameliorate problems associated with solid waste disposal. This comprehensive review provides the state-of-the-art of mercury and arsenic capture using adsorbents prepared from CFA. It is intended to advance our fundamental understanding of this emerging research field and outline directions to spur future research and development of sustainable and cost-effective mercury/arsenic adsorption technologies based on CFA re-utilization. • Cost of activated carbon for mercury removal is very high, and its price is up to 1190 $/ton. • Fly ash is likely to achieve zero cost due to a very wide range of sources. • Fly ash has low surface area (mostly below 20 m 2 /g), but can reach 8–12 times of original after activation. • Hg removal efficiencies are only 11–66% for raw fly ashes, and are up to 44–100% for modified fly ashes. • Using fly ash to prepare adsorbent can reduce Hg/As capture costs and ameliorate disposal problem.

Daniel A.I., Fadaka A.O., Gokul A., Bakare O.O., Aina O., Fisher S., Burt A.F., Mavumengwana V., Keyster M., Klein A.

There is a direct correlation between population growth and food demand. As the global population continues to rise, there is a need to scale up food production to meet the food demand of the population. In addition, the arable land over time has lost its naturally endowed nutrients. Hence, alternative measures such as fertilizers, pesticides, and herbicides are used to fortify the soil and scale up the production rate. As efforts are being made to meet this food demand and ensure food security, it is equally important to ensure food safety for consumption. Food safety measures need to be put in place throughout the food production chain lines. One of the fundamental measures is the use of biofertilizers or plant growth promoters instead of chemical or synthesized fertilizers, pesticides, and herbicides that poise several dangers to human and animal health. Biofertilizers competitively colonize plant root systems, which, in turn, enhance nutrient uptake, increase productivity and crop yield, improve plants’ tolerance to stress and their resistance to pathogens, and improve plant growth through mechanisms such as the mobilization of essential elements, nutrients, and plant growth hormones. Biofertilizers are cost-effective and ecofriendly in nature, and their continuous usage enhances soil fertility. They also increase crop yield by up to about 10–40% by increasing protein contents, essential amino acids, and vitamins, and by nitrogen fixation. This review therefore highlighted different types of biofertilizers and the mechanisms by which they elicit their function to enhance crop yield to meet food demand. In addition, the review also addressed the role of microorganisms in promoting plant growth and the various organisms that are beneficial for enhancing plant growth.

Feio M.J., Hughes R.M., Callisto M., Nichols S.J., Odume O.N., Quintella B.R., Kuemmerlen M., Aguiar F.C., Almeida S.F., Alonso-EguíaLis P., Arimoro F.O., Dyer F.J., Harding J.S., Jang S., Kaufmann P.R., et. al.

The biological assessment of rivers i.e., their assessment through use of aquatic assemblages, integrates the effects of multiple-stressors on these systems over time and is essential to evaluate ecosystem condition and establish recovery measures. It has been undertaken in many countries since the 1990s, but not globally. And where national or multi-national monitoring networks have gathered large amounts of data, the poor water body classifications have not necessarily resulted in the rehabilitation of rivers. Thus, here we aimed to identify major gaps in the biological assessment and rehabilitation of rivers worldwide by focusing on the best examples in Asia, Europe, Oceania, and North, Central, and South America. Our study showed that it is not possible so far to draw a world map of the ecological quality of rivers. Biological assessment of rivers and streams is only implemented officially nation-wide and regularly in the European Union, Japan, Republic of Korea, South Africa, and the USA. In Australia, Canada, China, New Zealand, and Singapore it has been implemented officially at the state/province level (in some cases using common protocols) or in major catchments or even only once at the national level to define reference conditions (Australia). In other cases, biological monitoring is driven by a specific problem, impact assessments, water licenses, or the need to rehabilitate a river or a river section (as in Brazil, South Korea, China, Canada, Japan, Australia). In some countries monitoring programs have only been explored by research teams mostly at the catchment or local level (e.g., Brazil, Mexico, Chile, China, India, Malaysia, Thailand, Vietnam) or implemented by citizen science groups (e.g., Southern Africa, Gambia, East Africa, Australia, Brazil, Canada). The existing large-extent assessments show a striking loss of biodiversity in the last 2–3 decades in Japanese and New Zealand rivers (e.g., 42% and 70% of fish species threatened or endangered, respectively). A poor condition (below Good condition) exists in 25% of South Korean rivers, half of the European water bodies, and 44% of USA rivers, while in Australia 30% of the reaches sampled were significantly impaired in 2006. Regarding river rehabilitation, the greatest implementation has occurred in North America, Australia, Northern Europe, Japan, Singapore, and the Republic of Korea. Most rehabilitation measures have been related to improving water quality and river connectivity for fish or the improvement of riparian vegetation. The limited extent of most rehabilitation measures (i.e., not considering the entire catchment) often constrains the improvement of biological condition. Yet, many rehabilitation projects also lack pre-and/or post-monitoring of ecological condition, which prevents assessing the success and shortcomings of the recovery measures. Economic constraints are the most cited limitation for implementing monitoring programs and rehabilitation actions, followed by technical limitations, limited knowledge of the fauna and flora and their life-history traits (especially in Africa, South America and Mexico), and poor awareness by decision-makers. On the other hand, citizen involvement is recognized as key to the success and sustainability of rehabilitation projects. Thus, establishing rehabilitation needs, defining clear goals, tracking progress towards achieving them, and involving local populations and stakeholders are key recommendations for rehabilitation projects (Table 1). Large-extent and long-term monitoring programs are also essential to provide a realistic overview of the condition of rivers worldwide. Soon, the use of DNA biological samples and eDNA to investigate aquatic diversity could contribute to reducing costs and thus increase monitoring efforts and a more complete assessment of biodiversity. Finally, we propose developing transcontinental teams to elaborate and improve technical guidelines for implementing biological monitoring programs and river rehabilitation and establishing common financial and technical frameworks for managing international catchments. We also recommend providing such expert teams through the United Nations Environment Program to aid the extension of biomonitoring, bioassessment, and river rehabilitation knowledge globally.

Olarinoye I.O., El-Agawany F.I., El-Adawy A., Yousef E.S., Rammah Y.S.

Mechanical properties, alpha particles, gamma-ray, proton, and neutron interaction parameters of 40TeO2-(60-x)V2O5-xMoO3: 20 ≤ xMoO3 ≤ 60 mol% (TVM20-TVM60) semiconductor glasses have been investigated. Based on Makishima–Mackenzie's model, the total ionic packing density (Vt) and the total dissociation energy (Gt) for TVM-glasses have been computed. Elastic moduli, hardness, and Poisson's ratio haven been calculated. Utilizing WinXcom and EXABCal computer codes, mass attenuation coefficient (MAC), linear attenuation coefficient (LAC), half value layer (HVL), mean free path (MFP), effective atomic number (Zeff), equivalent atomic number (Zeq), energy absorption and exposure built up factors (EABF and EBF), and fast neutron removal cross section ∑R have been computed. Results reflected that the (Vt) of the TVM-glasses varied from 0.597 to 0.610 (m3/mol), while the (Gt) increased from 63.36 × 106 to 63.48 × 106 (KJ/m3) for TVM20 to TVM60 glasses. The highest elastic features were found for TVM60 glass sample with highest value of MoO3 content. The elastic properties varied from 75.77 to 77.45 GPa for Young's modulus, from 54.67 to 56.70 GPa for bulk modulus, and from 0.267 to 0.272 for Poisson's ratio. The TVM60 glass sample possess the highest MAC, followed by TVM50, TVM40, TVM30, and TVM20, respectively. The maximum HVL was obtained at 8 MeV for all glass samples with values of 5.75, 5.30, 5.05, 4.71 and 4.31 cm for TVM 20, TVM30, TVM40, TVM50, and TVM60, respectively. The TVM60 has a better fast neutron shielding capacity compare to the other glasses. The relative difference between EABF and EBF of the glasses were in the order TVM20 > TVM30 > TVM40 > TVM50 > TVM60. We can say that TVM60 glass can attenuate more photons than TVM20-TVM50 glasses.