Advances in Science and Technology Vol. 123

Abstract: Seawater desalination can be applied in Malaysia to overcome water supply issues which majorly due to water pollution. The desalination using membrane technology highly depends on the design of the membrane, operating conditions of the process, and the feed characteristics of the seawater. The aim of this research is to identify the effect of these factors on the performance of the reverse osmosis membrane in desalinating seawater in Malaysia. The simulation study is conducted by using the IMS Design program. The reverse osmosis (RO) membrane process that consists of three membrane stages arranged in series is designed accordingly. The effect of operating temperature, feed concentration, feed pH, and membrane stages on the salt rejection and permeate flux are evaluated. As a result, an increase in temperature and feed concentration reduces the salt rejection percentage, while increasing the permeate flux. However, there is no significant effect of feed pH on the salt rejection percentage and permeate flux since the type of membrane used is able to operate in a wide pH range. Lastly, the four stages membrane increases the permeate recovery and permeate flux but reduces the percentage of salt rejection.

Abstract: 2,4,6- Trichlorophenol (TCP) is a toxic, mutagenic, and carcinogenic compound found in the emission from fossil fuel combustion, municipal waste incineration, and water disinfection for domestic usage. TCP has been classified as one of the primary pollutants that should be treated for inland water discharge. This study aims to introduce a new approach to remove the TCP in wastewater through the simple and cost-effective progressive freeze concentration (PFC) method. The effect of coolant temperature and circulation flow rate in the PFC method was investigated, and its effectiveness was characterized by calculating the effective partition constant (K) and the TCP reduction (T_R). Optimisation was performed to determine the optimum condition for the TCP removal using Response Surface Methodology (RSM). The best circulation flow rate and coolant temperature for the one-variable-at-a-time (OVAT) experiment were found to be 900 rpm and -5 °C. Based on ANOVA, the PFC system was predicted to produce a low K value and high T_R with temperature in the range of -4.5 °C to -5 °C and circulation flow rate in the range of 900 rpm to 1000 rpm.

Abstract: Modification of activated carbon using chemical surfactant is not eco sustainable because the chemical will have the potential to desorb into aqueous medium. Due to the environmental concerns, this research aims to investigate the usage of plant-based surfactant as a modifying agent onto the surface of activated carbon (AC) to be used in the removal of lead from aqueous solution. AC was impregnated with sodium lauryl sulfoacetate (SLSA), a plant based anionic surfactant at different concentrations. Atomic absorption spectroscopy (AAS) was used to examine the percentage removal of lead and to identify the effect of pH on the adsorptive properties of SIAC. The results exhibited the enhancement in the adsorption of lead using modified AC with SLSA. It was found that SIAC at 25 mg/L has the highest lead removal which was 99%. The optimum concentration anionic surfactant obtained was used in parametric study effect of pH. The optimum pH was obtained at pH 6 as it indicated the highest removal of lead (84.92%). Excel software was used to fit the data using polynomial regression. R² and adjusted R derived from the analysis were 0.9043 and 0.9522, respectively. As a result of the ANOVA study, it was shown that the mathematical formula can be utilised to forecast the removal of lead from aqueous solution.

Abstract: This work's main objective is to investigate the flotation process's efficiency in removing the oil from a stable oil-water emulsion containing surfactant (MFOMAX) and polymer (GLP-100). A total of 45 flotation tests were carried out with varying factors such as gas bubble flowrate, MFOMAX and GLP-100 concentration, as well as the flotation time. These factors have become the model's input, and the effluent's oil concentration calculated in term of flotation efficiency (%) has been the model’s output. 75% of the total data was used for training and 25% was used for testing. Coefficient of determination (R2) and average absolute percentage error (AAPE) was used as the models' performance indicators. A high R2 value (0.956) was given by the ANFIS model and AAPE of 10.14%, indicating that the predicted data agrees well with the actual data. Potential optimization to the flotation equipment on separating oil-water in the stable emulsion containing MFOMAX and GLP-100 have been discussed.

Abstract: Crude Palm Oil (CPO) is extracted from the mesocarp of fruit obtained from the oil palm tree, which is also known as Elaeis guineensis. CPO contains Free Fatty Acid (FFA), which is one of the unnecessary constituents in CPO that is not good for food items and human consumption. Various methods for the deacidification process led to maximising the processing time, energy, and operating costs. Therefore, the aim of this research is to do a physical upgrading of the CPO, which may remove the FFA from the CPO while minimising the processing time, energy, and operating costs. However, prior to the physical upgrading of the CPO, it is important to highlight the physicochemical and quality characterisation of the CPO, which is essential and becomes a necessary procedure before the refining process. The purpose of this research is to examine the physicochemical and quality characteristics, which are fatty acid composition and FFA content, of the CPO, respectively. The American Oil Chemists’ Society (AOCS) method was used for this research work. The results showed the percentage of palmitic acid, stearic acid, oleic acid, and linoleic acid of the CPO were 40.1 %, 2.5 %, 37.5 %, and 19.9 %, respectively. The FFA content of the CPO was 4.90 %. The findings indicated the CPO met the recommended value by the Malaysian Palm Oil Board (MPOB). The physicochemical and quality characterisation of the CPO provide information as a guideline before the physical upgrading of the CPO that may produce palm oil products with good constituents for human health and the food industry.

Abstract: Phytochemical screening was conducted on Hylocereus undatus foliage to determine the presence of alkaloids, flavonoids, tannins, and saponins using methanol and chloroform solvents via oven-dried and open air-dried methods. As for the antioxidant activity, powdered Hylocereus undatus foliage were extracted using both solvents through Ferric Reduction Antioxidant Power (FRAP) assay; and the findings were then compared to 2,2-Diphenyl-1-Ipicrylhydrazyl (DPPH) assay from previous studies. Results revealed that for both methods in phytochemical screening, flavonoids were present only in methanol extract; however, saponins were present in both extracts. No alkaloid and tannins were present in both extracts using both methods. Antioxidant activity results revealed that the methanol extract (59.05%) and chloroform extract (20.58%) using the FRAP assay were comparable to that of DPPH assay in which methanol extract (88.81%) and chloroform extract (38.30%) were obtained. It concludes that Hylocereus undatus has comparable phytochemical constituents and antioxidant activity based on the different drying and assay methods.

Abstract: Fresh fruit has recently gained popularity in the market for healthy, organic, functional, and convenient foods. Production and consumption of fresh fruit increases from time to time. Consumer demand for fresh fruits that are rich in nutrition and health benefits have presented a challenge to the food industry to obtain appropriate technology to meet the need. However, there are some limitations regarding the storage of the fresh fruits. Fresh fruits cannot stand for a long term due to the rapid of ripening process in the fruit’s tissues. The ripening process commonly related to the respiration and transpiration process in the fruits tissue. Besides, the fresh-cut fruits also easily getting spoilage with a growth of microbial in the fruits. There are some innovations regarding packaging food film from synthetic materials which are quite wide applied in the food industry. This material is not an environmentally friendly due to the synthetic’s materials are not made by natural resources. Study towards the application of natural resources in the formation edible film packaging have been done. It is due to the global demand to replace the synthetic plastic film packaging with biodegradable film packaging that are environmentally friendly and users friendly. This review aims at providing a broad overview of recent scientific research related to preservation of fruits in the food industry and its health effects in consumers. It involved recent analysis of edible film incorporate with different type of essential oils from natural sources such as plants for preservations of fruits.

Abstract: Landfill Gas (LFG) composed of approximately 50% methane and 50% carbon dioxide is known as one of the Greenhouse Gases (GHGs) that could pollute the environment and contribute to the global warming. In the conventional approach, volume of methane is approximated from its emission using the Intergovernmental Panel on Climate Change (IPCC) 2006 First-order Decay (FOD) model. This model has been formalized as a USEPA landfill gas emission model (LandGEM) in 2005 and IPCC Waste Model in 2006. LandGEM is a Microsoft Excel based software application that uses a first-order decay rate equation to calculate methane and LFG generation. It is the most widely used LFG model and is the industry standard. However, the software requires a number of parameters estimates such as organic content, disposal data and rates, site closure dates, expansion schedules or collection efficiencies and knowledge of waste composition. Inaccuracies in the estimates can result in large errors in predicting future recovery, which could affect the production system. This research evaluate the potential of deploying the volumetric estimation technique in oil and gas exploration to locate methane accumulation location and estimate the volume prior to its emission to the atmosphere on the Air Hitam Landfill as the case study. The gross rock volume is an approximation of the total area covered by the landfill, while porosity and water saturation are simulated estimations. The result gives an approximation of 1.65 billion standard cubic feet (BSCF) of LFG in-place that could generate 25,948 tonnes of methane worth RM6 to RM8 millions of carbon credit and RM55 millions of revenues from electricity sale.