ChemSearch Journal <p><em>Chemsearch Journal</em> is a peer – reviewed journal that publishes original research work, scientific papers and technical reports in all the field of Chemistry (pure science, agriculture, environmental science, science education and related fields).</p><p>This journal is now Open Access so the content can be freely accesses online.</p> en-US ChemSearch Journal 2276-707X The copyright belongs to Chemical Society of Nigeria, Kano State Chapter. Editorial No Abstract A.A. Audu Copyright (c) 2020-01-09 2020-01-09 10 2 10.4314/csj.v10i2. Potentiometric determination of pKa of some selected antibiotics in mixed solvent media <p>The ionization constants of some selected antibiotics namely sulfamethoxazole, trimethoprim and metronidazole have been determined by potentiometry in some mixed solvent media by varying the concentrations at 25<sup>o</sup>C. The ionization constants varied with the proportion and nature of different solvent mixtures used, as most exhibited their highest pKa values in 100% DMSO. Specifically, it has been found that in MeOH-DMSO mixture as the proportion of methanol increases, there is reduction in the pKa values for all the antibiotics. In all the solvent mixtures, the pKa values of 7.92, 8.29, 7.61, 7.98, 7.78 (trimethoprim) and 2.99, 2.87, 2.58 and 2.97 (metronidazole) obtained are higher than the reported values at physiological pH for trimethoprim and metronidazole. However, the pKa values obtained for sulfamethoxazole are comparable to the equilibrium dissociation of its amine moiety.</p><p><strong>Keywords:</strong> Antibiotics, pKa values, mixed solvent, drug permeability, ionization constants</p> T.T. Eugene-Osoikhia M.C. Emesiani Copyright (c) 2020-01-09 2020-01-09 10 2 1 9 10.4314/csj.v10i2. Synthesis, characterization, kinetic, thermodynamic and antimicrobial activity studies of complexes of Cd(II), Cr(III), and Zr(IV) derived from benzaldehyde and ethylenediamine <p>A Schiff base ligand N,N’-Bis(Benzoin)ethylenediimine (B<sub>2</sub>ED) obtained from benzaldehyde and ethylenediimine and its Cd(II),Cr(III) and Zr(IV) complexes was synthesized and characterized using electronic spectra (ultra-violet visible spectroscopy), infrared spectra (vibrational spectroscopy), molar conductivity measurement, solubility test and melting point determination. The ligand and the metal complexes were insoluble in the solvents distilled water, hexane, aqueous ammonia, potassium hydroxide and sulphuric acid but soluble in acetone, glacial acetate, DMSO and DMF. The conductance data showed that both the ligand and the metal complexes exhibited weak ionic (non-electrolytic character) while the melting point for ligand and decomposition temperature for complex showed they are fairly stable. The IR spectrum of B<sub>2</sub>ED showed characteristic vibrations of C=N and OH groups at 1677 and 3377 cm<sup>-1</sup>, respectively. In the spectra of Cd<sup>2+</sup>, Cr<sup>3+</sup> and Zr<sup>4+</sup> complexes, the azomethine band (V<sub>C=N</sub>) was shifted to lower wave number (1630–1634 cm<sup>-1</sup>) whereas, the v(OH) is shifted by 18–48 cm-1 to lower frequency upon complex formation suggesting involvement of C=N and OH groups in coordination. The electronic spectra showed that the metal complexes exhibited single, double or triple bands which are consistent with the octahedral and tetrahedral geometry for the metal complexes. The Kinetics of the complex formation were studied by determining the amount of complex formed with time at different temperatures of (25, 35, 45, 55 and 65<sup>o</sup>C). The kinetic results showed that increase in time and temperature respectively increased the yield of the complexes. The activation energies of the reactions were in the range of 12.288-18.707 kJ mol<sup>−1</sup>. The high values of the activation energies reflect the thermal stability of the complexes. The metal complexes exhibited antimicrobial performances, such as low minimum inhibitory concentration (MIC ≤ 250) and bactericidal effect than the ligand. These could become promising antimicrobial agents with potential applications in pharmaceutical industry for controlling the pathogenic bacteria.</p><p><strong>Keywords:</strong> Antimicrobial studies, kinetics, Schiff base Complexes, thermodynamics</p> Moses Saviour Iorungwa Chuckwuemeka Luke Mamah Raymond Ahulle Wuana Copyright (c) 2020-01-09 2020-01-09 10 2 10 24 10.4314/csj.v10i2. <i>In vitro</i> evaluation of the antioxidant and antimicrobial activity of leaf extracts of <i>Petroselinum cripsum</i> (Parsley) <p>Petroselinum crispum also known as parsley belongs to the<em> Apiaceae</em> family. It is a biennial herb native to the Mediterranean region but now cultivated worldwide. It has been claimed in Arab traditional medicine to possess variety of properties including laxative, diuretic and antiurolithiatic benefit. This study investigated the antioxidant and antimicrobial activity of the leaf extracts of parsley grown in Kano, Nigeria. The results showed that the ethyl acetate extract has the highest antioxidant activity with an IC<sub>50</sub> value of 49.7 and 59.9 μg/ml of ascorbic acid equivalence in the total antioxidant assay. The petroleum ether fraction showed poor radical scavenging ability and a low total antioxidant activity hence, making it the least active fraction. The antimicrobial activity was examined using micro dilution technique against six standard human pathogens (<em>Salmonella typhi</em>, <em>Staphylococcus aureus</em>, <em>Klebsiella pneumoniae Mucor specie</em>, <em>Aspergillus flavus</em> and <em>Candida albicans</em>). Significant activity of the fractions was observed in Minimum Inhibitory Concentration and Minimum Bactericidal/Fungicidal Concentrations. The fractions were all active against all the tested microorganisms at the highest concentrations. The chloroform fraction was the most active with MIC against all the tested microbes found to be 62.5 μg/ml while the ethanol fraction was found to be the least active fraction. The result obtained justifies part of the ethno medicinal claims on the medicinal uses of parsley.</p><p><strong>Keywords:</strong> Antimicrobial activity, Antioxidant activity, Leaf extract, <em>Petroselinum crispum</em></p> K Abdu D.G. Hauwa Copyright (c) 2020-01-09 2020-01-09 10 2 25 29 10.4314/csj.v10i2. Comparative studies on the adsorption of rhodamine B and malachite green from simulated wastewater onto bentonite clay <p>Bentonite clay, a readily available adsorbent was employed in the investigation of the removal of synthetic basic dyes from simulated wastewater. Batch adsorption experiments were carried out for the sorption of the basic dyes, i.e. Rhodamine B and Malachite green onto the clay. The specific surface area (Sear’s method), point of zero charge (Solid addition method) and functional groups present on the clay were determined using the Fourier Transform Infrared Spectroscopy (FTIR). The influence of process variables such as initial dyes concentrations, ionic strength, pH and contact time were also investigated. The isotherm equilibrium data were fitted to the linear forms of the Langmuir, Freundlich and Temkin isotherm models. The result of the Freundlich plots showed that both dyes were adsorbed onto a heterogeneous adsorbent surface with sorption capacities of Rhodamine B and Malachite green being 0.386 mg/g and 0.805 mg/g respectively. The data from the kinetic studies were fitted into the pseudo-first order, pseudo-second order and Boyd kinetic models. Over the study of these parameters, the pseudo-second order and film diffusion mechanism was found to predominate in the adsorption process of the dyes. Process variables such as pH and ionic strength was found to have a significant effect on the uptake of both dyes.</p><p><strong>Keywords:</strong> Adsorbent, Adsorption, Fourier Transform Infrared Spectroscopy, Simulated, Synthetic</p> O.K. Akeremale S.E. Olaseni Copyright (c) 2020-01-09 2020-01-09 10 2 30 40 10.4314/csj.v10i2. Phytochemical screening and antibacterial activity of the root bark extracts of <i>Neocarya macrophylla</i> <p><em>Neocarya macrophylla</em> is a medicinal plant commonly used in traditional medicine in Northern Nigeria to treat asthma, skin infections, treatment of wounds, dysentery, pulmonary troubles and a number of inflammations, as ell as treatment of eye and ear infections. In this work, the root back extracts of <em>Neocarya macrophylla</em> were screened for phytochemical constituents as well as the antibacterial activity against <em>Escherichia coli</em>, an ear infection-causing pathogen. The results revealed that some of the common phytoconstituents are present in most of the extracts. The susceptibility test results gives inhibition range of 13, 13, 13, 14 and 13 mm for the crude extract (NM), methanol extract (NM4), ethyl acetate extract (NM3), chloroform extract (NM2) and n-hexame extract (NM1) respectively against test organism at 50 mg/ml. The test results also showed inhibition range of 12, 11, 11, 12 and 12 mm for NM, NM4, NM3, NM2 and NM1 respectively at 25 mg/ml. Lastly, the results showed inhibition range of 11, 10, 09, 10 and 11 mm for NM, NM4, NM3, NM2 and NM1 respectively at 12.5 mg/ml. This indicates that NM2 is the most active fraction against the organism at 50 mg/ml, and the least active fraction was NM3 at 12.5 mg/ml. The test results also show that the root back extract NM2 has the potentials of providing the active components that could be developed into new antibacterial agents.</p><p><strong>Keywords:</strong> Antibacterial activity, <em>Escherichia coli</em>, <em>Neocarya macrophylla</em>, Phytochemicals</p> A.S. Bayero Y Datti M.M. Shuaibu A.M. Nafisatu A.A. Asma’u M.A. Dikko A.H. Zakari M Yusuf Copyright (c) 2020-01-08 2020-01-08 10 2 41 45 10.4314/csj.v10i2. Study on physico-mechanical behaviour of <i>Acacia nilotica</i> (gum tree) and glass fiber blend reinforced epoxy resin composite <p>The mechanical properties of <em>Acacia nilotica</em> were investigated by chemical modification of the fiber-reinforced composite. For this, the bast fiber was retted enzymatically, washed, dried, combed and alkali treated using a mixture of benzoyl peroxide and sodium hydroxide. This treatments on the composite material was undertaken in order to achieve improved modification of the interface between the matrix and fiber bond. A portion of the glass fiber was used for enhancing the mechanical properties of the hybrid composite. Epoxy resin and hardener were also used being 60:40 respectively in composition, to fabricate the composite. The results show an improvement in all the properties tested in relation to the alkali and the acid treatments of the <em>Acacia nilotica</em>/glass fiber blend composites. Tensile strength of the <em>Acacia nilotica</em> treated with the glass fiber by benzolation improved from (40 to 240 MPa) the flexural strength, of the <em>Acacia nilotica</em> treated by benzolation also significantly improved from 8 to 28 MPa strength value. FTIR analysis confirmed that the chemical modification of the fiber bond was carried out.</p><p><strong>Keywords:</strong> <em>Acacia nilotica,</em> Composite, Epoxy, Glass fiber, Natural fiber</p> A.H. Birniwa S.S. Abdullahi H.N.M. 3Ekramul Mahmud Copyright (c) 2020-01-09 2020-01-09 10 2 46 53 10.4314/csj.v10i2. Physicochemical parameters, levels of Cu and Pb in water and water lily plant from the Bank of River Benue <p>In this study three (3) water samples were collected from the River Benue Basin, within the catchment of the Benue State Works. The water samples were collected at different points within this region alongside water Lilly plants at the same points in the study area. This research was aimed at assessing the physicochemical properties and heavy metals (Cu and Pb) content in water and water lily plant around Benue Water Works in Makurdi. The physicochemical parameters of the water samples as well as determination of Cu and Pb in the water samples, and water lily plant was done using standard methods. Results were compared to the World Health Organisation (WHO) guidelines to assess suitability. The results of the physicochemical parameters were either below or within the accepted limit except for colour (179 - 220 mg/units) and electrical conductivity (919 – 1760 μS/cm) which were above the WHO recommended limits of 15 TCU and 1000 μS/cm respectively. Trace metal contamination was exceedingly above WHO recommended level of 0.01 mg/L for Pb in water. Similarly, Pb concentration (48.5 – 53.6 mg/kg) in the plant samples was above the WHO/FAO recommended value of 5 mg/kg indicating pollution. It was concluded that the water is not completely safe for drinking and with the high level of Pb both in the water and plant samples, the water poses environmental health risk to inhabitants and the society in general.</p><p><strong>Keywords:</strong> Heavy metals, Physicochemical parameters, Water quality, WHO/FAO guidelines</p> Ande Sesugh Atungwu Blessing Iorungwa D. Patience Idowu Obolo Aondo Titus Copyright (c) 2020-01-09 2020-01-09 10 2 54 61 10.4314/csj.v10i2. Proximate composition and the mineral contents of soya beans (<i>Glycine max</i>) available in Kano State, Nigeria <p>Soya bean is an important source of high-quality protein and oil, as well as other nutritious substances. The higher the content of these nutritious substances in a given soya bean, the higher it’s quality. The mineral and proximate contents of the variety of soya beans available in Kano state, Nigeria, were determined using standard procedures. The percentage (%) proximate composition was found to be Moisture 8.13%, Crude Protein 39.24%, Crude Fibre 6.84%, Crude Lipid 30.31%, Ash 4.61%, and Carbohydrate 5.08%. While the average mineral contents (%) were found to be 0.003 (Na), 0.216 (K), 0.281 (Mg), 0.324 (Ca), 0.722 (P), 0.003 (Zn), 0.002 (Cu), 0.291 (Mn) and 0.018 (Fe). The result is an indication of the nutritional importance of soya beans, and thus its production and quality require to be improved.</p><p><strong>Keywords:</strong> Mineral content, Nutritional value, Proximate composition, Soya beans</p> A.S. Bayero Y Datti M Abdulhadi A.T. Yahya I Salihu U.A. Lado T Nura B Imrana Copyright (c) 2020-01-08 2020-01-08 10 2 62 65 10.4314/csj.v10i2. Levels and spatial distribution of heavy metals in Lake Chilwa Catchment, Southern Malawi <p>The aim of this study was to assess the levels and distribution of heavy metals in Lake Chilwa and its catchment, and to understand the associated level of pollution. Water and sediment samples were collected from the lake and main inflowing rivers. A total of 23 surface water samples were sampled and analysed for pH, EC, Cu, Cr, Zn, Cd, Pb, As and Hg. Conductivity and pH were measured on-site with a Hanna portable multi meter, while metals were analysed by Inductively Coupled Plasma Optical Emission Spectrometer (ICP-OES). The pH was found within the alkaline range (7.87-10.13), while conductivity ranged from 97-390μS/cm. The following metals were detected in the water samples; Zn (6.24–1168.70 μg/L), Cu (BDL–47.83 μg/L), Pb (BDL–49.94 μg/L), Cr (0.22–33.05 μg/L), Ni (0.40–8.20 μg/L) and Cd (BDL–0.53 μg/L). Hg and As were not detected in all sampling locations. Strong positive correlations were observed between Cd and Pb (r = 0.70), Cu and Zn (r = 0.70), while Cd and Ni (r = 0.50), Pb and Ni (r = 0.41) showed mild correlations, suggesting similar sources of input. Sediments were sampled from 2 locations in the lake and the following metals were detected; Zn (66.13 mg/Kg), Pb (7.74 mg/Kg), Ni (35.39 mg/Kg), Cu (20.02 mg/Kg), Cr (54.81 mg/Kg) and As (1.0 mg/Kg). Mercury and arsenic were not detected from both sampling locations. The heavy metal pollution index ranged from 2.24 to 114.45. All points except Kachulu harbour had values far below the critical pollution index value of 100. The values observed were well below the tolerable limits recommended by the World Health Organisation (WHO) standard for potable water, except for Pb at Kachulu Bay (P19) which was above the limit. Concentrations of the metals in the rivers were low upstream and increased downstream. Highest values for most of the elements were observed from the lake. Though levels are low now, the persistent and cumulative properties of these elements would render them unsafe in the near future if proper controls are not enforced.</p><p><strong>Keywords:</strong> Heavy metals, Lake Chilwa, Water pollution, Water quality</p> Chisomo Mussa Timothy Biswick Wisdom Changadeya Annett Junginger Ephraim Vunain Copyright (c) 2020-01-09 2020-01-09 10 2 66 73 10.4314/csj.v10i2. Characterization of formulated copper chitosan nanoparticles for the controlled release studies of dicamba dimethylamine herbicide <p>In this study, a dicamba herbicide was encapsulated onto copper nanoparticles (CuNPs) via a green chemical reduction method in order to improve its herbicidal activity, with the intention of reducing its negative impacts on the environment. The synthesised Dicamba-copper chitosan nanoparticles (Dic-CuCtsNPs) was characterised using UV-visible spectroscopy, scanning electron microscopy (SEM), Fourier transform- infrared (FT-IR), powder x-ray diffraction (PXRD), differential scanning calorimetry (DSC), thermo gravimetric analysis/differential thermal analysis (TGA/DTA) and energy-dispersive x-ray spectroscopy (EDX). The maximum absorption peak of the Dic-CuCtsNPs was observed at 556 nm. The encapsulation efficiency of the Dic-CuCtsNPs formulation was 86 %. The average crystalline size of the nanoparticles, from its PXRD pattern, estimated using the Debye- Scherrer’s equation was 45.94 nm. The SEM image obtained indicated particle size distribution of 16 – 64 nm. The DSC curve showed that the formulation exists in the crystalline state while the TGA data indicated that the formulation was thermally stable up to 425.75<sup>o</sup>C. Aqueous release study of Dic- CuCtsNPs was carried out using three different pH media and two agricultural soils. The leaching profile of the formulated nano-herbicide through the University of Agriculture (UAM) and college of advance and professional studies (CAPS) soil layer index showed a high value for the UAM soil being 43.84 % higher than in the CAPS soil value of 26.92 %. Thus, an eco-friendly herbicide delivery system was formulated using CuCtsNPs, for the successful release of Dicamba in aqueous medium and agricultural soils.</p><p><strong>Keywords:</strong> Controlled release, Dicamba, Encapsulation, Green synthesis, Herbicide, Soil</p> R.A. Wuana L.A. Nnamonu R Sha’Ato H.U. Itodo Copyright (c) 2020-01-08 2020-01-08 10 2 74 87 10.4314/csj.v10i2. Application of <i>Peperomia pellucida</i> leaves extract as a green corrosion inhibitor for mild steel in 1.0 m hydrochloric acid solution <p>The inhibition efficiency of <em>Peperomia pellucida</em> (PP) leaves extract against the corrosion of mild steel in 1 M hydrochloric acid was investigated by weight loss and electrochemical methods. The inhibition efficiency (%I) decreased with increase in temperature. Results from weight loss, electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PDP) studies revealed that PP acted as a good inhibitor and inhibition efficiency reached 98.1 % at 1000 ppm inhibitor concentration. The values for Gibbs free energy (ΔG = -18.79 kJ mol<sup>-1</sup> at 343 K) were negative, indicating that the adsorption of PP on the surface of mild steel is spontaneous. The values of ΔG also indicated that adsorption of PP on the mild steel surface was by physisorption and the generated data fitted the Langmuir adsorption isotherm. A decrease in entropy with increase in PP concentration was also observed. At 1000 ppm inhibitor concentration, ΔH = -32.58 kJ mol<sup>-1</sup> was obtained. The negative value of ΔH indicated the exothermic nature of the orrosion process and adsorption of PP molecules on mild steel surface. Activation energy increased with a rise in PP concentration. Polarization studies revealed that PP acts as a mixed type inhibitor. Results of weight loss and electrochemical studies validate the use of <em>Peperomia pellucida</em> as inhibitor for corrosion of mild steel in acidic medium</p><p><strong>Keywords:</strong> Corrosion, inhibition efficiency, inhibitor, mild steel, <em>Peperomia pellucida</em></p> N.W. Odozi R Saheed M.M. Mchihi Copyright (c) 2020-01-09 2020-01-09 10 2 88 93 10.4314/csj.v10i2. Physicochemical and heavy metal analysis of well water obtained from selected settlements around Dangote cement factory in Gboko, Nigeria <p>Drinking water in developing countries especially Nigeria is susceptible to toxins as a result of effluents and pollutants. This study investigated the physicochemical characteristics and heavy metal contents of water samples collected from six different hand-dug wells from some settlements around Dangote Cement Plant Gboko. The concentration of all the physicochemical parameter studied were generally below maximum limits prescribed by WHO except for turbidity which was found in two of the samples opposite the factory (OF) and Tarhembe (T) to be 51.8 NTU and 17.5 NTU respectively which were higher than the maximum limit of (5.0 NTU) set by WHO. Total metal digestion of water samples was carried out using concentrated nitric acid (HNO<sub>3</sub>). The digests were analyzed for heavy metals (Cd, Cr, Cu, Fe, Mn, Pb, and Zn.) using AAS. Results showed that Cd, Cr and Pb in all the water samples were not detected, the concentrations of Cu and Zn ranged from 0.01-0.05 mgL<sup>-1</sup> and 0.08-0.13 mgL<sup>-1</sup> respectively and were below the permissible limit set by WHO. The concentration of Fe and Mn ranged from 0.25-1.16 mgL<sup>-1</sup> and 0.33-0.92 mgL<sup>-1</sup> respectively and were found to be above the permissible limits recommended by WHO for drinking water. In this study, contaminants level were generally below the WHO maximum recommended limits except Fe and Mn contents which showed elevated values above the recommended levels, hence the need to put mechanisms in place to control the levels of these heavy metals in the well water sources around the area under study.</p><p><strong>Keywords:</strong> Atomic Absorption Spectrophotometer, Heavy metals, Ground water, WHO</p> Ande Sesugh Obolo E. Idowu Aondo Titus Agbendeh Zack Oije Mavis Tuma Joseph Copyright (c) 2020-01-09 2020-01-09 10 2 94 99 10.4314/csj.v10i2. Determination and comparison of ascorbic acid contents in selected fruits and vegetables obtained from Ilorin Metropolis <p>The ascorbic acid contents of eight different fruits and four vegetable types were determined by iodometric titration method using standardized sodium thiosulphate against ascorbic acid in the fruit and vegetable extracts. A blank titration was first carried out on the thiosulphate only followed by titration with the extracts. From the blank titre, the total amount of water-soluble iodine produced in the reaction was calculated while the amount of water-soluble iodine that reacted with the sample was obtained from the test titre. The quantity of ascorbic acid in milligrams, present in each fruit and vegetable sample was obtained by calculations. The results showed that the amount of ascorbic acid in the selected fruits was in the order of Orange &gt; Tangerine &gt; Water melon &gt; Pineapple &gt; Grape &gt; Apple &gt; Lemon &gt; Lime and the vegetables, in the order of Pumpkin &gt; Bitter leaf &gt; Water leaf &gt; Amaranth leaf.</p><p><strong>Keywords:</strong> Ascorbic acid, Fruits, Iodometry, Vegetables, Water-soluble Iodine</p> O.T. Odeyemi E.O. Amira I.R. Hassan Copyright (c) 2020-01-09 2020-01-09 10 2 100 103 10.4314/csj.v10i2. RETRACTED: Synthesis and characterization of BiVO<sub>4</sub> nanoparticles and its photocatalytic activity on levofloxacin antibiotics <p><strong>RETRACTION NOTICE:</strong> “Synthesis and Characterization of BiVO4 nanoparticles and its Photocatalytic Activity on Levofloxacin Antibiotics”. (ChemSearch Journal 10(2): 104 – 111, December, 2019) by Usman Saidu, Department of Chemistry, SuleLamido University Kafin Hausa, P.M.B. 048, Jigawa State, Nigeria, Received: 29/10/2019, Accepted: 06/12/2019. The retraction is agreed upon after discovering that the author utilized data that was not authorised/approved by his PhD supervisor leading to his requesting for the retraction of the article.</p> <p>In this research, BiVO<sub>4</sub> photocatalyst was successfully synthesized through a facile chemical precipitation method. The as-synthesized photocatalyst was characterized using X-ray diffraction (XRD), scanning electron microscope accompanied with an energy-dispersive X-ray spectroscopy (SEM/EDS) and UV–Vis diffuse reflectance spectroscopy (UV–Vis/DRS). The photocatalytic activity of the as-synthesized photocatalyst was tested on the degradation of levofloxacin as a model pollutant. 85% degradation of 20 ppm levofloxacin was achieved within 90 min of visible light irradiation as compared with 18% using commercial photocatalyst P25, under the same experimental conditions. Such enhanced activity was attributed to higher absorption of visible light by the as-synthesized BiVO<sub>4</sub> that led to formation of a large number of reactive species. The kinetics of the photodegradation process was explained in terms of the Langmuir Hinshelwood model. The values of the kinetic rate constant (k) of the photodegradation were 2.52 x 10<sup>-3</sup> min<sup>-1</sup>,and 22.35 x 10<sup>-3</sup> min<sup>-1</sup> for commercial P25 and the as-synthesized BiVO<sub>4</sub> photocatalysts, respectively. The investigation of the total organic carbon (TOC) indicated high mineralization of levofloxacin was achieved. Finally, the as-synthesized BiVO4 photocatalyst was found to retain its high degradation efficiency even after 5 cycles, indicating its stability for repeated applications.</p> <p><strong>Keywords:</strong> Antibiotics, BiVO<sub>4</sub>, Levofloxacin, Photocatalyst, Photodegradation</p> Usman Saidu Copyright (c) 2020-01-09 2020-01-09 10 2 104 111 10.4314/csj.v10i2. Reclamation of malachite green-bearing wastewater using desert date seed shell: adsorption isotherms, desorption and reusability studies <p>A low-cost activated carbon adsorbent was prepared from desert date seed shell (DDSS) and utilized for the removal of hazardous malachite green (MG) from aqueous solution using batch mode technique. Different isotherm models were applied to acquire the theoretical data of MG adsorption onto the adsobent at variable initial concentration of 100-1000 mg dm<sup>-3</sup>. Based on the coefficient of determination (R<sup>2</sup>), isotherm models exhibit the following sequence: Freundlich &gt; Langmuir &gt; Redlich-Peterson &gt; Temkin &gt; Jovanovic &gt; Harkin- Jura &gt; Elovich &gt; Dubinin-Radushkevic. The maximum monolayer capacity of the adsorbent was found to be 312.5 mg g<sup>-1</sup> at 303 K. The mean free energy value (0.91 kJ mol<sup>-1</sup>) obtained from D-R isotherm suggests that the adsorption process follows physisorption mechanism. Desorption studies for reusability revealed that acetic acid offered the best recovery (52.09%) and the process follow pseudo-second-order kinetics. The conducted reusability test revealed the decline of the adsorbent performance from 96.5% MG removal down to 70.5% MG removal after 5 successive adsorption/desorption cycles.</p><p><strong>Keywords:</strong> Activated Carbon, Desorption, Isotherms, Malachite Green, Reusability</p> U Yunusa M.B. Ibrahim Copyright (c) 2020-01-09 2020-01-09 10 2 112 122 10.4314/csj.v10i2. Degradation of methyl red using Cd-Sb/C layered double hydroxide catalyst under visible light <p>This research work presents the degradation of Methyl red using cadmium-antimony-carbon (Cd-Sb/C) catalyst under visible light. The double layered hydroxide was successfully prepared from cadmium fluoride (CdF<sub>2</sub>), antimony chloride (SbCl<sub>3</sub>), and rice husks activated carbon, and then characterized by X-ray Diffaractometry (XRD) Scanning Electron Microscopy (SEM) and Fourier Transform Infrared (FTIR) methods. The peaks at 2Ө 10.0, 23.4 and 35.5 in the XRD result confirmed the presence of double layered hydroxide. The effect of catalyst dosage, pH and initial concentration, on the photo degradation of Methyl red was investigated. The experimental results showed that after 100 min visible light irradiation, the percentage degradation using 200 mg Cd-Sb/C, pH 5 and 3ppm Methyl red concentration reached to 50.36%. For kinetics studies the data obtained were analysed using pseudo first order and pseudo second order kinetic models. From the linear regression coefficient values the data were found to be best fitted to pseudo second order kinetics. The results revealed that the Cd-Sb/C show good catalytic activity.</p> F.A. Garzali A.S. Muhammad Copyright (c) 2020-02-09 2020-02-09 10 2 123 129 10.4314/csj.v10i2. Antihyperglycaemic and antilipidaemic properties of ethanol stem bark extract of <i>Crossopteryx febrifuga</i> in alloxan-induced diabetic rats <p>This study investigated <em>Crossoptyerx febrifuga</em> stem bark extract for antihyperglycemic and antihyperlipidemic effects in alloxan–induced diabetic rats. Thirty diabetic albino rats were assigned into six groups of five rats each and treated with extract of varying doses (500mg/kg, 1000mg/kg and 1500mg/kg) and standard antidiabetic drug- glibenclamide. Treatment of the diabetic rats was done in seven days through orogastric procedure. The extract showed a significant (p ˂ 0.05) hypoglycemic and hypolipidemic effect in all the doses compared to the diabetic control and standard antidiabetic drug, glibecamide. The high density lipoprotein (HDL) increased significantly (p ˂ 0.05) and the low density lipoprotein (LDL) decreased in all the groups, as against the diabetic control. On percent scale, the HDL increased by 55.18% and the LDL reduced significantly (p ˂ 0.05) by 73.52% at the dose of 500mg/kg as against the standard drug which showed just 20.69% reduction. Acute toxicity study was done prior to the diabetic study. The method adopted was that of Lorke and plant extract was found to be safe up to the dose of 5000mg/kg. Phytochemical screening revealed the presence of alkaloids, tannins, saponnins, cardiac glycosides, flavonoids phytosterols and polyhenolics. The presence of these rich phytoconstituents was the reason for the antihyperglycemic and hypolipidemic property of this plant thus, confirming its use in folklore.</p><p><strong>Keywords:</strong> Antihyperglycemic, <em>Crossoptyerx febrifuga</em>, Diabetes mellitus, Phytochemical, Toxicity</p> M.M. Idris H.P. Nenge Copyright (c) 2020-01-09 2020-01-09 10 2 130 137 10.4314/csj.v10i2. Kinetics of adsorptive removal of Congo red using activated kola nut pod <p>The objectives of this study is to evaluate the kinetics for the adsorption of Congo red (CR) onto activated kola nut pod (AKP) from aqueous solutions using a batch adsorption process. The effect of contact time (10 min to 180 min) and initial concentration (5 mg/l to150 mg/l) of the adsorption of CR onto AKP were optimized. Characterization of the adsorbent was undergone using Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM), and the result obtained showed shifting and disappearance of peaks after adsorption. The results of the adsorption kinetics revealed that Congo red (CR) was adsorbed according to the pseudo second-order kinetic model, the data showed the highest correlation coefficient for pseudo Second-order (0.997) and an agreement between the amount adsorbed experimentally (1.907 mg/g) and the calculated amount (1.839 mg/g).</p><p><strong>Keywords:</strong> Activation, Adsorption, Congo red, Dye, Kinetics</p> M.A. Abdurrahman A.S. Muhammad Copyright (c) 2020-01-09 2020-01-09 10 2 138 144 10.4314/csj.v10i2. Evaluation of heavy metals contamination in some irrigated vegetables from Kano, Nigeria <p>The content of Pb and Cr in some vegetables (viz lettuce, onion, carrot, tomato, pepper and amaranthus) grown on irrigated farm lands in the vicinity of Sharada industrial waste water drainage basin at Kaba village, Challawa, Kano, Challawa-Yandanko rivers and Thomas Dam, Danbatta, Kano, Nigeria were evaluated. It is situated at 8<sup>o</sup> 29` 42” to 8<sup>o</sup> 30` 54” E longitude and 11<sup>o</sup> 5`18” to 11<sup>o</sup> 5` 54” N latitude, also 8<sup>o</sup> 30` 18” to 8<sup>o</sup> 31` 30”E Longitude and 12<sup>o</sup> 17` 6” to 12<sup>o</sup> 16` 30”N Latitude. The objectives have been mainly to determine Cr, and Pb in edible parts of these vegetable samples which were frequently consumed by people in Kano and other parts of Nigeria in order to compare the heavy metals contents with the results obtained in analogous studies carried out in relation to the permissible limits specified by WHO/FAO, standards. Samples of vegetable were obtained in the dry season for the year 2018 from upstream and downstream portion of the sample sites. Analyses for the concentration of these heavy metals (Pb and Cr) were conducted by the use of Mass plama-Atomic Emission spectrometry (MP-AES) method. The Data obtained were expressed in terms of descriptive statistics while the figures were presented with mean values of three replicates. The statistical significance was computed using pair samples T-test to test the variation among the heavy metals in the vegetables and sites with a software JMP4 version 14. Results for the study indicated that concentration values of Pb (0.71-8.39 mgkg<sup>-1</sup>) and (Cr 9.58-28.30 mgkg<sup>-1</sup>) were higher than WHO/FAO maximum permissible limits for (Pb 0.3mgkg<sup>-1</sup>) and (Cr 2.3mgkg<sup>-1</sup>). The two way Anova test showed significant differences by farming site, vegetable type and their interaction. Furthermore, the study revealed that some areas of the sample site were more polluted by a particular metal than the other due to the revealing and anthropogenic activities such as the use of untreated industrial and municipal effluents, pesticides, fertilizer supplements for irrigation purposes in the area. Therefore, consumers of these vegetables run the risk of health problems like elevated blood pressure, developmental and neuro-behavioural effects on fetuses, in infants and children, cardiovascular, tubular dysfunction in kidneys and nervous disorders due the elevated concentrations of Cr and Pb in the vegetables.</p><p><strong>Keywords:</strong> Effluent, Heavy metals, Kano, Nigeria, Vegetables</p> S.A. Ringim M.I. Mohammed Copyright (c) 2020-01-09 2020-01-09 10 2 145 154 10.4314/csj.v10i2. <i>Schistocerca gregaria</i>-derived chitosan: antimicrobial activity and cytotoxicity studies of its Schiff Bases and metal complexes <p>Chitosan prepared by deacetylation of chitin extracted from <em>Schistocerca gregaria</em> (desert grasshopper) has been coupled with different aldehydes to afford the corresponding Schiff bases and consequently reacted with metal (II) salts to provide the corresponding complexes. The compounds were evaluated for their<em> in vitro</em> antimicrobial activity against two Gram positive (<em>Escheria coli</em> and <em>Salmonella typhii</em>), one Gram negative bacterial strains (<em>Staphylococcus aureus</em>), and three fungal strains (<em>Aspergillus niger</em>, <em>Aspergillus flavus</em>, and <em>Tricodma spp</em>). Chitosan and its derivatives were evaluated for their <em>in vitro</em> antimicrobial activity against two Gram positive bacterial (<em>Escheria coli</em> and <em>Salmonella typhii</em>), one gram negative (<em>Staphylococcus aureus</em>) and three fungi (<em>Aspergillus niger</em>, <em>Aspergillus flavus</em>,<em> Tricodma spp</em>) The MIC, MBC, and MFC values revealed that compared to the parent chitosan, the Schiff bases and their complexes have higher antibacterial and fungal activities which are in the order of chitosan metal complexes &gt;chitosan Schiff bases &gt; non-modified chitosan with BMC values of &gt;500, &gt;250 and 125μg/ml respectively, where MIC and MFC results showed similar trend. The cytotoxicity assay using brine shrimps revealed that parent chitosan was the most active against at all concentrations, 10μg/ml, 100μg/ml, and 1000μg/ml compared to chitosan Schiff bases, metal complexes.</p><p><strong>Keywords:</strong> Antimicrobial activity, Chitosan, Complexes, Desert grasshopper, Schiff bases, <em>Schistocerca gregaria</em></p> U Ali M.U. Baffa Y Shamsuddeen A.A. Salisu Copyright (c) 2020-01-09 2020-01-09 10 2 155 165 10.4314/csj.v10i2.