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Full-Text Articles in Engineering

Characterization Of Acetogenic And Methanogenic Leachates Generated From A Sanitary Landfill Site, Aik Heng Lee, Hamid Nikraz, Yung Tse Hung Dec 2010

Characterization Of Acetogenic And Methanogenic Leachates Generated From A Sanitary Landfill Site, Aik Heng Lee, Hamid Nikraz, Yung Tse Hung

Civil and Environmental Engineering Faculty Publications

Decomposition processes take place in landfill generate leachates that can be categorized mainly of acetogenic and methanogenic in nature. BOD:COD ratio computed in this study for a landfill site over a 3 years duration revealed as a good indicator to identify acetogenic leachate from methanogenic leachate. Correlation relationships to predict pollutant level taking into consideration of climatic condition are derived.


The Effectiveness Of Silica Sand In Semi-Aerobic Stabilized Landfill Leachate Treatment, Ezlina Othman, Mohd Suffian Yusoff, Hamidi Abdul Aziz, Mohd Nordin Adlan, Mohammed J.K. Bashir, Yung Tse Hung Dec 2010

The Effectiveness Of Silica Sand In Semi-Aerobic Stabilized Landfill Leachate Treatment, Ezlina Othman, Mohd Suffian Yusoff, Hamidi Abdul Aziz, Mohd Nordin Adlan, Mohammed J.K. Bashir, Yung Tse Hung

Civil and Environmental Engineering Faculty Publications

© 2010 by the authors. This study examines the suitability of natural silica sand as a low-cost adsorbent for the removal of ammoniacal nitrogen and heavy metals, particularly iron and zinc, from semi-aerobic stabilized landfill leachate. Leachate samples were collected from the Pulau Burung landfill site (PBLS) in Penang, Malaysia. The above-mentioned contaminants are highlighted in this study because of their unsafe concentrations at PBLS. The effects of shaking time, settling time, and silica sand dosage on the study parameter removal efficiencies were investigated to predict the performance of the process. The adsorptions of ammoniacal nitrogen, iron, and zinc were …


Optimization Of Basic And Reactive Dye Uptakes In Binary Dye Solution Using Statistical Experimental Methodology, Siew-Teng Ong, Weng-Nam Lee, Pei-Sin Keng, Siew-Ling Lee, Yung-Tse Hung Nov 2010

Optimization Of Basic And Reactive Dye Uptakes In Binary Dye Solution Using Statistical Experimental Methodology, Siew-Teng Ong, Weng-Nam Lee, Pei-Sin Keng, Siew-Ling Lee, Yung-Tse Hung

Civil and Environmental Engineering Faculty Publications

In the present study, the optimum adsorption conditions for the uptake of methylene blue (MB) and reactive orange 16 (RO16) in binary dye solution by ethylenediamine tetraacidic acid (EDTA) modified rice hulls was studied. By using the Plackett-Burman design, the significant variables in affecting the MB and RO16 uptake in binary dye solution were identified as pH and contact time. The combined effects of interaction between the variables were determined using response surface methodology (RSM). The model predicted that at optimum conditions: pH 6.77 and contact time of 205.58 min, the MB uptake greater than 95% could be obtained. As …


Equilibrium Studies For The Removal Of Basic Dye By Sunflower Seed Husk (Helianthus Annuus), Siew-Teng Ong, Pei-Sin Keng, Siew-Ling Lee, Ming-How Leong, Yung-Tse Hung Aug 2010

Equilibrium Studies For The Removal Of Basic Dye By Sunflower Seed Husk (Helianthus Annuus), Siew-Teng Ong, Pei-Sin Keng, Siew-Ling Lee, Ming-How Leong, Yung-Tse Hung

Civil and Environmental Engineering Faculty Publications

The sorption characteristics of sunflower (Helianthus annuus) seed husk (SSH) to remove Methylene Blue (MB) from aqueous solution under batch conditions have been investigated. Sorption of MB was found to be pH, concentration and agitation dependent. The kinetics of sorption was rapid with 80% sorption taking place within the first 60 min regardless of its initial concentration. The fast attainment of equilibrium implying the biosorbent could be suitable for continuous flow system. Using the pseudosecond order kinetics model, the predictive model for MB sorbed at time t (qt) with the initial concentration of (Co) is given by qt = Cot/[0.0607Co …


Failure Literacy In Structural Engineering, Norbert J. Delatte Jul 2010

Failure Literacy In Structural Engineering, Norbert J. Delatte

Civil and Environmental Engineering Faculty Publications

The history of the development of practice in many engineering disciplines is, in large part, the story of failures, both imminent and actual, and of the changes to designs, standards and procedures made as the result of timely interventions or forensic analyses. All engineers, and more particularly structural engineers, should be failure literate. Failure literacy means knowing about the critical historical failure cases that have shaped the profession: not merely the surface technical details, but the environment, the communications difficulties and the procedural issues. In the US, an intensive effort has been under way for nearly a decade to promote …


Equilibrium Studies And Kinetics Mechanism For The Removal Of Basic And Reactive Dyes In Both Single And Binary Systems Using Edta Modified Rice Husk, Siew-Teng Ong, Weng-Nam Lee, Pei-Sin Keng, Yung-Tse Hung, Sie-Tiong Ha May 2010

Equilibrium Studies And Kinetics Mechanism For The Removal Of Basic And Reactive Dyes In Both Single And Binary Systems Using Edta Modified Rice Husk, Siew-Teng Ong, Weng-Nam Lee, Pei-Sin Keng, Yung-Tse Hung, Sie-Tiong Ha

Civil and Environmental Engineering Faculty Publications

The potential of using ethylenediamine tetraacetic acid modified rice husk (ERH) to remove different types of dyes, namely basic and reactive dyes were studied. Sorption characteristic of ERH showed that it was pH dependent. The kinetics of sorption for both dyes was rapid within the first 60 min regardless of its initial concentration. Using the pseudo-second order kinetics model, the predicted uptakes of Methylene Blue (MB) and Reactive Orange 16 (RO16) agreed closely with experimental values obtained. Three isotherm models were used to fit with equilibrium data, namely Langmuir, Freundlich and BET models. It was found that the equilibrium fitted …


Tartaric Acid Modified Rice Hull As A Sorbent For Methylene Blue Removal, Siew Teng Ong, Pei Sin Keng, Ai Wen Chong, Siew Ling Lee, Yung Tse Hung Jan 2010

Tartaric Acid Modified Rice Hull As A Sorbent For Methylene Blue Removal, Siew Teng Ong, Pei Sin Keng, Ai Wen Chong, Siew Ling Lee, Yung Tse Hung

Civil and Environmental Engineering Faculty Publications

Problem statement: Improper dye discharge from various industries such as textile, paper, cosmetic and plastics into receiving streams can be one of the sources towards water pollution. The release of these effluents not only causes various disruptions in the ecosystems, but also poses hazard effect as most of the dyes are highly toxic, mutagenic and carcinogenic in nature. Approach: To prepare an inexpensive and efficient sorbent by chemically modifying rice hull for the removal of Methylene Blue (MB) which is predominantly used in coloring acrylic fiber. Batch experiments were carried out for the removal of MB from aqueous solution by …


Optimal Design Of Trusses With Geometric Imperfections, Mehdi Jalalpour, Takeru Igusa, James K. Guest Jan 2010

Optimal Design Of Trusses With Geometric Imperfections, Mehdi Jalalpour, Takeru Igusa, James K. Guest

Civil and Environmental Engineering Faculty Publications

The present paper focuses on optimization of trusses that have randomness in geometry that may arise from fabrication errors. The analysis herein is a generalization of a perturbation approach to topology optimization under geometric uncertainties. The main novelty in the present paper is in the consideration of potential buckling due to misaligned structural members. The paper begins with a brief review of the aforementioned perturbation approach, then proceeds with the analysis of the nonlinear effects of geometric imperfection. The paper concludes with some numerical examples.