Weng Nam Lee - Academia.edu (original) (raw)

Papers by Weng Nam Lee

Research paper thumbnail of Synthesis, phase transition behaviour and dielectric properties of smectogenic palm-based liquid crystals containing schiff base ester and phenyl ring

Journal of Molecular Structure

Research paper thumbnail of Ethylenediaminetetraacetic acid (edta) modified rice husk as an adsorbent for dyes and heavy metals removal

ACKNOWLEDGEMENTS APPROVAL SHEET SUBMISSION SHEET DECLARATION FORM LIST OF TABLES LIST OF FIGURES ... more ACKNOWLEDGEMENTS APPROVAL SHEET SUBMISSION SHEET DECLARATION FORM LIST OF TABLES LIST OF FIGURES LIST OF ABBREVIATIONS

Research paper thumbnail of Utilization of Chemically Modified Rice Hull for the Treatment of Industrial Wastewater

Effectiveness of using chemically modified rice hull (MRH) in the treatment of industrial wastewa... more Effectiveness of using chemically modified rice hull (MRH) in the treatment of industrial wastewater was investigated. The optimised chemical modification process was preformed by treating 1.00 g of rice hull with 0.02 mol of ethylenediamine (EDA) in a “well stirred” water bath at 80 C for two hours. Batch and column studies were performed under various experimental conditions and the parameters studied included pH, contact time and bed depth. The experimental results revealed that the optimum pH for the treatment of wastewater from textile industry was in the range of 2 to 5. Uptake of dye under both batch and continuous flow conditions shows similar behavior as in synthetic solutions.

Research paper thumbnail of Equilibrium and Continuous Flow Studies on the Sorption of Congo Red Using Ethylenediamine Modified Rice Hulls

Academic Journals, Nov 30, 2009

The effectiveness of using ethylenediamine rice hulls (EDA-RH) to remove Congo Red (CR) from synt... more The effectiveness of using ethylenediamine rice hulls (EDA-RH) to remove Congo Red (CR) from synthetic dye solution was carried out in batch and column experiments under various experimental conditions. Surface morphology analysis was carried out also using atomic force microscopy (AFM). The experimental data obtained at different initial dye concentrations fitted well to pseudo-second order kinetic model. Application of Langmuir isotherm indicated that maximum sorption capacity of EDA-RH for CR was enhanced by 2-fold as compared to natural rice hulls. Column studies revealed that the breakthrough curves of CR followed the typical S shape of packed-bed systems and it was bed-depth and influent-concentration dependent. The BDST model was used to predict the bed-depth service time data at different bed depths. A plot of BDST at 50% breakthrough yielded a straight line that, however, does not pass through the origin.

Research paper thumbnail of Synthesis and characterization of new Schiff base ester liquid crystals with fatty acids from palm oil as flexible alkyl chain

Industrial Crops and Products, 2021

Research paper thumbnail of Dyes Waste Treatments

Dyes waste represent one of the problematic groups of pollutants because their presence can be ea... more Dyes waste represent one of the problematic groups of pollutants because their presence can be easily identified by the human eye and they are not easily biodegradable. This literature review paper highlights and provides an overview of dyes waste treatments for 3 years period, from 2008-2010. The noteworthy treatment processes for dyes waste include biological treatment, catalytic oxidation, filtration, sorption process and combination treatments.

Research paper thumbnail of Optimization of basic and reactive dye uptakes in binary dye solution using statistical experimental methodology

In the present study, the optimum adsorption conditions for the uptake of methylene blue (MB) and... more 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 for RO16, the RSM indicated that pH 3.17 and contact time of 205.59 min were optimal for maximum percent dye uptake. These predicted values were also experimentally validated to confirm the reliability of the models.

Research paper thumbnail of Evaluation on the efficiency of ethylenediaminetetraacetic acid (EDTA)-modified rice husk as a low-cost sorbent for various dyes removal under continuous flow condition

Desalination and Water Treatment, 2015

AbstractThe potential of ethylenediaminetetraacetic acid (EDTA)-modified rice husk (ERH) as a sor... more AbstractThe potential of ethylenediaminetetraacetic acid (EDTA)-modified rice husk (ERH) as a sorbent to remove both methylene blue (MB) and reactive orange 16 (RO 16) in single and binary dye solutions was studied. Surface characterization of natural rice husk and ERH was investigated using field emission scanning electron microscope (FESEM) and atomic force microscope (AFM). From the FESEM micrographs, due to the absence of pores and cavities, it can be concluded that ERH is a non-porous material. The adsorption behaviour of MB and RO 16 onto column packed with ERH was investigated under continuous flow mode with three different parameters: the effect of influent concentration, the effect of bed depth and the effect of flow rate. Column studies indicated that the breakthrough time is longer for MB at lower influent concentration and flow rate. Unusual breakthrough curves were obtained for RO 16 in both single and binary dye solutions with very rapid initial breakthrough. This implies that the adsorption...

Research paper thumbnail of Application of response surface analysis for optimization of dyes sorption onto EDTA modified rice hull

The batch removal of basic and reactive dyes from aqueous solution using ethylenediamine tetraace... more The batch removal of basic and reactive dyes from aqueous solution using ethylenediamine tetraacetic acid modified rice husk (ERH) was studied. Plackett-Burman design coupled with response surface methodology (11SM) were adopted to evaluate the effect of various operating parameters, such aspH (2-10), contact time (5-420 mins) andsorbent dosage (0.05-0.2 g) on the percentage of dye removal. The optimum adsorption conditions for Methylene Blue were determined as pH: 8.6, contact time: 131 mins and sorbent dosage: 0.13 g. As for Reactive Orange 16, a greater uptake was observed at a lower pH. The empirical model developed from the interactive effects of important operating variables was validated using ANOVA analysis. The percentage uptakes predicted by the model are in good agreement with the experimental values, thus confirming the reliabilily of the models.

Research paper thumbnail of Dye Waste Treatment

Research paper thumbnail of Synthesis, phase transition behaviour and dielectric properties of smectogenic palm-based liquid crystals containing schiff base ester and phenyl ring

Journal of Molecular Structure

Research paper thumbnail of Ethylenediaminetetraacetic acid (edta) modified rice husk as an adsorbent for dyes and heavy metals removal

ACKNOWLEDGEMENTS APPROVAL SHEET SUBMISSION SHEET DECLARATION FORM LIST OF TABLES LIST OF FIGURES ... more ACKNOWLEDGEMENTS APPROVAL SHEET SUBMISSION SHEET DECLARATION FORM LIST OF TABLES LIST OF FIGURES LIST OF ABBREVIATIONS

Research paper thumbnail of Utilization of Chemically Modified Rice Hull for the Treatment of Industrial Wastewater

Effectiveness of using chemically modified rice hull (MRH) in the treatment of industrial wastewa... more Effectiveness of using chemically modified rice hull (MRH) in the treatment of industrial wastewater was investigated. The optimised chemical modification process was preformed by treating 1.00 g of rice hull with 0.02 mol of ethylenediamine (EDA) in a “well stirred” water bath at 80 C for two hours. Batch and column studies were performed under various experimental conditions and the parameters studied included pH, contact time and bed depth. The experimental results revealed that the optimum pH for the treatment of wastewater from textile industry was in the range of 2 to 5. Uptake of dye under both batch and continuous flow conditions shows similar behavior as in synthetic solutions.

Research paper thumbnail of Equilibrium and Continuous Flow Studies on the Sorption of Congo Red Using Ethylenediamine Modified Rice Hulls

Academic Journals, Nov 30, 2009

The effectiveness of using ethylenediamine rice hulls (EDA-RH) to remove Congo Red (CR) from synt... more The effectiveness of using ethylenediamine rice hulls (EDA-RH) to remove Congo Red (CR) from synthetic dye solution was carried out in batch and column experiments under various experimental conditions. Surface morphology analysis was carried out also using atomic force microscopy (AFM). The experimental data obtained at different initial dye concentrations fitted well to pseudo-second order kinetic model. Application of Langmuir isotherm indicated that maximum sorption capacity of EDA-RH for CR was enhanced by 2-fold as compared to natural rice hulls. Column studies revealed that the breakthrough curves of CR followed the typical S shape of packed-bed systems and it was bed-depth and influent-concentration dependent. The BDST model was used to predict the bed-depth service time data at different bed depths. A plot of BDST at 50% breakthrough yielded a straight line that, however, does not pass through the origin.

Research paper thumbnail of Synthesis and characterization of new Schiff base ester liquid crystals with fatty acids from palm oil as flexible alkyl chain

Industrial Crops and Products, 2021

Research paper thumbnail of Dyes Waste Treatments

Dyes waste represent one of the problematic groups of pollutants because their presence can be ea... more Dyes waste represent one of the problematic groups of pollutants because their presence can be easily identified by the human eye and they are not easily biodegradable. This literature review paper highlights and provides an overview of dyes waste treatments for 3 years period, from 2008-2010. The noteworthy treatment processes for dyes waste include biological treatment, catalytic oxidation, filtration, sorption process and combination treatments.

Research paper thumbnail of Optimization of basic and reactive dye uptakes in binary dye solution using statistical experimental methodology

In the present study, the optimum adsorption conditions for the uptake of methylene blue (MB) and... more 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 for RO16, the RSM indicated that pH 3.17 and contact time of 205.59 min were optimal for maximum percent dye uptake. These predicted values were also experimentally validated to confirm the reliability of the models.

Research paper thumbnail of Evaluation on the efficiency of ethylenediaminetetraacetic acid (EDTA)-modified rice husk as a low-cost sorbent for various dyes removal under continuous flow condition

Desalination and Water Treatment, 2015

AbstractThe potential of ethylenediaminetetraacetic acid (EDTA)-modified rice husk (ERH) as a sor... more AbstractThe potential of ethylenediaminetetraacetic acid (EDTA)-modified rice husk (ERH) as a sorbent to remove both methylene blue (MB) and reactive orange 16 (RO 16) in single and binary dye solutions was studied. Surface characterization of natural rice husk and ERH was investigated using field emission scanning electron microscope (FESEM) and atomic force microscope (AFM). From the FESEM micrographs, due to the absence of pores and cavities, it can be concluded that ERH is a non-porous material. The adsorption behaviour of MB and RO 16 onto column packed with ERH was investigated under continuous flow mode with three different parameters: the effect of influent concentration, the effect of bed depth and the effect of flow rate. Column studies indicated that the breakthrough time is longer for MB at lower influent concentration and flow rate. Unusual breakthrough curves were obtained for RO 16 in both single and binary dye solutions with very rapid initial breakthrough. This implies that the adsorption...

Research paper thumbnail of Application of response surface analysis for optimization of dyes sorption onto EDTA modified rice hull

The batch removal of basic and reactive dyes from aqueous solution using ethylenediamine tetraace... more The batch removal of basic and reactive dyes from aqueous solution using ethylenediamine tetraacetic acid modified rice husk (ERH) was studied. Plackett-Burman design coupled with response surface methodology (11SM) were adopted to evaluate the effect of various operating parameters, such aspH (2-10), contact time (5-420 mins) andsorbent dosage (0.05-0.2 g) on the percentage of dye removal. The optimum adsorption conditions for Methylene Blue were determined as pH: 8.6, contact time: 131 mins and sorbent dosage: 0.13 g. As for Reactive Orange 16, a greater uptake was observed at a lower pH. The empirical model developed from the interactive effects of important operating variables was validated using ANOVA analysis. The percentage uptakes predicted by the model are in good agreement with the experimental values, thus confirming the reliabilily of the models.

Research paper thumbnail of Dye Waste Treatment