Research Members & Other Activities (2005), Kg Gajah, Perak

Research members, Kg Gajah, Perak (2005)

Heavy Metals1

VERTICAL PROFILE OF SELECTED METALS CONCENTRATION IN SEDIMENT OF FORMER TIN MINING LAKE[1]

(PROFILE MENEGAK KEPEKATAN LOGAM TERPILIH DIDALAM SEDIMEN TASIK BEKAS LOMBONG)


Zaharidah Abu Bakar 1, Abd. Khalik Wood2, Ahmad Saat1, Zaini Hamzah1 and, Nazaratul Ashifa Abdullah Salim2

1Faculty of Applied Sciences, Universiti Teknologi MARA Malaysia
40450 Shah Alam Selangor, Malaysia.

2Malaysian Nuclear Agency, 43600 Bangi Selangor, Malaysia.


Abstract
Increasing of interest on metals contaminant in the sediment lakes was due to the fact that sediment can act as sink and storage of heavy metals. Profile of metal elements against sediment depth enables us to obtain valuable information about environmental and deposition of contamination in that area. In the present study sediment cores were sampled from ex-tin mining lake in Perak. Ex-tin mining lakes were suspected to have higher concentration of anthropogenic toxic metals in sediment due to past mining activities. The objective of study was to confirm contamination of metals in a former tin mining sediment lake. Sediment cores were analyzed using Instrumental Neutron Activation Analysis (INAA) technique to determine concentration of Al, As, Co, Cr and Mn in the sediment core. The results showed range of metal concentration and mean value in vertical profile for Al, As, Co, Cr, and Mn were 12.8% - 15.46% (13.92%), 42.12 - 58.98 (48.72) ppm, 10.17 - 11.82 (10.82) ppm, 35.52 – 42.65 (38.62) ppm and 393.28 - 618.11 (500.80) ppm respectively. While, the enrichment factor (EF) value was employed to estimate the degree of contaminant in the sediment lake. Result for enrichment factor (EF) for As, Co, Cr and Mn were 16.10, 0.51, 0.31 and 0.18 respectively. The result depicted only As was showed high EF value and anthropogenic influence in the lake sediment as compared to Co, Cr and Mn.


Abstrak
Peningkatan minat terhadap pencemaran logam toksk didalam sediment tasik adalah disebabkan keupayaan sedimen bertindak sebagai singki dan penyimpan logam toksik. Profil logam toksik bertentangan kedalaman membolehkan kita memperolehi maklumat berharga tentang persekitaran dan mendapan pencemaran di kawasan tersebut. Didalam kajian ini sampel turus sedimen telah diambil dari tasik bekas lombong di Perak. Sediment bekas tasik lombong disyaki mengandungi kepekatan logam toksik berbahaya disebabkan oleh aktiviti-aktiviti perlombongan yang lalu. Objektif kajian ini ialah untuk mengesahkan pencemaran logam didalam tasik bekas lombong. Turus sediment telah dianalisa dengan menggunakan teknik analisa pengaktifan neutron (INAA) digunakan untuk menentukan kepekatan Al, As, Co, Cr dan Mn. Hasil analisis untuk profil menegak menunjukkan julat kepekatan logam dan nilai purata untuk Al, As, Co, Cr dan Mn masing-masing ialah 12.8% - 15.46% (13.92%), 42.12 - 58.98 (48.72) ppm, 10.17 - 11.82 (10.82) ppm, 35.52 – 42.65 (38.62) ppm and 393.28 - 618.11 (500.80) ppm. Manakala, nilai faktor pengayaan (EF) telah digunakan untuk menganggarkan darjah pencemaran didalam sedimen tasik. Hasil analisa menunjukkan untuk faktor pengayaan (EF) untuk As, Co, Cr dan Mn masing-masing 16.10, 0.51, 0.31 and 0.18. Hasil keputusan menunjukkan hanya As telah menunjukkan nilai EF yang tinggi berbanding dan pengaruh antropogenik didalam sedimen tasik barbanding Co, Cr dan Mn.


[1] Presented at Nuclear Malaysia Internal Seminar 2008, Bangi, Malaysia

Pb-210 Method1

APPLICABILITY OF Pb-210 METHOD FOR AGES AND SEDIMETATION STUDY OF A RECENT FRESH WATER EX-MINING LAKE


Ahmad Saat1, Zaini Hamzah2, Zaharidah Abu Bakar2 , Zaharudin Ahmad3 and
Abdul Khalik Wood3

1Institute of Science,
2Faculty of Applied Sciences
Universiti Teknologi MARA, 40450 Shah Alam.
3Malaysian Nuclear Agency, Bangi, Selangor.
E-mail: ahmad183@salam.uitm.edu.my

ABSTRACT

Pb-210 method is an environmental dating method, taking advantage of the steady supply rate of Pb-210 radioisotope in a given locality, and its natural decay with a half-life of 22.26 years. The method has been successfully applied in many chronological and sedimentation studies in older natural water systems such as seas, rivers, estuaries, lakes, and marshes. The present study explores the applicability of this method on recent (less than 50 years) man-made fresh water lakes. The study was carried out in 2007 on one of the lake in the former tin mining lakes system in the vicinity of Universiti Teknologi MARA Training Centre, in Kampong Gajah, Perak. For sampling procedures of the five hectare lake, five representative cores were collected from the deepest water column in the middle zone. Representative sediment cores (depth down to 30 cm) collected were sliced at 2 cm length, mixed according to depth to form aggregate, dried and homogenized, and analysed for Pb-210 activity concentration by using alpha-spectrometry facilities at the Malaysian Nuclear Agency laboratory. The Pb-210 depth profiles of the cores enable the respective sediment age and sedimentation rate to be determined. The sedimentation rate was found to be 0.57 ± 0.10 cm.y-1. Age wise, the sediment were about 40 – 50 years old, and this is historically in agreement with the cease-operation year of the mining activities during the year 1960’s. Study on the concentration of a number of heavy metals in the sediment cores show higher concentration beginning the last few years, which coincides with the increment of anthropogenic activities such as human settlement, animal farming and agricultures around the lakes in recent years. The results show that to a certain extent the Pb-210 method is also applicable to recent sediments in water system.

Keywords: Pb-210 method, mining lake sediment, heavy metals.

Amang1

Extraction of Ce(IV) and Gd(III) in monazite in ‘amang’ from ex-mining area


Zaini Hamzah1, Ahmad Saat2 and Nor Monica Ahmad1

1Faculty of Applied Sciences, Universiti Teknologi MARA (UiTM), 40450 Shah Alam, Selangor Darul Ehsan
2Institute of Science (IOS), Universiti Teknologi MARA (UiTM), 40450 Shah Alam, Selangor Darul Ehsan



ABSTRACT
One of the by products of the tin mining activities is tin tailing which known as ‘amang’ very rich in rare earth elements, especially the lanthanides which are present as a mixture of phosphate minerals, mainly as ilminite, xenotime and monazite. This study was conducted in Kg Gajah in Kinta Valley occupying the State of Perak, since this area used to be the largest mining area in the 60’s and 70’s. The soil samples were separated using wet separation technique followed by magnetic separation. The monazite was then digested using a mixture of HF/HNO3 acids. The digested samples were extracted for its Ce and Gd content. The extraction behaviour of this rare earth element in those samples has been investigated as a function of Cyanex-302 concentration in diluents. Extractant of bis(2,4,4-trimethylphenyl)-mono-thiophosphinic acid (Cyanex 302) in a n-heptane was used throughout the analysis. Aqueous phase from extraction was analyzed spectrometrically using Arsenazo (III) while organic phase was subjected to rotavapour followed by analysis by fourier transform infrared spectrometer (FTIR). Results from UV/VIS, FTIR shows the best concentration of Cyanex 302, distribution ratio and confirmation of the structure of the compound.

Keywords: rare earth element, Ce, Gd, amang, monazite.

MINERALOGICAL STUDY OF CLAY SAMPLES FROM NORTH-WEST PENINSULAR MALAYSIA USING X-RAY DIFFRACTION METHOD[1]

Ahmad Saat, and Zaini Hamzah1
International Education Centre (INTEC), UiTM Kampus Seksyen 17,
40200 Shah Alam, Malaysia.
1Faculty of Applied Sciences, Universiti Teknologi MARA
40450 Shah Alam, Malaysia.
Tel: 603-55227070, E-mail: ahmad183@salam.uitm.edu.my

ABSTRACT
Clay has been regarded as very important natural industrial materials. All these industries exploit the properties that clay can be molded into any shape and fired to dry without losing its form. A study was carried out on clay samples from eight sites in the north-eastern part of Peninsular Malaysia. The study was accomplished by using X-ray diffraction (XRD) technique. The x-ray diffraction spectra obtained enable the determination of the lattice spacing associated with the types of clay and non-clay minerals present in the samples. The major components of clay minerals present in all samples studied are kaolinite and illite. Non-clay minerals such as quartz, mica, feldspar, goethite and chlorite are also present in small quantities in the samples studied.
Keywords:Clay minerals, XRD, Kaolinite, Illite

INTRODUCTION
Clay has been used in a wide range of areas, ranging from building materials industry and pottery up to agricultural and ceramic industries. All these industries exploit the properties that clay can be molded into any shape and fired to dry without losing its form. In the present study, qualitative mineralogical study of clay samples from north-western of Peninsular Malaysia was carried out by using x-ray diffraction. Thus, for the analysis only the values of lattice spacing (d) as well as the corresponding relative intensities (I) of the particular diffraction peaks were the only variables determined.

X-ray diffraction technique (XRD) is one of the very popular analytical methods used by mineral and soil scientists for mineralogical study [1, 2 ,3 ,4, 5, 6] as well as geochemical or elemental analysis [7,8] of soil and sediments. Sometimes in the study XRD is coupled with other methods such as x-ray fluorescence [9], analytical electron microscopy (AEM) [10] or modified with internal standard or spiking [11] for quantitative mineralogical determination. The popularity of this method is partly due to the simple sample preparation, uncomplicated data analysis and moreover the results are reasonably reliable.

Experimental Method
Sampling and sample preparation
Samples were obtained from various factories in the north-western region of Peninsular Malaysia. The samples were collected in such a way that contamination was minimized. In the laboratory, foreign organic matter and coarse sands particles in the clay samples were removed and oven-dried overnight at 50 oC. Then samples were crush into powdery form, and then sieved to remove finer sand particles. Slurries were prepared by adding adequate amount of distilled water to the powdery clay samples. The clay from the top portion of the slurries was removed and dried for the subsequent XRD study.

Instrumentation
The x-ray diffraction (XRD) of the samples was carried out using a Phillips horizontal diffractometer Model PW1380, with horizontal goniometer. The samples’ spectra were obtained using CuKa x-ray (l = 1.542 Å) with a nickel filter and tube ratings of 40 kV 30 mA. The detector used was a proportional counter. The scanning rate of the spectra was 1o/cm/min. This scanning rate was found to give a reasonably good peak resolution with satisfactory width of peaks.

Results and Discussions
The XRD spectra obtained were analyzed to determine the lattice spacing by using Bragg’s formula, and the corresponding peak relative intensity. The lattice spacing values (d) and relative intensities (I) are compared with those for kaolinite and illite as described by Jasmund and Mering [12]. The peak of the spectra of the samples can be divided into two groups; one group due to the clay minerals present in the samples while the other due to non-clay minerals such as mica, quartz, feldspar and goethite. It was found that the peaks of the samples match very closely with the diffraction peaks for kaolinite and illite combined. This observation shows that kaolinite and illite are the two main minerals found in clay samples.

The existence of kaolinite in the samples is made certain by the presence of peaks at around 7.20 Å correspond to the d(001) spacing of kaolinite, as well as latticing spacing of 3.75 Å and 1.98 Å [4, 10, 13, 14, 15]. Although the spacing of 7.20 Å and 3.75 Å could be attributed to chlorite as well, the absence of 14.2 Å lattice spacing from all samples except two, confirm the absence of chlorite [13, 14]. The presence of relatively small intensity peak correspond to 14.2 Å lattice spacing in two samples showed that chlorite present in small amount in these samples.

On heating at 600 oC, the mineralogical structure of kaolinite will collapse and turn into amorphous. This will results in the disappearance of major kaolinite 7.20 Å, 3.75 Å and 1.98 Å spacing [13, 14, 15]. A study on the effect of heating was also carried out on all the samples, where the samples were heated at 600 oC for one hour before being scanned in the diffractometer. Results of the study showed that the kaolinite diffraction peaks disappeared in the spectra of the heated samples.

Illite in the clay samples can be confirmed by the presence of d(001) lattice spacing at about 10.0 Å, as well as major diffraction peaks corresponds to lattice spacing of 5.05 Å and 3.34 Å. Unfortunately, the 3.34 Å lattice spacing which corresponds to the most intense peak in every sample diffraction spectrum obtained, is also shared by quartz [13], while the 5.05 Å spacing is interfered by the 5.02 Å lattice spacing peak of mica [12]. Nevertheless, the spacing obtained by XRD in the present study coincides well with the combination of kaolinite and illite lattice spacing obtained by Jasmund and Mering [12].

The effect of heating up to 600 oC is not very significant on illite, because illite will only loses hydroxyl water from the lattice, and still retains its essential crystal character although assuming the form of anhydrous modification (Carroll, 1974). This phenomenon was also observed on the heated samples studied.

The clay samples studied also contained non-clay minerals. The main non-clay minerals present in the sample is mica. However the presence of quartz cannot be ignored as shown by the presence of the 4.25 Å and 2.13 Å lattice spacing apart from the 3.34 Å spacing that is common to illite as well. Feldspar was also detected in most of the samples.

Finally, it is worthwhile to mention that the experimental procedure was repeated for moist samples. The spectra obtained show no significant different between the dry (powder) and moist samples, except that there are occasionally small non-significant shift in the diffraction peaks position.

CONCLUSION
From the results of the study it may be concluded that the major clay minerals present in the samples studied are kaolinite and illite. Non-clay minerals such as mica, quartz and feldspar are also present in small quantity in the samples.

ACKNOWLEDGEMENTS
The first author would like to thank INTEC for the financial support to present the paper at ICXRI 2006.

REFERENCES
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[1] Presented at ICXRI 2007, Kota Kinabalu, Sabah