Abstract
Complexes of Co(II) and Mn(II)were prepared from tridentate Schiff base, (E) – N1- (2-hydroxybenzylidene)nicotinohydrazide. The Schiff base ligand was synthesisedfrom nicotinicacid hydrazide and salicylaldehyde. These metal complexes were characterised byelemental analysis, molar conductivity, magnetic susceptibility, thermalanalysis, x- ray diffraction, FTIR and UV – visible. The analytical data ofthese metal complexes showed metal: ligand ratio (1:2). The physicochemicalstudy supports the presence of octahedral geometry in all the complexes. The IRspectral data reveal that the ligand behaves as tridentate with ON donor atomsequence towards central metal ion. The molar conductivity values of the metalcomplexes suggest their non electrolytic nature. The x ray diffraction datasuggests orthorhombic crystal system for these complexes. Thermal behaviour(TGA/DTA) described the general decomposition patterns of the complexes. Theligand and its complexes were screened for their nematicidal activity and theresults show that the complexes exhibit promising nematicidal activity. Theresults reveal that the metal complexes are more potent nematicides than theSchiff base ligand.
Abstract
Dental caries remains the most prevalent chronic disease of kids in the world. Fluoride has shown effectiveness in the prevention of caries and giving maximum protection against dental caries while reducing the likelihood of enamel fluorosis. Fluoride is most effective in dental caries prevention when a low level of fluoride is constantly maintained in the oral cavity. Meanwhile, there are some undesirable side effects of too much fluoride exposure. This research involves the determination of the total soluble fluoride concentration of five brands of fluoridated toothpastes using ion-selective electrode (ISE). The different brand of adult toothpastes was purchased from local market/shops in Anyigba, Kogi State. Four of the samples contain sodium fluoride as active ingredient while one of them contains sodium monofluorophosphate. The total soluble fluoride content found for the various samples are as follows; sample A and B 0.066%; C: 0.05%; D: 0.138%; and sample E: 0.101% which are approximately 0.1 % (1000ppm) and 0.14%(1400ppm). These results fell within the standard given by the World Health Organization (WHO) and other agencies
Abstract
In process synthesis, design, and optimization of solid-liquid extractor, extraction yield (EY) has been the only process parameter used for centuries in determining the process performance. Solid-liquid extraction (SLE) is one of the crucial units in phytochemical processing. This communication introduces a concept of extraction selectivity (ES) as a new tool for green process analysis, design and development of solid-liquid extractor that overcomes the limitations of EY. New and simple equations have been developed based on the fundamental concepts of physical sciences, chemical, and process engineering. In addition, it proposes new schemes for the green SLE based on the concept of multiple extractions analogous to multiple reactions. Some of the equations were employed in the analysis of green SLE of andrographolide water extract and other phytochemical compounds from Andrographis paniculata (AP) as a case study. It was found that the performance indicator, ES is more sensitive and pronounced to changes in the process variables of SLE than EY. .
Abstract
Water stress is a limited factor affecting agricultural production worldwide, especially in the Mediterranean regions. It is estimated that over 800 million hectares of land worldwide are affected by abiotic stress. As part of the evaluation of the effect of water stress on the morphophysiological and biochemical behavior of the plant, we are interested in dentata lavender given its medicinal, aromatic and socio-economic interests in order to assess its tolerance to water stress by applying three water treatments: 100, 60 and 20% ET0.
Abstract
Adsorption capacity of plantain peel was evaluatedusing batch adsorption studies and quantum chemical calculation. The plantain peel without anymodification, was characterized by Fourier transform infrared spectroscopy(FTIR) and Scanning Electron Microscopy (SEM). In batch optimization studies,the maximum adsorption capacity was obtained at the optimum levels of contacttime (60 minutes at 14.3884mg/g) adsorbent dose (0.1g at 23.4431mg/g), initialdye concentration (60mg/L at 27.8547mg/g) and pH6 (22.6127mg/g). The mechanismof adsorption, kinetic data were modelled using the pseudo-first-order,pseudo-second-order, Elovich and Intraparticle diffusion. Among the kineticmodels studied, the pseudo-second-order equation was the best applicable modelto describe the adsorption process of the dye onto the adsorbent employed inthis work. Equilibrium isotherm data were also analyzed using the Langmuir,Freundlich, Temkin and Dubinin-Raduskevich isotherms. The Freundlich isothermmodel yielded a better result. Isotherm parameters have also been used toobtain the thermodynamic parameters such as Gibb’s free energy, enthalpy, andentropy of adsorption. The thermodynamic parameters: change in enthalpy, ΔH = 0.2690 kJ/mol, change in entropy ΔS =-0.0143J/mol. K. The change in Gibbs freeenergy ΔG = -2483.60 kJ/mol, -2886.50 kJ/mol, -3628.00 kJ/mol, -4516.08 kJ/mol at 303, 313, 323 and 333 K respectively. Theseresults show that plantain peel is a good low-cost adsorbent for the removal ofthis hazardous dye from wastewater and quantum chemical calculation is also ingood agreement with the experimental results. Quantum chemical calculation isfound to be one of the best method to determine the adsorption property of anymaterial because of its reliability and simplicity.
Abstract
Fossil fuel which is the world’s major source of energy is desperately sort for globally. The economic and social benefits of exploiting this natural resource sometimes relegate the environmental consequences to the background. The environmental degradation in oil and gas producing communities emanating from oil and gas operations is therefore discussed in this paper. The study shows that all the three streams of the petroleum sector generate some form of pollutants that affect every component of the environment. Some sources of pollution are exploration activities, gas flaring, oil spillage, accidental explosions, produced formation water, produced formation fines and sands, drill cuttings, drilling fluids, effluents and waste discharges from refineries. The environmental damages caused by these pollutants affect humans, plants, animals, the ecosystem, climate and infrastructure. Other impacts include social problems and economic losses to host communities that depend on the environment to eke out a livelihood. It is not morally right to sacrifice environmental safety for economic benefits, the dilemma needs to be properly handled and priorities should be rightly set. Responsible hydrocarbon exploitation cannot be over emphasized because environmental protection and preservation for continuity of life is a duty and should be every one’s business
Abstract
The current research was carried out to evaluate some heavy metal levels in potato and corn chips which purchased from Benghazi markets - Libya. The worldwide consuming of chips by children and young people around the world was the reason for performing the study. The collected samples were analyzed by Atomic Absorption Spectrophotometer (AAS) after wet digestion. Five metals; chromium (Cr), cadmium (Cd), manganese (Mn), zinc (Zn), and Lead (Pb), in twelve samples were evaluated. The heavy metal contents of the present study were compared with those reported in the literature. The concentration range of heavy metals in potato chips was found as follows: (2.325-6.950 mg/kg), (NE-0.722 mg/kg), (0.405-4.985 mg/kg), (1.580-2.545 mg/kg), and (2.325-6.950 mg/kg), for Cr, Cd, Mn, Pb, and Zn, respectively, whereas that in corn chips was (NE-0.716 mg/kg), (NE-0.421 mg/kg), (0.043-4.013 mg/kg), (0.450-2.900 mg/kg), and (1.325-7.500 mg/kg), for Cr, Cd, Mn, Pb, and Zn, respectively. Mostly, the results revealed that the potato chips were containing heavy metal levels higher than the corn chips except for Zn contents. The trend of metal levels for potato chips was: Zn>Mn~Cr>Pb~Cd, whereas for corn chips was: Zn>Pb>Mn>Cr~Cd. The levels of the selected heavy metals in the foods were comparable with data reported in studies carried out in other countries. The consumption of snacks with such metal loads over a long period of time may result in metal accumulation in the body beyond tolerable limit.
Abstract
Gum Arabic (GA) has been given the approval to be used in food, pharmaceuticalapplications, cosmetics, paints and textile industry due to its emulsifying,stabilizing, thickening and binding properties.GA,as dietary fiber was found toprovide therapeutic effects in patients with gastrointestinal disorders. Irritable6bowel syndrome (IBS) is one of the most common functional gastrointestinaldisorders, affecting around 10-20% of the adult population worldwide which is characterized by chronic, recurrent abdominal pain and altered bowel habit.Wide varieties of herbal medications have historically been used by variousraces all over the world and are still used today by some physicians or as homeremedies. Patients with IBS can use them as complementary and alternativemedicine (CAM), among these herbal products GA is most commonly used. ThePubMed, Google scholar databases were searched in English for studies about GumArabic and IBS published between 2010 and 2021 by using the terms: irritablebowel syndrome, IBS, gum arabic, Acacia gum, microbiota, prebiotic, probiotic,synbiotic, bifidobacteria, lactobacillus, dietary fiber, diarrhea,constipation, gastrointestinal disorders, anti-ulcer, anti-fibrotic,gastroprotective, anti-inflammatory, toxicity. Results of this study indicated that GA is a safe natural product that is found to reduce symptoms ofirritable bowel syndrome mainly due to its prebiotic and synbiotic effects,also by acting as dietary fibers. GA also possesses other effects ongastrointestinal tract such as gastroprotective, anti-fibrotic,anti-inflammatory and anti-ulcerogenic effect
Abstract
The adsorption of Alizarin Red S from aqueous solution by base activated typha grass (T. Latifolia) (ACT-TG) was investigated in this study using a batch system under controlled conditions. The adsorbent surface was characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) methods and the point of zero charge (PZC). The kinetic data were best described by pseudo-second order models. Adsorption parameters including effect of contact time, adsorbent dosage, initial concentration and pH were studied for optimization purposes and the optimum adsorption capacity was found to be 46.611mg/g. The isotherm for the adsorption processes were also modelled and evaluated and the data generated fitted well the Freundlich isotherm model relative to other models tested. It was estimated through this study that the adsorption rate is positively affected by increase in dose of ACT-TG, dye initial concentration, contact time, pH and temperature. Van’t Hoff’s plot was used to determine thermodynamic quantities of the adsorption process including ΔS (5.5862J/molK), ΔH (-4.9001kJ/mol) and ΔG (-6.419 to -6.734kJ/mol). The results indicate the adsorption process to be feasible and spontaneous. Therefore, the base activated typha grass can be a potential adsorbent for the removal of hazardous dyes from wastewater.
Abstract
The purpose of this research is to analyze and develop the application of Heat Exchanger (HE) in the production process of cobalt (II, III) oxide (Co3O4) nanopowder using hydrothermal method. The type of HE used is the Shell and Tube Heat Exchanger (STHE) type which is designed simply, but still refers to the existing design rules. The specifications of the HE equipment used are shell length of 1.364 m, shell diameter of 0.228 m, inner shell diameter of 0.203 m, inner tube diameter of 0.02119 m, outer tube diameter of 0.0254 m, wall thickness of 0.002108 m, tube length 5.4864 m, tube pitch is 0.03175 m and the number of tubes used is 592 pieces. The results of calculations using Microsoft Excel show that the appropriate design of the heat exchanger on the shell and tube is turbulent flow type, and shows an effectiveness value of 90.35%. The magnitude of the effectiveness value indicates that the STHE design is suitable for the production of Co3O4 nanopowder. This design is expected as a reference material in designing a heat exchanger to be more economical, effective, and has high reliability
Abstract
Benzoyl thiourea compounds (PBTU, MBTU) were used to remove the cadmium ion from its aqueous solution. The effect of benzoyl thiourea concentration and the initial concentration of cadmium ions on the removal process was examined at varied contact times, and temperatures ranging from 25 to 50 °C. Cadmium ions concentration was measured using an atomic absorption instrument. The distribution coefficients (KD), loading coefficients (Z), and extraction efficiency were determined using the experimental extraction findings (E % ). The results showed that at 60 min, and 25 °C, the percentage of cadmium ion removal increased with the increase in the concentration of benzoyl thiourea compounds. The optimum efficiencies of MBTU and PBTU substances were 92.86 % and 98.21 % respectively. Density function theory (DFT) was used to study the interaction of cadmium ions with benzoyl thiourea compounds. Computational studies have shown that the donor atoms of the benzoyl thiourea are the oxygen and the sulfur atom.
Abstract
Developing and analyzing a heat exchanger design for the production of silicon dioxide nanoparticles is the aim of this research. In designing the heat exchanger design for the production of silicon dioxide nanoparticles, shell and tube heat exchangers are used. The specifications of the equipment used for the design of the heat exchanger are tube outer diameter of 0.0254 m, tube inside diameter of 0.0212 mm, tube length of 5.49 m, and thickness of 0.002 m. The results of calculations performed using Microsoft Excel show that the design of the heat exchanger on the shell and tube shows an effectiveness value of 96.09%. This value indicates that the shell and tube in the heat exchanger design is a laminar type. Therefore, judging from its effectiveness, this shell and tube heat exchanger meets the requirements and standards to be used in the production of silicon dioxide nanoparticles.
Abstract
The aim of this study is to design a heat exchanger using water as a cooling fluid and Triethylene glycol as a heating fluid to obtain a product which is cerium oxide nanoparticles. The type of shell and tube on the HE is designed in a simple way but still refers to the existing design rules. The type of shell used is one pass shell and tube with laminar flow. Specifications of HE design among others; 25.4 mm of tube diameter, 21.2 mm of inner tube diameter, 2.1 mm of thickness, 5.4864 m of tube length, 27.78 mm in pitch tube, outer shell diameter is 228.6 mm, and inner shell diameter of the amount 203 mm. The results were obtained in the form of a Q value in 188280 W with an effectiveness value of 92.00%. This design can be used as a reference in designing a heat exchanger to be more effective, economical, has high reliability, and can also be useful as a learning method regarding the design process, working mechanism, and HE performance analysis.
Abstract
In this work, the synthesis of reasonable-priced photocathode for the photoelectrochemical solar cell was enhanced by way of the easily reached thin film thermal oxidation method. Copper II oxide (Cu2O) thin films have been synthesized on copper (Cu) substrates using thermal oxidation technique. The heteroepitaxial growth Bi/ZnO/Cu2O thin films were successfully grown on Cu2O prepared with spiraling steadiness and pre-eminence in a variety of constituents by a cost-effective, straightforward and dependable method using Bromine powder as transporting mediator. The materialization of Cu2O thin films is further recognizable by Fourier transforms infrared spectroscopy. Bi/ZnO/Cu2O demonstrates a brilliant performance on PEC solar cell because of the creations of extra active species as ∙O2- and ∙OH. These benefits from the higher photogenerated charge severance and electron transport possessed by Bi/ZnO/Cu2O analogized to Cu2O. In totaling to performing as the shielding layer of Cu2O to decreased the photo-corrosion of Cu2O, the oxygen containing functional groups C=O on the surface of the sample layer could provide an electron transfer channel between the interface of Bi/ZnO/Cu2O and Cu2O to decrease the interfacial charge-transfer resistance and accelerate the electron transfer. The synthesized PEC solar cells under illumination of Cu- Bi/ZnO/Cu2O and Cu-Cu2O results in the short circuit current density (ISC) of 50.0 and 13.7mA, power conversion efficiency (PCE) of 0.0050and 0.01%, and open-circuit voltage (Voc) of 18 and 6.30mV correspondingly. Our conclusion discloses that the PCE of Bi/ZnO/Cu2O heteroepitaxial growth thin-film PEC solar cell is improved via the manipulation of Bi/ZnO as absorber stratum in evaluation to the Cu2O layer.
Abstract
This study aims to analyze and development a heat exchanger (HE) design in a magnesium oxide (MgO) production process using the sol-gel method. The HE equipment used has a shell length specification of 0.228 mm; shell diameter 0.203 mm; outer tube diameter 0.0254 m; inner tube diameter 0.0211 mm; wall thickness 0.0021 mm; tube length 5.4864; and tube pitch 0.02778. The method used in this study uses the Microsoft Excel application to perform calculations manually. The results showed that the HE design on the one-pass type shell and tube was laminar flow, with an effectiveness value of 93.70%. Thus, the HE with one-pass shell and tube meets the standard requirements based on the effectiveness value. However, when viewed from a factor perspective, the fouling value has not been calculated. The results of this study are expected to be used as learning media for the design process, operating mechanisms, and HE performance analysis.
Abstract
In this research investigation, the performance evaluation of rapid sand filters for water treatment plant (WTP) was examined using Chanchanga Water Works (CWW), Niger State, as a case study. During the investigation, a filter was chosen out of the eight filters in operations in the plant. The performance indicators used in the studies were the head loss on the filtration rate, turbidity, and pH of clarified and filtered water through the filter unit operation equipment. These indicators were observed on the daily basis for a period of 29 days. It was found that the time when the filter was newly cleansed, the turbidity of filtered water was higher than before it was backwashed. This is the breakthrough point when it reduces to minimum level after maturing time. The time required for the turbidity to reach a certain maximum value after backwashing was also found to be dependent on the quality of clarified water’s turbidity. Acidity of the treated water was also found to be slightly affected by sand filter. It was observed that the filtered water is still ineffective against taste and odour which must be further treated in other unit operation equipment. It was also noticed that the filter produces large volumes of sludge which needed to be disposed immediately..
Abstract
Water is one of the most vital ingredients for life and can easily become deleterious when contaminated with foreign materials. This research paper focused on the comparative studies on the systems performance assessments for the slow sand filtration (SSF) and rapid sand filtration (RSF) in the water treatment and purification plant (WTPP). The raw water was sourced from Tagwai Dam and utilized as the essential material. The performance indicators employed in the evaluation studies are total hardness, turbidity, total alkalinity, presence of chloride ions, pH, electrical conductivity, and bacterial removal. It was found that the performance indicators for the slow and rapid sand filters are as follows: total hardness of 60 mg/L and 58 mg/L, turbidity of 1.5 NTU and 3 NTU, total alkalinity of 62 mg/L and 40 mg/L, presence of chloride ion to be 11 mg/L and 10 mg/L, pH of 7.4 and 7.2, electrical conductivity of 85 and 72, and bacterial removal of 98% and 86%, respectively. The result of the studies is in conformity with the national standards of Nigerian Standard Drinking Water Quality (NSDWQ) and World Health Organization (WHO), which discloses the slow sand filters are more efficient in getting rid of bacteria and turbidity than the rapid sand filters. However, the rapid sand filter appears to be more efficient in the removal of total hardness, alkalinity, presence of chloride ions, pH adjustment towards neutrality, and electrical conductivity.
Abstract
In this work, we have undertaken the electrodeposition of tin in deep eutec solvant consisting of a mixture of choline chloride-ethylene glycol. The objective is to determine the potential at which tin (Sn) can be electrodeposit with a view to its recovery and recycling in electrical, electronic and electrotechnical waste. Cyclic voltammetry experiments were performed to study the electrochemical behavior of the tin redox system. By application of Randles-Sevcik equation, the coefficient of diffusion reflecting the mobility of Sn(II) ions at the surface of the electrode is 105.10-4 cm2/s. From the CV obtained, a window of synthesis potential is defined in which the electrodeposition of Sn was studied. The analysis of the deposits obtained by chronoamperometry at a fixed potential of -0.61V on a glassy carbon electrode indicates the presence of a tetragonal phase of metallic tin. SEM images of the surfaces of deposits obtained shows a butterfly microstructure.
Abstract
In this work, the comparative studies on the performance evaluation of synthetic and phytochemical coagulants in water treatment and purification plant (WTPP) was investigated in a newly fabricated pilot plant at the Department of Chemical Engineering, Ahmadu Bello University Zaria. The effectiveness of three (3) synthetic coagulants, namely: polyacryl amide, sodium aluminate, and aluminium sulphate were examined together with water extracts of the cake for Moringa oleifera seeds, a phytochemical-based coagulant. The raw water was sourced from Kubanni Dam and supplied by Ahmadu Bello University Water Works (ABUWW). The analysis of the water quality performance indicators was conducted according to comprehensive performance evaluation (CPE), and analytical hierarchy process (AHP) methods, and the results were compared with the standards of World Health Organizations (WHO). The indicators used in the assessments are turbidity, pH level, conductivity, hardness, alkalinity, nitrates, and total coliform counts. The turbidity and pH level of the extracts of the cake for Moringa oleifera seeds, polyacryl amide, sodium aluminate, and aluminium sulphate were found to be 2, 5, 1, and 2 NTU; 6.9, 9.2, 8.2, and 5.9, respectively. On the other hand, the conductivity, hardness, alkalinity, nitrates of the extracts of the cake for Moringa oleifera seeds, polyacryl amide, sodium aluminate, and aluminium sulphate were estimated to be 4, 17, 4.8, and 3 ppm; 42, 80, 72, and 71 mg/L; 70, 77, 75, and 48 mg/L; 10, 51, 22, and 24 mg/L, respectively. The phytochemical coagulant appeared to be the best and the second best in the nitrates, conductivity, and hardness removal, lowest number of coliform counts and turbidity removal, respectively. The results of the water quality parameters are in conformity with the WHO standards.