Conference Publications

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Nur Liza Rahim

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Samsudin S.

Coal bottom ash (CBA) is a co-combustion product material, which may cause hazards to human health and the environment. Rapid growth in technology causes the increase of CBA waste and this situation led to a waste disposal crisis. Reuse waste material as an alternative material instead of natural materials can led to sustainable and environmentally friendly construction. The main objective of this study is to determine the physical properties of CBA and its suitability to be used as replacement material in civil construction. The physical properties test conducted in this research were aggregate impact value test, aggregate crushed value test, flakiness and elongation test. The results show that the ability of CBA to resist sudden shock and repeated load was lesser than natural aggregate (NA). The differences of aggregate impact value (AIV) and aggregate crushing value (ACV), between NA and CBA were 50.4% and 48.9%, respectively. In addition, CBA has higher amount of flaky and elongated particles compared to NA. The flakiness index value for NA and CBA were 7.12% and 26.10%, respectively while the difference value of elongation index between NA and CBA was 37%. However, even though the properties of CBA were not as good as NA, the results for ACV and the flakiness index of CBA meet the minimum requirement of Jabatan Kerja Raya (JKR) Standard Specification which indicates that CBA has potential to be used in civil construction.

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Publication

Effect of bottom ash and limestone on the optimum binder content in Hot Mix Asphalt (HMA)

( 2022-01-01)

Nur Liza Rahim

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Syakirah Afiza Mohammed

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Noor Aina Misnon

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Nurhidayah Hamzah

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Christina Remmy Entalai

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Deák György

One of the most effective and simplest methods to minimize waste as well as reduce the environmental problems associated with waste disposal is by utilizing waste materials as a cement replacement in hot mix asphalt (HMA) mixtures which can provide the same or better stability as the conventional method. Fillers play an important role in the stability and strength of the pavement by filling voids between the aggregate particles in the performance of the HMA mixture. This research investigated the effect of the utilization of different types of filler (bottom ash and limestone) on the optimum binder content of HMA. Flow, stability, stiffness, air void in mix (VIM) and void filled with bitumen (VFB) were determined using the Marshal Method test in order to determine the optimum binder content of HMA for all mineral filler. The results of the Marshall test for each filler have been compared with the JKR standard specification. The optimum binder content for bottom ash, limestone and Ordinary Portland Cement (OPC) was 5.42%, 5.65% and 5.54%, respectively. All values of mineral filler used meet the JKR standard specification, where the range is between 4 and 6%. From the result achieved, the bottom ash has the lower optimum binder content value compared to the limestone and OPC. When the lower binder content is used in the bituminous mixture, the cost for pavement construction will be reduced.

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Publication

Influence of Cement Paste Containing Municipal Solid Waste Bottom Ash on the Strength Behavior of Concrete

( 2022-01-01)

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Nur Liza Rahim

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Khairul Nizar Ismail

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Ainaa Syamimi Abdul Hamid

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Boboc M.

Cement in construction has become a vital requirement to build up the buildings, which may increase the expenses in construction. Materials that have the potential to replace cement would be proposing. This study used municipal solid waste incineration bottom ash (MSWIBA) as a partial replacement for cement. MSWIBA used in this study was a by-product from the incineration process and had compound content that was almost the same as cement. The treated bottom ash in the range of 0 to 30% and 10% of untreated bottom ash mixture use in this study. Mechanical and physical properties of concrete analysed with a few tests such as slump test, water absorption test, compressive strength test, heat exposure test and residual strength test after heating has proceeded. The workability of fresh concrete was measured by performing a slump test. Based on the compressive strength result, the 10% substitution of treated bottom ash was achieved the highest strength in testing in 7 and 28 days. Meantime, the control concrete obtained the best thermal insulator because of a smaller number of cracks on the surface of the concrete than that bottom ash concrete surface. After heated, the concrete was tested on compressive strength again to investigate the residual compressive strength. The highest residual surpasses gained by 10% bottom ash (treated) as a partial substitution in cement. Based on the overall test carried out, 10% of bottom ash replacement as cement is the optimum amount of bottom ash required to surpass the strength of the control sample.

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Publication

Influence of Glucose Supplementation on the Organic Removal and Biomass Growth in Anaerobically Digested Vinasse (AnVE) by Using Aerobic Sequencing Batch Reactor (SBR)

( 2022-01-01)

Kee Wei Chin

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Wong Yee Shian

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Ong Soon An

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Nabilah Aminah Lutpi

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Sam Sung Ting

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Audrey Chai Yee Chieh

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Deák G.

This paper analyses the effect of glucose supplementation in the treatment of anaerobically digested vinasse (AnVE) through reduction performance and biomass growth by using aerobic SBR system. The result revealed that the COD and ammonium reduction with the addition of glucose supplementation (65.3 ± 6.0 and 30.0 ± 5.5%) was greater than the reactor without glucose supplementation (23.6 ± 10.8 and 18.7 ± 6.0%). This can be due to the additional glucose as the carbon source for microbe metabolism nutrients. The biomass growth in the reactor with glucose supplementation increased rapidly over time, while there was no obvious biomass growth shown in the reactor without the addition of glucose. It is because glucose supplementation increased biomass accumulation in biomass production. The increment of biomass in the reactor with glucose supplementation can be further explained by the F/M ratio and biomass yield. The F/M ratio reduced when the biomass growth increased. Thus, the biomass yield started to decrease after the operation in week 2, until it reached maximum biomass growth. Therefore, it concluded that the addition of glucose supplementation in the treatment of AnVE showed a positive effect on the removal performance and biomass growth by using aerobic SBR.

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Publication

Influence of rice husk ash (RHA) on performance of green concrete roof tile in application of green building

( 2020-06-10)

Khairunnisa Muhamad

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Norrazman Zaiha Zainol

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Norhaizura Yahya

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Siti Nur Aishah Mohd Noor

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Nurul Huda Hashim

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Danial Zikry Shahrazi

This paper studies on the development of green concrete roof tiles by using rice husk ash (RHA) as a partial replacement of cement as a green material. Rice husk is a product of agricultural waste that can be found easily and in large quantities due to increased annual paddy production in Malaysia. Demand for cement in construction has increased over the years as a result of over dependence on the modern building materials, which are so expensive that low income earners cannot afford building houses of their own. Besides, the satisfaction of building users is closely related to thermal comfort which is a complex dynamics of temperature and humidity. In this study, cement was replaced by the RHA at 0% until 20% by weight. Roof tiles performance were assessed based on Malaysian Standard (MS) requirement comprised of transverse strength, water absorption and water permeability. Results show that up to 10% of RHA give a good performance of concrete roof tiles which comply with Malaysia Standard.

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Publication

Influence of superplasticizer on performance of cement - Bottom ash concrete

( 2020-06-10)

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Khairul Nizar Ismail

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Azmi N.J.

The issue related to disposing waste material from industries has become one of the major environmental, economic and social problems. However, natural resources consumed worldwide, while at the same time increased amount and type of the waste material has resulted in waste disposal crisis with a growing consumer population. Therefore, the solution to this crisis is recycling waste into useful materials. In this project, Municipal Solid Waste Incineration (MSWI) by product which is bottom ash is used as partial replacement in cement. However, its properties as water absorbent become the issue for concrete strength. This research paper is to investigate the influence of superplasticizer on performance of cement-bottom ash concrete and designed for strength of 20 MPa at 28 days will be evaluated for its early stage properties. Superplasticizer is used to reduce water in cement while keeping up a consistent workability. The percentage of replacement in cement is by 0% (control), 10% and also 10%, 20% and 30% with addition of 0.30% by weight of cement of superplasticizer. In order to achieve the objective, few tests were carried out including slump test, density test, water absorption test and compression test. The result of this research indicates that 10% of replacement of bottom ash with superplasticizer shows highest compressive strength with 33.215 MPa with density 2417 kg/m3, water absorption of 1.41% and 122 mm for slump loss at 28 days. This study proved that the addition of superplasticizer can increase the workability and strength of concrete containing bottom ash as replacement for cement.

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Publication

Influence of Worker's Attitude and Communication Skill towards Safety Performance in Construction Site

( 2020-06-10)

Norrazman Zaiha Zainol

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Mohd Zulham Affandi Mohd Zahid

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Muhammad Munsif Ahmad

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Zawin Najah Zailani

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Mohd Badrul Hisyam Ab Manaf

The construction site is one of the most hazardous working places with numerous sources of hazards and potentially high risk to deals with. Typically, the main sources of hazards are unsafe condition and unsafe act by the human. Eventually, both sources related to human errors which potentially have an effect on the performance of the site. To reveals the underlying, this study aims to determine the influential factors that governed the success of safety performance of a construction site. The study involved a self-administered three-part questionnaire among the construction personnel. Part A measures the workers' attitude and safety performance while Part B on communication skills. The respondents randomly selected from construction sites range from school building and infrastructure renovation. The sample size was 113. From the survey, it was found that the most influential factor was the worker's attitude and followed closely by communication skills. Suggestion and recommendations on equipment design and improved work practices and procedures to improve efficiency and productivity of construction workers were proposed. Management was urged to get their workers better informed about safety matters.

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Publication

Iron removal efficiency in synthetic Acid Mine Drainage (AMD) treatment using peat soil

( 2022-01-01)

Mohd Syazwan Mohd Halim

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Abdul Haqi Ibrahim

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Suhaina Ismail

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Ku Esyra Hani Ku Ishak

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Moncea Andreea

Acid mine drainage (AMD) formation is due to the sulfide minerals reaction either chemically or biologically when exposed to atmospheric conditions. The AMD formation often occurred in the region involved with anthropogenic activities, including mining, agricultural plantation, urban development and logging. Treatment of AMD is a challenging part of most mining operations around the world. Selection of method treatment is crucial depending on the area’s geological, mineralogical, topography and AMD characteristic. There are two types of method treatment; active and passive treatment method. In this study, passive treatment method was adopted; which is successive alkalinity producing system (SAPS). The study aims to analyze effect of variable parameters on iron (Fe) concentration and propose optimum operating condition for AMD treatment. Peat soil and limestone aggregate was used as treatment media in treatment tank. Synthetic AMD was formulated using sulphuric acid (H2SO4) and iron sulfate (FeSO4) to represent actual AMD. Once the synthetic AMD was introduced, water samples were collected and analyzed using UV–Vis test after 6 to 48 h’ retention time. Based on the analysis, the proposed methodology has successfully reduced more than 85% iron content only after 6 h of retention time. The maximum Fe removal percentage recorded was 95%, using the higher peat soil depth configuration. The statistical analysis results show that the optimum operating condition for SAPS with high Fe removal is using high peat soil depth. Experiments with higher peat soil depth provide satisfactory results in treating the high initial Fe concentration regardless of the retention time for the AMD treatment.

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Publication

Life cycle assessment of expanded polystyrene

( 2021-01-26)

Lim Y.S.

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Irnis Azura Zakaria

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Sara Yasina Yusuf

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Siti Khadijah Za'aba

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Mohamad M.A.

Expanded polystyrene (EPS) is one of the most common materials used in packaging. In Malaysia, EPS is a type of plastic which is not in the recycling category. Usually, EPS wastes will end up in landfill and incinerator, leading to severe environmental impacts. Therefore, a cradle-to-grave life cycle assessment (LCA) study of EPS was carried out to investigate the potential environmental impacts of EPS. The most significant potential environmental impact will also be identified. Both will be identified under 2 different scenarios. The study was analyzed using GaBi Education Software with the method of TRACI 2.1 to the environmental indicators of global warming potential (GWP), acidification potential (AP), eutrophication potential (EP), and ozone depletion potential (ODP). In scenario 1, the emission percentage for GWP, AP, EP, and ODP are 99.73 %, 0.21 %, 0.06 %, and 3x10-6 %, respectively. As for scenario 2, all the 3 conditions show similar trend with scenario 1. The LCA study of EPS is particularly focused on the manufacturing, distribution, and the end-of-lifetime treatments, with the introduction of recycling into the system. The findings show that manufacturing of EPS is the major contributor of the environmental impacts and GWP contributes to the most significant potential environmental impacts. Overall, recycling was found to have the least impact to the environment, which possibly be used as the new end-of-lifetime treatment of EPS in Malaysia.

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Publication

Optimization of copper adsorption from synthetic wastewater by oil palm-based adsorbent using Central Composite Design

( 2020-06-10)

Wong H.W.

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Naimah Ibrahim

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Muhammad Adli Hanif

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Norazian Mohamed Noor

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Sara Yasina Yusuf

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Masitah Hasan

Oil palm empty fruit bunch (EFB) was chemically activated by phosphoric acid and heat treatment to produce porous activated carbon (AC) for adsorption of copper ions from synthetic wastewater using static batch test. Copper adsorption process was optimized using Response Surface Method (RSM) by varying four operating parameters i.e. pH (A), initial concentration (B), adsorbent dosage (C) and contact time (D) through a quadratic model developed based on Central Composite Design (CCD) approach. Within the tested parameter range, copper adsorption was found to be at optimum condition at pH 5, initial concentration of 200 mg/L, adsorbent dosage of 0.55 g per 200 mL copper solution and contact time of 2.5 hours, yielding 52.5% of copper removal. A good agreement was achieved by comparing the predicted model with experimental data (R2=0.9618). All four operating parameters tested are significant in affecting the adsorption process, with pH being the most significant with an F-value of 171.70. The interaction between pH and initial concentration (AB) has the most significant interacting effects (F-value of 18.30), while quadratic effects of pH (A2) and adsorbent dosage (C2) are most significant with F-values of 62.80 and 42.58 respectively.

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Publication

Performance of two phase anaerobic digestion on food waste for biogas production

( 2022-01-01)

Irnis Azura Zakaria

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Siti Khadijah Za'Aba

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Nur Adlina Mohd Hilmi

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Mohammad Rizam Che Beson

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Monica Matei

Every year, the total amount of solid waste generated in Peninsular Malaysia grew, according to the Malaysia government. The typical solid waste management system practiced in developing country brings many problems that can cause risks and hazards for living things and the environment in Malaysia if there are not managed properly. For example, illegal dumping cause groundwater and soil pollution. The methane gas produced from the landfill causes greenhouse effect. Food waste is categorized under household waste, where it is produced in residential areas, restaurants, cafeteria, markets and commercial areas. Therefore, anaerobic digestion process is introduced for organic waste with higher solids contents such as food waste as an alternative method. The effectiveness of anaerobic digestion process can be investigated through this process. In this study, two phase of anaerobic digesters was proposed. The reactor was operated at a temperature 35 °C, analyzed for biogas production, pH values and C/N ratio. The highest biogas production in this study is 50.4%. For a co-digestion containing more sludge can increase the pH value and biogas production.

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Publication

Preliminary screening oxidative degradation methyl orange using ozone/ persulfate

( 2018)

Nur Aqilah Razali

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Che Zulzikrami Azner Abidin

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Ong Soon An

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Fahmi Muhammad Ridwan

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Abdul Haqi Ibrahim

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Siti Nasuha Sabri

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Su Huan Kow

The present study focusing on the performances of advanced oxidation process by using ozonation method towards Methyl Orange based on the efficiency of colour removal and Chemical Oxygen Demand (COD) removal. Factorial design with response surface methodology (RSM) was used to evaluate the interaction between operational conditions, such as pH, initial concentration, contact time and persulfate dosage to obtain the optimum range conditions using a semi-batch reactor. The range of independent variables investigated were pH (3-11), initial concentration (100-500mg/L), contact time (10-50min) and persulfate dosage (20-100mM) while the response variables were colour removal and COD removal of Methyl Orange. The experimental results and statistical analysis showed all the parameters were significant. Thus, from this findings, optimization of operational conditions that had been suggested from the ozone/persulfate RSM analysis were (pH 3, 100 mg/L, 50min, 60mM) that would be produced 99% Colour Removal and 80% COD Removal and help in promoting an efficient ozonation process. The effect list data that showed the most contributed effects to increase the percentages of colour removal were pH and persulfate dosage whereas the contact time and initial concentration had the highest positive effects on the COD removal. Other than that, the interaction between pH, contact time and persulfate dosage were found to be the most influencing interaction. Therefore the least influencing interaction was interaction between persulfate dosage and pH. In this study, the correlation coefficient value R2 for colour removal and COD removal of Methyl Orange were R2= 0.9976 and R2= 0.9924 which suggested a good fit of the first-order regression model with the experimental data.

Publication

Processing, tensile and morphological characteristics of polylactic acid/chitosan biocomposites prepared by melt compounding technique

( 2020)

N. H. I. Kamaludin

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H. Ismail

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A. Rusli

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Sam Sung Ting

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A. A. N. Gunny

Biodegradable polymers of polylactic acid (PLA) and chitosan (Cs) has a great potential as alternative candidates to replace conventional synthetic plastic apart to reduce the plastic waste pollution due to the unique properties of superior mechanical strength, feasible processability and rapid degradation. In this work, PLA/Cs biocomposites were prepared via melt compounding and compression moulding techniques in the absence of any plasticizer and additive. The effect of chitosan loading (2.5, 5, 7.5, 10 php) on processing, tensile and morphological characteristics of PLA/Cs were evaluated using internal mixer, universal testing machine and field emission scanning electron microscopy (FESEM), respectively. Processing characteristic indicates PLA/Cs biocomposites demonstrated higher processing torque in comparison to neat PLA due to the increase in melt viscosity and decrease in chain mobility of the polymeric materials. Tensile test results revealed that the maximum strength (54.60 ± 0.51 MPa) and tensile elastic modulus (2.67 ± 0.01 GPa) was attained by PLA/2.5Cs biocomposite. In fact, the addition of chitosan content up to 10 php results in significant decreased in tensile strength and elongation at break of 23.38 ± 0.37 MPa and 0.96 ± 0.04 %, respectively. This is supported by the electron micrograph observation of the PLA/2.5Cs tensile fractured surfaces that exhibits uniform dispersion and good interfacial adhesion between chitosan and PLA matrix which signifies higher tensile properties. However, more agglomeration and poor filler-matrix interaction was observed with further addition of chitosan content of above 7.5 php which implies deterioration in tensile properties. The results suggest that the incorporation of low chitosan loading improve the processing, tensile and polymer compatibility in PLA/Cs biocomposites.

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Publication

Removal of ammonia from municipal solid waste (MSW) landfill using hydrated lime

( 2020-06-10)