Kamaruzzaman Yunus

Phytosterols and their extraction from various plant matrices using supercritical carbon dioxide: a review

Phytosterols provide important health benefits: in particular, the lowering of cholesterol. From environmental and commercial points of view, the most appropriate technique has been searched for extracting phytosterols from plant matrices. As a green technology, supercritical fluid extraction (SFE) using carbon dioxide (CO2) is widely used to extract bioactive compounds from different plant matrices. Several studies have been performed to extract phytosterols using supercritical CO2 (SC-CO2) and this technology has clearly offered potential advantages over conventional extraction methods. However, the efficiency of SFE technology fully relies on the processing parameters, chemistry of interest compounds, nature of the plant matrices and expertise of handling. This review covers SFE technology with particular reference to phytosterol extraction using SC-CO2. Moreover, the chemistry of phytosterols, properties of supercritical fluids (SFs) and the applied experimental designs have been discussed for better understanding of phytosterol solubility in SC-CO2.

Coastal water quality of Tioman Island: effects of human activity and the distance from shoreline

A study was conducted to know the (i) effect of anthropogenic activity and (ii) effects of distance from shoreline on the coastal water quality of Tioman Island, Malaysia. This study was a part of marine expedition conducted on 4 July 2012 to understand coral diversity and distribution around coastal water of Tioman Island. A series of physicochemical parameters namely temperature, dissolved oxygen (DO), pH, salinity, transparency, total suspended solids, nitrate, ammonia, phosphate phosphorus, and silicate were determined in this study. A total of 16 different study sites (stations 1‐16) were selected in the coastal water around the Tioman Island. Half of the study sites was located within 1 km from the shoreline and other half was located approximately 6 km away from the shoreline. Some study sites are characterized by no human activity, while some sites are characterized by diving activities. A few study sites are characterized with both diving activity and near residential area. The overall mean values of different water quality parameters recorded in the all sampling stations were temperature 27.98 ± 0.40˚C, pH 8.34 ± 0.02, DO 6.92 ± 0.43 (mg l �1 ), salinity 33.54 ± 0.11 pss, TSS 0.39 ± 0.03 g l �1 , nitrate 0.85 ± 0.55 μM, ammonia 1.89 ± 0.56 μM, phosphate 0.16 ± 0.09 μM, and silicate 2.62 ± 0.76 μM. Temperature, DO, transparency, salinity, and ammonia were significantly affected by anthropogenic activity, while anthropogenic activity had no significant effect on pH, total suspended solids, nitrate, and phosphate. No significant difference was observed between the water quality of 1 km from shoreline and 6 km away from shoreline. Good and careful management by the authorities of this island may save the biodiversity and beauty of the coastal water of Tioman Island. Therefore, a balance between human activity and conservation of biodiversity on the coastal water of Tioman Island is needed.

Selection of the Most Significant Variables of Air Pollutants Using Sensitivity Analysis

This study was conducted to determine the most significant parameters for the air-pollutant index (API) prediction in Malaysia using data covering a 7-year period (2006–2012) obtained from the Malaysian Department of Environment (DOE). The sensitivity analysis method coupled with the artificial neural network (ANN) was applied. Nine models (ANN-API-AP, ANN-API-LCO, ANN-API-LO3, ANN-API-LPM10, ANN-API-LSO2, ANN-API-LNO2, ANN-API-LCH4, ANN-API-LNmHC and ANN-API-LTHC) were carried out in the sensitivity analysis test. From the findings, PM10 and CO were identified as the most significant parameters in Malaysia. Three artificial neural network models (ANN-API-AP, ANN-API-LO, and ANN-API-DOE) were compared based on the performance criterion [R2, root-mean-square error (RMSE), and squared sum of all errors (SSE)] for the best prediction model selection. The ANN-API-AP, ANN-API-LO, and ANN-API-DOE models have R2 values of 0.733, 0.578, and 0.742, respectively; RMSE values of 8.689, 10.858, and 8.357, respectively; SSE values of 762,767.22, 1,191,280.60, and 705,600.05, respectively. The findings exhibit the ANN-API-LO model has a lower value in R2 and higher values in RMSE and SSE than others. ANN-API-LO model was considered as the best model of prediction because of fewer variables was utilized as input and far less complex than others. Hence, the use of fewer parameters of the API prediction has been highly practicable for air resource management because of its time and cost efficiency.

Determination of Two Different Aeration Time on Food Waste Composting

Increasing volume of organic waste especially food waste due to increased population can affect human and also the environment if it is not managed properly. One of the methods to treat food waste is composting. However, there are many problems regarding composting, for example, time taken to complete the composting process. Thus, the objective for this study is to compare two aeration times used for composting. Methodology for this study started with collecting the food waste, drying and grinding process before starting the composting, and finishing the process in 3 days. Results show that from the two different aeration times, it shows that pH of Compost A (at 34th hour) become neutral faster than Compost B (at 55th hour). There is no significant different for compost temperature between Compost A and Compost B (minimum and maximum). Besides that, total weight reduction for Compost B (45%) is higher compared with Compost A (31%). Even though Compost B is slower to reach pH neutral, it is faster in reduction of total weight. Thus, it can solve the problem especially in increasing volume of food waste.

AN Overview of Radioisotopels Study in Water Pollution

Radioisotopes can be defined as the radioactive isotopes of an element. They refer to the atoms that contain an unstable combination of neutrons and protons. The combination can occur naturally or by altering the atoms. Nowadays, radioactive materials have become major contributing pollutants for a lot of cases of disability and mortality in all over the world. They have become a serious fear of the human, environment, and aquatic organism, although they are exposed to low levels of exposure. Therefore, to overcome these problems, the effective and easier prevention strategies should be taken and encouraged by all related parties such as industries, resi-dents, and government. Radioisotope becomes as an essential part in medical, radiography and other fields of research including the environmental study. One of the applications is they can be used as the indicators in order to identify the pollutant sources. This method can be applied in surface water around industrial area and non-industrial area. As the example, the standard limit concentra-tion of Uranium is 10ppb while for Thorium is 0.50 ppb. The study regarding radioisotope usually uses analytical instruments, for example, Inductively Coupled-Plasma Mass Spectrometry (ICP-MS) and X-Ray Fluorescence (XRF). Basically, this paper will give ideas on overview of radioisotope study and reference for acquiring a better quality of surface water in the present and future by us-ing the environmental forensic study application.

Phytochemical Composition, Biological Activities and Processing Method of Genus Anisophyllea : A Review

Anisophyllea disticha is one of the species of genus Anisophyllea that is not pharmacologically investigated despite its high utilization by the folklore. Leaf, stem and root of this plant are being used especially in treating diarrhea, dysentery, jaundice, refreshing men’s body, revitalizing the birth canal of women after delivering the baby as well as relieving weariness and body aches. The medicinal properties of A. disticha are predicted based on a literature review that provides information on secondary metabolites present and biological activities of this genus. The most reported biological activities comprise of antimicrobial, antioxidant, anti-diabetic and DNA damaging activity. From the previous studies, it can be observed that the extraction of bioactive components from this genus has been conducted using conventional method such as maceration, percolation and soxhlet. In this review, phytochemical contents, bioactivities and the methods of extraction of bioactive compounds from genus Anisophyllea have been broadly discussed. The advantages, as well as disadvantages of both conventional and non-conventional extraction methods have also been explained. Therefore, the extraction using non-conventional method like supercritical fluid extraction could provide the opportunity to obtain highly purified chemical constituents with potential in the application of various fields.

Stereospermum fimbriatum as a potential source of phytochemicals: A review of Stereospermum genus.

Stereospermum fimbriatum is one of the medicinal plants that has been claimed to be used traditionally to treat several illnesses such as stomachache, earache, skin irritation and postpartum illness. The genus of this plant is known to possess medicinal properties in every part of the plant. Therapeutic potential of S. fimbriatum is anticipated based on numerous previous studies that documented variety of phytochemical contents and bioactivity of the genus. The most reported bioactivities of its genus are antimicrobial, antioxidant, anti-diabetic, anti-inflammatory, anti-diarrheal and analgesic activities. S. fimbriatum is a rare species that has not been discovered yet. Thus, this review aims at highlighting the potentials of S. fimbriatum by collecting available data on the bioactivities of its genus and set the directions for future research on this plant.

Phosphoric acid activated carbon as borderline and soft metal ions scavenger

Three activated carbons have been prepared, two from oil-palm shell and one from coconut shell, by the phosphoric acid activation process. Adsorption isotherms of copper(II) were determined to evaluate and compare the performance of experimental carbons. The obtained data are fitted very well to Langmuir and Freundlich adsorption models. All prepared activated carbons show 4–7-fold high adsorption capacity (qmax 19.5–23/18.6–21 mg g−1) than that of the commercial ones (qmax 5.6/2.9 mg g−1) under the conducted experimental conditions. The mechanism of adsorption was evaluated from the competitive adsorption of copper(II) and calcium(II) in a binary solution depending on their behaviour as Lewis acid and assessed as inner-sphere complexation. The competitive adsorption of copper(II) with other borderline and soft metal ions was evaluated by the best scavenger using a solution of ternary solute of copper(II), nickel(II) and lead(II). The adsorption selectivity order is determined as follows: Pb > Cu ≫ Ni.

A Highly Efficient Activated Carbon by Chemical Activation Method for Adsorption of Paraquat (Toxin)

The optimum condition for preparing a highly efficient activated carbon has been investigated in this work. The effects of different activation temperatures on the pore structure and surface morphology of highly efficient activated carbon (AC) derived from waste palm shell by chemical activation method using phosphoric acid as activating agent were studied. For activation, different activation temperatures in the range of 550 °C-650 °C were carried out. Activated carbon with well developed pore size were produced at activation temperature of 600 °C for 2 hours. At this temperature the Brunauer , Emmett and Teller (BET) surface areas are 1287 m2g-1, the total pore volume for adsorption and desorption are 0.742 cm3 g-1. Scanning Electron Microscope also confirmed the porosity of the highly efficient activated carbon. Finally it was tested in vitro to determine its adsorbing capacity for paraquat as a toxin. For optimum adsorption ability of activated carbon for paraquat, 0.9% NaCl solution is the most suitable solvent. The paraquat preferentially adsorbed onto the activated carbon in NaCl solution. The adsorption ability of the activated carbon (the amount adsorbed) for paraquat observed to be 99.9 mg g-1.