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Dive into the research topics where Amat Ngilmi Ahmad Sujari is active.

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Featured researches published by Amat Ngilmi Ahmad Sujari.


Food Chemistry | 1998

Analysis of anions and cations in drinking water samples by Capillary Ion Analysis

Bahruddin Saad; Fen Wei Pok; Amat Ngilmi Ahmad Sujari; Muhammad Idiris Saleh

Abstract The use of capillary ion electrophoresis (CIE, Waters’ tradename: Capillary Ion Analysis, CIA) for the analysis of four anions and four cations in drinking water samples available on the Malaysian market, such as natural mineral water, bottled drinking water and tap water, was investigated. In addition, zam-zam water (an underground water, much sought-after by Muslims and only available in Mekah, Saudi Arabia) was also analyzed. The anions analyzed were chloride, sulphate, nitrate and fluoride while the cations analyzed were potassium, calcium, sodium and magnesium. Results of this determination generally show a low content of anions and high content of calcium and magnesium in natural mineral water and non-detectable amounts of anions and cations in bottled drinking water. Out of the 15 mineral waters of different brands that were analyzed, four brands show anionic and cationic levels almost similar to that of tap water. With the exception of fluoride, an abnormally high level of both anions and cations were detected in all the zam-zam water samples analyzed, as compared to the other drinking waters.


Bioresource Technology | 2011

Bioregeneration of granular activated carbon in simultaneous adsorption and biodegradation of chlorophenols.

Wen-Da Oh; Poh-Eng Lim; Chye-Eng Seng; Amat Ngilmi Ahmad Sujari

The objectives of this study are to obtain the time courses of the amount of chlorophenol adsorbed onto granular activated carbon (GAC) in the simultaneous adsorption and biodegradation processes involving 4-chlorophenol (4-CP) and 2,4-dichlorophenol (2,4-DCP), respectively, and to quantify the bioregeneration efficiency of GAC loaded with 4-CP and 2,4-DCP by direct measurement of the amount of chlorophenol adsorbed onto GAC. Under abiotic and biotic conditions, the time courses of the amount of chlorophenol adsorbed onto GAC at various GAC dosages for the initial 4-CP and 2,4-DCP concentrations below and above the biomass acclimated concentrations of 300 and 150 mg/L, respectively, were determined. The results show that the highest bioregeneration efficiency was achieved provided that the initial adsorbate concentration was lower than the acclimated concentration. When the initial adsorbate concentration was higher than the acclimated concentration, the highest bioregeneration efficiency was achieved if excess adsorbent was used.


Environmental Technology | 2009

Performance of sequencing batch biofilm and sequencing batch reactors in simultaneous p‐nitrophenol and nitrogen removal

Chin‐Ping Goh; Chye-Eng Seng; Amat Ngilmi Ahmad Sujari; Poh-Eng Lim

The objective of this study is to evaluate the performance of sequencing batch biofilm reactors (SBBRs) and sequencing batch reactor (SBR) in the simultaneous removal of p‐nitrophenol (PNP) and ammoniacal nitrogen. SBBRs involved the use of polyurethane sponge cubes and polyethylene rings, respectively, as carrier materials. The results demonstrate that complete removal of PNP was achievable for the SBR and SBBRs up to the PNP concentration of 350 mg/l (loading rate of 0.368 kg/m3 d). At this loading rate, the average ammoniacal nitrogen removal efficiency for the SBR and SBBR (with polyethylene rings) was reduced to 86% and 96%, respectively. However, the SBBR (with polyurethane sponge cubes) still managed to achieve an almost 100% ammoniacal nitrogen removal. Based on the results, the performance of the SBBRs was better than that of SBR in PNP and ammoniacal nitrogen removal. The results of the gas chromatography mass spectroscopy, high‐performance liquid chromatography and ultraviolet–visible analyses indicate that complete mineralization of PNP was achieved in all of the reactors.


Bioresource Technology | 2012

Kinetic modeling of bioregeneration of chlorophenol-loaded granular activated carbon in simultaneous adsorption and biodegradation processes

Wen-Da Oh; Poh-Eng Lim; Chye-Eng Seng; Amat Ngilmi Ahmad Sujari

A kinetic model incorporating adsorption, desorption and biodegradation processes was developed to describe the bioregeneration of granular activated carbon (GAC) loaded with 4-chlorophenol (4-CP) and 2,4-dichlorophenol (2,4-DCP), respectively, in simultaneous adsorption and biodegradation processes. The model was numerically solved and the results showed that the kinetic model was well-fitted (R(2)>0.83) to the experimental data at different GAC dosages and at various initial 4-CP and 2,4-DCP concentrations. The rate of bioregeneration in simultaneous adsorption and biodegradation processes was influenced by the ratio of initial chlorophenol concentration to GAC dosage. Enhancement in the rate of bioregeneration was achieved by using the lowest ratio under either one of the following experimental conditions: (1) increasing initial chlorophenol concentration at constant GAC dosage and (2) increasing GAC dosage at constant initial chlorophenol concentration. It was found that the rate enhancement was more pronounced under the second experimental condition.


Desalination and Water Treatment | 2013

Biodegradation of o-cresol by polyvinyl alcohol–alginate immobilized mixed culture

Run-Hong Toh; Chye-Eng Seng; Poh-Eng Lim; Rohana Adnan; Amat Ngilmi Ahmad Sujari

AbstractThe performance of polyvinyl alcohol (PVA)–alginate immobilized biomass in the biodegradation of o-cresol was evaluated and compared with that of the suspended biomass. The effects of initial o-cresol concentration, initial pH, and immobilized biomass bead size on the biodegradation of o-cresol were investigated. Compared with the o-cresol biodegradation rate by suspended biomass, the biodegradation rate by immobilized biomass was barely affected at higher initial o-cresol concentration and extreme pH conditions suggesting that the immobilized biomass was protected by the PVA–alginate matrix. The reusability of the immobilized biomass beads up to three cycles of use could be achieved, but only at relatively lower initial o-cresol concentration.


International Journal of Electrochemical Science | 2016

Electrooxidation of nitrite ions on gold/polyaniline/carbon paste electrode

Mohammad Etesami; Nurul S N M S Chandran; M. Hazwan Hussin; Adnan Ripin; Rohana Adnan; Amat Ngilmi Ahmad Sujari; Norita Mohamed

Nitrite ions can penetrate from fertilizers into underground water and consequently contaminate the water and food sources. A facile two-step electrochemical method was used to fabricate gold/polyaniline/carbon paste electrode (Au/PAni/CPE) for nitrite sensing. The Au/PAni/CPE was visualized and characterized by scanning electron microscopy, energy-dispersed X-ray spectroscopy, X-ray diffraction and electrochemical methods. The electrocatalytic activity of bare CPE, PAni/CPE and Au/PAni/CPE toward the electrooxidation of nitrite was examined and compared via cyclic voltammetry. To obtain the optimal condition for fabrication of the electrode, the number of cycles in cyclic voltammetry for synthesis of polyaniline and the deposition time in potentiostatic deposition of gold were optimized with respect to the electrooxidation of nitrite. In a phosphate buffer solution (PBS, pH 7.0), the peak current was linear to the concentration of nitrite in the range from 3.8×10-5 M to 1.0×10-3 M with a detection limit of 2.5×10-5 M. The interference effect on the nitrite detection was also studied. The proposed method was also employed for the determination of nitrite in rain and lake water samples.


Electrochimica Acta | 2012

Electrochemical fabrication, characterization and application of carboxylic multi-walled carbon nanotube modified composite pencil graphite electrodes

Zhu Qing Gong; Amat Ngilmi Ahmad Sujari; Sulaiman Ab Ghani


Sensors and Actuators B-chemical | 2013

Nafion-MWCNT composite modified graphite paste for the analysis of quercetin in fruits of Acanthopanax sessiliflorus

Qing-Gong Zhu; Amat Ngilmi Ahmad Sujari; Sulaiman Ab Ghani


Journal of The Electrochemical Society | 2013

MWCNT Modified Composite Pencil Graphite Electrodes Fabricated by Direct Dripping and Electrophoretic Deposition Methods: A Comparison Study

Qing-Gong Zhu; Amat Ngilmi Ahmad Sujari; Sulaiman Ab Ghani


Journal of Solid State Electrochemistry | 2012

Electrophoretic deposited MWCNT composite graphite pencils and its uses to determine hyperin

Qing-Gong Zhu; Amat Ngilmi Ahmad Sujari; Sulaiman Ab Ghani

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Chye-Eng Seng

Universiti Sains Malaysia

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Poh-Eng Lim

Universiti Sains Malaysia

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Qing-Gong Zhu

Universiti Sains Malaysia

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Rohana Adnan

Universiti Sains Malaysia

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Wen-Da Oh

Universiti Sains Malaysia

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Adnan Ripin

Universiti Teknologi Malaysia

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Bahruddin Saad

Universiti Sains Malaysia

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Chin‐Ping Goh

Universiti Sains Malaysia

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Fen Wei Pok

Universiti Sains Malaysia

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