Emmanuel Iyayi Unuabonah

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Emmanuel verified their affiliation via an institutional email.

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• PhD
• Research Director at Redeemer's University

The integration of photocatalysis and membrane filtration has emerged as a promising technology for water treatment, offering the dual advantages of physical separation and degradation of organic pollutants. However, the high cost and complexity of current membrane materials limit their large-scale application. This review aims to provide a compreh...

Aquaculture operations are synonymous with high freshwater consumption, followed by the discharge of large volumes of heavily contaminated wastewater.

This Study focuses on the preparation of sustainable and efficient Chitosan catalyst for the removal of three organic pollutants, 17β-Estradiol (E2), 17α-ethynyl estradiol (EE2) and triclosan (TCS) from water. The prepared nanocomposites were characterized by different techniques which confirmed the presence of the key components Chitosan, Carica P...

Environmental antibiotic residues (EARs) and antibiotic-resistant bacteria (ARB) are known to contribute to global antimicrobial resistance (AMR). This study investigated EAR levels in selected wells, river, abattoir wastewater, bottled water and sachet water from Ede, Nigeria. Ecological risk quotient (RQ) and health risk (Hazard quotient) of the...

Mycotoxins in drinking water are neglected pollutants that have serious health implications when ingested. Common mycotoxins with health concerns include deoxynivalenol (DON), ochratoxin A (OTA), and zearalenone (ZEN). This study considers the distribution and apparent health risks of these mycotoxins in drinking water sources (groundwater, surface...

The leaching of pharmaceutical ingredients into water bodies poses an escalating threat, demanding urgent remediation strategies. Among several techniques advanced for their remediation, advanced oxidation methods utilizing persulfate (PS) and peroxymonosulfate (PMS) stand out as promising avenues for pharmaceutical degradation in wastewater. This...

Background Parabens, which are chemicals used as preservatives in cosmetic and pharmaceutical products, have been reported to be associated with low sperm quality in animal and human models. Despite the high exposure of men to paraben-containing products in Nigeria, there are no known studies that investigate the association of parabens with sperm...

Over the decades, the rise in nitrate levels in the 6 ecosystem has posed a serious threat to the continuous existence of 7 humans, fauna, and flora. The deleterious effects of increasing 8 levels of nitrates in the ecosystem have led to adverse health and 9 environmental implications in the form of methemoglobinemia and 10 eutrophication, respecti...

Aerosols from filters in air conditioning systems in three indoor 8 environments (staff offices, libraries, and laboratories) across nine universities in Southwest 9 Nigeria were analysed for the presence of endocrine disrupting chemicals (EDCs): 10 methylparaben (MeP), ethylparaben (EtP), propylparaben (PrP), butylparaben (BuP), 11 triclosan (TCS)...

The objective of this study was to determine the association between mycotoxins and the quality of spermatozoa in Nigeria. We designed a prospective case-control study involving 136 men diagnosed with reduced sperm count and quality in five infertility clinics in southwest Nigeria and 154 normal fertile controls. Sperm analysis was conducted in acc...

The presence of antimicrobial in water has grown into a major global health concern. This study thus focused on the presence, ecological implications, and potential health risks associated with nine...

This study provides, for the first time, data on the distribution and toxicity of catechol (CAT) and hydroquinone (HQ) in drinking water sources from Africa. Groundwater (boreholes and hand-dug wells) and surface water in three Southwestern States in Nigeria served as sampling sites. The concentrations of CAT and HQ in groundwater and surface water...

New orange peel biochar/clay/titania nanocomposites (NCs) were studied for photocatalytic tetracycline (TET) degradation under both UV and natural solar irradiation by variation of NC dose, initial TET concentration, ionic strength,...

One of the significant water-related health challenges globally is due to pollutant fate. Contaminants endanger the lives of humans, animals, and even plants. The present mathematical analysis explains reactive wastewater sludge ejected into a drinking water source from wastewater treatment plants. The assumption that wastewater sludge follows a po...

New TiO2 hybrid composites were prepared from kaolin clay, predried and carbonized biomass, and titanium tetraisopropoxide and explored for tetracycline (TET) and bisphenol A (BPA) removal from water. Overall, the removal rate is 84% for TET and 51% for BPA. The maximum adsorption capacities (qm) are 30 and 23 mg/g for TET and BPA, respectively. Th...

Cellulose has attracted interest from researchers both in academic and industrial sectors due to its unique structural and physicochemical properties. The ease of surface modification of cellulose by the integration of nanomaterials, magnetic components, metal organic frameworks and polymers has made them a promising adsorbent for solid phase extra...

This study reports the occurrence and risk assessment of 2,4-dinitrophenol (2,4-DNP), phenol (PHE), and 2,4,6-trichlorophenol (2,4,6-TCP) in drinking water sources in three south-western States in Nigeria (Osun, Oyo, and Lagos). Groundwater (GW) and surface water (SW) were collected during dry and rainy seasons of a year. The detection frequency of...

The advent of civilization, coupled with growing industrialization in many countries, is placing more demand on the available water sources. At the same time, the daily surge in wastes generated by man's anthropogenic activities has led to microbial, organic and inorganic contamination of water sources. Based on available evidence, significant rese...

Benin's waterways are affected by several forms of pollution that are linked in particular to anthropic activities. This study aims to detect the presence of antibiotic residues, the frequency of antibiotic resistant bacteria and the levels of heavy metals in Benin's waterways. 160 surface water samples from streams in Benin were collected. They we...

The inability of environmental litigation plaintiffs to discharge the evidential burden of proof imposed on them often frustrate their attempts to obtain remedy for injuries suffered. Scientific evidence is an effective approach to aid victims of pollution ground their claims and help the court determine whether contested facts are proved or not. T...

This study reports the occurrence and risk assessment of 2,4- Dinitrophenol (2,4-DNP), Phenol (PHE), and 2,4,6- Trichlorophenol (2,4,6-TCP) in drinking water sources in three South western States in Nigeria (Osun, Oyo and Lagos). Groundwater (GW) and surface water (SW) were collected during dry and wet seasons of a year. The detection frequency of...

The aquatic environment is a hotspot for the transfer of antibiotic resistance to humans and animals. Several reviews have put together research efforts on the presence and distribution of antibiotic resistant bacteria (ARB), antibiotic resistance genes (ARGs), and antibiotic chemical residue (ACRs) in food, hospital wastewater, and even in other a...

Background Despite the evidence of declining sperm counts worldwide and the increasing prevalence of male infertility, there has been limited documentation of the potential causes and risk factors for male infertility. With limited methods of primary treatment of male infertility, understanding the causes and risk factors will pinpoint specific lin...

This study reports the synthesis of sunlight-active zinc oxide-tungstate-kaolinite photocatalytic composite prepared via a green process (solvent-free mechano-thermal process) at an optimum temperature of 500°C for 1 h in a furnace. Electron Paramagnetic Resonance (EPR) study suggests the presence of W⁵⁺ defect states in the prepared photocatalytic...

The aquatic environment as a hotspot for the transfer of antibiotic resistance to humans and animals. Several reviews have put together research efforts on the presence and distribution of antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) in food, hospital settings, and even in aquatic environment. However, these reports ar...

Parabens are chemicals extensively used in pharmaceuticals, cosmetics, personal hygiene and food products as preservatives. They are classified as emerging contaminants with endocrine-disrupting capability. The concentrations of Methylparaben (MeP), Ethylparaben (EtP), Propylparaben (PrP) and Butylparaben (BuP) were obtained from groundwater, surfa...

Due to the adverse health and environmental effects of halogen, based on oxyanions in water, the occurrence and distribution have been of great concern, worldwide. Therefore, in this chapter, the occurrence, chemical structure, the natural and anthropogenic sources of these oxyanions were appraised. The impacts on human health and the environment a...

Water security and sanitation are precursors for socio-economic development, survival of flora and fauna, food security and healthy ecosystems. However, when these are compromised, they tend to have an adverse effect on the health of the populace and the socio-economic development of the entire society. This chapter investigates global laws and eco...

Selenium is a metalloid and an essential micronutrient needed by animals and humans at low concentrations but extremely toxic at high concentrations. It is found in the natural environment and can be present in soil, food, air, plant, and water. The chemistry of Se is linked to its different chemical forms. Se mobility and toxicity are strongly dep...

An assessment of the susceptibility of the raw and treated drinking water to microplastics (MP) contamination was conducted because of the inherent low density and size (<5 mm) of MP that enhances the mobility and pervasiveness in environmental media. Although, the ecological and physiological effects of MP is still under scrutiny but assessing the...

Preparation of biochar from kaolinite and coconut husk (KCB) and further activated with HCl (KCB-A) and KOH (KCB-B) via a microwave technique for the remediation of ciprofloxacin (CIP) and tetracycline (TET) from water was carried out. Characterization using scanning electron microscopy, energy dispersive X-ray, Fourier transform infrared spectrosc...

Parabens are biocides used as preservatives in food, cosmetics and pharmaceuticals. They possess antibacterial and antifungal activity due to their ability to disrupt cell membrane and intracellular proteins, and cause changes in enzymatic activity of microbial cells. Water, one of our most valuable natural resource, has become a huge reservoir for...

Carbon materials were prepared from eco-friendly pawpaw seeds and Kaolinite clay using green ‘microwave’ synthetic methods to give KPZ which was further activated with HCl (A-KPZ). The synthesized materials were employed in the removal of ciprofloxacin and tetracycline from water. Characterisation was carried out using Fourier Transform Infrared Sp...

Drinking water contaminated with antibiotic resistance bacteria could result in loss of antibiotic effectiveness in humans, increased healthcare cost and ultimately death. New delaminated photocatalytic composite (DPC) has been prepared. DPC (2 g) doped with Cu/Zn kept multidrug resistant (MDR) E. coli and its sulphonamide resistance genes in conta...

This study reports the development of biomass-assisted sunlight-active semiconductor-tungstate-clay photocatalytic composite for the removal of pharmaceutical contaminants (PCs): Acetaminophen (ACT), Ampicillin (AMP) and Sulfamethoxazole (SMX), from water. Materials prepared (Cu[email protected]4-K, [email protected]4-K and Cu/[email protected]4-K)...

This book is a compendium of research efforts and findings on the sources, occurrences, hydrochemistry, and several operating variables that influence the presence of oxyanions in aqua system. The content of this book has been designed to provide an insightful account of an array of innovative technologies for the management of the impacts of oxy...

This study reports the development of an efficient photosensitive nanocomposites made from Clay, Fe 2 O 3 , and Graphene oxide (GO). These nanocomposites were used for the removal of steroid estrogens (E1, E2, E3 and EE2) from water under visible-light. The use of these photocatalytic nanocomposites lead to complete oxidation of the steroid estroge...

The concentrations of Cr, Cu, Fe, Mn, Pb, Ni, V and Zn in sediment, surface and groundwater were determined in a total of 180 samples acquired bi-monthly for one year to evaluate the impact of bitumen spills. Principal component analysis (PCA) and cluster analysis (CA) were also used to identify the possible sources of contamination. The concentrat...

This study demonstrates the efficiency of a new visible-light p-n ZnO/GO heterostructured composite catalyst supported on clay with carbon interlayer. This photocatalyst was prepared via microwave assisted technique for the removal of four steroid estrogens in water: Estrone (E1), 17-β-estradiol (E2), Estriol (E3) and the synthetic estrogen 17-α et...

New solar-active nanocomposites free from toxic reagents or precious metals were developed. They were prepared from natural kaolinite clay, Na2WO4, titania, and biomass. The photocatalytic activity of the nanocomposites against two antibiotics [Ampicillin (AMP) and Sulfamethoxazole (SMX)] and an antimalarial drug [Artemether (ART)] under sunlight s...

The sustainable development goal six (SDG 6) of the United Nations (UN) is hinged on the provision, availability and sustainability of water for the global populace by 2030. In a bid to achieve this goal, the quest to seek for ubiquitous and low cost adsorbents to treat effluents laden with industrial dyes, such as Methylene Blue (MB) is on the inc...

Western colonization of nations has long ended; however, it appears that many of the affected people, particularly Africans, are still captive of Western- imposed mentality and standards. „Globafricalisation‟, a newly coined term partly expressed as „the westernisation of researches and research outputs from Africa‟ is critically examined in this s...

This study reports a new class of photocatalytic hybrid clay nanocomposites prepared from low-cost sources (kaolinite clay and Carica papaya seeds) doped with Zn and Cu salts via a solvothermal process. X-ray diffraction analysis suggests Cu-doping and Cu/Zn-doping introduce new phases into the crystalline structure of Kaolinite clay which is linke...

This study describes a simple and cost effective method for the synthesis of silver nanoparticles from locally available Vigna unguiculata L. stem extract, as alternative method to the expensive and toxic chemicals used, and its application as adsorbent for malachite green (MG) in a Batch system. The AgNPs were synthesized using AgNO3 as precursor...

It has been reported that almost two billion people today drink water mostly contaminated with faeces, thus putting them at risk of contracting various waterborne diseases (WHO, 2017). Invariably, improving access to safe drinking water can result in tangible improvement to health. This study extends our previous research where we developed efficie...

Pistachio wood-derived activated carbon prepared by a two-stage process (PWAC-2), conducting two consecutive chemical activation processes with NH4NO3 and NaOH, respectively. The results showed that explosive characteristic of NH4NO3 can primarily be employed to produce a char, with a large surface area and a highly-ordered pore structure, which ca...

The need to elucidate the influence of the presence of the major components (i.e. organic matter phosphate and nitrate) of nutrient-rich wastewater on the process of nutrient recovery, using calcined gastropod shell (CGS), necessitated this study. The time–concentration profiles of the recovery of organic matter, phosphate and nitrate were studied...

Modeling of adsorption processes is vital especially in water treatment processes. To ensure that the right adsorbent is used to remove the target pollutant in water with good efficiency, at the right rate and in the right conditions, mathematical models are employed. Furthermore, these models provide valuable data that are useful in developing an...

A new micro/mesoporous hybrid clay nanocomposite prepared from kaolinite clay, Carica papaya seeds, and ZnCl2 via calcination in an inert atmosphere is presented. Regardless of the synthesis temperature, the specific surface area of the nanocomposite material is between ≈ 150 and 300 m2/g. The material contains both micro- and mesopores in roughly...

Effective treatment of metals polluted water may be achieved using low-cost materials synergistically modified to obtain composite adsorbents. Thus, feldspar–biomass composites have been prepared via calcination of feldspar (FLC) and Carica papaya seeds or pine cone seeds to yield Carica papaya-FLC (CPF) and pine-cone-FLC (PCF) composite adsorbents...

Clay minerals are not only abundant in nature but can be easily engineered to make highly efficient materials for disinfection of water. A combination of their abundance and efficiency makes them a sustainable source of material for water disinfection. Several works have reported the use of clay minerals in modified form to make the removal of harm...

Toxic anions removal for increased access to potable water remains a problem that has not been adequately addressed. This study, reports the successful preparation and modification of kaolinite-papaya seed based adsorbents under vacuum (VHYCA) for the removal of Nitrate (NO3⁻), Fluoride (F⁻) and Phosphate (PO4³⁻). Modified adsorbents via metal-dopi...

Toxic anions removal for increased access to potable water remains a problem that has not been adequately addressed. This study, reports the successful preparation and modification of kaolinite-papaya seed based adsorbents under vacuum (VHYCA) for the removal of Nitrate (NO3-), Fluoride (F-) and Phosphate (PO43-). Modified adsorbents via metal-dopi...

Hybrid clay composites were prepared from Kaolinite clay and Carica papaya seeds via modification with chitosan, Alum, NaOH, and ZnCl2 in different ratios, using solvothermal and surface modification techniques. Several composite adsorbents were prepared, and the most efficient of them for the removal of gram negative enteric bacteria was the hybri...

New hybrid clay materials with good affinity for phosphate ions were developed from a combination of biomass-Carica papaya seeds (PS) and Musa paradisiaca (Plantain peels-PP), ZnCl2 and Kaolinite clay to produce iPS-HYCA and iPP-HYCA composite adsorbents respectively and functionalized with an organosilane to obtain NPS-HYCA and NPP-HYCA composite...

Environmental remediation has been a strategy employed by scientists to combat water pollution problems that have led to the scarcity of potable water. Hence, in this study, Terminalia ivorensis seed waste (TISW) was explored for the removal of Congo Red, Methylene Blue, Cadmium and Lead from aqueous solutions. Some experimental variables such as p...

The critical need for water and wastewater treatment has become more crucial in recent years as a large portion of the world’s population do not have access to safe potable water sources. Currently, half a billion people worldwide do not have access to improved water sources especially in developing countries where recycling and reuse of wastewater...

In order to optimise the coagulation efficiencies of polysaccharide-based coagulants (PBC), it is expedient that the underlying coagulation mechanism of this green resource should be elucidated to enable proper understanding of the process. Consequently, the present chapter provides an overview of the active coagulating species in PBCs that have be...

In the last two decades, adsorbents have been developed from a variety of sources. Several of these adsorbents, though very efficient, are either still in their developmental stages in the laboratory or are not viable candidates for a large-scale treatment of water. Some of the adsorbents in the latter category are usually expensive to develop or s...

Coagulation/Flocculation (CF) and adsorption-based water treatment operations are important unit processes in water treatment systems. CF is used in any of the stages of the water treatment protocol while adsorption is used only at the tertiary stage of treatment. Adsorption enriches the surface of a liquid or a solid with chemical species from a f...

Synergistically combined low-cost composites may be effective for the potential treatment of effluents containing organic pollutants. Hence, preparation of Carica-papaya-modified-kaolinite (CPK) and pine-cone-modified-kaolinite (PCK) composites via calcination of pure kaolinite (KAC), Carica-papaya and pine-cone seeds is demonstrated. The composite...

The adsorption efficiency of a new hybrid clay adsorbent for polynuclear aromatic hydrocarbons (PAHs) is compared with known modified clay adsorbents. The new hybrid clay adsorbent (HYCA) showed far higher adsorption capacities for the adsorption of various PAH molecules compared with sodium dodecyl sulfate modified and humic acid modified Bentonit...

This study highlights the potential use of yellow Zea mays seed chaff (YZMSC) biomass as a biosorbent for the removal of Cr3+, Cd2+ and Pb2+ ions from aqueous solutions. Fourier transformed Infrared analysis of the biomass suggests that YZMSC biomass is basically composed of cellulose and methyl cellulose. The biosorption capacities, qmax, of YZMSC...

This study highlights the potential use of yellow Zea mays seed chaff (YZMSC) biomass as a biosorbent for the removal of Cr3+, Cd2+ and Pb2+ ions from aqueous solutions. Fourier transformed Infrared analysis of the biomass suggests that YZMSC biomass is basically composed of cellulose and methyl cellulose. The biosorption capacities, q(max), of YZM...

Pollutants in the atmosphere are influenced by weather and chemistry thus making it difficult to know when they will concentrate and cause poor air quality. The only way to be sure of this is to monitor the air pollution at as many sites as possible and very often as well. In this study, particulate matter was captured at ten locations using SKC Ai...

Recent studies have shown that kaolinite clay modified with biosorbents are promising low cost adsorbents for the removal of metals from aqueous solution because the resultant composites have higher adsorption capacities, and hence a better aqueous metal ions removal efficiencies. However, some clay properties suggest that not all such modification...

A binary mixture of humic acid and geothite was prepared and used to modify kaolinite to produce geothite–humic acid (GHA)-modified kaolinite adsorbent useful for the adsorption of Pb2+, Cd2+, Zn2+, Ni2+ and Cu2+ from Single and Quinary (5) metal ion systems. The cation exchange capacity (CEC) and specific surface area of GHA-modified kaolinite cla...

The competitive extraction of Cr(III) onto Nauclea diderrichii seed epicarp doped with MnO2 nanoparticles (MnO2 nano-bioextractant (MNB)) in a single and binary batch system was studied. For validity of experimental data, chi square test, root mean square error, sum of the square errors, hybrid fractional error function, Marquart’s percent standard...

This work highlights the removal dynamics of some industrial dyes, such as Congo Red (CR) and Methylene Blue (MB), Cd2+ and Pb2+ by two low-cost and readily available tree wastes (Pentaclethra macrophylla tree bark (PMTB biosorbent) and Malacantha alnifolia tree bark (MATB biosorbent). In this research work, experimental variables such as pH, bioma...

Toxic Cr(III) which poses environmental hazard to flora and fauna was efficiently abstracted by low-cost Nauclea diderrichii seed biomass (NDS) with good sequestral capacity for this metal was investigated in this study. The NDS surface analyses showed that it has a specific surface area of 5.36 m2/g and pHpzc of 4.90. Thermogravimetric analysis of...