Hajar Alias

Chemically treated chicken bone waste as an efficient adsorbent for removal of acetaminophen

Present of pharmaceutical as the emerging pollutants arise the concerns of environment community regarding the potential impact of acetaminophen (ACT) on ecological and human health. Adsorption process has been proven as an effective treatment being activated carbon as the adsorbent to remove many types of pollutant including low concentration of pollutants. However, on large scale industrial processes, utilisation of activated carbon is limited because of their high production cost. Synthesis of waste materials as a precursor of adsorbent is an attractive approach in sustainable management and economic availability. In this study, the removal of ACT from aqueous solution by chemically treated chicken bone (AC) waste was investigated. The adsorption process was conducted in a batch adsorption and affected by several experimental parameters including contact time, pH, adsorbent dose, initial concentration and temperature. With AC dosage of 0.1 g about 93 % of 1,000 mg/L ACT was removed from the aqueous solution that had pH of 2 and temperature of 25 °C. Kinetic of ACT adsorption was well described by pseudo-second order kinetic model. Meanwhile, effect of initial concentration of acetaminophen adsorption data was fitted well with Freundlich isotherm model with an R2 of 0.9909. Finally, the data obtained from effect of temperature was used to determine the adsorption thermodynamic including the enthalpy, ΔH, Gibbs energy, ΔG and entropy, ΔS. It was found that the ΔG was negative at all temperature while both, ΔH and ΔS was also negative between temperatures of 25 °C to 70 °C indicating the process of ACT adsorption was exothermic reaction and the adsorption reaction is spontaneous at low temperature.

A Linear Programing Approach for Landfill Gas Utilization for Renewable Energy Production

Landfill gas (LFG) is a mixture of gases mainly CH4 and CO2 which are the most problematic of the greenhouse gases (GHGs) due primarily to their highest rate of accumulation in the environment. These two main GHGs are emitted from most landfills in developing countries. As a mitigation measure, the gases can be collected and utilized as renewable energy source. This research therefore aimed at planning the utilization of LFG for renewable energy production using linear programing approach executed in general algebraic modeling system (GAMS) and applied to Seelong landfill in Johor, Malaysia as the case study. GAMS (the optimizer) selects the most profitable LFG utilization technology from a number of options such as: gas engine, gas turbine and steam turbine for electricity or combined heat and power production; steam boiler for steam production; direct LFG distribution to residences/industries as substitutes to natural gas. The results from the optimizer gave a maximum profit of USD2.54 million per year. This included revenues from product sale and carbon credit. The results also revealed that GHG reduction of about 9,000 tons CO2eq were accomplished, and thus this is environmentally and economically beneficial environmentally (in terms of carbon credit). Furthermore, the optimization results revealed that steam turbine running on low grade LFG is the most feasible option in terms of profitability and environmental consideration. This approach can be applied to any sanitary landfill as a means of simultaneously curbing GHG emission and generating revenue.

Renewable Coconut Shell Activated Carbon Based for Ethyl Orange Dye Removal

A study on the performance of a renewable activated carbon towards concentration reduction for ethyl orange dye was conducted. The coconut shell activated carbon was prepared by varying the carbonization temperature and impregnation ratio of chemical activation agent and coconut shell. The effect of adsorbent dosage and temperature on performance of the synthesized AC was determined. The finding showed that the impregnation ratio of 2 and carbonization temperature of 800 °C were the best condition to synthesis the activated carbon. The result also showed that the increment in adsorbent dosage increased the sorption capacity for coconut shell AC. However, the temperature changes caused the fluctuation in reduction of dye concentration. Comparison with commercial activated carbon indicated that coconut shell AC had proved to be a low cost and efficient adsorbent in this research.

Thermal Characteristic of Nanofluids Containing Titanium Dioxide Nanoparticles in Ethylene Glycol

Rapid development of technology requires high-performance of cooling devices especially in heat transfer industries. In these recent years, there has been a lot of researchers show some interest in nanofluids because nanofluids is believed to be a very good coolant that exhibit some attractive characteristics as a coolant due to its high thermal properties. This research was conducted to formulate stable nanofluids containing titanium dioxide (TiO2) nanoparticles in ethylene glycol (EG) base fluid with the aid of gum Arabic (GA) as the surfactant. The thermal conductivity of nanofluids were measured. Two-step method was employed for nanofluids preparation. The results showed that in the presence of surfactant, the stability of nanofluids samples was increased because of modification of TiO2 nanoparticles surface area. The nanoparticles tend to repulse each other and decrease the agglomeration in the nanofluids. The thermal conductivity was enhanced by increasing the concentration of nanoparticles and temperature due to effect of Brownian motion. The research showed that TiO2 in EG nanofluids has the potential to be employed as a heat transfer fluids compared to the conventional fluids.

Heat transfer of alumina-deionized water nanofluids in concentric tube heat exchanger

This research studied the characteristics of nanofluids in a concentric tube heat exchanger. The objectives of this research are to prepare the stable nanofluids with addition of surfactant and to investigate the stability, properties, and heat transfer of nanofluids in concentric tube heat exchanger. Aluminium oxide (Al2O3) was added to base fluid deionized water (DW) with addition of polyvinylpyrrolidone (PVP) as surfactant by two-step method. First, the best stability ratio of nanofluids to surfactant PVP was determined by preparing several samples of 0.50 wt% nanofluids with addition of different weight fraction of surfactant. Thus, each sample has different ratio and being observed for one week by visual observation. Then, nanofluids samples (0.25, 0.50, 0.75 and 1.00 wt%) were prepared based on the best stability ratio. The properties and heat transfer of nanofluids were analyzed at different concentration of nanofluids and at different temperatures (room temperature, 40 °C, 50 °C, 60 °C and 70 °C)....

Production of Biodiesel from Waste Cooking Oil via Ultrasonic-Assisted Catalytic System

In this study, production of biodiesel from waste cooking oil (WCO) was carried out via ultrasonic-assisted transesterification method. Calcium oxide (CaO) was used as a catalyst. The effects of methanol to oil molar ratio, reaction temperature and the catalyst amount towards the percentage conversion of oil to biodiesel were investigated. The biodiesel produced was analyzed using GC-FID method. The results obtained showed that 82 % of oil was successfully converted into biodiesel. This indicates that the used oil (WCO) has the potential to be the future source of biodiesel. Catalyst concentration of 3 w/w%, methanol to oil molar ratio of 15:1 and temperature of 65°C are the best condition for the conversion of oil to biodiesel. The result obtained was found out that, methanol to oil molar ratio and catalyst amount has given significant effect on the conversion of oil. However, temperature ranged from (35 to 75) °C apparently, showed no significant effect on percentage conversion of oil.