Theses & Dissertations

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https://hdl.handle.net/20.500.14170/201

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Now showing 1 - 5 of 51
  • Publication
    Assessment and prediction of PM₁₀ concentration during haze event in Malaysia using quantile analysis
    (Universiti Malaysia Perlis (UniMAP), 2024)
    Nur Alis Addiena A Rahim
    Haze event in Malaysia occurs typically during the summer monsoon season. Consequently, high atmospheric particles, particularly PM₁₀, were recorded mainly by transboundary air pollution from the neighboring country, affecting human health and the environment. The air pollutants were widely forecasted in various studies previously, especially PM₁₀. However, there was a lack of research conducted specifically during haze events. Therefore, this research aims to develop a reliable modified quantile regression (QR) forecasting model for the next-day (PM₁₀+24), the next-two-day (PM₁₀+48), and the next-three-day (PM₁₀+72) of PM₁₀ levels during a haze event. The development of a PM₁₀ prediction model specifically for haze events play a crucial role in managing and mitigating the impacts of haze on society, making them as essential tools in air quality management and decision-making. Hourly PM₁₀, air quality parameters, and weather parameters datasets at Klang, Melaka, Pasir Gudang, and Petaling Jaya during historical haze events in 1997, 2005, 2013, and 2015 are obtained from the Department of Environment (DOE) Malaysia. The locations were chosen due to their susceptibility to pollution transported from the Sumatra region, being situated on the west coast of peninsular Malaysia Peninsular. The mean value for each year at all location exceeded the Recommended Malaysian Ambient Air Quality Standard (RMAAQG), except for at Pasir Gudang in year 1997 and 2005, where the mean recorded are 47.72 and 46.59 μg/m3, respectively. Three feature selection methods (weight by Relief, weight by correlation, and weight by principal component analysis (PCA) along with quantile regression (QR) and multiple linear regression (MLR) were implemented in this study. The performance of modified QR model was evaluated by using several performance indicators namely Root Mean Squared Error (RMSE), Mean Absolute Error (MAE) and Normalized Absolute Error (NAE). The modified QR model i.e. QR-Relief, QR-PCA and QR-Correlation models were proven as the best method at all locations and prediction time. In Klang, QR-Relief was chosen for PM₁₀+24 (with percent reduction error of approximately 21.5%) and PM₁₀+72 (with percent reduction error of 11.6%) meanwhile for PM₁₀+48 prediction, the QR-Correlation was selected with percent reduction error of 17.4%. QR-PCA was chosen as the best prediction model for all three days predictions in Melaka with error reduced by 2.08%, 0.69%, and 0.88%, for PM₁₀+24, PM₁₀+48, and PM₁₀+72, respectively. In Pasir Gudang, QR-Relief performed the best for all three days predictions with error reduced by 27.6% until 31.1%. In Petaling Jaya, QR-Relief outperformed other models for PM₁₀+24 (with percent error reduction of 16.5%). Meanwhile, QR-Correlation is the model with the best performance for PM₁₀+48 (with error reduced by 10.9%) and PM₁₀+72 (with error reduced by 15.9%) in Petaling Jaya. Feature selection helps identify and include only the most relevant variables in the model which eventually improve the models accuracy. The verification of the models using the unseen dataset from 2019 proved that the model can be deployed in the real-world PM₁₀ data. This proposed model can be used as a tool for early warning alerts to the local authorities to mitigate and plan preventive measures.
  • Publication
    Removal of azo and anthraquinone dye from textile wastewater using ozone-based advanced oxidation processes
    (Universiti Malaysia Perlis (UniMAP), 2018)
    Siti Nasuha Sabri
    Ozonation (OJ) and advanced oxidation processes (AOPs) involving ozone in combination with persulphate (OJIS2082-) has been considered as an emerging technology to treat dyes and dyestuff industrial effluents. However, the performance of dye removal remains unclear. Therefore, this research aim to evaluate the performance of two treatment methods by employing OJ and OJ/S2082- for synthetic dye wastewater, consist of azo Reactive Red 120 (RR120) and anthraquinone Reactive Blue 19 (RB 19). The main objective of the research are to compare the performance of 0 3 and 0 3/S2082-processes for colour, and chemical oxygen demand (COD) removal for two different types of dye. The experiments of 0 3 and OJIS2082- process were conducted in a semibatch reactor originated from cylindrical glass reactor. For better understanding of the treatments, the research focused on the most significant parameter that govern the treatments such as initial dye concentration, contact time, pH and S2082- dosage. Furthermore, the performance is compared by evaluating the key parameters such as colour and COD. The degradation and oxidation products are characterized based on the change in ultraviolet-visible (UV-Vis) and Fourier transforms-infrared (FT-IR) spectra. In addition, the optimization of process parameters was performed by Design Expert 7.1 Software. This study has found that, the OJ/S2082- advanced oxidation treatment provides good performances in the colour removal of the RR120 in water. The change in the UV-Vis and FT-IR spectra indicated the cleavage of the dye structure and formation of intermediates. The initial S2082- dosage, dye concentration and pH play an important role in the generation of hydroxyl and sulphate radicals for the dye degradation. The results of this investigation show that, the decolourisation was strongly depending on initial S2082 dosage. The decolourisation efficiency increased with increasing S2082- dosage and reaction time. While, decolourisation efficiency decreased with raising the initial dye concentration.
  • 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
    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.
      29  6
  • Publication
    Recycling of municipal solid waste incineration ash as raw material in cold-bonded lightweight aggregate
    ( 2021)
    Norlia Mohamad Ibrahim
    This study focusses on the development of new lightweight aggregate (LWA) that eventually have comparable properties with existing natural aggregate which is granite. The main objective of this study is to examine potential use of recycled municipal solid waste incineration (MSWI) ash as raw material in LWA production with a method of cold-bonded pelletization process. The ashes are collected from Cameron Highland Incineration Plant, Malaysia that can be divided into bottom ash (BA) and fly ash (FA). The properties of BA and FA are studied by means of X-Ray Fluorescence (XRF), Scanning Electron Microscope (SEM) and apparent density test. The LWA is denoted as bottom ash lightweight aggregate (BALA) and fly ash lightweight aggregate (FALA). Both BALA and FALA have experienced two different curing process for 28 days namely room-room (RR) and room-water (RW) curing conditions. The percentage of BA and FA used in this study were 10 %, 20 %, 30 %, 40 % and 50 % of partial cement replacement and the size of aggregate is fixed between 10 mm to 20 mm with circular shape. The properties of BALA and FALA produced in this study is examined including loose bulk density, water absorption, aggregate impact value (AIV) and specific gravity. Other physical properties including colour and texture are also being investigated. Potential use of BALA and FALA in concrete is investigated by selecting optimum samples of both aggregates to be incorporated in the manufacturing of semi-lightweight aggregate concrete (SLWAC). 30 specimens of SLWAC were produced having water-cement ratio of 0.5 and percentage of aggregate replacement is fixed at 20 %. Characteristics of SLWAC were examined including workability, density, water absorption, capillary water sorption, ultra-pulse velocity (UPV), compressive strength and permeability. Distribution of BALA and FALA in SLWAC is examined through cut-section of concrete. From the results of LWA it is clearly seen that 20 % BA and 20 % FA were the best percentage of ash used to produce good quality LWA. Loose bulk density of BALA selected is 739.53 kg/m3 with water absorption 20 % and AIV 13.94 %. Meanwhile, for FALA, optimum percentage is as follows; loose bulk density 716.72 kg/m3, water absorption is 19.7 %, AIV 13.80 % and specific gravity 1.670. However, for SLWAC, the results show that by incorporating BALA and FALA in the concrete improved the workability of concrete. The obvious impact due to the reduction of loose bulk density in LWA can be evident by the reduction of apparent density of SLWAC. Compressive strength of FASLWAC is comparable with NWC. Well-distributed BALA and FALA in concrete specimens is believed to contribute to the properties of SLWAC.
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