School of Engineering and Technology

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ACTI-ZYME BIOCHEMICAL PROPERTIES: POTENTIAL FOR USE IN ANAEROBIC SEWAGE TREATMENT CO-GENERATING BIOGAS
(Asian Journal of Science and Technology, 2015-03) Manyuchi, M.M; Ikhu-Omoregbe, D. I. O; Oyekola, O. O.
The biochemical properties for Acti-zyme, a biocatalyst were characterized for potential use in anaerobic sewage treatment with the aim of producing biogas. Sterile Acti-zyme media containing peptone water was plated on the MacConkey Agar, Starch Agar, Kliger Agar, Urease Agar, Sulphide Indole and Motility Agar at 37.5°C for 24 hours, at a pH of 7±0.2. Acti-zyme was found to be immotile and contained several enzymes that have different applications in sewage treatment. These included catalase which detoxified harmful substances, protease which broke down the proteins as well as amylase which broke down the polysaccharides available in sewage. However, Acti-zyme did not contain urease; an ammonium catalyzing enzyme. Acti-zyme did not to promote H2S production which is a contaminant in biogas production. Acti-zyme also did not contain pathogenic Enterobacteriaceae such as E. Coli and Salmonella. The identified Acti-zyme biochemical properties make it useful in sewage treatment co-producing biogas
Adsorption of Methyl Orange, Pb2þ and Cd2þ from Aqueous Solution by Composites of LignocelluloseMontmorillonite Modified with Methacryloxypropyl Trimethoxysilane
(WILEY-VCH Verlag GmbH & Co. KGaA,, 2012-03-07) Tavengwa, Bunhu; Lilian, Tichagwa
A composite material based on lignocellulose and montmorillonite clay (MPSgLig-NaMMT) was prepared and evaluated as an adsorbent for the removal of pollutants (dyes and heavy metals) from aqueous solution. The lignocellulosemontmorillonite composite was prepared by in situ intercalative polymerisation, using methacryloxypropyl trimethoxysilane (MPS) as a coupling agent. The composite material was characterised by FTIR, TGA and SAXS. The lignocellulose-montmorillonite composite was assessed as an adsorbent for methyl orange dye from aqueous solution. The composite material showed enhanced adsorption of methyl orange (MetO) compared with the NaMMT or lignocellulose separately. Competitive adsorption studies were carried out from binary mixtures of MetO with Cd2þ or Pb2þ in aqueous solution. The adsorption process of MetO onto the composite material was found to follow the Freundlich adsorption model. The adsorption of methyl orange from binary mixtures, were found to follow both the pseudo first-order and pseudo second-order models
Analysis of Jitter and Shimmer for Parkinson’s Disease Diagnosis Using Telehealth
(International Conference on Cognitive Informatics & Soft Computing (CISC-2017), 2017-12-20) Kuresan, Harisudha; Masunda, Sam; Samiappan, Dhanalakshmi
The future of telecommunications is premised on high fidelity net-works with extreme precision, which in turn capacitates deployment of tele-diagnostic tools. Parkinson’s disease (PD) clinical characterization is based on, speech problems, tremors in hands, arms, legs and face, body swelling, muscle rigidity and movement problems. Speech problems are cited as one of the earliest prodromal for PD. However, using clinical diagnosis it takes upto five or more years to detect PD. Therefore with this regard speech can be used as an early biomarker for PD. Features of interest for detecting PD will be prosodic, spectral, vocal tract and excitation source speech features. We infer from the analysis, MFFC with jitter and shimmer feature extraction provides a promising method that can help the clinicians in diagnostic process.
Analysis of soft tissue in cervical traction therapy using finite element methodl
(IOP Conference Series: Materials Science and Engineering, 2018-11-19)
Cervical traction is a therapeutic method used for treating neck pain. As of July 2016 according to the Institute for Health Metrics and Evaluation the healthy life lost per 100000 people from neck pain in India has increased by 18.7% since 1990 as a result of individuals devoting about 10 to 15 hours a day in an undesirable position. This project is an approach using a finite element method for a 30 year old male to investigate the response of soft tissue related to cervical traction therapy affecting the lordosis angle of the cervical spine. Research work is done concerning the material properties of the soft tissues to be incorporated in the model for validation. Once validated the lordosis angle of the cervical region was measured and compared against the lordosis angle of the model when exposed to traction forces. Results of the study gave evidence on the reduction of the lordosis angle and extend at which the lordosis angle is reduced. These results of the study when considered minimize the potential harm to soft tissues during cervical traction therapy and help in allocating the appropriate force on the appropriate position during cervical traction therapy and cervical traction therapy equipment design.
ARTIFICIAL NEURAL NETWORKS IN TENSILESTRENGTH AND INPUT PARAMETER PREDICTIONIN FRICTION STIR WELDING
(International Journal of Medical Engineering and Robotics Research, 2014-01-13) Chiteka, Kudzanayi
Welding speed and rotational speed have been singled out as the most influential welding parameters which affect the tensile strength as well as the hardness in Friction Stir Welding (FSW). It is however problematic to determine the possible welding speed and rotational speed given the Ultimate Tensile Strength (UTS) since there are several combinations of welding speeds and rotational speeds that can yield the same UTS. At the same time, however, the input parameters predicted may not be available on the machine. This research is therefore aimed at using Artificial Neural Networks (ANN) in predicting the UTS given rotational speed and welding speed as well as exploring the possibility of obtaining the input parameters given the output UTS.
Bio-conversion of Food Wastes into Vermicompost and Vermiwash
(International Journal of Science and Modern Engineering (IJISME), 2013-09-10) Manyuchi, Mercy; Phiri, Anthony; Muredzi, Perkins; Chirinda, Ngoni
Vermicomposting technology is the bio-conversion of organic waste into bio-fertilizers using earthworms. Vermicomposting is widely being used for solid waste management. Various food wastes were vermicomposted over 30 days using Eisenia fetida earthworms. Vermicompost and vermiwash were obtained as vermi-products. The vermicompost nitrogen, phosphorous and potassium composition was 2.1%, 0.29% and 0.19% respectively. Whereas, the vermiwash only contained 0.58% nitrogen and 0.47% potassium. Vermicomposting technology is necessary as a food wastes management strategy.
Biogas Production from Saw dust using Acti-zyme as Digestion Catalyst and its Upgrading to Bio methane using Chemical Absorption
(World Energy Council Congress, 2016-01-01) Manyuchi, Musaida Mercy; Bobo, Arthur. E.; Ikhu-Omoregbe, Daniel I. O; Oyekola, Oluwaseun O.
Zimbabwe has one of the largest deposits of timber in Southern Africa (about 500 000 tons per annum) such that most entrepreneurs venture into timber processing. The venture results in generation of a lot of sawdust dumps that are of no economic use if they are left lying around. There is 10000 metric tons that go to waste each year which when bio-converted can result in biogas. This paper therefore presents the potential for biogas production from saw dust bio-catalysed by Acti-zyme a biocatalyst to enhance the digestion hence biogas yield. This paper presents the bio-catalysed digestion of 4000 metric tons of saw dust per year to produce biogas using Acti-zyme. The generated biogas is then upgraded using chemical absorption for removal of carbon dioxide so as to increase the bio methane energy efficiency. Biogas produced was approximately 24 m 3 per day and was upgraded to 97% from 72% bio-methane composition per day using chemical scrubbing technique in an absorption column. The absorption column design considerations are also presented as well as its process control and the hazard analysis. These are essential in the optimal upgrading of the biogas. Purified bio methane has a higher calorific value of 99 % relative to the 77 % of raw biogas. An economic analysis showed that a 2 year payback period with a return on investment of 48% and break even sales at $331 580.00 with the upgraded bio methane being sold at $2.50/kg. The conversion and upgrading of biogas produced by anaerobic digestion using Acti-zyme is technologically, economically and environmentally feasible.
BIOLOGICAL NUTRIENT REMOVAL FROM MUNICIPAL SEWAGE USING ACTI-ZYME: RECOVERING BIOGAS AND BIO-SOLIDS FROM SEWAGE SLUDGE
(Cape Peninsula University of Technology, 2016-02-05) Manyuchi, Musaida Mercy
Water scarcity is a global problem hence the need for sustainable wastewater management. Sewage, a form of wastewater is being disposed-of to river bodies untreated. Additionally, disposal of sewage sludge, a by-product from the sewage treatment process, is resulting in landfilling problems. This study focused on the sustainable anaerobic treatment of sewage, coharnessing biogas and bio-solids as value added products utilizing Acti-zyme, an enzyme biocatalyst through bio-augmentation. Emphasis was given to the optimum sewage treatment conditions for removal of bio-nutrients, biogas and bio-solids generation, kinetic and statistical modelling of the bio-nutrient removal in sewage as well as the biogas and bio-solids production from sewage sludge. A techno-economic analysis was then done to check the viability of applying this technology on a large scale. The biochemical properties for Acti-zyme were characterized for potential use in anaerobic sewage treatment with the aim of producing biogas. Acti-zyme was then used for sewage treatment at a temperature of 37 °C, agitation rate of 60 rpm, Acti-zyme loadings of 0-0.070 g/L and retention times of 0-60 days. The total Kjeldahl nitrogen (𝑇𝐾𝑁), biochemical oxygen demand (𝐵𝑂𝐷5), total suspended solids (𝑇𝑆𝑆), total dissolved solids (𝑇𝐷𝑆), electrical conductivity (𝐸𝐶), 𝑝𝐻, chloride ions concentration (𝐶𝐼 −), total phosphorous (𝑇𝑃), sulphate ions concentration (𝑆𝑂4 2−), dissolved oxygen (𝐷𝑂) and the chemical oxygen demand (𝐶𝑂𝐷) of sewage were measured using standard methods. The bio-nutrient removal ratios from the sewage were determined and statistical modelling was carried out for the bio-nutrient removal ratios: The 𝐶𝑂𝐷⁄𝐵𝑂𝐷5, 𝐵𝑂𝐷5⁄𝑇𝐾𝑁, 𝐶𝑂𝐷/𝑇𝐾𝑁 and the 𝐶𝑂𝐷/𝑇𝑃. The sewage sludge was anaerobically digested using Acti-zyme in order to obtain biogas and bio-solids. Sewage sludge loading of 5-10 g/L.d and mesophilic and thermophilic temperatures of 37 °C and 55 °C were applied. The biogas quantity produced was measured using the water displacement method. Samples of the biogas were analysed for bio-methane (𝐶𝐻4), carbon dioxide (𝐶𝑂2) and traces gases composition using gas chromatography. The bio-solids obtained were tested for nitrogen, phosphorous and potassium (𝑁𝑃𝐾) content using 𝑢𝑣 − 𝑣𝑖𝑠 spectrophotometry. Kinetic modelling was carried out in MATLAB R2013A to simulate bio-methane production from sewage sludge. Statistical models for anaerobic sewage sludge digestion for generation of biogas and bio-solids utilizing Acti-zyme, were then simulated from the experimental data. SPSS Statistics 19.0 was used as the statistical modelling package at a p-value of 0.05. Capital budgeting techniques were then used for techno-economic assessment of sewage treatment recovering biogas and bio-solids. vii | P a g e D T e c h C h e m i c a l E n g i n e e r i n g Acti-zyme was found to be immotile and contained catalase, proteolytic enzymes and amylase. Acti-zyme did not promote 𝐻2𝑆 production, making it useful in sewage treatment producing biogas. Sewage treatment using Acti-zyme resulted in >60% decrease of the sewage contaminants through bio-augmentation. Optimum sewage treatment conditions were obtained at 0.050 g/L Acti-zyme loading and retention time of 40 days. The 𝐶𝑂𝐷⁄𝐵𝑂𝐷5, 𝐵𝑂𝐷5⁄𝑇𝐾𝑁, 𝐶𝑂𝐷/𝑇𝐾𝑁 and the 𝐶𝑂𝐷/𝑇𝑃 ratios obtained were > 1.2, 4.0, 8.0 and 15.0 respectively. The 𝐶𝑂𝐷⁄𝐵𝑂𝐷5, 𝐵𝑂𝐷5⁄𝑇𝐾𝑁, 𝐶𝑂𝐷/𝑇𝐾𝑁 and the 𝐶𝑂𝐷/𝑇𝑃 bio-nutrient removal models were developed. Optimum biogas production was obtained at a sewage sludge loading of 7.5 g/L.d and Acti-zyme loading of 0.050 g/L with a 78% bio-methane composition was achieved at mesophilic temperatures of 37 °C. Bio-solids with 8.17, 5.84 and 1.34 % of 𝑁𝑃𝐾 respectively were produced. The bio-methane production was simulated to the linear, exponential, logistics kinetic, exponential rise to a maximum, first order exponential model and the modified Gompertz kinetic models. The logistics kinetic model accurately simulated the bio-methane production with a k-value of 0.073 day-1 . Furthermore, linear, quadratic, compound and exponential statistical models were tested and validated for the biogas and the bio-solids generation. The quadratic statistical models were significant for simulating biogas and bio-solids production respectively. A sewage plant with a capacity of 19.6 600 ML/day was considered for techno-economic assessment, with an operating efficiency of 60% and a life span of 20 years. $5.125/day of Actizyme were required for production of 12 769.69 kg/day for biogas costing $1.50/kg and 672.08 kg/day of bio-solids costing $16.00/50kg. A net benefit of $5 656 363.92 per annum for using the Acti-zyme technology in sewage digestion was forecasted, whilst a net energy of 1 387.33 KWh was set to be produced. An investment of $22 199 501.40 was required for kick-starting the project. A positive net present value of $1 186 239.23 was realized with an internal rate of return of 17.6% and a payback period of 5.9 years. For breakeven to be realised, only 183 059.16 KWh must be produced. The techno-economic assessment indicated it is viable to treat sewage using Acti-zyme as bio-augmentation catalyst; co-harnessing biogas and bio-solids as valued added products to an extent of contributing 0.04% to the Zimbabwe gross domestic product.
Biomedical Signal Processing
(HIT, 2025-11-25) HIT
Bioremediation of Transport Industry Contaminants Using Vermicompost
(International Journal of Environmental Engineering Science and Technology Research, 2014-01-01) Manyuchi, M.M; Phiri, A
Transport industries pose environmental challenges due to leaks of engine oils both to soil and water. Engine oil is highly organic therefore there is need to bio-remediate the contaminated soil and wastewater in order to preserve the environment. Soil and wastewater contaminated with diesel engine oil were bio-remediated using vermicompost containing live Eisenia Fetida earthworms and cocoons over a 4 week period. The contaminated soil and water pH and electrical conductivity (EC) were monitored during this period. Furthermore, the wastewater dissolved oxygen (DO) and biological oxygen demand (BOD) were determined. The pH in the contaminated soil decreased from 7.2 to 6.2 whilst that in the contaminated wastewater increased from 5.8 to 7.2. The EC in both the diesel contaminated soil and wastewater showed a decrease of more than 19%. The DO in the wastewater showed a decrease upon addition of vermicompost and then later on increased. Lastly, the BOD in the wastewater, decreased by 16.9% upon addition of the vermicompost. Vermicompost can be used for the vermiremediation of soil and wastewater contaminated with engine oil in the transport industries.
Biosorbents for the removal of synthetic organics and emerging pollutants: Opportunities and challenges for developing countries
(Environmental Development, 2016-05-23) Chaukura, Nhamo; Gwenzi, Willis; Tavengwa, Nikita; Manyuchi, Musaida Mercy
Contamination of aquatic systems by synthetic organic contaminants and emerging pollutants poses significant public and environmental health risks in developing countries. These contaminants mainly originate from textile, agrochemical, and pharmaceutical industries. The removal of such contaminants is problematic in developing countries because advanced water treatment methods are still lacking in developing countries due to their high costs. The application of biosorption for removal of organic contaminants in developing countries is attractive for three reasons; (1) large quantities of biomaterials for use as biosorbents are readily available; (2) lack of advanced water and wastewater treatment systems for removal of organic contaminants; and (3) the technology is relatively cheap compared to advanced methods (e.g. membrane filtration) often used in developed countries. Overall, this has the potential to remove organic contaminants from aqueous systems while simultaneously reducing the public health and environmental impacts associated with the disposal of such biowastes. However, large-scale application of biosorption faces potential challenges including lack of funding, poor mechanical properties of biosorbants, complex adsorption mechanisms involved, and poor regeneration capacity. In addition, spent biosorbents present an environmental risk and their disposal is problematic due to the potential of contaminating surface and ground water. Possible disposal methods for spent biosorbent include use as a filler in road surfacing, as a soil amendment, and in phytoremediation cells where the organics are absorbed and broken down by plants. Overall, biosorption is a potentially viable alternative, but further research on its ability to remove pollutants from multi-component systems, its regeneration capacity, and plant design parameters is required before the benefits of the technology are realised in developing countries.
CAD/CAM 1
(HIT, 2023-11-13) HIT
Catalytic Activity of CeO2 -NiO for Low Temperature Soot Combustion
(IJERT, 2014-09-20) Mahofa, Eubert Privilege; Narsaiah, T. Bala; Chakra, Shilpa; Kumar, Pramod; Aftabtalab, Adeleh
CeO2 (Ce) and CeO2-NiO (CeNi) nano- catalysts were synthesized by co-precipitation from nitrate precursors using 25% ammonia solution (NH4OH) as the precipitating agent. The catalysts were calcined in air at 500ÂºC and 800ÂºC for 4h to evaluate the thermal stability. XRD and DLS techniques were used for catalyst characterization. A Thermo gravimetric/Differential Thermal Analyzer (TG/DTA) was used to determine the catalytic activity and soot oxidation reactions. Compared with Ce, Ce-Ni nanocomposite showed lower soot oxidation temperature.
Cleaner Production options in sand casting in foundries.
(International Journal of Sustainable Energy and Environment, 2013-04-06) Masike, Rujeko; Chimbadzwa, M.J
The purpose of this paper was to assist foundries in pollution prevention by devising clean technologies which maintain or improve the quality of the ambient surrounding. The paper used Cleaner Production and its opportunities to minimize material consumption, optimize production yield and to prevent polluting the air, water and land. The reseachers reviewed how sand casting foundries can implement Cleaner Production and benefit from the created conducive environment as well as saved financial capital. The review gave an overview of the environmental aspects and impacts of foundry operations. It also outlined best practices to improve the energy, material, and environmental efficiency, and the product output of the operation. The current environmental status and performance of foundry companies in Zimbabwe was determined from the initial environmental review, energy and environmental audits. Once the environmental status was established, Cleaner Production options were then modelled. The feasibility of the options were also analysed, and life cycle analysis of casted products was carried out. The researchers concluded that raw materials, water, and energy were to be saved if foundry companies implemented Cleaner Production options.
Comparison of Vermicompost and Vermiwash Bio-fertilizers from Vermicomposting Waste Corn Pulp
(World Academy of Science, Engineering and Technology, 2013-07-07) Phiri, A; Muredzi, P; Manyuchi, M.M; Chitambwe, T
—Vermicomposting is the conversion of organic waste into bio-fertilizers through the action of earthworm. This technology is widely used for organic solid waste management. Waste corn pulp blended with cow dung manure was vermicomposted over 30 days using Eisenia fetida earthworms species. pH, temperature, moisture content, and electrical conductivity were daily monitored. The feedstock, vermicompost and vermiwash were analyzed for nutrient composition. The average temperature and moisture content in the vermi-reactor was 22.5◦C and 42.5% respectively. The vermicompost and vermiwash had an almost neutral pH whilst the electrical conductivity was 21% higher in the vermicompost. The nitrogen and potassium content was 57% and 79.6% richer in the vermicompost respectively compared to the vermiwash. However, the vermiwash was 84% richer in phosphorous as compared to vermicompost. Furthermore, the vermiwash was 89.1% and 97.6% richer in Ca and Mg respectively and was 97.8% richer in Na salts compared to the vermicompost. The vermiwash also indicated a significantly higher amount of micronutrients. Both bio-fertilizers were rich in nutrients specification for fertilizers.
Competitive sorption of Cd2+ and Pb2+ from a binary aqueous solution by poly (methyl methacrylate)-grafted montmorillonite clay nanocomposite
(Applied Water Science, 2016-03-24) Tavengwa, Bunhu; Tichagwa, Lilian; Chaukura, Nhamo
Poly(methyl methacrylate)-grafted montmorillonite (PMMAgMMT) clay and sodium-exchanged montmorillonite (NaMMT) clay were prepared through in situ graft polymerisation and used to remove Cd2+ and Pb2+ from synthetic wastewater. The modification of adsorbent materials was confirmed by fourier transform infra-red spectroscopy (FTIR), thermogravimetric analysis (TGA) and X-ray powder diffraction (XRD) techniques. BET surface area measurements showed NaMMT had a higher surface area than PMMAgMMT. Batch experiments were used to assess the simultaneous uptake of Cd2+ and Pb2+ from a synthetic binary solution. Pb2+ was preferentially sorbed, exhibiting greater affinity for the sorbents compared to Cd2+ as shown by its relatively higher uptake onto the sorbents than Cd2+. The maximum sorption capacities for NaMMT and PMMAgMMT were 18.73 and 19.27 mg/g for Cd2+, and 30.03 and 34.25 mg/g for Pb2+, respectively. The sorption data obeyed the Langmuir model and the pseudo-second order kinetic model with R 2 of at least 0.9800 for both models. The sorbents could also be regenerated up to three cycles without a significant loss in the sorption capacity. FTIR measurements showed the presence of metal–oxygen bonds after sorption, confirming the occurrence of adsorption as one of the heavy metal removal processes. The work demonstrated the potential of using low-cost nanoscale composite material for the removal of Cd2+ and Pb2+ from aqueous solution.
Composite Materials
(HIT, 2024-12-13) HIT
Computer Engineering
(HIT, 2024-12-13) HIT
Conceptual Design Framework for Developing a Cylindrical Robot Manipulator for Material Handling in Zimbabwean Small to Medium Enterprises: A Finite Element Approach
(Int'l Journal of Advances in Mechanical & Automobile Engg. (IJAMAE);, 2014) Masike, Rujeko; Garikayi, Talon; Tigere, Godfrey
In many small to medium engineering companies in Zimbabwe the need for material handling devices has become a necessity. There is lack of machinery that could increase production rate, improve product quality and reduce manufacturing costs while maintaining safe working environments. Material handling is a bottle neck during production due to lack of proper equipment and plant layout thus this research seeks to improve the material handling system through the conceptual design of a framework for the application of a cylindrical robot. There are many robots in the market that will improve material handling effectively. The purpose of this paper is to present a framework that has a structured approach for developing cylindrical robots based on finite element analysis methods that will be used by small and medium engineering enterprises (SMEs).This will enable the SMEs in developing nations to maintain competitive prices on products with minimal work accidents. The research explores the current literature and design approaches used to develop cylindrical robots. The paper also provides detailed methodologies to be used for structural analysis, component simulation and performance evaluation of the machine through finite element analysis (FEA). The framework provides suitable guidelines for designers to make appropriate decisions from the initial design stage to the commercialization of the design. The authors conclude that the preliminary framework be applied to formalize design steps for sim ilar material handling machinery implementation in the SME sector.
Continuous flow-through vermireactor for medium scale vermicomposting
(Asian Journal of Engineering and Technology, 2013-04-01) Manyuchi, Musaida Mercy; Chitambwe, Trymore; Chigumo, Michelle T. C.; Phiri, Anthony; Muredzi, Perkins; Kanhukamwe, Quinton
Vermicomposting is increasingly becoming popular as an organic waste management technology whereby earthworms feed on the organic waste to produce vermicasts and vermiwash. Several vermireactors have been used for this process as batch systems. However, there is need to design a continuous flow-through vermireactor which allows the simultaneous addition of the organic waste at the same time harvesting the vermicasts. A 5m X 2m X 1.5m vermireactor was proposed to process an initial feed of 7 500kg. A 10cm thick bedding comprising of office paper, card board paper and Eisenia fetida earthworms stocked at 1kg/m2 of the vermireactor was used as an initial bedding. The feed bed was 20cm thick and comprised of paper, cow dung, corn pulp and vegetables. The pH, temperature and moisture content in the vermireactor ranged between 5.5-7.5, 19-25°C and 28-52% respectively. 7kg/day of vermicasts were produced given the earthworms produced 75% of their bodyweight as vermicasts per day. The caked vermicasts were expelled by the aid of a breaker bar. The vermireactor was constructed from polyvinyl chloride. Vermicasts containing nitrogen (4.19%), phosphorous(1.15%) and potassium (6.18%) were obtained. The continuous flow-through vermireactor design allowed the production of stable vermicasts and can be used in medium scale vermicomposting.