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In recent years, nanocomposite materials have received much interest in nanotechnology. This new trend in nanotechnology is aimed at producing materials of unique properties. In view of this, zeolite goethite nanocomposite was synthesized to reinforce zeolite properties. Zeolite was synthesized hydrothermally from sodium aluminate, sodium silicate and sodium hydroxide at 100 oC for 24 h. The composite was synthesized using in-situ method by adding aqueous solution of the synthesized zeolite during the synthesis of goethite. The structure, morphology and surface area of the zeolite and the composite were investigated using Fourier Transform Infrared (FTIR), Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD) and Brunnauer Emmet Teller (BET) surface area analyzer respectively. The FTIR spectra and SEM micrographs confirmed the formation of zeolite–goethite composite with the surface area increase from 163.491 m2/g for zeolite to 304.839 m2/g for zeolite goethite nanocomposite. It is evident that properties of zeolite can be improved upon by compositing with other materials like goethite. It can also be employed as an adsorbent for different environmental applications as revealed by the surface area.

Abstract

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Zeolite Y was synthesized using commercial sodium hydroxide and Kankara kaolin as starting material in the presence of sodium silicate formed from kaolinite clay. Synthesis was done at 90°C, 95°C and 100°C for crystallization time of 12, 18, 24 and 36 hours. Results showed that commercial sodium hydroxide could be used to successfully produce zeolite Y from Kankara kaolin when gelling ratios of =30, =0.8 = 0.7 are used. Zeolite Y with the best crystallinity was produced at 90°C for 18 hours. Crystallisation of zeolite materials from kaolin and low grade NaOH is quite different from commercial zeolite because the sources of Si and Al are relatively less reactive due to the presence of competitive cation ions, like K+, Mg2+, present in the monomer. Additionally, the sodium silicate, selectivity induces the formation of zeolite NaY and eliminate the processes of induction and nucleation. Cost analysis per unit catalyst, showed an overwhelming $185.524 difference between imported high grade chemicals and local chemicals in favour of locally obtained chemicals. The as-synthesized zeolite was characterized using XRF, XRD and SEM analyses. The resulting NaY zeolite can find application in refining process, as shown by the XRD results

Abstract

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Bagasse ash results from burning bagasse, a matted cellulose fiber residue from sugarcane that has been processed in sugar mills. In this paper, Bagasse ash has been chemically characterized in order to evaluate the possibility of its use in glass manufacture. The result of X-ray fluorescence (XRF) showed the ash to contain SiO2 - 31.67%, K2O - 31.41%, P2O5 - 8.14%, MgO - 4.89%, CaO - 3.92%, Na2O - 3.17%, Fe2O3 - 1.23% the ash was normalized as no LOI was carried out. Qualitative and quantitative X-ray diffractometry (XRD) for determination of composition and presence of crystalline material, showed the presence of silica in free and various combined states and potassium magnesium carbonate. Scanning electron microscopy (SEM/EDS) at 100µm and 300µm showed clusters of spherical and rod like microstructure at different spectra

Abstract

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The study explored solid modelling for possible optimization of conventional laboratory heat exchangers. 240mm, 360mm, 480mm, 600mm and 720mm lengths conventional and unconventional Allihn, Graham, Liebig and Zigzag condensing models were designed and fabricated. An automated coolant system for test running the condensing models was sketched, constructed and used for test running the models using tap water as purification liquid in distillation flasks and coolant from the automated system for condensing vapour. Distillation temperatures range between 93-110oC; while differences between inlet and outlet temperatures were between 6-10oC. Optimal designs for 240mm, 360mm, 480mm, 600mm and 720mm based on distillation rates were Model Nos. 43=BZBZBWB (TA) with distillation rate (WDR) of 477mLs/hr, 38=SBSBS (TB) WDR of 458mLs/hr, 18=BSB (TB) WDR of 438mLs/hr, 18=BSB (TB) WDR of 422mLs/hr and 38= SBSBS (TB) WDR of 428mLs/hr respectively. The models could potentially be used for separation, purification, extraction and teaching aids in science and engineering laboratories and tertiary institutions of higher learning.

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A comparative analysis was carried out for essential quality parameters of five different bed sheets fabrics; Two foreign and three locally produced flat bedsheet fabrics. These fabrics were compared on parameters such as fabric thickness, air permeability, water absorption, fabric flammability, abrasion resistance, tensile strength, crease recovery, fabric shrinkage, stain removal, fabric handle, fabric sett, fabric drape, yarn count and yarn crimp using the appropriate techniques and apparatus. The results obtained show that the locally produced fabric exhibited comparably better end-use performance characteristic in terms of air permeability, water absorption, flammability, and drape. The foreign flat bed sheets are better in terms of crease recovery, handle, tensile strength, yarn crimp and shrinkage. These fabrics are therefore valued for their end-use performance.

Abstract

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The concentrations of some selected heavy metals were assessed by atomic absorption spectrophotometry in noodles sold in the study area. Total of eight different brands of noodles were investigated. The results of heavy metals in samples in mg/kg were in the order: Fe (13.15 – 144.75); Pb (0.00 – 0.55); Cd (0.00 – 0.01); As (0.00 – 0.14); Ni (0.01 – 0.09); Cu (0.02 – 0.33); Zn (1.45 – 8.05) and Cr (0.06 – 0.25). Estimates of daily intakes of metals and health risk index for noodles revealed that the local consumers were safe but were at risk of potential bioaccumulation arising from dietary of Ni, Cd, Cu, Zn in some samples.

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The kinetics of the removal of manganese cadmium and lead in aqueous solution using cocoa shell as an adsorbent was investigated. The effect of contact time, kinetic of sorption mechanism and the adsorbate concentrations on sorption of Mn2+, Cd2+ and Pb2+ ions were examined. The kinetic of the sorption mechanism of Mn2+, Cd2+ and Pb2+ was evaluated using pseudo-first order (Lagergren) rate and the pseudo-second (Ho-model) rate model. The rate limiting sorption step was physisorption and results indicate that pseudo-second order model provides a more appropriate description of the adsorption rate for the metals ions sorption in cocoa shell. The maximum adsorption capacities per unit gram of the adsorbent at equilibrium time, neutral pH, 200 r p m, and temperature of 25 0C are 9.02 to 40.04 mg kg-1 for Mn2+, 7.02 to 25.89 mg kg-1 for Cd2+ and 5.25 to 11.01 for Pb2+ under 10 to 50 mg kg-1 initial metal concentration. Sorption equilibrium isotherm was determined and correlated with Langmuir and Freundlich model. It was found that the Freudlich adsorption model best fitted the isotherm data. It is concluded that cocoa shell can be use as an effective adsorbent for removal of heavy metals from aqueous solution.

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This paper reports the findings of an investigation into the admixture potential of bone ash (BA) with a focus on the setting time of ordinary Portland cement (OPC). Cow bones are agricultural waste and constitute a sizeable proportion of solid waste in many cities of the world. Heaps of cow bones constitute aesthetic problem to the environment, unnecessary occupation of space and exude unpleasant odour that pollutes the environment. Cow bones need to be properly disposed to check the nuisance they constitute to the society. In the ever increasing endeavours to convert waste to wealth, investigation into the potentials of converting cow bones to beneficial applications in concrete becomes relevant. Bone vis-à-vis cow bone is mainly composed of compounds of calcium. The presence of calcium compounds in bone as well as in cement warrants effects of bone ash on cement to be envisaged. Cow bones were air-dried and incinerated to ash. The resulting ash was sieved through 75µm sieve. Based on weight of cement, 0%, 0.1%, 0.15%, 0.25%, 0.5, 1.0, 1.5%, 2.0%, and 2.5% of the ash were separately mixed with OPC to produce cement-bone ash (CBA). The required quantity of water determined from consistency test was added to the CBA mixture and mixed thoroughly to obtain CBA paste. The CBA paste was tested for setting time. Results show that BA decreases the setting time of OPC; the higher the content of BA, the faster is the reduction in the setting time of OPC. Reaction mechanisms are articulated and developed to explain reasons for the decrease in the setting time of OPC due to the addition of BA. It is concluded that BA is an accelerator; hence BA is recommended for use as an accelerator in concrete.

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In this research, factorial design have been employed to study the influence of four important factors; pH, catalyst dosage, irradiation time and dye concentration in the treatment of C.I. Direct Yellow 96 dyestuff using UV/TiO2 and UV/H2O2 photo-degradation processes. The results indicate that the adsorbent dosage and irradiation time exhibit a significant positive effect on the efficiency of decolourization, whereas the initial dye concentration and pH of dye solution show a significant negative effect in UV/TiO2 for the dye. Under UV/TiO2, maximum degradation of 73% was obtained at dye concentration of 5mg/l, pH 4, reaction time of 90min and catalyst dose of 2g/l. Under UV/H2O2 the irradiation time and initial dye concentration exhibit a significant positive effect on the efficiency of decolourization, whereas the pH of dye solution and adsorbent dosage show a significant negative effect for the dye. However, the UV/H2O2 gave a maximum degradation of 58% at dye concentration of 5mg/l, pH 4, reaction time of 90min and H2O2 catalyst dose of 25mM. Hence, both methods can be adopted as a preliminary treatment process for dye wastewaters

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This work has investigated gold cyanidation and characterization of Itagunmodi gold deposit using cyanide from cassava. The gold ore was subjected to selective removal of associated minerals, treated to varied concentrations of cyanide extracted from cassava and precipitation of the gold. The precipitated gold was characterized using optical microscope, SEM - EDX, EDXRF and XRFS. The result showed that after 24 hours of cyanidation using analar grade sodium cyanide of 60 mg/l, 10 g Itagunmodi gold ore concentrate yielded 0.096 g (96 mg) gold. Also, under the same condition, using cassava based cyanide concentration of 60 mg/l, 10 g Itagunmodi gold ore concentrate yielded 0.08 g (80 mg) gold. This work has shown that sourcing cyanide from cassava waste for gold leaching is the appropriate alternative to the conventional cyanidation.

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This study investigated the heavy metal status of soils around waste dumpsites in Ughell, metropolis, Delta State, Nigeria. Two different dumpsites were used for this study. For the metal analysis, soil samples were collected at 0-15cm depth. The soil samples were air dried for five days and sieved. 2.0g of the soil sample was digested with HNO3/HClO4 mixture and analysed for heavy metals (Fe, Pb, Cd, Zn, Cu and Mn) concentration using Atomic Absorption Spectrophotometer (AAS) Buck 200A model. The result obtained ranged from18.23-32.31mg/kg for Fe; 1.28-1.36mg/kg for Pb; 4.72-6.23mg/kg for Cd; 13.6-17.62mg/kg for Zn; 1.32-1.35mg/kg for Cu and 26.36-29.82mg/kg for Mn. The mean concentration of all the metals in the two sampling stations is in the order: Mn>Fe>Zn>Cd>Cu>Pb. The results when compared with the control site were quite higher indicating the metal enrichment of soil from the waste in the dumpsites. The results were within DPR target value except cadmium. The level of Cadmium in the present study calls for concern, considering the location of the sites and toxicity of cadmium. All hands must therefore be on deck to check the effect of these metals now and in the future in order to promote a healthy environment for sustainable development

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This study was aimed at the evaluation of the stabilization potential of sawdust ash (SDA) on black cotton soil. Soil samples were treated with up to 10 % SDA content by dry weight of soil compacted with reduced British Standard light (RBSL) energy. Index properties of the natural soil showed that the soil belongs to A-7-5 (36) in American Association of State Highway Transportation Officials (AASHTO) classification system and CH in Unified Soil Classification System (USCS) classification system. The natural soil has liquid limit, plasticity index and free swell values of 60.0, 32.4 and 50.0 %, respectively. These properties suggest a soil that cannot be used for engineering purpose in its natural state and requires improvement. The liquid limit, plastic limit and linear shrinkage decreased to minimum values of 54 %, 24.4 %, and 14.2 %, respectively, while plasticity index increased to 14.2 % at 10 % SDA content. Also optimum moisture content (OMC) increased to a maximum value of 30 % while maximum dry density decreased to a minimum value of 0.86Mg/m3 at 10 % SDA content. Peak unsoaked California bearing ratio (CBR) value of 4 % was recorded at 2% SDA content. On the other hand peak 7 days unconfined compressive strength (UCS) value of 90kN/m2 was recorded at 8 % SDA content. This value fell of specification requirement of the CBR value to be used as sub-base or base material. The durability of samples determined by immersion in water recorded peak resistance to loss in strength of 48.24 % (i.e., loss in strength of 51.76 %) at 8 % SDA content. The results recorded indicate that black cotton soil compacted with RBSL energy cannot be used as a road pavement material, but for low load bearing structures such as road shoulders and pedestrian walkways. However, SDA can be beneficially used as an admixture in road construction when a higher compactive effort is used.