Fakhrul Razi Ahmadun

Digital Image Processing of Palm Oil Fruits

The oil content of the flesh of mesocarp has direct relationship with color bands red, green and blue. By running intensive experiments, it was found that oil content correlated with the red color band, with a regression value of 0.86. The finding of this study may be useful for determining the ripeness of oil palm for harvesting and for the use in the operation and control of continuous steriliser in palm oil mill.

Performance of flexible membrane using kaolin dynamic membrane in treating domestic wastewater

A study using a laboratory experimental rig with a tubular configuration microfiltration fabric membrane in treating secondary effluent from domestic waster treatment plant was carried out. Several inert materials; kaolin (both heavy and light), diatomite and Fullers earth, were studied to identify an appropriate dynamic membrane material. Heavy kaolin was found to be effective and relatively easily to clean. A rapid decline in flux was observed when filtering the secondary effluent with a turbidity of about 5 NTU without using a dynamic membrane. The development of a heavy kaolin dynamic membrane was found to be a function of the kaolin concentration and crossflow velocity. However varying crossflow velocities within a limited range, such as 1.6 and 2.5 m/s produced a similar steady state flux. Permeate turbidity, which is an indication of the formation status of a dynamic membrane, improved with higher kaolin concentration and reduced with increasing crossflow velocity, within the range considered. The time taken to produce low permeate turbidity (of less than 1 NTU) was shorter with a higher heavy kaolin concentration. A similar steady state permeate turbidity is reached after prolonged filter run despite using a low heavy kaolin concentration. It was also found that a 10-min membraning time at heavy kaolin concentration of 333 mg/l was enough to lay the dynamic membrane before proceeding with filtering the secondary effluent. Permeate turbidity as low as 0.2 NTU could be attained. Secondary effluent was found unsuitable to be applied as a membraning liquid. The purity of membraning or carrier liquid was crucial in the production of an effective dynamic membrane. Feed concentrates turbidity was noticed to increase with the semi-continuous feeding. However, it does not have a significant impact on the permeate turbidity unlike when introducing a new batch of feed regardless of its concentration level.

Bench Scale Studies for Pretreatment of Sanitary Landfill Leachate with Moringa Oleifera Seeds Extract

A laboratory study using a bench scale model of two unit operations involved processes of coagulation (using Moringa oleifera seeds as a natural coagulant) and flocculation-sedimentation have been adopted to treat the leachate from Air Hitam Sanitary Landfill at Puchong in Malaysia. The results of this study has shown, that M. oleifera has a potential for the removal of heavy metals from the leachate, and may be used as a pre-treatment stage for biological treatment to eliminate a portion of the toxic heavy metals, which limit the activity of micro-organisms in the leachate.

CH4 and CO2 Detection by Using Carbon Nanotube-Based Sensors

This research was carried out to investigate the effect of gas adsorption towards the electrical resistance of carbon nanotubes (CNTs) thin film. CNTs were synthesized by Floating Catalyst Chemical Vapor Deposition (FC-CVD) method on quartz substrate at 950°C under methane gas flow rate of 150 Standard Cubic Centimeters per Minute (SCCM). Then, the electrical resistance of CNTs was measured by exposing the sensors to CO2 and CH4 gases operating at room temperature. The sensors showed high responses to the gaseous molecules. In the same experimental conditions, the recovery of the sensors was different for CO2 and CH4. It was also observed that the CNTs device behaves as a p-type semiconductor when exposed to gaseous molecules. The fabrication process was relatively simple and did not require special techniques.

The Effect of CH4 and CO2 Exposure on Carbon Nanotubes Electrical Resistance

This research was carried out to monitor and investigate the gas sensing effects on carbon nanotubes (CNTs) by a systematic study of the variations in the electrical resistance as sensor signal induced by adsorption of CO2 and CH4 gaseous molecules. The CNTs were synthesized by Floating Catalyst Chemical Vapor Deposition (FC-CVD) method on quartz substrate under benzene bubble at temperature of 700°C. Then, they were tested for gas sensing applications operating at room temperature. Upon exposure to gaseous molecules, the electrical resistance of CNTs dramatically increased for both CO2 and CH4 gases with short response time and high sensitivity. It was also observed that the CNTs device behaves as a p-type semiconductor when exposed to gaseous molecules. In addition, the recovery of the sensors and mechanism of gas sensing procedure are discussed.

Optimization for Development of Carbon Nanotubes Using Taguchi Method at Constant Temperature

In this study, an optimization of floating catalyst chemical vapor deposition (FC-CVD) using Taguchi method is done in developing multiwall nanotubes (MWNTs) at constant temperature. The reaction is run at the temperature of 850°C in atmospheric pressure with ferrocene as the catalyst precursor and benzene as the carbon feedstock. By applying Taguchi’s method as the design of experiment, three parameters: namely reaction time, hydrogen flow rate and catalyst weight have been varied during the optimization of the experiment. The results show that the BET specific surface area increases as the reaction time increases, the degree of graphitization reduces as the mass of the catalyst increases and the relative value of amorphous carbon to graphite carbon decreases as the hydrogen flow rate increases.

ARSENIC REMOVAL FROM AN EX-TIN MINING WATER POOL USING A MICROFILTRATION-COAGULATION PROCESS

The removal of arsenic from water by a microfiltration‐coagulation process was investigated. In general, arsenic removal was enhanced in the presence of a coagulant. Arsenic was removed (83% and 72%) from water containing 243–255μg/l arsenic, resulting in arsenic concentrations of 40μg/L and 68μg/L, using microfiltration‐coagulation and microfiltration, respectively. Furthermore, arsenic removal increased with decreasing specific flux, in which an almost linear relationships (r2 = 0.905) was found to relate the specific flux to arsenic removal during the microfiltration‐coagulation process. Coupling microfiltration with coagulation was also found to be effective in turbidity removal. Turbidity was decreased by 94% using microfiltration‐coagulation processes, while 70% turbidity removal was achieved using microfiltration.