Theses & Dissertations

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  • 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
    The direct and catalytic pyrolysis of rice straw
    ( 2010)
    Razi Ahmad
    A study of the catalytic pyrolysis on rice straw was carried out in a fixed-bed reactor. The work objectives were to determine the influences of pyrolysis parameters i.e pyrolysis temperature, heating rate and holding time on distribution of product yield. The optimization process was analyzed by employing central composite rotatable design (CCRD) in response surface methodology (RSM). The catalysts used in this research were zeolite ZSM-5 and dolomite. The catalytic pyrolysis was carried out based on optimized condition of bio-oil yield. The characterization of pyrolysis product between non-catalytic and catalytic pyrolysis were investigated, by elemental, spectroscopic and chromatographic techniques. The char yield produced from pyrolysis process was high at low heating rates, while the gas yield produced was high at higher temperature and longer holding time. The experimental value of the optimum bio-oil yield was 27.62% as compared to the predicted value which bio-oil yield was 27.87% at pyrolysis temperature of 450 oC, heating rate of 77.63 oC/min and holding time of 2.61 min by using optimization process in the Design Expert (DOE) software. The chemical characterization studies of uncatalysed bio-oil derived from pyrolysis of rice straw contained considerable amounts of carbonyl and oxygenated compound, resulting in higher oxygen content in elemental composition and low pH value. Used of zeolites ZSM-5 and dolomite caused an increase in gas yields and a decrease in bio-oil yields. The product yields and the quality of the produced bio-oil were affected by the used of catalyst. The major improvement in the quality of liquid product with the use of catalyst was the increase of phenol concentration (useful chemicals) and the reduction of some corrosive acids which are undesirable compound in bio-oil. Dolomite catalyst having the most impacts than zeolite ZSM-5 in removing some of aldehyde and ketone compounds which are responsible for the thermal or storage stability. The influence of the zeolite ZSM-5 and dolomite catalyst used in this study caused only enhancement of liquid production in terms of quality but not the bio-oil produced.
      2  29
  • Publication
    The effect combination of acid treatments for silicon carbide (SiC) production from rice straw
    ( 2011)
    Noridayu Ismail
    Rice straw is an abundant and low cost agricultural waste with is locally available. On the basis of this study, it is concluded that 96.45 % silicon carbide pre-cursor can be produced by the process of pyrolysis of rice straw at 1100 ºC with a holding time of 82.65 minutes and a flow rate of 2.00 L/min nitrogen. The SiC pre-cursor was produced without additional catalyst process, thus which can reduce the cost of the product. The most significant parameter that contributes to the highest yield of SiC pre-cursor is the holding time and the nitrogen flowrate. This outcome is important because of the short pyrolysis time and at low temperature will result in reduced manufacturing costs. The rice straw itself have a high percentage of inorganic compound material; which is SiO2, SO3, K2O, CaO, TiO2, MnO, Fe2O3, CuO, ZnO, Cl compared to the other acid treated samples and consecutive acid treated (CATS) samples. With the removal some of the inorganic compound such as ZnO and CuO will increase the percentage of the SiO2 produced. In the HCl acid treated samples which are a commonly used acid for the SiC production produce only SiO2 at 54.3 % compared to other treatments. In the H2SO4 acid treated samples, the SiO2 yield is at 65.8 % which is higher than HCl sample which can be believed it can be the choice of impurities removal but when compared to the citric acid (C6H8O7) the efficiency of sulphuric acid (H2SO4) are low because in the C6H8O7 the SiO2 percentage is the highest which is at 81 % but have the highest percentage of 2.98% Fe2O3. The Fe2O3 is an unwanted inorganic compound because the Fe2O3 can inhibit the process of SiC production thus, resulting the lower production value and SiO2. The consecutive acid treatment giving the essential result to produce SiC which is having the lowest value of Fe2O3 and also eliminate the ZnO and CuO and the C6H8O7 acid treated sample can be the second option to produce the SiC respectively. Regarding to leaching process it was found that acid treatment helped to reduce the level of inorganic compound, leading to higher purity of raw material with porous structure as confirm in FTIR analysis. The characterization results showed the possibility for production of silicon carbide with well-developed whiskers and crystal structure from rice straw by pyrolysis process in this experiment. With these it confirms that the CATS have a higher potential in SiC production with purity were found to be comparable to a moissanite -3C and acceptable in the market.
      3  22
  • 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.
      4  13
  • Publication
    Productionof catalytic and non-catalytic gases from pyrolysis of municipal solid waste (MSW)
    ( 2012)
    Tursunov Obid
    Municipal Solid Waste (MSW) is primarily waste produced by the household, but also includes some commercial and industrial waste that is similar in nature to household waste and has been deposited in municipal landfill site, causing multitude of harmful impacts to the environment and to human beings. Currently, recycling of MSW is an essential issue in many developed and developing countries like in Malaysia as well. One of the effective techniques for MSW recycling is pyrolysis. Pyrolysis is the degradation of macromolecular materials with heat in the absence of oxygen. It has both applied and analytical aspects. The development of advanced fast pyrolysis process for gas production has gained much attention in the last decade, because they offer a convenient way to convert low value MSW residues into gas yield and value-added products. In this study, pyrolysis process has been used for municipal solid waste recycling into renewable kind of energy. Pyrolysis offer more scope for recovering products from waste than incineration. When MSW is burnt in a modern incinerator the only practical product is energy, whereas the gases, oils and solid char from pyrolysis can be used as a fuel but also purified and used as a feedstock for petro-chemicals and other applications. In addition, catalyst in pyrolysis has been playing significant role to increase product yields. However, a few literatures were found on catalyst in pyrolysis process. This study focused on gas production from pyrolysis process of municipal solid waste by using three types of catalysts (zeolite, raw dolomite and calcined dolomite). Thus, this study focused on gases (HC, CO and CO₂) analysis from pyrolysis of municipal solid waste (MSW) with catalysts zeolite, four types of calcined (700⁰C/4h, 800⁰C/5h, 900⁰C/4h and 950⁰C/3h) and raw dolomite as catalyst, and also non catalytic pyrolysis of MSW. Calcined dolomite 950⁰C/3h and 800oC/5h were selected as suitable catalyst among others for CO and CO₂ production. Research project has been investigated in a “catatest” downstream fixed – bed reactor over the temperature range between of 30-750⁰C. Gas production from pyrolysis of MSW varied in the range of 35-57 mol%. The results indicated the presence of calcined dolomite influenced significantly the product yields and gas composition in pyrolysis process, and revealed essential catalytic performance on increasing gas yield and decreasing oil yield and char yield comparing to zeolite and non – catalytic pyrolysis process. A higher temperature of 550-750⁰C resulted in a higher conversion of MSW into gas production with a greatly increasing of CO and slight increasing of CO₂ contents.
      1  5
  • 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.
      4  12
  • Publication
    The potential of satellite imagery in soil compaction studies for implementation of precision farming
    ( 2013)
    Norasmanizan Abdullah
    The objective of this study is to evaluate the potential of satellite imagery and GIS (Geographic Information System) in soil compaction studies by investigating the spectral reflectance in producing soil compaction maps for implementation of precision farming. It analyzes the significant correlation between soil penetration resistance data and reflectance data of the Landsat 5 TM image. This study identifies the possible areas of soil compaction by analyzing the spectral indexes of moisture content (NDMI), vegetation indexes (SAVI,MSAVI) and soil index (BSI). The relationship between variables is investigated using coefficient of determination (R²). The results of gravimeter measurement showed had a significant relationship of water content level in soil compaction. Thus, NDMI reflectance data were studied and it was found that it had significant correlation (R²=0.755) with soil penetration data. Linear regression of SWIR channel indicated highest significant correlation (R²=0.84) with (p<0.05) compared to several channels visible band of Band 1, (R²=0.209) Band 2, (R²=0.142), Band 3, (R²=0.382) and Band 7, (R²=0.305). The expression of linear regression was used in predicting the compact area using Band Math function and the compaction status map was created using geostatistical method. The mathematical models of spectral indexes also indicated a correlation with the significant correlation of SAVI is (R²=0.724), MSAVI (R²=0.725) and BSI (R²=0.422). The combined information of the soil compaction map and space technology is valuable for farmers and growers in land treatment, tillage activities and consequently in the implementation of site specific agricultural management.
      3  18
  • Publication
    The production of lightweight aggregates using ordinary portland cement
    ( 2013)
    Hamizi Yahya
    The research study covers the production of lightweight aggregates using Ordinary Portland cement (OPC) without involved any heat treatment. The main aim of this research was to produce lightweight aggregate as artificial aggregate which can be used to replace natural aggregate such as granite in concrete. OPC, liquid Alkylbenzenesulfonates and rice husk were the main raw materials were used in this study in order to produce lightweight aggregate. The production processes of lightweight aggregate from OPC involved grinding, mixing of raw materials, agglomeration and curing process for binding of the particles. This study involved on the physical, mechanical and chemical properties of raw materials such as OPC, liquid Alkylbenzenesulfonates and rice husk. The effect of using liquid Alkylbenzenesulfonates and rice husk in lightweight aggregate on bulk density, percentage of water absorption, pore and texture, specific gravity and also microstructure of lightweight aggregates were examined. The raw samples were characterized by X-ray fluorescence (XRF) and the porosity of aggregate was examined by scanning electron microscope (SEM). XRF result showed that rice husk of highest contained of SiO2 equal to 56.3%. Lightweight aggregates LWARH produced from rice husk have low density equal to 761 kg/m3 indirectly will reduce the self weight of concrete but the strength only 9.80 MPa at 28 days. The best lightweight aggregates LWA obtained from this study consisted of OPC, 15% of liquid Alkylbenzenesulfonates, 15% of water and potential for further research study. Successfully test result obtained showed the lightweight aggregate LWA had aggregate bulk density of 1215 kg/m3 for coarse aggregates. The 24 hours water absorption for aggregate LWA was 8.48% and contained 0.001973mm2 area of porosity. Lightweight concrete LWAC was produced using the lightweight aggregates LWA. The compressive strength at the average of 28 days compressive strength was recorded as 20.39 MPa (20.39 N/mm2). This result successfully achieved the required compressive strength of lightweight concrete is 17 MPa at 28 days by ASTM C330 (2009). However, the bulk density equal to 2080 kg/m3 is not categorized as lightweight aggregate concrete by BS EN 206-1 (2000) because the bulk density is more than 2000 kg/m3 but only 4% higher.
      4  10
  • 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
    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).
      3  6
  • Publication
    Removal of dyes from industrial effluents using combination of Advanced Oxidation Processes (AOPs) and biological treatment
    ( 2014)
    Che Zulzikrami Azner Abidin
    Nowadays, the removal of dyes from industrial effluents is still far away to a satisfactory solution. Even though the AOPs are known strong technologies for wastewater treatment, it still requires further advancement and extent. Hence, a new promising treatment is their combination with biological treatment, by taking the advantages of the individual potentials. Therefore, this research evaluated four treatment techniques, namely ozonation, ozone/hydrogen peroxide (O3/H2O2), ultraviolet/hydrogen peroxide (UV/H2O2), and a combination of ozonation-biological for synthetic dyes, consist of monoazo Methyl Orange (MO), disazo Reactive Red 120 (RR120) and anthraquinone Reactive Blue 19 (RB19). Finally, the treatments are evaluated with batik wastewater as a real wastewater sample from industries. The finding revealed that ozonation, O3/H2O2, UV/H2O2, and ozonation-biological become an effective treatment for monoazo, disazo, anthraquinone, and real wastewater. The treatments accomplish, under appropriate conditions, a full decolourization and a substantial mineralization. However, O3/H2O2 and ozonation works well with the dyes, in contrast to UV/H₂O₂. It reveals that complete decolourization by ozonation and O3/H2O2, with less than 20 min contact. Two decolourization curves of ozonation and O3/H2O2 almost overlapped suggesting that H2O2 hardly affects decolourization rate. Contrariwise, it takes more than 60 min for complete decolourization with UV/H₂O₂ for RR120, but requires more than 120 min for MO and RB19. Nevertheless, there was a significant difference for COD and TOC removals. It is apparent that O₃/H₂O₂ showed higher removal, suggesting that the presence of H₂O₂ promote the oxidation reaction. The final COD removal of O₃/H₂O₂ reached 100% within less than 10 min for RR120 and RB19, while 15 min for MO. Likewise, the higher TOC removal was observed for O₃/H₂O₂ in comparison to ozonation and UV/H₂O₂. On the whole, the COD removal was similar to TOC removal for each treatment. It is obvious that high decolourization from the start of biological was contributed from ozonation pre-treatment. In addition, the results indicate that 59.6 and 69.4% COD removal from ozonation and ozonationbiological, respectively for MO. While, resulted about 40.7 and 72.9% removal for RR120, and 51.4 and 59.8% for RB19, respectively. Thus, it represents small organic molecules that contribute considerably to the COD that cannot be completely removed by ozonation-biological treatment. Similar to COD, the results indicate that 49.1 and 73.7% TOC removal from ozonation and ozonation-biological, respectively for MO. While it leads to 39.3 and 64.3% removal for RR120 and 37.5 and 70.8% removal for RB19, respectively. It is clear that the biological further degrades the dyes from ozonation. In addition, each dye shows different decolourization pattern and degradation behaviour according to its chemical structure. The change in UV-vis and FT-IR spectra indicated the evidence of dye structure cleavage and intermediates formation. While, the NO₃-, SO₄2- and Cl- anions formed indicate dye mineralization. The decolourization conform first-order kinetics, with R2 values greater than 0.92. The O₃/H₂O₂ performs better with the batik wastewater, as compared to ozonation and UV/H₂O₂. Therefore, the results for synthetic wastewater support its application for real wastewater, even though the batik wastewater was more difficult to be decolourized and degraded because of its complex composition.
      2  15
  • Publication
    Study on Photocatalytic mineralization of various azo dyes under solar light irradiation
    ( 2014)
    Wan Fadhilah Wan Mohd Khalik
    Azo dyes represented by azo chromophores (-N=N-) are the largest class of dyes used in many industries especially textile industries. Other chemicals that mutagenic or toxic to the environment and human life will present in the water bodies if the wastewater effluent from industries was released without treating them properly. There are many conventional treatment methods in order to remove azo dyes in wastewater, for example adsorption, membrane filtration, aerobic or anaerobic process and others. However, these conventional treatment methods required high cost and generated other pollutants which difficult to be destroyed. In order to minimize the cost for wastewater treatment but effective in removal of azo dye, solar photocatalytic had been discovered by previous researchers. Therefore, the main purpose of this research was to evaluate the mineralization of various azo dyes by solar photocatalytic process. The main photocatalyst and azo dye used in this study was zinc oxide (ZnO) and New Coccine (NC), respectively. In the first section, the study was to compare the solar photocatalytic between decolorization of Orange G and New Coccine. The comparison between the azo dyes was determined through several operating parameters such as with and without solar light irradiation, initial dye concentration, catalyst dosage, pH and with and without aeration. The results showed that concentration NC decreased rapidly in each parameter and almost achieved 100 % removal efficiency compared to OG. The second section in this study was to evaluate the effect of molecular structure of five azo dyes (Acid Orange 7, Orange G, New Coccine, Reactive Black 5, Reactive Green 19) in photocatalytic mineralization under solar light irradiation. Among these azo dyes, Reactive Green 19 showed great performance in photocatalytic process and achieved 100 % of removal efficiency under solar light irradiation. Moreover, this study also focused on the effectiveness of other photocatalysts (CuO, Fe₂O₃, TiO₂) on the degradation of dye and showed that photocatalyst with higher band gap (ZnO) rapidly decolorized and mineralized the azo dye. The surface area and patterns of all photocatalysts were also examined. The reduction in dye concentration was determined by UV-Vis spectrophotometer. The mineralization of dye was examined by ion chromatography (IC) and chemical oxygen demand (COD) measurement. The final concentration of New Coccine achieved 100 % removal after 5 h irradiation time. Among all the photocatalysts, ZnO showed highest removal which suggesting that it absorbs large fraction of the solar spectrum and absorption of more light quanta. Batik wastewater also showed great color removal within 10 h sampling and its COD concentration decreased from 1332 mg/L to 286 mg/L after 12 h irradiated time. Both of azo dyes and photocatalysts followed pseudo-first-order rate constant and well fitted the Langmuir-Hinshelwood kinetic model. In conclusion, either synthetic dye or real textile wastewater, both of them can be degraded and mineralized by photocatalyst with presence of solar light.
      2  21
  • Publication
    Solar-photocatalytic of zinc oxide for mineralization of Phenol
    ( 2014)
    Nik Noor Athirah Nik Yusoff
    There are increasing concerns on the significant of phenols as an organic contaminant from industrial wastewater such as pesticides, coal conversion, polymeric resin, petrochemical industry, pharmaceutical and oil refinery industries. Phenols can be threatening to human being and ecosystems due to its biorecalcitrant and acute toxicity behavior. There are some limitations for phenols treatment via conventional wastewater treatment such as in biological treatment, a longer time which is required; membrane treatment is expensive and another pollutant are generated via activated carbon treatment. Zinc oxide (ZnO) utilization in Advanced Oxidation Process (AOP) via solarphotocatalytic process was a promising method for treating wastewater containing phenol. The photocatalytic degradation of phenol was investigated with zinc oxide (ZnO) as photocatalyst under solar light irradiation. Operating parameters such as initial phenol concentration, catalyst loading, pH, effect of aeration, H2O2 dosage and effect of solar light irradiation were investigated. The low initial concentration of phenol indicates more efficient photocatalytic degradation. The optimum catalyst loading to provide sufficient active site for the photocatalytic activity is 0.6 g. While, the optimum pH condition is in acidic condition as it show a better performances than in alkaline condition. The photocatalytic activity improved with aeration and the photodegradation rate is 14.325 mg L-1 h-1 . Besides that, the addition of 0.1 M H2O2 also enhanced the degradation of phenol. The results obtained fitted well with Langmuir-Hinshelwood kinetic model. Analysis of UV-VIS and chemical oxygen demand (COD) attested the complete degradation of phenol concentration and possibility for mineralization. The environmental friendly ZnO photocatalyst semiconductor was synthesis by precipitation (ZnO-P), hydrothermal (ZnO-H) and sol-gel (ZnO-S) method. The morphologies of the photocatalyst were observed by SEM showed the morphology of ZnO-P and ZnO-H are pseudo-spherical shape with sizes of 20 nm until 130 nm. While, an irregular shape with sharp edges was observed for ZnO-S. The particles sizes of 110-400 nm were obtained for ZnO-S. The results from XRD analysis interestingly indicate all the characteristic peaks observed in synthesized ZnO are in a good agreement with the pure ZnO standard pattern taken from the Joint Committee of Powder Diffraction Standard (JCPDS) card No. 36-1451. The XRD patterns of all photocatalyst are the same with different intensity indicates different crystallite sizes. Particularly, the strongest characteristic peaks were described at 2θ 36.24 °, 36.31 °, and 36.32 ° for ZnO-P, ZnO-H and ZnO-S, which correspond to plane (1 0 1). The peak indexed as hexagonal with space group P63mc (186). Thermal analysis suggested the ideal calcinations temperatures are within range of 350 °C until 400 °C. The destruction of hydrocarbonate (OHˉ and CO 3 2ˉ) takes place at temperature 370 °C and 73.08 % of ZnO-P, 74.52 % ZnO-H and 72. 41 % ZnOS weight left. The decomposition of the ZnO precursor was complete at this temperature and can be considered as the optimum calcinations temperature for synthesized process. No further weight loss was observed from 430 °C until 800 °C. This plateau indicates the formation of the ZnO as a decomposition product. The comparison of photodegradation showed that the photocatalytic performances of all five tested photocatalyst could be arranged as ZnO-C > ZnO-S > ZnO-P > ZnO-H > TiO2. The finding of this study was described in Langmuir-Hinshelwood model. The apparent rate constant is proportional to the efficiency of the photocatalyst. Further research to evaluate ZnO photocatalyst would be of great help in developing the semiconductor solar-photocatalytic treatment which are currently still in an experimental phase worldwide. Hence, pilot plant design can be a good start to study the application of ZnO as photocatalyst in real wastewater treatment.
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  • 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
    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
    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
    Synthesis, characterization and performance study of Calcium Oxide catalyst from waste eggshell for Pyrolysis of empty fruit bunch
    ( 2016)
    Rohazriny Rohim
    Catalytic pyrolysis of empty fruit bunch with eggshell waste catalyst were conducted in this studied to synthesized calcium oxide catalyst from waste eggshell, to investigate the physical and chemical properties of calcium oxide catalyst, and to characterize and evaluate the performance of bio-oil from catalytic pyrolysis. Calcination process was conducted in tube furnace at temperature of 900 °C for 1 hour for converting the calcium carbonate to CaO in the eggshell. Elemental composition, crystallite structures, and morphological structures were performed for characterization of eggshell while ultimate and proximate analysis, heating value, and thermogravimetric analysis was performed for characterization of biomass. Catalytic pyrolysis was conducted by different parameters such as temperature, heating rate, holding time and catalyst loading to study the effect of pyrolysis parameters on oil yield. Optimization was performed by Design Expert 7.1 Software. Oil yield were analyzed in order to determine the quality of oil. High oil yield were obtained at temperature of 400 °C, heating rate of 80 °C/min, holding time at 4 min and 10% of catalyst loading. For temperature parameter, oil yield was increased by 14%, while gas yield reduced by 13.7% and char yield reduced by 0.3%. For heating rate, oil and char yield was increased by 15.4% and 3.9%, respectively, while gas yield decreased by 19.3%. Meanwhile, for holding time parameter, the oil and gas yield was increased by 10.4% and 13.1%, respectively while char yield decreased by 23.5%. The oil and char yield increased by 14.7% and 9.6%, respectively after the addition of eggshell catalyst. However, gas yield reduced by 24.3%. Meanwhile, from optimization studied, high oil yield were obtained at temperature of 434.63 °C, heating rate of 76.03 °C/min, holding time at 2.55 min, and 8.02% of catalyst loading, with predicted bio-oil yield was 31.81%. Confirmation runs were performed by using the same conditions and gave an average of 31.41%. Analysis from FTIR and GCMS showed that most of oxygenated and nitrogen compound were reduced after the addition of catalyst such as carboxylic acids, amide, amines and ketones compound while hydrocarbon and phenols were increased.
      4  4
  • Publication
    Ozonation and advanced oxidation process of wastewater containing azo dye
    ( 2016)
    Nazerry Rosmady Rahmat
    Ozonation (O3) and AOP involving O3/H2O2 have been considered as an emerging technology for degradation of dyes in textile and dyestuffs industrial effluent. However, the comparative performance of these processes for dye removal is remains unclear. Therefore, the performance of O3 and O3/H2O2 processes for azo dye removal in industrial effluent was evaluated in this study. The specific objectives of the research are to compare the performance of O3 and O3/H2O2 processes for colour, COD and TOC removal, and to evaluate the effect of initial concentration and initial pH on the performance of O3 and O3/H2O2 processes. The dyes used were Reactive Black 5 (RB5), Remazol Brilliant Blue (RBB), Reactive Green 19 (RG19) and Reactive Red 120 (RR120). The experiments of O3 and O3/H2O2 processes were conducted in a semibatch reactor originated from cylindrical glass reactor. The result shows that the colour removal of RB5, RBB, RG19 and RR120 in O3/H2O2 treatment was slightly higher than O3 treatment for ozonation time less than 5 minutes and the comparison value approximately only 0.5 %. Moreover, complete colour removal was achieved for ozonation time more than 5 minutes in both processes. The significant removal efficiency of both O3 and O3/H2O2 processes showed that both processes are efficient for colour removal of reactive dyes.
      2  4
  • Publication
    Understanding the electrochemical reduction of carbon dioxide into formate using a tin-plated cathode
    ( 2016)
    Tan Tiek Aun
    Sn has been a research interest for its ability in converting CO2 into its reduced form very efficiently and at a relatively low energy cost. However, a complete and exhaustive study for the usage of Sn in electrochemical reduction of CO2 still does not exist. Researchers often provide conflicting reports on the role of variables such as cathodic CO2 transport or electrolyte pH. Cathode degradation also has been reported by various researchers in literature but however, disagreement as to the cause of the degradation exists. This thesis presents a fundamental study on the electrochemical reduction of CO2 into HCOO¯ HCOO¯ using a tin plated electrode. Sn was successfully deposited on glassy carbon electrode satisfactorily with a good even surface. The Sn plated electrodes are mechanically stable and give reproducible electrochemical characterizations. The produced Sn electrode is used to investigate the effects of cathode rotating speed, electrolyte pH, and applied cathode potential on the Faradaic efficiency for HCOO¯. A higher cathode rotating speed is detrimental to the HCOO¯ Faradaic efficiency. CO2 molecules entering the reactor have shorter residence time at higher cathode rotating speeds and some leave without undergoing electrochemical reaction. Basic conditions are preferable for CO2 reduction to HCOO¯. H2 evolution is prevalent at low pH due to the high amount of available [H+] to be reduced. HCO3¯ may have contributed as a precursor chemical for the formation of HCOO¯. The Faradaic efficiency for producing HCOO¯ increases until it tapers off to a maximum at -1.75 V vs SCE. When the potential is made negative further, the Faradaic efficiency decreasesdue to the enhancement of H2 evolution which is consistent with literature. The Sn plated electrode was found to degrade and strip off during electrochemical reduction likely due to mechanical stress caused by hydrogen embrittlement. When the electrolyte is basic, it is possible that when the Sn-CO2 is formed, the bond between the two does not always break afterwards and thecomplex is brought into the bulk electrolyte. Sn is a potential selective cathode material in electrochemically reducing CO2 into HCOO¯. The roles of several, select, important variables have been made clear for the benefit of future studies. Future studies will also be made aware of the Sn degradation with time during electrochemical reduction.
      2  5
  • 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.
      5  2