Nature And Properties Of Soils

Journal of Colloid and Interface Science. Editorial.

Encyclopedia of Life Support Systems (EOLSS)

Recent progress in the structural modification of chitosan for applications in diversified biomedical fields

Recent progress on synthesis, property and application of modified chitosan: An overview

Problem statement: Mosses had been widely used as bioindicator especially to study the levels of trace metals pollutants in the surrounding ambient air because of their high efficiency to accumulate heavy metals contamination. There had been increasing demand to get a suitable analytical tools to determine the chemical contents of moss samples in this type of media. This study was conducted with the aims to get one of the best analytical methods for the analysis of moss samples. Approach: Despite the various spectroscopic techniques that normally used to analyzed heavy metals in moss, each of these techniques had its advantages and disadvantages which been summarized elsewhere. We try not to use any chemical to decompose the samples where the samples were analyzed directly in its solid form by Energy Dispersive X-Ray Fluoresence Spectrometer, EDXRF technique. The EDXRF technique optimized for its main analytical parameters. Calibration procedure was made based on the in-house standard samples. The reliability of the optimized analytical procedure was established by analyzing two certified reference materials, Pine Needle, NIST 1575 and Lichen, IAEA-336. Results: The results showed that the metals could be analyzed with percent recoveries range within 84-102% for Pine Needle and 92-125% for Lichen. The possible factors influencing the percent recoveries of the elements were discussed in details. Conclusion: On overall, it is strongly suggest that the applied EDXRF method is adequate enough to analysis the heavy metal contents in moss samples even at very small concentration with high accuracy and precisely.

Optimization of Energy Dispersive X-Ray Fluorescence Spectrometer to Analyze Heavy Metals in Moss Samples

Naturally occurring radionuclides such as 40 K, 226 Ra and 228 Ra which emit gamma radiation through their decaying process could reach the human in vicinity. The study area was chosen for its variety of surface conditions such as slope, flat land catchments and also forest area, which is used as a reference place. Soil samples were collected using hand auger, and the sampling positions were determined using a Global Positioning System (GPS). The amount of radioactivity concentration of these radionuclides is the important factor in assessing whether it is harmful or otherwise. In this study, the surface doses rate measurements were done in-situ using dose rate meter, and the radioactivity concentration levels were done by counting the soil samples using gamma spectrometer with HPGe detector in the laboratory. The amount of uranium, thorium and potassium in soil were determined using neutron activation analysis (NAA) technique. The results show a reasonably low radiation absorb dose and radiation hazard index, which is a good indication for the farmers to work in the area. Abstrak Radionuklida semulajadi seperti 40 K, 226 Ra dan 228 Ra yang memancarkan sinar gama melalui proses pereputannya boleh mengenai manusia yang berhampirannya. Kawasan kajian ini telah dipilih berdasarkan keadaan permukaan tanah yang berbeza seperti tanah rata, cerun, dan kawasan rendah yang berpaya serta kawasan hutan untuk dijadikan kawasan rujukan. Sampel tanah telah dipungut menggunakan auger dan lokasi pensampelan ditentukan dengan menggunakan sistem penempatan global (GPS). Jumlah kepekatan radioaktiviti dari radionuklida ini adalah faktor penting bagi menentukan samada ianya berbahaya atau tidak. Dalam kajian ini, pengukuran radioaktiviti dalam makmal dilakukan dengan membilang sampel tanah menggunakan spektrometer gama dilengkapkan dengan pengesan HPGe. Jumlah uranium, thorium dan kalium di dalam tanah ditentukan dengan teknik analisis pengaktifan neutron. Hasil kajian menunjukkan kadar serapan dan indeks radiasi berbahaya yang agak rendah yang menunjukkan indikasi yang baik untuk petani yang bekerja di kawasan tersebut.

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An assessment of absorbed dose and radiation hazard index from natural radioactivity

The amount of natural radionuclide present in environment, especially soils, sediment and water in the abundance tin mining area are varies depending on the amount of heavy minerals left over in that particular place. If the place used to be the processing area for tin ores, the left over known as ‘amang’ contains heavy minerals. This study was carried out in UiTM Training Center, Kg Gajah, within Kinta Valley Perak which used to be the active tin mine area in the past. Surface doses were measured using Ludlum dose rate meter, at the surface and 1 meter above the surface. The radionuclides content were measured by collecting soil samples, dried, ground, sieved using 250 µm sieve, packed in a container and counted after 4 weeks using gamma spectrometer with HPGe detector. The level of surface dose varies from one location to another, but there is a critical area which has a significantly high surface dose approaching 30 µSv/hr. The mean activity concentrations in the critical area for 40 K, 226 Ra and 228 Ra are 2521±298 Bq/kg, 3798±419 Bq/kg and 12896±1533 Bq/kg respectively. The hazard index for the critical area seems to be extremely high and is not safe for people to be there.

/pdf/surface-radiation-dose-and-radionuclide-measurement-in-ex-48fqr4rtk7.pdf

Surface radiation dose and radionuclide measurement in ex-tin mining area, kg gajah, perak

Biomonitoring of multi-element atmospheric deposition using terrestrial moss is a well-established technique in Europe. Although the technique is widely known, there were very limited records of using this technique to study atmospheric air pollution in Malaysia. In this present study, the deposition of 11 trace metals surrounding the main petroleum refinery plant in Kerteh Terengganu (eastern part of peninsular Malaysia) has been evaluated using two local moss species, namely Hypnum plumaeforme and Taxithelium instratum as bioindicators. The study was also done by means of observing whether these metals are attributed to work related to oil exploration in this area. The moss samples have been collected at 30 sampling stations in the vicinity of the petrochemical industrial area covering up to 15 km to the south, north, and west in radius. The contents of heavy metal in moss samples were analyzed by energy dispersive x-ray fluorescence technique. Distribution of heavy metal content in all mosses is portrayed using Surfer software. Areas of the highest level of contaminations are highlighted. The results obtained using the principal components analysis revealed that the elements can be grouped into three different components that indirectly reflected three different sources namely anthropogenic factor, vegetation factor, and natural sources (soil dust or substrate) factor. Heavy metals deposited mostly in the distance after 9 km onward to the western part (the average direction of wind blow). V, Cr, Cu, and Hg are believed to have originated from local petrochemical-based industries operated around petroleum industrial area.

Assessment of the impact of petroleum and petrochemical industries to the surrounding areas in Malaysia using mosses as bioindicator supported by multivariate analysis.

Naturally occurring radionuclides in water such as, 222 Rn which emit gamma radiation through its decaying process could reach to human. Water samples were chosen to present ground and surface water. The groundwater samples were collected from, Perak, Selangor, Kelantan and Sembilan. The surface water samples were collected from Perak, Kelantan, and Pahang. In this study, the surface doses rate measurements were done in-situ using LUDLUM rate meter, and the radioactivity concentration levels were done by counting the water samples using gamma spectrometer with HPGe detector. The activities are ranged from (0.29-1.41 Bq/l).

/pdf/determination-of-radon-activity-concentration-in-hot-spring-4blcz88tl9.pdf

DETERMINATION OF RADON ACTIVITY CONCENTRATION IN HOT SPRING AND SURFACE WATER USING GAMMA SPECTROMETRY TECHNIQUE (Penentuan Kepekatan Aktiviti Radon Di dalam Air Panasdan Air Permukaan Dengan Menggunakan Teknik Spektrometri Gama)

Ahmad Saat

Papers

Optimization of Energy Dispersive X-Ray Fluorescence Spectrometer to Analyze Heavy Metals in Moss Samples

An assessment of absorbed dose and radiation hazard index from natural radioactivity

Surface radiation dose and radionuclide measurement in ex-tin mining area, kg gajah, perak

Assessment of the impact of petroleum and petrochemical industries to the surrounding areas in Malaysia using mosses as bioindicator supported by multivariate analysis.

DETERMINATION OF RADON ACTIVITY CONCENTRATION IN HOT SPRING AND SURFACE WATER USING GAMMA SPECTROMETRY TECHNIQUE (Penentuan Kepekatan Aktiviti Radon Di dalam Air Panasdan Air Permukaan Dengan Menggunakan Teknik Spektrometri Gama)