Nilai C1/Br dan Halida/pb di dalam minyak petrol tempatan

Unsur Br (dan C1) juga) sering dikaitkan dengan logam Pb sebagai bahan pencemaran dari ekzos automobile, sehubungan dengan ini, kajian telah dijalankan bagi menganalisis unsure Br dan C1 di dalam sample minyak petrol daripada 6 buah syarikat pengeluar minyak petrol terkemuka di Negara ini. Nisbah C1/Br yang diperolehi adalah di antara 0.017 - 0.515, manakala nisbah puratanya ialah 0.322  0.200. Anggaran purata Br/Pb ialah 0.862, manakala nilai purata bagi C1/Pb ialah 0.195. Keputusan kajian tersebut menunjukkan bahawa nilai Br/Pb dan C1/Pb di dalam petrol tempatan tidak sama dengan yang terdapat di Negara-negara lain. Seterusnya faktor-faktor yang menyebabkan perbezaan ini dibincangkan di dalam kertas kerja ini

Characterization of Fine and Coarse Atmospheric Aerosols in Kuala Lumpur

From July 1988 to December 1990 daily samples of atmospheric aerosols segregated into fine particlas, FP (aerodynamic diameter, da 2.5 !Lm) and coarse particles, CP (2.5!Lm ~ da ~ 10 !Lm) were collected using a dichotomous sampler sited at the Universiti Teknologi Malaysia, Kuala Lumpur. Eighteen elements (AJ, As, Br, Ca, Cl, Co, Fe, K, Mn, Na, i, P, Pb, S, Sb, Si, V, and Zn) were determined from the aerosol samples. On average, the total elemental concentration made up 19, 33, and 23% of the FP, CP, and TP (TP=FP+CP) fractions respectively, and approximately 70% of As, Br, K, Na, Pb, S, and V were found to be in the fine fraction. Both Sand Si constituted the largest percentage of the total elemental concentration of 61 and 44% in the FP and CP fractions, respectively. Based on a source apportionment study, the soil and marine environments contributed 21 and 5% of the TP fraction while the remaining 74% of the aerosol concentration is yet to be explained

Rare earth elements distribution in marine sediments of Malaysia coasts

In the east coast Peninsular Malaysia region, sediments are transported by several rivers from the east Malaysia into the South China Sea estuary. In the vicinity of the five river estuaries core sediments were collected in order to investigate rare earth elements (REEs) profile. Core sediments were divided into strata of between 2 to 4 cm intervals and prepared for analyzing by ICP-AES. REE concentrations of 54.3 μg/gr at 24–26 cm in EC4 increased to 114.1 μg/gr at 20–22 cm in EC5. The measured concentration of LREEs and Fe normalized enrichment factors indicated that sediments were not enriched with light rare earth elements derived from effluents of anthropogenic activities. Results of the total concentration were used to establish baseline data in environmental pollution assessment and to develop the correlations between the Ce/Ce* and Eu/Eu* anomalies and the distribution patterns of some light rare earth elements (LREEs) and the heavy rare earth elements (HREEs). The chondrite-normalized ratios of REEs showed LREEs enrichment and flat HREE depletion

Weathering product of granite as a possible source of strategic mineral

Several soil samples and granite bedrock samples from Cameron Highlands were analyzed for its elemental concentration using instrumental neutron activation analysis. A total of 34 elements were identified and their concentrations were determined in a single analytical session. Enrichment factor of elemental concentration in the top soil were computed. The findings indicate certain elements were enriched that may facilitates economic beneficiation

Determination of trace metals in lichens under different ecological conditions in Malaysia urban proximity and pristine environment

This study is carried out to report the concentrations of trace elements (As, Cd, Cr, Cu, Mn, Pb, V and Zn) in several species sample of lichens which were collected from Maliau Basin, Sabah and Universiti Kebangsaan Malaysia (UKM) Bangi campus in Selangor. Comparison with the natural concentration of trace elements from different species of lichens collected in Maliau Basin with the samples collected in UKM Campus provides unambiguous evidence of pollutions from both study locations. Eight species of lichens were sampled from Maliau Basin, Sabah, and two more species from UKM campus, Bangi. The eight species collected from Maliau Basin were Coccocarpia dissecta, Cladonia cf. floerkeana, Cladonia adspersa, Pseudocyphellaria cf. gilva, Parmotrema acrotrychum, Parmotrema cristiferum, Parmotrema cf. pseudonilgherrense, and Sticita weigelii, while the species collected from UKM campus were Parmotrema praesorediosum and Dirinaria picta. Generally, the results of this study showed that concentrations of trace elements in the lichens from UKM campus were relatively higher than those from Maliau Basin. Besides that, the distribution of each trace metal is uneven in each lichen species from Maliau Basin. The ranges of concentrations (µg/g) of each trace element in the lichens from UKM campus were V (0.38-0.67), Cr (1.02-3.78), Mn (3.48-7.94), Cu (9.97-44.39), Zn (68.38-98.36), As (0.76-1.73), Cd (0.05-0.09) and Pb (12.36-31.99), whereas that of each trace element in the lichens from Maliau Basin were V (0.01-0.14), Cr (0.46-0.93), Mn (3.28-234.35), Cu (3.05-13.74), Zn (1.61-16.01), As (<2.00), Cd (0.0004-0.09) and Pb (1.49-7.73). The fast pace of modernization together with air pollution may probably be the reason for the difference in level of metals accumulated compared from both study locations. The present study will be a reference record for conducting future biomonitoring studies in this fast-growing country

Geochemistry of sediments in Johor Strait between Malaysia and Singapore

We report the results of a study of the geochemistry of sediments of the Strait of Johor between the southern tip of peninsular Malaysia and the island nation of Singapore. This shallow channel in the continental shelf connects the South China Sea to the east with the Strait of Melaka to the west. We analyzed sediment layers collected at 25 locations along the east-west axis of the Strait, from the estuary of the Johor river at its eastern end to the estuary of the Pulai river at its western end, using a box corer to minimize disturbance of surficial layers. Both trace metal concentrations and bulk sediment properties change drastically between the relatively pristine open ends of the Strait and the dam-like causeway near the east-west center of the Strait, where the greatest anthropogenic discharges occur and water flows become too sluggish to disperse them. Reasonably “normal” muddy sediments with oxygenated surface layers and apparently healthy benthic communities are found at both open ends of the Strait. Anoxic, watery, black muds, smelling of H2S and with no macrobenthic organisms, are found in a zone extending several kilometers on either side of the causeway built in 1924 to facilitate commerce between the island of Singapore and peninsular Malaysia. This zone of anoxic sediment has developed since the causeway was built, due primarily to discharges of sewage wastes with their high oxygen demand, and to greatly reduced water dispersion. Total concentrations of V, Cr, Mn, Ni, Cu, Co and possibly Cd and Sc in Johor Strait sediments are lower than concentrations estimated for average shales and mean crustal materials. This is attributed to increased solubility of all these elements during intense chemical weathering in the hot, humid tropical climate of the drainage basin. Total concentrations of U and Th are greater in Johor sediments than in both types of average materials, due to greater abundance of granites and monazites in the Johor drainage basin. Greater than global average concentrations of Pb and Zn are found in surface sediments near the causeway, due principally to additional inputs associated with large volumes of vehicular traffic across the causeway. Concentrations of As are higher in Johor sediment than in global average materials, for unknown reasons. Johor Strait sediments have rare earth concentrations less than or equal to those in average shales, and no evidence of enrichments of light rare earth elements from wastes from the large oil refineries south of Singapore Island. Excess 210Pb activities and inventories in sediments of the shallow, low latitude Johor Strait are similar to those in nearby Gulf of Thailand sediments. They are several times lower than those in sediments underlying deeper waters from mid-latitude continental shelves, due to less in situ production of 210Pb from decay of parent 226Ra in the shallower Johor Strait water column, lower input of 210Pb from atmospheric fallout at lower latitudes, and less riverine input of particulare 210Pb to Johor Strait. Johor Strait sediment activities and inventories of this natural radionuclide are limited by its supply rather than by particulate scavenging reactions. Sediments on the tropical Amazon shelf have similar 210Pb activities, but inventories over ten times those in Johor Strait sediments. The differences are because of much faster sediment accumulation rates on the Amazon shelf, and because lateral water transport brings more offshore waters with dissolved excess 210Pb produced in situ on to the Amazon shelf than into Johor Strait. The low excess 210Pb activities in Johor Strait sediments often show erratic changes with depth that cannot be reliably modeled by assuming steady state; constant deposition rate of particles of uniform bulk chemistry, mineralogy and initial unsupported 210Pb activity; and that mixing is limited to a recognizable surface layer. The 210Pb profiles are still essential in explaining differences in As/Sc and Zn, Pb, and Cr concentration profiles in the cores

Testing the applicability of the k(o)-NAA method at the MINT's TRIGA MARK II reactor

The Analytical Chemistry Laboratory at MINT is using the NAA technique since 1980s and is the only laboratory in Malaysia equipped with a research reactor, namely the TRIGA MARK II. Throughout the years the development of NAA technique has been very encouraging and was made applicable to a wide range of samples. At present, the k0 method has become the preferred standardization method of NAA (k0-NAA) due to its multi-elemental analysis capability without using standards. Additionally, the k0 method describes NAA in physically and mathematically understandable definitions and is very suitable for computer evaluation. Eventually, the k0-NAA method has been adopted by MINT in 2003, in collaboration with the Nuclear Research Institute (NRI), Vietnam. The reactor neutron parameters (a and f) for the pneumatic transfer system and for the rotary rack at various locations, as well as the detector efficiencies were determined. After calibration of the reactor and the detectors, the implemented k0 method was validated by analyzing some certified reference materials (including IAEA Soil 7, NIST 1633a, NIST 1632c, NIST 1646a and IAEA 140/TM). The analysis results of the CRMs showed an average u score well below the threshold value of 2 with a precision of better than 710% for most of the elemental concentrations obtained, validating herewith the introduction of the k0-NAA method at the MINT

Assessment of Elemental Pollution in Marine Sediment from Talang-Satang and Bako National Park of Sarawak, Malaysia (Special Issue> Malaysian Nuclear Agency)

The assessments ofelemental polluti oinn sediment collected from national park ofSarawak were done based on their distribution pattern ,geoaccumulation index and enrichment factor ,The enrichment factor s(EF )were determined by the elemental rationing method, whilst the geoaccumulati oinndex (Ig .by. )comparing of current concentration to background concentration of metals, The elements were analyzed by using Instmmenta1 Neutron Activatio nAnalysis (INAA) .The results of enrichment facto rshow tha tTalang-Satang and Bako National Park have significant contaminated by toxic elements such as As, Cr, Sb, Ti and U. Base on the classification system proposed for sediment qualit ywith referring to Ig. ,the sediment quali tyof the Talang-Satang and Bako National Park for Arsenic (As) contamination can be categorized as moderate to extremely contaminated. Contamination of element such as Cr, Sb and Ti can be categorized as uncontaminated to moderate contaminated, and U can be categorized as uncontaminated to moderate and strong contaminated, The average concentration of As in sediment of Bako shown surpassed sediment qualit yguidelin eCprobable effect concentration - PEC) value, whilst Cr concentration in sediment of Talang-Satang shown above midpoint effect concentration (MEC) .This indicatin gt,he sediment ofBako and Talang-Satang could have a potentia lfor producing chronic effect to the marine biot aor benthi ocrganism

Analysis of PM10 in Kuala Terengganu by Instrumental Neutron Activation Analysis

Instrumental neutron activation analysis was used for the determination of trace elements in airborne particulate matter (PM10) for air pollution monitoring. For the collection of air samples, the PM10 high volume sampler unit and Whatman 41 cellulose filter papers were employed. Samples were collected at 13 selected sampling sites covering areas in the city center, inner and outer city of Kuala Terengganu during the month of March 2005. The average PM10 was 69.64 μgm-3, 83.58 μgm-3 and 72.22 μgm-3 for sampling stations located in the city center, inner and outer city of Kuala Terengganu, respectively. It was found that the mass of air particles in the study area was higher compared to Bangi and Kuala Lumpur. Chemical analysis of selected elements (Al, Fe, Cu, Pb, V, Mn, Zn, Cr, As Cd), ionic species (Na+, SO4 2-, Cl-, NH4 +,Mg2+, K+ , Ca2+) and some rare earth elements (REE) were included in this study. In general, most of the average concentration of trace elements in the city center sampling stations was generally higher than the inner and outer city sampling stations. The concentrations of trace elements in sampling stations follow the general trend of Al>Fe>Zn>Cu>Mn>Pb>V>Cr>As>Ni>Cd. The elements concentration ranged from 680-2119 ngm-3, 170-1132 ngm-3, 8.13-122.4 ngm-3, 8.48-77.3 ngm-3, 7.68-14.4 ngm-3, 1-90.4 ngm-3, 1.47-3.25 ngm-3, 1.43-5.03 ngm-3, 1.15-4.45 ngm-3, 0.24-3.75 ngm-3 and 0.28-1.36 ngm-3, respectively

Polycyclic aromatic hydrocarbon (PAH) contamination in the sediments of East Coast Peninsular Malaysia

The polycyclic aromatic hydrocarbons (PAHs) are pollutants of concern due to their persistent in the marine ecosystem, thus its can cause long-term adverse effect to the marine life. In this study the concentrations of PAHs in east coast Peninsular Malaysia sediments were determined. About ten stations along the east coast of the coastal area were selected to collect sediment samples using grab sampler. The PAHs from the sediment samples were soxhlet extracted using mixture of hexane and dichloromethane (DCM). Fractionation was done using the silica-alumina column. About 17 compounds of the PAHs were determined using the Gas Chromatography-Mass Spectrometer (GCMS model QP5050A). The Σ PAHs was found in range between 0.26μg/g to 0.59μg/g dry weight. The data from the study signified that the main source of PAHs in the sediment of the east coast peninsular Malaysia is originated from the pyrolytic source