DEPARTMENT OF CHEMISTRY

Quinoline or benzopyridine, a nitrogen containing compound has been known to possess antimalarial, anti-bacteria, and anti-fungal properties. In this study, a derivative of quinoline-N-oxide-4-thiol was obtained by a five step reaction. The compounds synthesized in the stepwise reactions were: quinoline-N-oxide, 4- nitroquinoline-N-oxide, 4-chloroquinoline-N-oxide and quinoline-N-oxide-4-thiol. Furthermore, the latter was coupled with benzoyl chloride under basic condition to obtain quinoline-N-oxide-4-benzoylsulphide. The physical properties of the compound obtained are percentage yield 1.86%, melting point 96-98 oC, and retention factor value 0.83.

This study utilized cellulose for the adsorption of Zn(II) from aqueous solution via batch adsorption process. The effect of the adsorption parameters: Adsorbent Dosage, Initial Concentrations, and Contact time were investigated. examined under various conditions using heavy metal ion (Zn 2+ ) as the adsorbate. The amounts of Zn(II) adsorbed were estimated by using flame atomic absorption spectrophotometer. It was found to obey the langmuir isotherm as it gave the best fit to the isotherm data. The result of kinetic studies revealed that the adsorption process obeyed pseudo-second order. After the completion of the adsorption process of Zn(II), the result obtained shows that cellulose can be used as an effective adsorbent for the removal of Zinc ion (Zn 2+ ) from aqueous solution

This study is to assess heavy metal content in three leafy vegetables. Telfairia occidentalis (Pumpkin leaf), Amaranth green (Green leaf) and Celosia argentea (Shoko leaf). Samples were collected from Uselu market, Egor local government area of Benin city in Edo State, Nigeria in the month of February. The samples were prepared using Atomic Absorption Spectroscopy (AAS) method. The level of five different heavy metals namely Lead (Pb), Cadmium (Cd), Zinc (Zn), Chromium (Cr) and Iron (Fe) were
analyzed using Atomic Absorption Spectroscopy (AAS). Result obtained from the analysis shows that Pumpkin leaf contained a mean value of 2.00mg/kg Fe, 0.01mg/kg Cr, 2.11mg/kg Zn, while Cd and Pb were below detection limit (BDL). Shoko leaf had a mean value of 3.85mg/kg Fe, 0.04mg/kg Cr, 1.52mg/kg Zn, 0.01mg/kg Cd and Pb was below detection limit (BDL). Green leaf had a mean data of 7.70mg/kg Fe, 0.03mg/kg Cr, 1.64mg/kg Zn while Cd and Pb were below detection limit (BDL). Among
the three samples, the mean value of all the heavy metals are below standard regulatory limit of 425.50mg/kg Fe, 0.03mg/kg Cr, 99.40mg/kg Zn, 0.20mg/kg Cd and 0.30mg/kg Pb except for Cr in Shoko leaf which mean value is slightly above that of standard regulatory limit. The samples are safe for human and animal consumption, but attention should be paid to Shoko leaf to avoid the level of Cr to be higher than it is by being mindful of the site for cultivation of the crop.

Aquaculture is one of the fastest-growing food production sectors globally, and its sustainability depends heavily on maintaining optimal water quality. Poorly balanced feeds or excessive feeding introduce significant organic and nutrient loads into pond ecosystems, accelerating water quality deterioration. This study investigated how different fish feed sizes (2 mm, 3 mm, and 9mm pellets) and their proximate compositions influence pond water quality over a five-day period. Proximate analysis revealed notable variations among the feeds: moisture content exceeded FAO limits (2 mm = 11.3%, 3 mm = 15.2%, 9 mm = 23%), crude fibre ranged from 5.0–12.5%, and the finisher feed contained the highest ash (14%) and protein (32.01%). These compositional differences suggested varying potentials for nutrient leaching and organic loading. Water quality parameters demonstrated clear feed-dependent trends. pH values, although fluctuating, were generally lower than the FAO recommended 6.5–9.0 range, with recorded values spanning 3.4–6.8, reflecting acidification linked to organic decomposition and nitrogenous waste accumulation. Electrical conductivity (EC) increased markedly across treatments, with values reaching as high as 7947 µS/cm, far above the recommended 100–2000 µS/cm range, indicating rapid ionic enrichment from mineral and protein leaching. Heavy metal analysis showed repeated detections of lead (Pb) and cadmium (Cd) at 0.01 mg/L, particularly in 3 mm and 9 mm feeds, matching FAO’s maximum permissible limits and signalling potential long-term risks of bioaccumulation. Major water quality indicators also showed progressive deterioration. Total Dissolved Solids (TDS) exceeded 4000 ppm in several treatments, while Total Suspended Solids (TSS) rose daily despite remaining within international guidelines. Dissolved Oxygen (DO) declined rapidly, falling below the safe threshold of 5 mg/L by Day 1 and reaching complete depletion by Day 5 in some ponds. Concurrently, Biochemical Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) increased sharply, exceeding recommended limits by more than ten-fold, driven by microbial activity and excessive organic matter decomposition. Overall, the study demonstrates that feed characteristics—particularly excessive moisture, high protein, and elevated ash contents—combined with feeding intensity, significantly accelerate water quality decline. While nutrient-rich feeds are essential for fish growth, improper management can destabilize pond ecosystems through acidification, mineral accumulation, oxygen depletion, and heavy-metal introduction. Sustainable aquaculture therefore requires not only balanced feed formulation but also controlled feeding practices, continuous monitoring of key water parameters, and the integration of aeration or water-exchange strategies to prevent environmental stress and ensure fish survival.

This study was carried out to evaluate the Equilibrium of the removal of 2-Chlorophenol from aqueoussolution onto bone char and the parameters that were studied were Concentration, Adsorbent dosage and Time. The bone char was obtained from by calcination process occurring at 500⁰C for 2hours. This char was characterized by using FT-IR, XRD,SEM/EDS and BET. Batch adsorption experiment was carried out to investigate the following variables, pH, Concentration and Adsorbent dosage. The morphology of the bone char showed fine hexagonal shaped particles and a have homogenous structure with rough edges also the presence of elements Carbon, Oxygen, Silicon, Phosphorus, Aluminum,Potassium andCalcium was observed. It was observed that as the concentration increased the amount adsorbed increased, the pH study showed that the adsorption capacity was highest at pH 7.3, lowest at acidic condition and followed by the basic condition. It revealed that cow bone char has good adsorption properties and could be utilized for the treatment of 2Chlorophenol in waste water

Crude oil spills in Nigeria poison farmland, killing plants and microbes while adding dangerous hydrocarbons and heavy metals that hurt crops and human health. This study tests a low-cost, eco-friendly fix using fermented whey from guinea grass (Panicum maximum) leaves to boost soil microbes that eat oil. The aim was to see how well this whey cleans oil-polluted soil by cutting total petroleum hydrocarbons (TPH) and restoring soil quality. The scope included collecting leaves (Panicum maximum) from University of Benin sports complex, processing the leaves into whey and fermenting the whey at various periods for twelve days. The whey samples were further characterized to further determine pH, electrical conductivity, moisture, organic matter, carbon, nitrate, phosphate, nitrogen, phosphorus, potassium, and microbial counts to evaluate the whey with the best potential with respect to fermentation time—day 12 with pH 5.74, EC 4804 µS/cm, TOC 67.27%, nitrate 394.17 mg/kg, and high microbial growth (819 CFU/ml at 10⁻¹). Bioremediation potential of the whey was evaluated by treating agricultural soil. The day-12 whey results showed that soil treated with 200 ml was best, raising pH from 5.21 to 7.19, nitrogen from 19.10 to 27.18 mg/kg, phosphorus from 12.65 to 14.98 mg/kg, potassium from 6.23 to 12.45 mg/kg. TPH results showed that hexatriacontane rose to 1.17mg/L increased in the treated soil compared to the untreated contaminated soil, indicating its formation as a biodegradation intermediate during the breakdown of heavier hydrocarbons. Hexatriacontane showed a significant reduction to 0.05mg/L after whey treatment, demonstrating effective microbial attack on heavy hydrocarbon fractions. Heavy metals analysis indicates a significant reduction in metal concentration as in iron from 45.67mg/kg to 32.45mg/kg, zinc 18.90 mg/kg to 12.34 mg/kg copper 7.56 mg/kg to 5.12 mg/kg. Day 12 fermented Panicum maximum whey gave the best remediation potential.

Industrial activities contribute deeply to high emission rates of particulate matter (PM) and other pollutants into the ambient air. The siting of industrial plants in proximity to a populated area can have adverse effects on human health and the environment at large. The industrialization and urbanization of Sagamu city in Ogun state, has led to increased pressure on the city especially on air quality. The chemical complexity of airborne particles makes it necessary to consider their composition and sources of emission. This study was aimed at quantifying Fine particulate (PM2.5) and its heavy metals content in ambient air of industrial areas in Sagamu, Ogun state. The study locations of this research work were Ikorodu- Sagamu industrial area (majorly metal recycling industries) and Sagamu- Abeokuta interchange industrial area (majorly a mixed of Food, Agro￾allied and Brewery industries). The control site is located at Ode-lemo farm settlement in Sagamu, Ogun state. A total of 108 air samples of fine air particulate (PM2.5) were collected. Triplicate samples were collected each month with the aid of Conical Inhalable Sampling (CIS) head at a flowrate of 3.5Lmin-1 for 8hrs per day and for a period of one year. Meteorological data were collected simultaneously with PM2.5 via a specialised weather monitoring equipment (Automated Meteorological station). The PM2.5 filter papers collected were carefully sealed in a polythene bag and preserved prior to the laboratory for analysis. The PM2.5 mass concentration was computed gravimetrically. The loaded filters were subjected to acid digestion prior to analysis. Sixteen (16) metals were identified and quantified using Inductively Coupled Plasma- Optical Emission Spectrometer ICP-OES). Pollution indices such as Contamination factor (CF), Degree of contamination (DC) and Pollution index load (PLI) were assessed on the two industrial areas. Source identification and profiling of PM2.5- bound metals were determined using multivariate analysis which included Enrichment factor, inter-metallic correlation matrix, Principal component analysis (PCA) and Cluster analysis (CA). The two predictive models, Linear Regression Model (LRM) and Gamma Regression Model(GLM) were acquired and tested using the data produced from this work and a software tool R version 2024 which is user friendly.

Sodium alginate is a commonly used encapsulation matrix for variety of materials such as plant cells, food products, oil and flavor. This compound is biodegradable, biocompatible and non-toxic. Also, it is cheap, available, has chelating ability and forms stable reversible gels. However, plant extracts have challenges of poor utilization, poor stability, chemical degradation, low bioavailbility and high molecular weight. Therefore, this study was aimed at isolation, characterization and use of sodium alginate nanoparticles to encapsulate acetogenin compound isolated from Annona muricata leaf. Sodium alginate nanoparticles loaded with acetogenin compound were prepared and characterized using Transmission Electron Microscope (TEM) and Fourier Transform Infrared Spectroscope (FTIR). TEM revealed a spherical and irregular nature of sodium alginate nanoparticles loaded with acetogenin compound with particle size of 280nm. The encapsulation efficiency was 89% and this result shows that encapsulation in nanosized matrics with different concentrations of sodium alginate nanoparticles produced higher encapsulation efficiencies which therefore, enhances solubility, biovailability of acetogenin compound.

Natural clay minerals are abundant and versatile, offering a broad range of applications across various industries due to their unique physical and chemical properties. Their adsorption capacity and catalytic capabilities were enhanced through specific treatments. This study examined the effect of temperature on base-activated clay from the Gegu-Egba region, Kogi State, Nigeria. Clay minerals, valued for their high surface area and structural properties, were widely used in catalysis, adsorption, and refining. In this research, the Gegu-egba clay samples were treated with 30% NaOH and heated at 200°C (F3A) and 400°C (F3B) to assess structural and chemical changes. Characterization techniques, including X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), energydispersive X-ray spectroscopy (EDX), and Brunauer-Emmett-Teller (BET) analysis, were employed to evaluate their structural, morphological, and textural properties FTIR analysis indicates progressive dehydroxylation, with the disappearance of free hydroxyl groups and shifts in Si–O and Al–O–Si vibrations, suggesting kaolinite transformation into metakaolin. XRD results confirm a decline in kaolinite content (23% to 3.1%) and increased feldspar influence, supporting amorphization at 400°C. SEM-EDX analysis shows increased porosity and redistribution of elemental composition, notably a decrease in Si and Ti with a rise in Al content. BET surface area decreases from 249.577 m²/g at 200°C to 214.149 m²/g at 400°C, indicating structural densification. These findings emphasized the role of optimized thermal treatment in enhancing base-activated clay for industrial applications such as catalysis, adsorption and wastewater treatment

Cases of dental and skeletal fluorosis have been reported in children especially in low income earning countries and this has been a major problem as documented in recent studies. Clay is an adsorbent material that is cheap and readily available relative to other industrially synthesized adsorbents and its properties has been explored by recent researchers. This study aims at assessing the adsorptive properties of raw and modified edible clay on fluoride from solution. The effect of concentration, adsorbent
dosage, and time and isotherm studies were conducted using standard procedures documented in literatures. From the result, activated edible clay had the highest percentage removal at 15 minutes with a value of 95.37%, 96.74% at a concentration of 50mg/L of fluoride, and 96.92% at an adsorbent dosage of 1.3g. The raw edible clay showed maximum adsorption at 25 minutes, at maximum concentration of 30mg/L fluoride, and at a dosage of 1.3g with values of 93.98%, 96.63%, and 96.34% respectively. The adsorption does not follow a monolayer coverage as the data could not fit into the Langmuir and Freundlich’s isotherms. These values indicate that the raw and oxalic acid modified clay are good adsorbents for the removal of fluoride from solution.