Theses & Dissertations

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  • Publication
    Adsorption of Hydrogen Sulphide using zeolite ZSM–5 for the enhancement of fermentative biohydrogen production
    ( 2024)
    Muhammad Khairul Adha Asman
    Biohydrogen production from mixed fruit waste (MFW) is a renewable energy source. However, the presence of highly toxic and corrosive hydrogen sulphide (H2S) might reduce performance and limit energy conversion equipment use. Adsorbents including zeolites, biochar, and activated carbons have become popular for treating harmful gases like H2S. Thus, the research examined the feasibility of employing ZSM-5 zeolite for H2S adsorption as an activating agent to improve biohydrogen quality from thermophilic condition. A suspension rich in carbohydrate from MFW was used at initial concentration 5 g/L during the fermentation process was conducted in a thermophilic anaerobic closed bioreactor (TACB) at an initial pH 6 and temperature 60 ℃. Hydrogen-producing bacteria via the butyric acid fermentation route were the most prevalent microbes in biohydrogen generation. Volumetric biohydrogen yield and substrate degradation efficiency was 22511.60 mL and 85% per total carbohydrate, respectively obtained in the experiments performed. The biogas that was produced had undergone adsorption process on zeolite ZSM-5. The effect of dosage of adsorbents and reaction temperature on the hydrogen yield and H2S removal investigated. The hydrogen yield after adsorption process increased from 89% to 92.78%. The optimum dosage and reaction temperature for H2S adsorption were 0.8 g (0.00889 mg/g) and 25 ℃ (0.00890 mg/g), respectively. The zeolite was subjected to consecutive regeneration and adsorption cycle where H2S adsorption capacities of 0.00890 mg/g were maintained for 3 cycles demonstrating reusability and stability of the sorbents. However, the adsorption capacity starts reducing at the fourth cycle. The H2S removal on zeolite ZSM-5 was the best represented by Avrami kinetics model showing that H2S were adsorbed via multiple adsorption pathways with multilayer adsorption on heterogenous surface. The adsorption is physical adsorption, exothermic, increasingly random, and non-spontaneous. Intra-particle diffusions were found to critically control the rate of adsorption. Higher H2S adsorption capacity and regenerability shown by fibrous zeolite in this this study confirmed its applicability as an alternative sorbent in enhance biohydrogen quality under thermophilic conditions.
      16  5
  • Publication
    Carbon foorprint for hostel construction using industrialised building system in Pauh Putra, Perlis
    ( 2018)
    Norashikin Razali
    Emission of carbon dioxide (CO₂) from construction sector has been estimated to contribute nearly 50% of total global emission. Identifying the sources of emissions and understanding their function and relationship to construction activities are essential if not crucial, in mitigating this global crisis. Sustainability research has been initiated to reduce and eradicate the carbon emissions problem, especially in the construction industry. This study evaluates the carbon footprint of the main machinery and materials used in constructing a five-storey hostel that implemented Industrialised building system (IBS) method in Perlis, Malaysia. A life cycle assessment (LCA) framework is used in conducting a partial LCA from pre-design to construction phase. LCA was performed in accordance with the four-step which is goal and scope definition, inventory analysis, impact assessment and interpretation. It also used as a method to systematically analyse the environment assessment. Results showed that the five-storey hostel in Pauh Putra,Perlis has obtained a total IBS Score of 73.4%. Theindirect carbon footprint hotspots are coming from prefabricated sandwich panels manufacturing factory, especially one which manufactured by boiler machine. During this process, 4.52 tonnes of CO₂e are released by the machines. This is due to the extensive energy used for steam heating and high engine rating for the boiler. Cement releases about 369.04 tonnes CO₂e. Its direct carbon footprint hotspots are caused by the large quantity of cement used in the shotcrete mixture and its high extraction–production CO₂ emission values. Meanwhile, overall onsite materials generated 65.60% of the total carbon footprint. Whereas, the direct carbon footprint hotspots by the fuel machinery at the construction site were heavily from excavator and construction of building superstructure task, which yields 81.59 tonnes CO₂e and 86.76 tonnes CO₂e, respectively. This is mainly due to the extensive use of both types of machinery in the daily construction activities. These results can be used as one of the samples in many problems to determine an adequate understanding the impact of IBS construction to carbon emissions in Malaysia.
      2  13
  • Publication
    Carbon footprint of road pavement rehabilitation: case study at KM 99.6 to KM 103.0 in southbound along Sungai Petani Utara to Sungai Petani Selatan section N2, north-south expressway
    ( 2017)
    Zainab Ali Hulail
    Several challenges are facing the development of the industrial sector as a response to resource depletion, environment degradation, and climate change. These phenomena result from substantial carbon dioxide (CO₂) emission and increased carbon footprint. The transportation infrastructure sector consumes a large amount of energy and draws upon natural resources, and carbon footprint can be used to measure the amount of CO₂ from road, highway, or an overpass exerts on earth. CO₂ emissions comprise 95% of the total greenhouse gas (GHG) emissions. A carbon footprint is made up of two parts. The primary footprint is a measure of direct emissions, and the secondary footprint is a measure of indirect emissions from the entire life cycle of products. This research identifies and determines the amount of total carbon footprints of fuel used by machineries and quantity of materials used in the pavement rehabilitation of the PLUS Malaysia Berhad at highway site from Sungai Petani Utara to Sungai Petani Selatan km 99.60 – km 103.00 in the state of Kedah, Malaysia. The data for the research are collected from relevant site engineers through interviews and daily logbooks containing records of material and machinery used in pavement rehabilitation. This research adopts the life cycle assessment approach for evaluating the impact of carbon emission using the materials and machineries utilized in pavement rehabilitation. Results reveal that carbon footprints from materials come from quarry dust material, which emits the highest CO₂ producing 3247.91 tons of CO₂e, followed by cement, stone aggregate, and bitumen emit 251.15, 130.74, and 0.11 tons of CO₂e respectively. The dense bitumen macadam (DBM) layer emits the highest carbon footprint, accounting for 45% of carbon footprint emissions, followed by the asphaltic concrete wearing course (ACWC) layer, and asphaltic concrete binder course (ACBC) layer at CO₂ 28% and 27% respectively. Milling machinery emits the highest carbon footprint producing 478.14 tons fossil of CO₂e due to the highest engine capacity of 448.8 kW/h followed by the lorry DBM, lorry ACWC, and lorry dump truck at 459.47, 352.50, 314.64 tons fossil of CO₂e, respectively. The highest carbon footprint emissions are also observed from milling work task, accounting for 38% of total carbon emissions followed by the tasks in DBM, ACWC, and ACBC layers at 27%, 21% and 14% of CO₂ emission, respectively. The premix cutter machinery emits the lowest carbon footprint emission producing 2.64 tons fossil of CO₂e because of engine capacity is 9.5 kW/h, which is the lowest among the machineries. In the long run, these data contribute to improve methods for implementing policies that monitor and mitigate GHG emissions. As a contribution, the findings of this research are expected to assist contractors, town planners, academics, and policy makers in this field to lessen the carbon footprints in the road infrastructure system in Malaysia.
      1  19
  • Publication
    Carbon from agricultural waste as an adsorbent in the removal of chromium and nickel ions from aqueous solution
    ( 2009)
    Nor Harlina Haji Hassan
    The objectives of this study were to produce carbon from sugarcane bagasse and rice straw by pyrolysis technique as an adsorbent for heavy metal removal and to determine the optimum condition with respect to contact time, pH of solution, adsorbent doses, particle sizes of adsorbent, initial metal concentration and temperature. Also adsorption isotherm and adsorption kinetic behavior ofnickel(II) and chromium(VI) removal by each adsorbent will be determined. Sugarcane bagasse and rice straw are inexpensive and locally available agricultural waste. The raw materials were pyrolized at different temperatures ranging from 300 - 700 °c for 30 minutes with the average heating rate of 30°C/minute. The adsorbents were characterized for the yield, density, pH, ash content, moisture content, surface area and porosity by using BET surface area and porosity analyzer, functional groups by using Fourier Transform Infrared, surface morphology by using Scanning Electron Microscope and element and chemical composition by using Energy Dispersive X-ray. Adsorptions were found to be effected by pyrolyzing temperature and surface area. The adsorbents that produced at 700°C have been chosen for this adsorption study because it produced the highest percentage of removal. The maximum removal efficiency of Ni(II) on RSC and SBC as 85.65% and 21. 79 %, respectively and Cr(VI) on RSC and SBC as 61.81 % and 76.10 %, respectively. The operation parameters included contact time (15 - 210 minutes), pH of solution (I.O - 10.0), temperature (25, 30, 45 and 55 °C), particle sizes of ads or bents (1.18 mm, 600 f,lm, 300 f,lm and 150 !1m), adsorbents doses (0.04, 0.10, 0.20, 0.40, 0.6 and 1.0 g) and initial concentrations of adsorbates (10, 25, 50, 75 and 100 mg/L). The experimental tests were conducted in batch process. The contact time, amount of adsorbent, temperature, particle size of adsorbent and initial concentration of the metal ions solutions affect the adsorption efficiency but most importantly depended on the pH of solution. The experimental isotherms data were analyzed by using Langmuir and Freundlich equation. The applicability of adsorption was described by using the Freundlich and Langmuir adsorption isotherm. It was found that Langmuir isotherm model fit well the data for nickel(II) and chromium(VI). The measured high linearity of correlation coefficient, R2 and the values dimensionless separation factor, RL indicated a favorable adsorption of both Ni(IJ) and Cr(VI) onto RSC and SBC, respectively. While, the adsorption kinetics, pseudo-first order model, pseudo second order model and intraparticle diffusion model were analyzed on the experimental kinetics data. it was Jouncl that the pseudo second order kinetic model described the adsorption kinetic of both adsorbent well. The performance of both adsorbent in the removal of nickel(l/) and chromium(VI) were also compared It was found that the adsorption capacity of rice straw carbon on nicke/(II) was high may be due to the present of surface oxygen groups, surface charge, high silica content and the properties of nickel. While, the adsorption capacity of sugarcane bagasse carbon on chromium(VI) was high was caused by the high surface area of the adsorbent, surface charge and the properties of chromium.
      3  18
  • Publication
    Characterization and properties of Polypropylene/recycled Acrylonitrile Butadiene rubber/palm kernel shell composites
    ( 2018)
    Ranggita Dwi Nindya Affandi
    Thermoplastic elastomer composites was developed by using polypropylene (PP) / recycled acrylonitrile butadiene rubber (NBRr) filled by palm kernel shell (PKS). All test samples were prepared by using heated two roll mill machine at temperature of 180 °C at a speed of 15 rpm with the total mixing time of 9 minutes. All the compound samples were shaped using compression moulding at temperature of 180 °C and followed by cool pressing for total time of 12 minutes. The particle sizes of the PKS and NBRr used in this study were 100-200 μm. The effect of NBRr loading and PKS loading were prepared and investigated as control series. The studies of composites properties were aimed to investigations of the effects of compatibilizer such as polypropylene maleic anhydride (PPMAH) and trans-polyoctylene rubber (TOR) and also ɤ-MPS as a coupling agent. The mechanical properties, morphological characterization, FTIR analysis, thermal properties, water absorption and swelling behaviour were investigated. Better properties such as tensile, thermal stability, crystallinity, water absorption and swelling behaviour of composites showed by PPMAH compared with TOR compatibilization. The treatment modification of PKS filler by using ɤ-MPS have improved the chemical compatibility, interfacial adhesion and stress distribution between PKS filler and PP/NBRr matrix which results in better properties.
      2  12
  • Publication
    Complexity factors in influencing the relationship between critical success factors and performance of building refurbishment projects
    ( 2019)
    Nurfadzillah Ishak
    Building is an important sector of today’s human life, where it meets the basic needs of modern humans for shelter and as a place for social activity and also to protect from the environmental threat. The importance of this sector is growing in line with the increasing number of population in need of new building development. Unfortunately, the high demand for new building development has become increasingly difficult due to the limited of vacant land available for development as a building development project. Consequently, refurbishment of existing buildings is one way to overcome this issue. However, recent studies have found that the success of the building refurbishment project is still not satisfactory. Previous studies have been conducted to determine the Critical Success Factors of building refurbishment projects, but they do not take into account important aspects of current development namely sustainability, technology and policy as well as Complexity Factors that are synonymous with building refurbishment projects compared to new building projects. Therefore, this study was conducted with the aim of establishing a multi-dimensional model of a building refurbishment project. To achieve this, Critical Success Factors are identified taking into account the sustainability, technology and policy aspects as well as Complexity Factors in influencing the building refurbishment project performance success. In this regard, the study was conducted through a quantitative method using the questionnaire form as a research medium to obtain feedback from the construction organization on the Critical Success Factors and the successful performance of the building refurbishment project. The questionnaire developed was distributed by employing self-administered method among managers to represent construction organizations operating in Kuala Lumpur and Selangor. As a result, 204 of the 240 questionnaires were fully completed. The analysis showed that all of the Critical Success Factors were categorized as critical to the success of the building refurbishment project and even had a strong relationship with the success of the building refurbishment project. The study also found that Complex Factors not only directly influence the success of the building refurbishment project but also have a significant impact on the relationship between the four Critical Success Factors and the success of the building refurbishment project namely project management, environment, economic and policy. Overall, this study met the goals and objectives of the study. Finally, this study outlines strategies that can be implemented by construction organizations that carry out building refurbishment projects not only to achieve better project success but also to impact the construction industry on leading a competitive industry and creating a better human environment
      1  11
  • Publication
    Composting of rice straw-derived biochar with food waste and its application as soil improver for paddy growth
    ( 2020)
    Siti Noor Baya Khalib
    One of the most important agricultural residues produced is rice straw, which represented as one of the major by-products from rice production process. The huge excess of rice straw in paddy field was due to the increases in size of paddy areas and rice productivity. The farmers from all over the world usually used a method of on-farm burning to eliminate this straw after the harvesting season. Rice straw can be manage by composting process, but it required a longer time for the decomposition process to happen since the main fraction of rice straw is lignocellulose which was difficult to degrade. In order to solve this problem, rice straw will be burned before being used for composting process. The main objective of this study was to produce soil improver by composting of rice straw-derived biochar with food waste at two selected temperature of rice straw burning with three different initial C:N ratios and three different aeration rates. The final compost will be tested to soil paddy field as a soil improver before the cultivation process to recover the nutrient content loss during the removing process of rice straw from paddy field. Two selected temperatures (300°C and 400°C) of rice straw burning at 30 minutes was chosen to be composted with food waste, from the burning of rice straw at different temperature range from 100°C until 800°C. There are three different aeration rates (0.4Lmin-1.kg-1, 0.6Lmin-1.kg-1, 0.8Lmin-1.kg-1) and three different initial C:N ratios (20, 25, 30) was used during composting process for each selected temperature of rice straw burning making that the total of 19 treatments of rice straw derived-biochar compost including control (rice straw without burning) were done. Each treatment of rice straw derived-biochar compost was analysis for pH, temperature, moisture content, organic matter, carbon content, C:N ratio, NPK values and germination index. The composting process was conducted in a laboratory-scale bin composter reactor for 30 days and 60 days for control. The final product of compost produced was applied towards the paddy field soil before the next cultivation season. The suitability used of compost produced as a soil improver was analysed in term of paddy production and potential yield. The best treatment of compost for rice straw burning at 300°C, was the rice straw derived-biochar compost treatment of T2-300-CN-30-AR0.6 because it recorded the highest thermophilic phase with temperature exceeding 55°C for 6 days for pathogen destruction, has a maximum germination index of 97% compared to the others treatments at the same temperature of rice straw burning. Meanwhile, the best treatment of compost for rice straw burning at 400°C, was the rice straw derived-biochar compost treatment of T11-400-CN-30-AR0.6 because it also recorded the highest thermophilic phase with temperature exceeding 55°C for 5 days for pathogen destruction and has a maximum germination index of 91% compared to the others treatments at the same temperature of rice straw burning. These two treatments also shown a higher value of nitrogen, phosphorus and potassium content. The application of final compost for treatments G1 and G4 towards paddy field soil as a soil improver has recorded the highest total paddy production with 2021gm-2 and 1797gm-2, respectively. Beside, these two treatments of G1 and G4 also recorded the best values for each component of potential yield for paddy growth.
  • Publication
    Composting of solid waste by using indigenous microorganisms (IMO)
    ( 2015)
    Siti Noor Baya Khalib
    Composting is a process for the treatment of organic solid waste and the biological decomposition of raw compost materials to form compost. The utilization of organic additives during composting of organic solid waste will produce an environmentally product of compost and can shorten the process. The objectives of this study were to characterize the chemical and biological properties of prepared indigenous microorganisms (IMO) consists of pH, temperature, moisture content and identification of bacteria, physico-chemical changes during the composting process; pH, temperature, moisture content, carbon: nitrogen ratio, total nitrogen, phosphorus, potassium and to study the productivity of mustard greens plant using the product of compost in term of; plant height and soil characteristics. Five phases involved during the preparation of indigenous microorganisms (IMO) with different materials added in each phase. There are seven different ratios used during composting; 2:3:1 (garden waste compost 1), 3:2:1 (garden waste compost 2), 2:2:1 (garden waste compost 3), 2:0:1 (control garden waste), 2:4:1 (food waste compost 1), 4:2:1 (food waste compost 2) and 4:4:1 (food waste compost 3). Each treatment was triplicate over 60 days and 30-48 days of garden and food waste composting duration. The final compost was applied to the mustard greens plant about 30 days with triplicate. Acidic condition of pH obtained during IMO preparation. The temperature was constant at the first and second phases with 28oC but increases starting at the third phase, from 32 to 38oC. At the fourth phase, the temperature was in a range of 36 to 48oC. Temperature of 30oC was recorded at the starting of fifth phase, increased and then also decreases to 32oC. Moisture content in the first, second and third phase of IMO was in a range of 35 to 42% and then was decreased until phase four IMO, in a range of 30 to 37 %. At phase five, the moisture content increases slightly and then constant at a range of 35 to 46%. Result for identification of bacteria shown that Bacillus sp involved in first and second phase of IMO. In phase III of IMO preparation, Bacillus thurigiensis was obtained. Proteus sp and Bordetella sp involved in fourth and fifth phase of IMO. During the composting process, all the parameters of IMO-compost obtained in a range like; pH value 5-9, temperature 29-55oC, moisture content 35-75%, nitrogen 1-7%, phosphorus 4-15%, potassium 11-23% and C:N ratio 5-20 . The best ratio of garden waste composting was at treatments of GWC2 and FWC3 for food waste due to their higher temperature of 48oC and 55oC and the end of C: N ratio of 12 and 15 recorded during the process. Application of IMO-compost towards mustard greens plant also shown a significant result for plant growth using final compost ratio GWC2 and FWC3 but there are some problems with insect pests that need to be concerned during plantation.
      3  4
  • Publication
    Contaminants’ immobilisation of incinerated air pollution control residue and rubber sludge using respectively Calcium Aluminate cement and ordinary portland cement with rice husk ash via stabilisation/solidification technique
    ( 2014)
    Abdul Latif Abdul Rani
    Treatment of incinerated wastes has become a challenge as the production of these wastes increased each year which become source of hazard to human and ecosystem. Corresponded to that, the first stage of experiment was to treat air pollution control (APC) residue from municipal solid waste (MSW) incineration using two types of calcium aluminate cements (CAC) known as Secar 71 and Ciment Fondu. While the second stage of experiment focused on the treatment of local incinerated waste from rubber gloves industry known as incinerated rubber sludge (IRS) using combination of ordinary Portland cement (OPC) and rice husk ash (RHA) mixtures which comprises of 50% rice husk activated carbon and 50% rice husk ash. The aim of this research is to immobilise heavy metals and non hazardous contaminants such as chlorides and sulphates within these wastes using stabilisation/solidification (S/S) technique. The objectives of this study were to study the effects of waste and RHA addition to compressive strength, to assess the effectiveness of RHA in immobilising the contaminants via analysing the leaching pattern and also to evaluate the stability and disintegration of the mineral phases from the stabilised/solidified sample. Series of factorial design were used to prepare mix formulations for CAC and OPC sample batches. As for APC residue treated with CAC, the focused is more towards incorporating the chlorides and sulphates in respective minerals known as Friedel’s salt and ettringite. Treatment of IRS using OPC was aided by including mixtures of RHA to functional as activated carbon and provide high silica content for enhancing sample strength. Findings on first stage of experiment show that, Friedel’s salt and ettringite were able to be formed successfully to immobilise chloride and sulphate. Whereas the second stage of experiment revealed that, there was reduction in terms of heavy metals and chlorides concentration that leached out from stabilised/solidified sample containing incinerated rubber sludge as RHA been incorporated into the batch samples as compared to OPC with IRS alone. Sulphates were able to be fully immobilised in the presence of RHA in the sample. In terms of unconfined compressive strength, most of the RHA addition batch samples have shown remarkable results as all compressive strength findings surpassed the minimum requirement of sanitary disposal which was at 1 MPa even at 50% waste addition or 1:1 waste to binder ratio. These findings have derived to conclusion that RHA is an excellent material to be included in hazardous waste treatment using S/S whereby the treated waste is also suitable to be reconsidered and utilised as secondary material for construction such as underneath road fillers or base foundation.
      3  15
  • Publication
    Cross sections optimization of plane trusses for various spans and depths
    ( 2015)
    Sumayah Abdulsalam Mustafa
    Steel trusses are widely utilized in real-world applications and a continuing motivation for research in optimal structural design exists. In civil engineering, weight optimized trusses are convenient since the easier transportation and less costly structural parts as well as construction work in connection with the build-up is simplified. One more advantage of developing a weight optimized truss is the fact that the minimum share of the load capacity is enrolled by the structure itself. Structural optimization is also very important in the aircraft and car industry whereas a much lighter structure often means a much better energy economy. Accordingly, a rich literature has advanced within the last two decades in analysis and design as well as optimization of truss. Still, only a diminutive number of researchers dealt with the problem of parameterization of the truss cross section. The optimization design of trusses needs to be carried out in accordance to two essential requirements. First the best geometrical layout for members and nodes requires being determined, and second the best adequate cross-sections need to be determined. Generally there is need to exist an optimum shape and a cross-section distribution that is definitely adapted for external loads. Many previous studies, use the areas of cross sections as a continuous design variable, although, the use of a continuous optimization procedure usually more accurate, but it will lead to non-available sizes and any trail to replace those values by the nearest available sizes can make the design unnecessarily heavier. Consequently, solution of the area will be adequate if the design procedure includes the use of cross-sectional areas as discrete design variable from available sizes, as well as if the design takes into account the effective cross section shape at the start of process. This is the topic of this paper, to study the effect of the cross section shape on the optimization of plane trusses problem. This is going to be done by using finite element method and simple linear element with the aid of steel structural analysis and design STAAD software. Four rolled steel sections (angle, tube, channel, and pipe) which are used in industrial roof trusses are applied for this purpose. Furthermore, in producing a structure element, the material properties is not the only factor considered, however, the geometry properties also is vital factor to be considered which is represented by component’s shape factor, that measures the efficiency of the material usage. Outcome results of this research prove that the chosen cross section shape has a significant effect on the optimum truss weight for exact same geometry of the truss type under the similar circumstances of loading and support. Pipe and tube section shapes offer least truss weight. The best truss shape and topology concerns with Mansard and Pratt truss topology at span over depth ratio of six.
      4  22
  • Publication
    Development of aerobic granular sludge using industrial latex wastewater
    ( 2015)
    Najihah Abdul Rashid
    An attempt of developing aerobic granules using industrial latex wastewater sludge was conducted. Optimization of cycling time were investigated and assessment of the effect of fluctuating organic loading was performed. Subsequently followed by investigation of physical characteristics of a stable aerobic granules under inconsistent and constant organic loading. Finally, aerobic granular sludge produced was then characterized by a height to diameter ratio (H/D) of 2.7 and 14. Experimental investigation was conducted in sequencing batch reactors R1, R2, R3 and R4 with cycling time of 4 hours after selection of cycling time was conducted based on preliminary investigation. Four batches of experiment were performed to support the objectives of this study. Similar size of sludge flocs was inoculated to all four reactors with reactor configuration of 2.7 and 14 together with various organic loading rate. R1 and R3 was introduced to real latex wastewater with varying chemical oxygen demand (COD) loadings from as low as 0.01 to 0.28 kgCOD/m3/d. However, granules in R1 were cultivated with superficial air velocity (SAV) of 4.25 cm/s, whereas granules R3 utilized SAV of 1.1 cm/s. R2 and R4 was fed with synthetic wastewater with consistent COD loadings of 0.07 kgCOD/m3/d but with different application of SAV. All four reactors achieve granulation, although granules developed in R1 and R3 is bigger and denser than in R2 and R4. But when compared to granules grown in R1 and R3, R2 and R4 granules were less compact and smaller in size. R2 and R4 granules can reach granule size of 0.2 to 0.6 mm within 210 days, compared to R1 and R3 granules that can only developed up to 4.75 mm within 150 days. This result shows significant difference between R1 and R3 with R2 and R4 granules, and that COD loadings appear to be a crucial factor for complete granulation. When R1 granules were compared to granules in R3, an apparent difference of granules characteristics were observed with a high average settling velocity (SV) value in R3 than in R1. On the other hand, R2 and R4, displayed unstable development of granules throughout the study but stable reactor performance after formation of granules. Utilization of a constantly low organic loading rate (OLR) does not seem to favour a stable granules formation, although high height to diameter ratio was applied to enhance the SAV within the reactor in order to intensify shear force optimizing the formation of a more stable and compact granules.
      2  4
  • Publication
    Development of Amine group modified silicon nanowire and integrated with microfluidic for lead ion detection
    ( 2020)
    Nuri A. Kh. Ehfaed
    This study describes the development of a chemical sensor that is portable, reliable, and rapid in the detection of lead ions. The developed sensor is based on silicon nanowire which distinguishes lead ions from ions present in water after the surface of the device was modified with 3-aminopropyl triethoxysilane (APTES) amino acid group which interacts with ions based on the mechanism of electronegativity of the element. This research broadly covers various important aspects of silicon nanowires and microfluidic devices for the creation of reliable chemical sensors. Also, this study created a new method of detecting lead ions by amine group modified silicon nanowire integrated with polydimethylsiloxane (PDMS) microfluidic. A new chemical sensor concept and implementation specifically developed to accurately detect lead ions in water through sensor modified with (3-aminopropyl) triethoxysilane (APTES) connected to microfluidic channel which send the sample to the sensing domain thereby decreasing the sensor response time by driving fluid through capillary phenomenon without undergoing diffusion or advection phenomenon. A silicon (Si) nanostructure was prepared using photolithography techniques, the device was fabricated via dry oxide etching approach with a controlled oxygen flow rate in oxidation furnace, network of uniform Si nanowires were successfully fabricated. Further, the device was functionalized with (3-aminopropyl) triethoxysilane (APTES) to serve as a sensor for heavy metal detection. The amino-functionalized Si nanowires were tested against the heavy metal lead ion (Pb+). The results indicated that Pb can be detected with high precision and selectivity, this was confirmed by atomic absorption spectroscopy in determining the level of lead content in water sample. The testing was carried with four (4) water samples, these include Tab water (H₂O), River H₂O, Treated (H₂O), DI (deionized) H₂O and found the levels of 0.0859 mg/L, 0.0929 mg/L, 0.0052mg/L, 0.0023 mg/L with 5.8pA, 7.2pA, 4.6pA, 3.3pA current responses, respectively. Thus, with this high response capabilities to the water samples, the sensor is effective for heavy metal detections and can be extended to a large sensor network in water treatment and monitoring plants. Further, new microfluidic bonding process based on SU8 cold pressed was implemented to achieve safe and reliable bonding. The requirement for a room temperature (cold pressed) process is particularly critical because the sensor must be functionalized with receptor molecules prior to bonding and cannot withstand significant heating after functionalization. Thus, the study developed new room temperature bonding method using SU8 as an intermediate adhesive layer. The SU8 modified bonding was compared with non-modified bonding. The bond strength of SU8 modified was found to be stronger than ordinary plasma bonding under the same curing conditions. Overnight room temperature curing and cold pressed yields an average burst pressure of 420 kPa, which is more than adequate for many PDMS sensor devices. In contrast, non SU8 coated plasma bonded resulted in a burst pressure of only 174 KPa.
  • Publication
    Development of integrated anaerobic-aerobic bioreactors for the complete degradation of synthetic wastewater containing mono and diazo dye
    ( 2014)
    Murali Viswanathan
    Dyes are carcinogenic and mutagenic nature. Eco-friendly, economical and not producing secondary pollutants are the merits of the biological treatment for azo dye than other methods. Purely anaerobic or aerobic treatment and combined treatments were not successful to attain the simultaneous removal of color and intermediates in most of the cases. Apparently, still there is a need to develop the bioreactors to perform complete removal of azo dye including color and intermediates. The present study aimed to develop the bioreactor which able to perform in effective color and intermediates removal of azo dye. The study conducted one anaerobic and three different integrated anaerobic-aerobic bioreactors namely, Upflow Anaerobic Sludge Blanket (UASB) reactor, Integrated Anaerobic-Aerobic Coconut Fiber (IAACF) reactor, Integrated Anaerobic-Aerobic Gravel and Coconut Fiber (IAAGCF) reactor and Integrated Anaerobic-Aerobic Granular Activated Carbon (IAAGAC) reactor. Performance of the above all reactors against the degradation of synthetic wastewater containing mono azo dye Methyl Orange (MO) and diazo dye Reactive Red 120 (RR120) were assessed in different influent color concentrations. . The color removals of MO in UASB reactor were 94%, 90% and 96% in phase 1A, 2A and 3A respectively. The color removals of MO in IAACF reactor were 97%, 96%, 97%, 97% and 96% in phase 1B to 5B, respectively. The intermediates of MO was not removed in UASB reactor and partially removed in other reactors. Symmetric cleavage of this azo bond in MO tends to the formation of the N,N-dimethyl pphenylenediamine and 4-amino sulfonic acid as intermediates. GC-MS analysis resulted the presence of N,N-dimethyl p-phenylenediamine in the effluent. The color removal of MO in IAAGAC and IAAGAC reactors were nearly 98% and 100%, respectively in all phases. The intermediates of MO were completely removed in IAAGAC reactor with increased operation time. The color removals of RR120 in UASB reactor with increased influent cosubstrate were 67%, 76% and 80% in phase IA, IIA and IIIA, respectively. In IAACF reactor, the color removals of RR120 were 87%, 88% and 86% in phase IB, IIB and IIIB, respectively. The color removal of RR120 in IAAGCF and IAAGAC reactors were more than 90% in all the phases. The cleavage of azo bonds in RR120 leads to the formation of sulfonated aromatic compounds as intermediates. The complete removal of RR120 intermediates were noted in IAAGAC reactor with increased operation time. The results of present study revealed that the highly reductive anaerobic environment suited for effective color removal of MO and RR120 rather than intermediates removal. Partial mineralization of MO and RR120 intermediates was observed in integrated anaerobic-aerobic system. Complete removal of MO and RR120 intermediates was possible in integrated anaerobicaerobic system with suitable biomaterials like granular activated carbon. The variation of kinetic constants in kinetic study revealed that the performance of color and COD removal was in decreasing trend with respect to increased color influent in both MO and RR120. However the performance was decreasing, effective color removal was observed in the reasonable color influents range (100 to 1000mg/L).
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  • Publication
    Development of microbial fuel cell for degradation of organic and inorganic containing wastewater and renewable energy recovery
    ( 2019)
    Oon Yoong Sin
    Nitrate and dye wastewater pollution has been a serious environmental threat. The development of green technologies is in great need to overcome the environmental crisis. Microbial fuel cell (MFC) is emerging as a sustainable technology in the field of wastewater treatment to treat environmental pollutants with concomitant energy recovery. The main objective of this study was to develop MFC system for effective nitrate and azo dye wastewater treatment and bioelectricity production simultaneously. The results indicated that MFC was effective in removing nitrate while utilizing it as terminal electron acceptor to generate electricity. Besides, closed circuit MFC system demonstrated higher efficiencies in COD and nitrate removal than in open circuit system. The long term performance of MFC was evaluated and the maximum COD and nitrate reduction achieved were 82±4% and 88±4%, respectively, with power output of 669 mW/m3. Azo dyes were also utilized as terminal electron acceptors at the abiotic cathode in order to investigate the influence of dye’s structure on the decolourisation and power performance. The findings indicated that decolourisation rates of monoazo dyes were ∼50% higher than diazo dyes. This indicated azo dye with electron withdrawing group at para substituent to azo bond is more susceptible for dye reduction. A double chamber MFC reactor with continuous flow from anodic chamber to cathodic chamber was also developed to study the fate of electrons in MFC for azo dye decolourisation and bioelectricity generation. The study revealed that the increment in organic loading enhanced the decolourisation efficiency but deteriorated the power output ascribed to the competition between azo dye molecules and anode for electrons. This finding also corroborates that azo dye, New coccine (NC), was a preferable electron acceptor than anode. In addition, baffled MFCs (BMFCs) were designed and developed without membrane to further investigate the performance of the system. The results demonstrated that BMFC able to achieve up to 94% of decolourisation efficiencies for 300 mg/L of NC. The findings also discovered that 50 mg/L of NC loading improved ~53% of power density to 12.4 mW/m2 as compared to the dye-free condition. This suggested that the accumulation of dye decolourised intermediates could function as the redox mediator, subsequently the electron-shuttling mechanism of NC decolourised intermediate was proposed. The degradation pathway of NC was proposed based on the identified intermediates products via the UV-visible spectra, high-performance liquid chromatography and gas chromatography-mass spectrum analyses. The results indicated that the degradation of NC in MFC initiated with azo bond cleavage in the anaerobic anodic chamber, which led to the formation of aromatic amines. Then, further degradation of carcinogenic intermediates to less harmful lower molecular products occurred in the aerobic cathodic chamber of the MFC system.
  • Publication
    Enhancing the thermal performance of courtyard office building in hot-humid climate : a case study of development department building UniMAP
    ( 2018)
    Esra'a Shehadeh Hussein Abbaas
    Courtyard is considered a natural alternative for cooling since it has high ability to create a local climate within a building that is nicer than the outside which leads to create temperature difference between indoor and outdoor. The efficiency of courtyard in hothumid climate still questionable due there are minimal research reported especially in Malaysia. The objective of this research is to perform a simulation study using EnergyPlus simulator to explore the influence of the presence of a courtyard in a single storey office building via investigating the impact of natural ventilation, window glazing and window blind shading on the thermal performance of the building on 21 April and 21 October that representing the dry season and wet season days in Malaysia. The Development Department building at University Malaysia Perlis (UniMAP) that is located in Pauh Putra Campus has been taken as a case study. The results show that the stack ventilation is the most effective way to reduce the indoor air temperature due to its high ability on exchanging the indoor warm air with the cooler one in the courtyard. In contrary, the cross ventilation has the greatest impact on reducing the relative humidity within the building since it is capable to dilute the moist concentration in the interior spaces as a result of airflow. The best PMV values for ventilation effect is obtained for stack ventilation, indicating its effectiveness in enhancing the thermal comfort of the building. Moreover, venetian blind shading is capable to reduce the indoor air temperature for the building and using external blind is more effective due to its impact on blocking sun radiation. Additionally, the external venetian blind causes to increase the relative humidity within the building compared to no window shading case due to the reduction of air temperature. Generally, window shading reveals an enhancement on PMV values and the external blind has the most effective where it is capable to shift PMV values within comfortable level during wet season, but it does not much impact on the thermal sensation level during dry season. Using double and triple glazing windows able to reduces the indoor air temperature and in contrary, relatively increases the humidity within the building compared to using single glazing window. The PMV values of glazing effect revealed that using multi-layered glazing window slightly enhances the thermal sensation for occupants but it is not able to reduce the uncomfortable hours on both design days. Finally, it can be observed that the ventilation is the most effective factor on reducing the air temperature and relative humidity, as well as to enhance the thermal comfort level for courtyard buildings in hot-humid climate among the other studied parameters. This work contributes to sustainable architecture where courtyard application concept is used in hot-humid climate specifically for Malaysia due to its effective ability to enhance the thermal performance and help in improving the thermal comfort level near to the desired values.
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  • Publication
    Extraction and characterization of coagulation active agent from Moringa Oleifera for turbidity and hardness removal in raw water sources
    ( 2012)
    Meutia Nurfahasdi
    The objective of this study is to explore the capacity of the active agent that extracted from Moringa oleifera (MO) by various solutions for turbidity and hardness removal in raw water sources. The extracted active agent was also characterized based on its functional group analysis. The solutions of NaCl, KCl and distilled water were used as the active agent extraction. To achieve these objectives, some experiments have been performed and a qualitative explanation and quantitative correlation have been made. The results showed that NaCl 1N as solution delivered better removal capacity for turbidity and hardness in raw water in comparison to KCl 1N and distilled water. Meanwhile, the functional group characterization by FTIR of the residual solid after extraction indicated that the order of N-H and C=O bond removal for solution of NaCl 1N is larger than KCl 1N and distilled water. Proteins in Moringa oleifera extracted with distilled water, NaCl 1N, and KCl 1N are the most effective at pH 7. The regression equation y = 1.634x + 0.0026, where the correlation coefficient (R2) value found is 0.9989.
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  • Publication
    Hybrid system up-flow constructed wetland integrated with microbial fuel cell for simultaneous wastewater treatment and bioelectricity generation
    ( 2019)
    Oon Yoong Ling
    Environmental pollution, particularly water pollution and energy crisis, are two significant challenges that our world is facing nowadays. This phenomenon has driven the exploration of sustainable wastewater treatment technology to address both challenges hand in hand. This thesis aimed to develop a hybrid system, which is up flow constructed wetland integrated with microbial fuel cell (UFCW-MFC) for simultaneous wastewater treatment and bioelectricity generation. The main objectives of the study were to investigate the feasibility, performance in terms of wastewater treatment and bioelectricity generation, the role of wetland plant, working principle and mechanism in UFCW-MFC. Six hybrid reactors were developed for a series of systematic study. Redox gradient present along the wetland bed was suitable for oxidation and reduction processes, and at the same time, they are needed by MFC as anaerobic anode and aerobic cathode. The present study revealed that the closed circuit system enhanced the organic matter degradation, denitrification and decolourisation, which inferred that the integration of CW into MFC can achieve higher treatment efficiency than CW and MFC standalone system. Besides that, the presence of plant achieved more promising result in bioelectricity generation compared to plant-free system. Wetland plant significantly contributed oxygen to the cathodic region through photosynthesis process. The increased sodium chloride concentration increased the conductivity and subsequently improved power generation. Furthermore, the study showed that aeration influenced power performance more than the electrolyte conductivity. The intermittent aeration at the rate of 600 mL/min found to be optimum for COD, nutrient removal and energy recovery. The fate of electron transport in UFCW-MFC in the presence of multiple electron acceptors (anode, azo dye and nitrate) was investigated. The presence of various pollutants, which are electron acceptor in anodic region, competed for electron and the most favourable electron acceptor in the study was nitrate, followed by azo dye and anode. Moreover, the influence of azo dye molecular structure on decolourisation rate and bioelectricity generation was investigated by using Acid Red 18 (AR18), Acid Orange 7 (AO7) and Congo Red (CR). The highest decolourisation rate was obtained from AR18 (96%), followed by AO7 (67%) and CR (60%). The power output also followed such trend. The higher decolourisation rate in AR18 was due to tautomerism, lower number of azo bond, more electron withdrawing groups and the position of electron withdrawing group substituent at para position to azo bond. Moreover, the degradation pathways of azo dyes were proposed and elucidated based on the respective dye intermediate products identified through UV-Vis spectrophotometry, high-performance liquid chromatography and gas chromatograph–mass spectrometer analyses. The results indicated that the dyes were decolourised at the anaerobic anodic region, and dye intermediates were further mineralized at the aerobic cathodic region to less harmful or non-toxic products
  • Publication
    Influence of vertical earthquake on the variations of axial load ratio of reinforced concrete buildings
    (Universiti Malaysia Perlis (UniMAP), 2016)
    Awang @ Abdul Halim Taib
    Current earthquake engineering field ignores the repeated and vertical ground motion in design and analysis of the structure system even though in actual condition these two phenomena impose the significant effect to the structural system. This gradually changing due to the increase in near source record obtained recently, coupled with field observation confirming the possible destructive effects of high vertical vibration. The aim of this study is to assess the behaviour of regular and irregular reinforced concrete frames due to multiple earthquakes with vertical component. The structural response quantities are expressed in term of variation of axial load. Axial load ratio obtained by dividing axial load in column induced by combined horizontal and vertical component of ground motion (VHGM) to axial load in column induced by horizontal component of ground motion (HGM) load. Obtaining vertical spectral shape by scaling the horizontal ground motion using V IH ratios of 2/3 rule as suggested by many codes can be seriously underestimate action on structures located near earthquake sources and overestimates action in far field regions. The frame models are subjected to the horizontal and vertical ground motions with various peak ground acceleration ratios between horizontal and vertical ground acceleration (V /H) ranging from 0.3 to 1.9 using RUAUMOKO software. This study found out that vertical ground motion showed significant effect to the reinforced concrete building with maximum axial load ratio of 54 for regular and 6 for irregular rc frame. Eight storey regular models showed typical graph with the shape of number three for plotted axial load ratio against height. Axial load ratio values was almost equal to one at base, mid and top floor but increases at one fourth and three fourth of the building height. Irregular model showed typical graphs with higher axial load at lower floor and decreased along the heights.
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  • Publication
    Integration of soil erosion assessment methods using geographic information systems and remote sensing techniques
    ( 2020)
    Ramzi Ameen Hussein Alma'aitah
    Soil erosion is a natural geological process but nowadays, it has become one of the most important environmental threats in the world. Unfortunately, the process has been accelerated due to human activities and climate change. The Mediterranean Basin is a region prone to erosion as climate change effects are already visible. Soil erosion is a threat to the economy of the developing countries that depend on agriculture such as Jordan. The purpose of this study is to estimate the soil erosion at Wadi Bin Hammad basin, examining the effect of factors on soil erosion, as well as comparing and verifying the measurement models, on a geographical area of 136.13 km2 located in the southern highlands of Karak, Jordan using Revised Universal Soil Loss Equation (RUSLE) and Soil and Water Assessment Tool (SWAT). The data input used for developing the model is collected from various sources, and the land cover data are prepared by examining both aerial photos and satellite images. RUSLE and SWAT maps were integrated by the GIS software application to create a final map to identify common areas affected by high erosion rates. By this way, accurate results can be achieved according to climate, morphology, geology, and hydrology. Similarly, the map will be used to accurately identify areas with high sedimentary production within the basin, for each sub-basin. The map will also be used in Jordanian mountain basins. Wadi Bin Hammad, achieved a mean value of 40.4 t ha-1 yr-1. The basin is classified according to erosion classes in the final map to five classes. The first class is the severe zone (81 - 100 t/h/y). It becomes clear that the severe zone of the erosion, covering more than 16.75% of the area, contributes 31.34% of soil loss from the basin in southeast Alqaser and northeast of Demna. The second class is the high zone (erosion between 41 - 80 t/h/y). The high erosion zone, covering more than 24.66% of the area, contributes 27.92% of soil loss from the basin in southeast Rakeen and Qaser. The third class is the moderate zone (erosion between 21 - 40 t/h/y). This zone, covering more than 29.03% of the area, contributes 24.36% of soil loss in the middle of the basin near Wadi bin Hammad village. The fourth class is the low zone (erosion between 11 - 20 t/h/y). The low erosion zone, covering more than 16.79% in the middle of the basin contributes only 12.30% soil loss. The final class is the very low zone (erosion between 0 - 10 t/h/y), which is estimated as 12.77% in the west of the basin in the Ghor near the Dead Sea contribute 3.99% soil loss. From the results of the spatial analysis between controlling factors and soil erosion; bare land, field cropland and high steep slope are all linked to extreme soil erosion.
  • Publication
    Kelestarian dalam pembangunan hartanah: faktor-faktor cabaran dan batasan terhadap praktis konsep bangunan hijau
    ( 2011)
    Mohd Nazaruddin Yusof @ Abdul Rahman
    Kajian penerokaan ini bertujuan menyelidik kojektur prima facie bahawa terdapat halangan·halangan terhadap keberkesanan penerapan dan praktis kosep kelestarian dan elemen·elemen bangunan hijau dalam pembangunan hartanah di kalangan peneraJu·peneraju utama di kawasan kajian iaitu, negeri-negeri Perlis, Kedah dan Pulau Pinang. Halangan-halangan ini mungkin dijadikan alasan oleh peneraju-peneraJu utama tentang mengapa mereka kurang responsif kepada keperluan penerapan dan praktis konsep serta elemen-elemen tersebut. Halangan-halangan tersebut boleh diandaikan sebagai faktor-faktor cabaran dan batasan daripada ditafsirkan sebagai faktor-faktor kritikal kejayaan yang pihak industri keseluruhannya dan pembuat-pembuat keputusan, khasnya perlu mengambil kira secara serius sekiranya penerapan dan praktis ini hendak digalakkan. Empat faktor cabaran dan batasan dikenalpasti iaitu kurangnya kemahiran dalam konsep kelestarian dan bangunan hijau dalam kalangan peneraju utama; ketiadaan peraturan spesifik kelestarian dan bangunan hijau ; kurangnya kesedaran tentang konsep kelestarian antara mereka dan kekurangan elemen kelestarian dan bangunan hijau dalam pembelajaran program alam bina di institusi pengajian tinggi. Faktorfaktor tersebut dijadikan empat hipotesis untuk diterima atau ditolak. Seramai lapan puluh responden telah dipilih secara persampelan bertujuan (purposive sampling) dalam kajian ini. Pembentukan soalan-soalan kajian adalah berdasarkan hipotesis yang dibentuk. Data yang dikumpulkan dari kajian dianalisis berdasarkan analisis faklor dan kebolehpercayaan menggunakan perisian SPSS versi 13. Penemuan kajian penyelidikan menunjukkan terdapatnya satu keselarasan pendapat antara responden-responden terhadap keempat faktor-faktor cabaran tersebut. Tiga hipotesis telah diterima berdasarkan analisis. Hipolesis kekurangan kesedaran dalam kalangan peneraju utama dapat menolak hipotesis nuI(Ho), membuktikan peneraju utama sememangnya sedar tentang konsep kelestarian dan bangunan hijau. Analisis min mendapati semua item soalan bernilai melebihi 3.0, menunjukkan item-item tersebut boleh dikategorikan sebagai 'penting'. (iaitu semua item pada kedudukan utama). Analisis faktor dijalankan agar kesemua faktor cabaran dikelompokkan. Hasilnya hanya cabaran dan batasan kemahiran serta cabaran dan batasan kesedaran dapat dikelompokkan dan dipecahkan kepada dua komponen faktor. Kajian ini mencadangkan agar semua pihak perlu terlibat dalam membangunkan rancangan pembangunan. peraturan-peraturan, prosedur-prosedur, garis panduan khusus dan input-input untuk program akademik berkaitan konsep kelestarian dan juga elemen-elemen bangunan hijau jika hendak melaksanakan pembangunan hartanah secara lestari dengan berkesan di negara secara keseluruhannya.
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