International Journal of Integrated Engineering
The International Journal of Integrated Engineering (IJIE) is a single blind peer reviewed journal which publishes 3 times a year since 2009 (April, August and December). The journal is dedicated to various issues focusing on 3 different fields which are: Civil and Environmental Engineering. Original contributions for civil and environmental engineering related practices will be publishing under this category and as the nucleus of the journal contents. The journal publishes a wide range of research and application papers which describe laboratory and numerical investigations or report on full scale projects. Electrical and Electronic Engineering. It stands as a international medium for the publication of original papers concerned with the electrical and electronic engineering. The journal aims to present to the international community important results of work in this field, whether in the form of research, development, application or design. Mechanical, Materials and Manufacturing Engineering. It is a platform for the publication and dissemination of original work which contributes to the understanding of the main disciplines underpinning the mechanical, materials and manufacturing engineering. Original contributions giving insight into engineering practices related to mechanical, materials and manufacturing engineering form the core of the journal contents. More details
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Effectiveness of Carica Papaya and Raphanus Sativus Seeds as Coagulants for Water Quality Enhancement
In this study, two plant seeds, Carica papaya (papaya) and Raphanus sativus (radish), were investigated as natural coagulants for treating commercial wastewater. These seeds, known for their bioactive compounds, offer the potential for a safe, cost-effective, and biodegradable solution for improving water quality. The research evaluated the application and performance of Carica papaya and Raphanus sativus seeds powders for treating commercial wastewater, focusing on key water quality parameters. Jar test experiments demonstrated that Raphanus sativus seeds coagulant, at an optimum dosage of 15 mg/L, achieved the highest turbidity removal efficiencies of 85.75% and 81.24% and COD removal efficiencies of 47.62% and 51.72% for wastewater from Points 1 and 2, respectively. In terms of oil removal, Raphanus sativus seeds also performed effectively, achieving maximum removal efficiencies of 26.19% at 20 mg/L and 54.60% at 25 mg/L for wastewater from Points 1 and 2, respectively. These results highlight the strong potential of Raphanus sativus seeds as an effective natural coagulant, outperforming Carica papaya seeds across all tested parameters.
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Multi-Test Homogeneity Assessment of Long-Term Rainfall Series in Peninsular Malaysia
The primary goal of this study is to analyse the homogeneity of rainfall in Peninsular Malaysia, crucial for understanding climate change impacts and water resource management. Despite the importance of rainfall data for hydrological and engineering applications, inconsistencies and inhomogeneities in long-term rainfall records can lead to misleading conclusions about climate trends and compromise infrastructure design. In Peninsular Malaysia, limited studies have systematically assessed rainfall data homogeneity, leaving uncertainty about the reliability of existing datasets. Given the rising implications of climate change, assessing the consistency and potential changes in rainfall patterns is essential for effective infrastructure and resource planning. Using rainfall data collected over a 21-year period (1998–2018) from 10 meteorological stations, the study employs various statistical methods, including the Von Neumann Ratio Test, Pettitt Test, Buishand Range Test, and Standard Normal Homogeneity Test, to evaluate temporal and spatial uniformity in rainfall patterns. Rainfall stations are categorised as 'useful', 'suspect', or 'doubtful' based on the results. 'Useful' stations show consistent and reliable data, while 'suspect' and 'doubtful' stations indicate potential inconsistencies. The findings in this study are Petaling Jaya in annual and Alor Setar in May were flagged as suspect, while Subang in May, Melaka in annual, Kuala Terengganu in August, and Bayan Lepas in January were considered doubtful. The remaining stations and time series exhibited consistent and reliable patterns. Additionally, the Sequential Mann-Kendall Test is used to detect trends and shifts in the data. The findings offer crucial insights into the homogeneity of rainfall distribution across Peninsular Malaysia, highlighting discrepancies that could impact water resource planning and climate change adaptation strategies. This research is valuable for engineers, researchers, and stakeholders involved in sustainable water resource management and infrastructure development, providing empirical evidence for hydrology and climate studies.
Sustainable Adsorbents: Characterisation of Banana Stem-Based Materials for Reactive Black 5 Dye Removal
Banana stems are agricultural plant waste from one of Asia's most popular fruits, which is grown primarily in India, Thailand, China, Indonesia, and Malaysia. Since coal-derived activated carbon is expensive and has limited availability, agricultural waste such as banana stems has been seen as an affordable and abundant alternative. Activated carbon banana stem (ACBS) was prepared by soaking with phosphoric acid (H3PO4) and heating in a furnace at 400°C for 1 hour. Both raw banana stem (RBS) and activated carbon banana stem (ACBS) were characterized using proximate analysis, Scanning Electron Microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR) and Brunauer–Emmett–Teller (BET). The results showed that ACBS had higher ash (25.45%) and fixed carbon (36.4%) contents, and lower moisture (2.3%) and volatile matter (35.85%) contents than RBS. Analysis of the surface morphology using SEM indicated that the ACBS was more porous than the RBS, thereby enhancing its adsorption capacity. BET analysis revealed that the surface area, pore volume, and average pore diameter of the ACBS (475.7 m²/g, 0.4491cm3/g, and 3.776 nm) were significantly greater than those of the RBS (1.886 m²/g, 0.0047 cm3/g, and 9.882 nm), demonstrating effective pore development during activation. The results showed that ACBS was more effective at removing Reactive Black 5 (RB5) dye, with a removal efficiency of 99.11%, compared to RBS, which had only 6.4%.
Exploring The Adsorption of Nutrients in Industrial Wastewater Using Zeolite
Industrial wastewater often contains excess nutrients that can trigger eutrophication if discharged untreated. Zeolite, with its distinct physical and chemical properties, is widely used in wastewater treatment. This work focused on investigating the morphological alterations on the zeolite surface, optimising adsorption operational parameters, and evaluating the adsorption behaviour of ammonium, nitrate, and phosphorus through isotherm and kinetic models. Zeolite was characterised by Scanning Electron Microscopy (SEM), and batch-mode adsorption experiments were operated with varying wastewater percentages (10 - 100% v/v), zeolite dosages (0.4 g - 1.2 g), pH (4 - 9), and contact times (5 - 120 minutes). SEM analysis showed that the initially porous, rough zeolite surface became smoother and less porous after adsorption, confirming nutrient attachment to the zeolite surface. Optimal nutrient removal was achieved at 10% (v/v) wastewater, 1.2 g of zeolite, pH 7, and a 120-minute contact time with agitation at 80 rpm, achieving efficiencies of 32% for ammonium, 67% for nitrate, and 59% for phosphorus. Isotherm analysis showed that ammonium adsorption was better represented by the Freundlich model, nitrate aligned strongly with the Langmuir model, and phosphorus exhibited weak agreement with both models. Also, ammonium and nitrate followed the pseudo-second-order kinetic model, whereas phosphorus was better described by the pseudo-first-order model. The adsorption capabilities of zeolite for nutrient removal were successfully explored, demonstrating its potential as a sustainable treatment option.
Gasification Product Characteristics from Torrefied Spent Coffee Grounds in A Fixed-Bed Reactor
Biomass resources, particularly spent coffee grounds (SCG), offer promising potential for renewable energy generation via gasification. However, the inherent limitations of raw SCG, including high moisture and volatile content, necessitate pretreatment to enhance its suitability as a feedstock. This study evaluates the effectiveness of torrefaction as a thermal pretreatment method for SCG prior to steam gasification in a fixed-bed reactor. Comparative analyses of untreated and torrefied SCG revealed significant improvements in fuel characteristics, with torrefaction at 250 °C for 60 minutes reducing moisture content from 8.35% to 0.74%, volatile matter from 78.7% to 76.32%, and increasing fixed carbon from 12.71% to 21.74%. Optimal gasification performance was achieved at 850 °C and a holding time of 50 minutes, yielding 85.06% bio-gas, with minimal char (12.84%) and tar (2.10%) production. Characterisation of the resulting biochar indicated an increase in fixed carbon and a reduction in moisture, both of which are beneficial for syngas generation. Tar's functional group analysis revealed a high concentration of aliphatic C-H bonds, suggesting it could serve as a biofuel alternative.
A Longitudinal Analysis of Construction Waste Recycling Performance in Peninsular Malaysia (2017–2024) Through Digital Monitoring Indicators
The construction sector in Malaysia is a major contributor to overall waste generation, underscoring the urgent need for sustainable waste management practices. Therefore, this study examines the longitudinal performance of Peninsular Malaysia’s construction and demolition (C&D) waste management system from 2017 to 2024, focusing on the effectiveness of digital monitoring tools in assessing recycling and reuse outcomes. The data for this study were obtained from the Construction Waste Monitoring System (CWMS), administered by the Solid Waste and Public Cleansing Management Corporation (SWCorp). The study analyses trends across 11 Peninsular states and 2 federal territories. Key performance indicators, including the Recycling to Generated (CG), Reuse to Generated (RG), and Landfill to Generated (LG) ratios, were employed to evaluate waste diversion efforts. Findings indicate intermittent rather than sustained improvements in recycling and reuse, particularly in urban regions, alongside a continued heavy reliance on landfilling, with LG ratios frequently exceeding 80%. State-level disparities and implementation challenges, such as voluntary reporting, limited infrastructure, and enforcement capacity constraints, further hinder progress. The study concludes that while digital systems offer valuable transparency and accountability, they have not yet translated into consistent improvements in diversion performance. Recommendations include mandating digital reporting, offering performance-based incentives, expanding recycling infrastructure, and institutionalising digital indicators within compliance frameworks. These measures are crucial to supporting Malaysia’s transition toward a circular economy in the construction sector.
Issue on Civil and Environmental Engineering
Optimization of Growth and Urease Production of Bacillus Tequilensis Through pH and Temperature Control
This study investigates the influence of pH and temperature on the growth density and urease enzyme production of Bacillus tequilensis. Bacterial counts and enzyme activity were measured across a range of pH levels (5.75 to 14.24) and temperatures (24.3°C to 42.7°C). The results showed significant differences in bacterial growth and urease production based on these conditions. The highest bacterial growth (6.34 log10 CFU/mL) occurred at pH 10.00 and 42.7°C, while optimal urease activity was also observed under these conditions, indicating that slightly alkaline pH and high temperature are favorable for both bacterial proliferation and enzyme activity. Conversely, high alkalinity at moderate temperatures significantly inhibited bacterial growth, and acidic conditions combined with high temperatures resulted in minimal bacterial presence. The Response Surface Methodology (RSM) analysis highlighted temperature as the most significant factor affecting urease production, followed by pH. ANOVA confirmed the substantial impact of these variables, with the model explaining 81.83% of the variance. This study underscores the critical role of pH and temperature in optimizing bacterial growth and enzymatic activity, providing valuable insights for industrial and environmental applications.
Estimation of Unconfined Compressive Strength (UCS) for Soft Soil Stabilized with Cement Using Multiple Linear Regression Analysis
This paper presents the development of precise linear regression model for predicting an unconfined compressive strength (UCS) for soft soil stabilized using cement in terms of main effective factors such as cement content and times of curing periods. The empirical UCS model was developed using the secondary dataset from the previous studies collected from the published data such as jurnals, technical papers, proceeding and theses. Meanwhile the multiple linear regression analysis was used to develop a UCS model. The results shows there is a strong significant relationship between cement content and times of curing periods to predict the UCS value and the results shows a reasonably good regression coefficient has been obtained for the UCS model which is R2 = 0.93. The UCS model developed demonstrated significant accuracy with the fitted regression model between the predicted UCS and measured UCS with the determination coefficient value is R2 = 0.97 and low value for mean square error (MSE) is 0.068. It shows the UCS model developed was present a good to estimate the unconfined compressive strength for soft soil stabilized using cement and it will be practical for a preliminary design of a project where there costs and time limitations.
Shallow Foundation Stability on Expansive Clay Using Group Granular Pile Anchor
Expansive soil is problematic because it undergoes significant volume changes due to its tendency to swell when it absorbs moisture and shrink when it dries out. This characteristic can lead to serious structural issues for buildings, roads, and other infrastructure. The solution for this problem is to use a Granular Pile Anchor (GPA) system, an innovative foundation technique that uses a steel anchor extended from a shallow foundation and embedded into a granular pile at depths below expansive soil layers. This enhances the load-bearing capacity, providing additional resistance to uplift forces or lateral loads on expansive soil. The effectiveness of GPA in overcoming uplift forces on structures can be further improved by studying its optimum design. Therefore, this research studies a comprehensive design by incorporating a group pile system on the GPA compared to varying steel anchor lengths and diameters in mitigating heaving using a 3D finite element software PLAXIS. Heave and uplift forces reduction was obtained through varying dimensional input parameters from the ratio of GPA length to the expansive soil layer thickness (L/H), the area replacement ratio (Ar), which is the ratio of the foundation footing area to GPA cross-section area, and the number of group GPA (N). The results indicated that with L/H = 1.5, where the length of GPA extends partly in the expansive soil, and N = 3, the heave and the uplift forces were reduced to 92.55% and 92.79%, respectively. These improvements were sufficient for the optimum performance of the GPA structure. This indicates the vast improvements in the performance of the shallow foundation to mitigate heaving problems due to expansive soil with the application of group GPA.
Granular Pile Anchor, Shallow Foundation, Expansive and Shrinking Soil
Microplastics in The Atmosphere and Their Interaction with Biological Systems Through Systematic Literature and Scoping Reviews
Microplastics in the biosphere have emerged as a pressing environmental and public health concern owing to their widespread occurence and interactions with biological systems. This systematic review investigates the occurrence, transmission mechanisms, and health implications of airborne microplastics. The study applies the PRISMA framework and advanced search strategies across the Scopus and Web of Science databases, resulting in the selection of 35 primary studies. These studies were synthesized into three thematic categories: (1) Characterization of Microplastics in Various Environments, (2) Airborne Transmission and Aerosolization Mechanisms, and (3) Health Implications and Biological Interactions. The first theme highlights the widespread distribution and diversity of microplastics, particularly fibers and fragments, across indoor and outdoor environments. The second theme examines the pathways through which microplastics become airborne, with a focus on the influence of environmental factors such as wind, humidity, and human activities on their dispersion. The third theme explores the potential health consequences of inhaled microplastics, including respiratory complications and their interactions with microbial communities. This review underscores the critical need for robust monitoring systems, stricter regulatory measures, and heightened public awareness to address the escalating risks posed by airborne microplastic pollution. The findings call for interdisciplinary research to better understand the dynamics of microplastics in the atmosphere and to develop effective mitigation strategies to safeguard ecosystems and human health.
Zinc Oxide and Tungsten Trioxide Photocatalysts for Acetaminophen Removal in Water
Untreated Acetaminophen in water is chemically stable and hard to biodegrade. Ozone, ultrasounds, photoelectrochemical oxidation, active carbon adsorption, membrane filtration, and microorganism biodegradation are used to remove Acetaminophen from water. All these methods are effective, but they have drawbacks like incomplete Acetaminophen waste removal, harmful metabolic intermediates, increased water pollution, and the need for additional treatment to remove secondary wastes. Photocatalysis, utilizing light and semiconductors, efficiently removes most wastewater contaminants by decomposing organic compounds. In this study, ZnO, tungsten trioxide (WO3) and combinations of both were investigated as photocatalysts to degrade Acetaminophen in water. The degradation efficiency was investigated using a glass photoreactor with a working volume of 100 mL and assisted by UV light. Operating parameters, including initial Acetaminophen concentration and photocatalyst dosage, were also studied. The degradation of Acetaminophen was measured using a UV-Vis spectrophotometer. ZnO (80%) shows superior photocatalytic activity for Acetaminophen degradation in water compared to WO3 (3.45%) and their composites (Z1W1, Z1W3, Z3W1). Adding ZnO into WO3 enhances its photocatalytic activity and Acetaminophen degradation efficiency compared to only WO3 as a photocatalyst. The optimal degradation of Acetaminophen in water was achieved at an initial Acetaminophen concentration of 10 mg/L and photocatalyst dosage of ZnO at 0.1g with a degradation efficiency of 92%. Therefore, this proved that ZnO exhibits superior photocatalytic activity in degrading Acetaminophen in water.
Artificial Neural Network Based Energy Optimization For Smart Building Energy Management Systems In Commercial Building
As the population grows and human needs increase, so does the number of buildings, leading to higher energy demand and challenges for sustainable use. Therefore, it is essential to develop strategies to reduce energy consumption. Previous studies indicate that poor control over energy usage in commercial buildings has resulted in significant energy wastage. To address this issue, energy management systems have been developed in recent years, playing a critical role in optimizing energy use in various building types. The PID controller, known for its simplicity and ease of use, has become the standard controller in many energy management systems. However, its performance limitations in complex tasks and the overshoot problem in system output reduce overall energy efficiency. This paper proposes an Artificial Neural Network (ANN) Controller to replace the PID Controller for managing and monitoring HVAC and lighting systems, which are the two largest energy consumers in commercial buildings. The controllers were designed and implemented using MATLAB Simulink, where their performance was evaluated under different operating conditions, including step changes and ramp behaviours. The ANN Controller was compared to the PID Controller to evaluate its effectiveness in energy management. In the HVAC system, it eliminates overshoot at 15°C, whereas the PID Controller shows 41.00%. For the lighting system, it achieves zero overshoot at 250 Lux, while the PID Controller reaches 26.67%. These findings confirm its effectiveness in enhancing energy efficiency in commercial buildings by minimizing energy fluctuations and improving system stability, making it a reliable solution for optimizing energy use.
Smart Building Energy Management, Commercial Building Rehabilitation, Building Construction, AI control, Sustainable Energy
Parallel Bending Strength Characterisation of Malaysian Bambusa Vulgaris Bamboo Culms
Bamboo has been utilized for decades due to its versatility and environmental benefits, making it increasingly significant in addressing modern sustainability challenges. Despite Bambusa vulgaris being one of the best bamboo species globally, limited research has been conducted on its natural form, particularly regarding its physical and mechanical properties. Most studies focus on engineered bamboo products, while natural bamboo's characteristics remain underexplored. This study focuses on analysing Bambusa vulgaris sourced from the northern (BVB) and middle regions (BVK) of Malaysia, assessing its suitability for structural use through 4-point-bending tests conducted on 85 treated samples in accordance with ISO 22157. Specimens were tested across three sections along the culm length (top, middle, bottom) to investigate variations in mechanical and physical properties. The study found that Bambusa vulgaris exhibits significant variations in physical and mechanical properties across regions and culm sections. The bottom section had the largest diameter and thickest walls, while the top was smallest, with both regions showing moisture content below 12%. Mechanical testing indicated that BVB outperformed BVK in bending moment, strength, and stiffness, with both showing similar failure modes of longitudinal and transverse cracks. Positive correlations between diameter and ultimate strength, as well as bending stiffness and linear mass, highlight its potential as a sustainable structural material in Malaysia.
The Effect of Housing Locations Towards Off-Campus Students’ Travel Behaviour
University students exhibit distinctive travel characteristics. Lately, the residential trends among university students in Malaysia, particularly those who live off-campus undergone a significant transformation. This study aims to analyze the effect of student housing location on the way they navigate their daily commutes. The methodology employs statistical analyses and spatial mapping techniques. Multiple variables were explored, including sociodemographic characteristics, residential locations, transport mode preferences, commuting patterns, and attitudinal tendencies of off-campus students at the Engineering Campus, USM. Data were obtained through an online questionnaire involving 190 participants, analysed using descriptive statistics and Pearson correlation to identify potential interrelationships among the variables. Additionally, QGIS-based spatial mapping techniques were used to visualise the spatial distribution of housing locations and corresponding mobility flows. Findings suggest that proximity and accessibility of accommodation relative to the campus may play a central role in shaping students’ commuting choices. Interestingly, students residing nearer to the campus appeared more inclined towards active travel modes, such as walking and cycling, whereas those living further away displayed a stronger reliance on motorised transportation.
Mitigating Slope and Embankment Erosion in Malaysia: Case Studies and Integrated Approaches
Malaysia faces severe slope and embankment erosion, a critical geohazard driven by heavy rainfall, intense tropical weathering, and poorly planned development. This results in significant economic and human losses, with failures largely attributed to human factors in design, construction, and maintenance. Current mitigation employs conventional methods such as gabions for immediate stability and soft or bioengineering for ecological control. While integrated approaches are crucial, they face challenges in long-term performance, maintenance, and addressing systematic human errors, which contribute to 57% of landslides, 29% of structure or design factors and 14% of geological factors. This paper critically analyzes integrated solutions in Malaysia, focusing on their long-term efficacy and capacity to mitigate human-induced vulnerabilities, aiming to provide actionable insights for resilient and sustainable erosion control.
Abang Nur’Iman Aiman Abang Mohamad Najib
Performance and Environmental Assessment of Fired Clay Bricks Incorporating Industrial Ceramic Sludge
The escalating environmental crisis and the rising volume of industrial waste have intensified the search for sustainable construction materials. Ceramic sludge, a by-product of the ceramic industry, poses a disposal challenge but also offers potential as a secondary raw material. This study investigates the incorporation of ceramic sludge into fired clay bricks and evaluates its effects on density, shrinkage, initial water absorption, compressive strength, and heavy metal leachability. Bricks were manufactured with ceramic sludge additions of 0%, 1%, 5%, 10%, 20%, and 30%, and tested in accordance with British Standard BS 3921:1985. The results indicate that ceramic sludge incorporation improved key performance parameters, with compressive strength reaching 25 N/mm², shrinkage remaining below 8%, density averaging 1800 kg/m³, and initial water absorption rates under 8 g/mm²·min, all within acceptable ranges. Heavy metal leachability, assessed using the Toxicity Characteristic Leaching Procedure (TCLP), showed that Pb, As, Zn, and Cu concentrations were well below the permissible limits set by the USEPA. In addition, bricks containing up to 30% ceramic sludge satisfied the SIRIM ECO 023:2016 eco-labelling requirement of incorporating at least 30% recycled content, confirming both structural performance and environmental compliance. These findings confirm that ceramic sludge can be successfully valorised in brick manufacturing, reducing dependence on virgin clay and diverting industrial waste from landfills.
GIS-Based Spatial Analysis and Python Transcript for Prediction Traffic Noise Pollution Over Kirkuk City, Iraq
As traffic increases in Kirkuk, Iraq, noise pollution has become a pressing issue, particularly on the major road, Baghdad Road in Kirkuk city, which connects densely populated areas. This study aims to assess traffic noise levels along Baghdad Road, addressing challenges such as time-intensive measurements, selecting appropriate mapping methods and integrating geographic and noise data. It also presents an innovative combination of GIS and Python scripting to model and predict traffic noise pollution in Kirkuk City, Iraq, offering a replicable method for urban areas with limited noise monitoring. Noise levels were measured using a digital sound level meter, with sampling points spaced 500–750 meters apart along entry and exit roads. Maximum noise levels (Max) were recorded during peak traffic hours (8:00–10:00 AM and 5:00–7:00 PM). The highest recorded noise level was 92.15 dB at site K-B.R4 in the morning while the lowest was 74.2 dB at site K-B.R13 in the evening. Temporal variations were notable, particularly on Fridays a local holiday with noise levels ranging from 92.1 dB to 75.5 dB Spatial analysis revealed that K-B.R4 was the most congested area, while K-B.R13 was the least The RLS 90 model implemented in Python, was used to create noise maps through spatial analysis and interpolation in ArcGIS Pro3.0.2. The model’s spatial approach provided higher accuracy and classification precision compared to other methods. These findings emphasize the importance of considering temporal and spatial factors in noise studies, offering valuable insights for environmental monitoring, urban planning, and noise management.