Fazlena Hamzah

Nanoclay Supporting Materials for Enzymes Immobilization: Kinetics Investigation of Free and Immobilized System

In this paper, the kinetic parameters of free and encapsulated enzymes in the calcium alginate-clay beads were determined using Lineweaver-Burk plot. The Michaelis constant, Km of free alpha-amylase, glucoamylase and cellulase were 2.0831, 1.8326 and 7.8592 mg/mL, respectively, whereas for the encapsulated system, the Km values were 3.1604, 2.1708 and 9.2791 mg/mL, respectively. The results showed encapsulation enzymes gave higher Km value than the free enzymes. Comparatively the encapsulated alpha-amylase was 1.5 times higher and the glucoamylase and cellulase were 1.18 times higher. This suggests that the affinity of encapsulated enzymes for substrate was lower which might be due to the diffusional limitation of the substrate and enzymes. Amongst the three in both systems, glucoamylase was determined to have highest affinity followed by alpha-amylase and cellulase enzymes.

Effect of Coating Adhesion on Turmeric Essential Oil Incorporated into Chitosan-Based Edible Coating

The main objective of this paper is to study the coating adhesion of edible coating incorporated with active ingredients from turmeric essential oil on cherry tomatoes. The effects of different concentrations (20, 10, 5, 2.5, 1.25, and 0.75 μL) of turmeric essential oil into chitosan-based edible coating were evaluated. The sessile drop technique was applied to measure the contact angles on the surface of the tomatoes. The critical surface tension of the tomato was 18.36 mN/m, and its polar and dispersive component was 3.55 mN/m and 27.31 mN/m. The surface tension of the tomato was found to be 30.86 mN/m. All these surface tension were obtained from the Zisman plot method.

Effect of N, S Co-doped TiO2 concentration on photocatalytic degradation of phenol

The effect of N, S Co-doped TiO2 concentration on photocatalytic degradation of phenol was investigated. The photocatalyst were prepared using sol-gel method with different concentration of dopant ranging from 0.5% to 1.0%. The precursor of titania was Titanium (IV) isopropoxide (TTIP) while the sources of nitrogen and sulfur were ammonium nitrate and thiourea respectively. The precursors were mixed to obtain a gel. The gel was dried, ground and calcined at 600 °C. The characterization of the photocatalyst using XRD showed the presence of anatase phase only and dopant concentration of 1.0% had the smallest size of crystallite which is 24 nm. The performance of the photocatalyst was tested under visible light for five hours of irradiation time. The highest degradation efficiency of phenol was at 81.8% by dopant concentration of 1.0%.

Combination of photocatalytic and biological process for treatment of wastewater

The combined phenol treatment approaches were carried out in two separate sequences (photo-biodegradation and bio-photodegradation). TiO2/ZnO/N was used in photodegradation part and mixed consortia in biodegradation part. In the sequence where the photocatalytic was employed as a pretreatment, nearly 70% of initial 50 ppm of phenol were removed within 6 h reaction, whereas a total phenol degradation of 81% was achieved in another sequence. The combined treatment enhanced overall phenol removal compared to single treatment alone. The characterization of catalyst powder synthesis by X-ray diffraction (XRD) confirmed the phase composition of TiO2/ZnO/N composites while Field Electron Scanning Electron Microscopy (FESEM) indicates intimate association of catalyst within surface methodologies.

Chemical Engineering students soft-skills in Integrated Project (IP) Part 4

Faculty of Chemical Engineering (FKK) has been implementing Integrated Project (IP) as one of the element in teaching. It is a defined short project formally introduced to combine assignments given by respective lecturers from 3-4 selected courses, mimicking the final year Chemical Engineering Capstone project but students are asked to present the findings in groups. By looking into the results of IP in 2012 and 2013, CDIO has been introduced to overcome issue of unmeasured soft skills, a vital communication aspect for engineers. CDIO has been incorporated by various factors such as disciplinary knowledge, personal and professional skills (problem solving and system thinking), interpersonal skills (communication and teamwork) and CDIO skills (Conceive-Design: experience learning). This paper presents the outcome of soft-skills results on Semester 4 students from Bioprocess Engineering Department (EH222) during their IP presentation in June 2015. Three courses have been involved; Genetic Engineering (CBE 552), Separation (CBE 582) and Chemical Reaction Engineering (CHE 594). Surveys shows that IP4 has been accepted by the students and results vary with implementation as well as students have really shows better soft-skills quality during the IP4 June 2015 through the thorough analysis and focused questions constructed using high-order thinking skill by The Bloom Taxonomy.

Effect of Temperature on the Colour and TSS Removal of Batik Dye Wastes in an Integrated Biological and Filtration Treatment System

In this study, conventional filter system (with a polypropylene membrane) was used with L. delbrueckii to treat dye waste from textile waste water. The purpose of this study was to determine the effect of temperature on the colour and TSS removal of dye wastes in an integrated biological and filtration treatment system. Temperature was varied in a range of 33oC, 35oC, 37oC and 39oC and pH was controlled at 6 for 50 wt% dilution of dye. Fourier Transform Infrared Sprectroscopy (FTIR), Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES), color removal, pH profile and total suspended solid (TSS) analyses were done on the dye waste before and after the treatment. The optimum temperature and pH identified for dye degradation were at 37oC and 6 with initial color removal of 22.6% and final removal of 75%. Initial total suspended solid removed was 5% whereas the final removal was 75%.

Optimization of Drying and Extraction Process of Pereskia bleo Leaves in Determining Antioxidant Properties Utilizing Pareto ANOVA

Pereskia Bleo is commonly used among the local traditional medicine practitioners to prevent or treat cancer by consuming the leaves either raw or taken as a concoction brewed from fresh leaves. However, more research, regulation and standardization are required before herbal medicines can be recommended as effective and safe therapies. The objectives of this study are to obtain the optimum drying parameter and to identify the concentrations of phenolic content expressed as gallic acid equivalents (GAEs) in Pereskia bleo leaves. Pareto ANOVA method was used to study the optimum condition and the total phenolic content via F-Test using three samples for variance and three-factor with replication. Taguchi ANOVA was performed using SN ratio with L9 orthogonal array to accommodate the three factor level. The drying time were tested for 3 hours, 4 hours and 5 hours. The result shows that drying time is the significant factor in drying process and followed by drying temperature and solvent volume used. The drying experiments were conducted at operating temperature of 35 °C, 40 °C and 45 °C. While the extraction were conducted at different volume using methanol of 150 ml, 180 ml and 200 ml. The standard curve of total phenolic content was based on the gallic acid compound. The total phenolic content in C2 was at the most suitable for being used as antioxidant for consumption in human body with drying time of 5 hours at 45 °C by using 180 ml of methanol for extraction of P.bleo leaves.

Microwave-Alkali Activation on the Morphology and Structure of Bamboo Activated Carbon

A study was conducted for production of activated carbon (AC) from industrial bamboo waste using carbonization and Microwave-alkali (Mw-A) activation techniques. The aim of the study is to produce activated carbon with higher surface area via Mw-A activation techniques. The study was focused on the effect of activation (KOH soaking and Mw-A) and carbonization temperature (400oC and 500oC) on the physical and chemical structure of AC. The analysis was conducted using proximate analysis, BET surface area, FESEM and FTIR analysis. The morphology and characteristic study on activated carbon shown that Mw-A activation techniques gave higher BET surface area and well develop pore structure. The results indicated that Mw-A activation of activated carbon gave BET surface area of 950m2g-1, whereas by using steam activation only 719 m2g-1 of BET surface area was recorded. Higher carbonization temperature for Mw-A treated bamboo produced higher surface area of AC. At 500oC, 1578m2g-1 BET surface area of AC was achieved. This work highlighted, Mw-A activation can be applied and further enhanced to obtain higher surface area of activated carbon derived from industrial bamboo waste.

Kinetic study of free and immobilized enzymes for bioconversion of tapioca slurry into BioSugar

This paper highlights the kinetic parameter of the free and immobilized enzymes (alpha-amylase, glucoamylase and cellulase) systems. The kinetic parameters were calculated using Lineweaver-Burk plot. The Michaelis constant (Km) of free alpha-amylase, glucoamylase and cellulase were 4.542, 1.069 and 9.082 mg/mL, respectively. For the immobilized enzymes (alphaamylase, glucoamylase and cellulase), the Km values were 4.488, 2.196, 6.309 mg/mL, respectively. In general, the results showed immobilized alpha-amylase performed better compared to free alpha-amylase. However, for glucoamylase the Km value doubled which indicated the affinity reduction of enzyme towards the substrate. The affinity of immobilized alpha-amylase and cellulase were equal or better than the free alpha-amylase and cellulase. The overall results for immobilized enzymes system showed that glucoamylase has higher affinity towards the substrate followed by alpha-amylase and cellulase. Therefore, the immobilized enzymes system has high potential for bioconversion of tapioca slurry into glucose.