Displaying publications 1 - 20 of 142 in total

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  1. Dorai CRT
    Med J Malaysia, 1987 Jun;42(2):119-21.
    PMID: 3503184
    A case of limy bile, i.e. bile in the gall bladder rendered radio-opaque due to excessive concentration of calcium carbonate, is reported and its pathogenesis discussed.
    Matched MeSH terms: Calcium Carbonate/analysis*
  2. Che Aziz Ali, Kamal Roslan Mohamed
    Sains Malaysiana, 1996;25(4):47-68.
    The Kodiang Formation which outcrops in Kodiang and Alor Setar areas has been well studied and documented. Various geological aspects of the limestone formation have been reported in detail including its stratigraphy, sequence startigraphy, sedimentology and paleontology. Diagenetic aspect of this rock formation, however, had not been specifically discussed before. The Kodiang limestone has undergone a complicated diagenetic history which started immediately after the sediments were laid down on the sea bed. Various diagenetic products have been identified including, early marine cement, meteoric cement, and deeper subsurface cement. The diagenetic features identified are as follows; Fibrous calcite cement, sparry and poikilotopic calcites, calcite overgrowth, dolomite, silica cements and evaporites. Close examination at outcrops shows that dolomite occurs at several levels in the sequence. Their systematic occurrences can be correlated across the area. Petrographic studies show that dolomite occurs in several modes as stratified dolomite and as non-stratified dolomite. The two dolomite groups are attributed to two phases of dolomitizations. The stratified dolomites are interpreted to have been formed early in the limestone diagenetic history. The non-stratified dolomite type is, however, attributed to dolomitization during deep burial under the control of deeper subsurface physico-chemical conditions.
    Batu Kapur Kodiang yang tersingkap di Kodiang dan Alor Setar telah banyak dikaji dan didokumentasikan. Berbagai aspek geologi formasi batu kapur ini telah dilaporkan termasuk stratigrafi, startigrafi jujukan, sedimentologi dan paleontologi. Walau bagaimanapun aspek diagenesis formasi batuan ini tidak pernah dibincangkan secara khusus. Batu kapur Kodiang ini telah melalui sejarah diagenesis yang rumit yang bermula sebaik saja sedimen dimendapkan di atas permukaan dasar laut. Berbagai hasil diagenesis telah dikenal pasti termasuk penyimenan samudera awal, penyimenan meterorik dan penyimenan di bawah permukaan yang lebih dalam. Secara asas fitur-fitur yang dikenalpasti adalah seperti berikut; simen kalsit berserat, kalsit spar dan poikilotopik, tumbuhlampau kalsit, dolomit, simen silika dan evaporit. Pemeriksaan rapi pada singkapan menunjukkan dolomit hadir pada beberapa aras di dalam jujukan. Kehadirannya secara bersistematik boleh dikorelasikan pada setiap singkapan. Kajian petrografi menunjukkan dolomit wujud dalam berbagai mod yang boleh diklaskan sebagai dolomit berstrata dan dolomit tidak berstrata. Dua klas ini boleh dikaitkan dengan dua fasa pendolomitan. Dolomit berstrata ditafsirkan telah terbentuk awal di dalam sejarah diagenesis batu kapur. Dolomit tidak berstrata pula dikaitkan dengan pendolomitan semasa timbusan dalam di bawah keadaan fiziko-kimia bawah permukaan.
    Matched MeSH terms: Calcium Carbonate
  3. Kamal Roslan Mohamed
    The Semantan Formation which is Middle to Upper Triassic age, comprises a rapidly alternating sequence of carbonaceous shale, siltstone and rhyolite tuff with a few lenses of chert, conglomerate and recrystallised limestone. The shale and tuff make up the bulk of the sequence. Jaafar Ahmad (1976) was introduced the formation name of the rock sequence in Karak-Temerloh area, but the similar sequence (in term of lithology, paleontology and structural pattern) found in the other areas were given different names. After an extensive study, the following formations or part of them, may be include in the Semantan Formation; Raub Series (Scrivenor 1911); Calcareous Formation (Richardson 1939); Calcareous Series (Richardson 1947); Younger arenaceous Series (Alexander 1956); Raub Group (Alexander 1959); Jengka Pass Formation (Ichikawa et al. 1966); Kerdau Formation (Burton 1973a); part of Jelai Formation (Burton 1973a); Gemas Formation (Lum 1977); Jurong Formation (Burton 1973a); Pahang Volcanic Series (Hutchison 1973c).
    Formasi Semantan merupakan jujukan batuan sedimen yang berusia Trias Tengah - Akhir di Jalur Tengah Semenanjung Malaysia. Jujukan ini terdiri daripada selang lapis batuan syal berkarbon, batu lodak, dan batu pasir yang kebanyakannya bertuf, serta terdapat kekanta konglomerat, batu kapur dan rijang dalam selang lapis ini. Syal adalah unit yang paling dominan dalam formasi ini. Jaafar Ahmad (1976) menamakan jujukan ini untuk kawasan Karak - Temerloh, tetapi jujukan yang serupa (dari segi litologi, paleontologi dan gaya struktur) juga ditemui di kawasan lain, tetapi dipanggil dengan nama lain. Dari hasil kajian menyeluruh yang telah dijalankan, didapati nama-nama unit batuan berikut atau sebahagian daripadanya mungkin merupakan penamaan yang serupa untuk Formasi Semantan, iaitu Siri Raub (Scrivenor 1911), Formasi Berkapur (Richardson 1939), Siri Berkapur (Richardson 1947), Siri Arenit Muda (Alexander 1958), sebahagian Kumpulan Raub (Alexander 1959), Formasi Jengka Pass (Ichikawa et al. 1966), Formasi Kerdau (Burton 1973a), sebahagian Formasi Jelai (Burton 1973a), Formasi Gemas (Lum 1977), Formasi Jurong (Burton 1973a) dan Siri Volkano Pahang (Hutchison 1973).
    Matched MeSH terms: Calcium Carbonate
  4. Umar Hamzah, Abd. Rahim Samsudin
    Identification of a possible source of engineering geological hazard in the limestone area such as cavities, sinkholes and an underground cavern have become necessity for site investigation before any construction of roads, bridges and buildings are carried out. The study is also necessary for tunneling and underground mining works where knowledge of the engineering properties of the rock mass is very important in order to assess the suitability and safety of a proposed building. Geophysical techniques have been widely used in engineering geological study to deal with such problems that normally arise at construction sites with limestone bedrock. In this study, shallow seismic reflection technique and dipole-dipole geoelectrical methods were used to detect the presence of cavity in lime stone area of Batu Cave, Kuala Lumpur. The exact location and depth of cavities in the area were determined from the existing borehole data and report provided by the Geological Survey Department of Malaysia. Based on the borehole data, several cavities that were filled-up with water and fine silt are encountered at depths of 15.7m to 17.8m, 20.2m to 21.1m and 21.4m to 25.7m. Three shallow seismic reflection profiles were established on the cavity area and the results show that the cavities in the limestone occur in the form of 20 to 30m long subterranean channel of 15 to 30 m depth. Dipole-dipole resistivity survey conducted on seismic lines one and three also indicates the presence of the channel and cavities in the limestone.
    Pengecaman punca bencana geologi kejuruteraan di kawasan batu kapur seperti lohong batu kapur, kewujudan lubang benam dan gua-gua batu kapur telah menjadi amat penting dalam penyiasatan tapak sebelum sesuatu pembinaan seperti jalan raya, jambatan dan bangunan dilakukan. Begitu juga dalam kerja-kerja penerowongan dan perlombongan, pengetahuan asas sifat kejuruteraan jasad batuan amat perlu diketahui untuk menitai kesesuaian dan keselamatan bangunan yang bakal dibina. Teknik geofizik telah digunakan secara meluas dalam kajian geologi kejuruteraan untuk menangani masalah yang terdapat di tapak-tapak binaan yang mempunyai batu kapur sebagai batuan dasar. Dalam kajian ini teknik seismos pantulan cetek dan kaedah geoelektrik dwikutub-dwikutub telah digunakan untuk mengesan rongga batu kapur yang terdapat di kawasan Batu Caves, Kuala Lumpur. Kedudukan dan kedalaman rongga batu kapur di kawasan kajian telah ditentukan melalui data lubang gerudi dan laporan yang diperoleh daripada Jabatan Kajibumi Malaysia. Berdasarkan data lubang gerudi tersebut terdapat beberapa rongga yang terisi air dan pasir halus berlodak di kedalaman 15.7 m hingga 17.8 m, 20.2 m hingga 21.1 m dan 21.4 m hingga 25.7 m. Tiga profil seismos pantulan cetek telah dibuat di kawasan berongga tersebut dan hasil survei menunjukkan rongga dalam batu kapur tersebut membentuk palung sepanjang hampir 20 - 30 m pada kedalaman antara 15 m hingga 30 m. Rentisan survei geoelektrik dwikutub yang dilakukan pada profil seismos satu dan tiga juga memperlihatkan kehadiran lohong dan palung dalam batu kapur tersebut.
    Matched MeSH terms: Calcium Carbonate
  5. Abu-Jaber N, Hess JW, Howcroft W
    Ground Water, 2001 4 5;39(2):223-9.
    PMID: 11286069
    Multi-year instrumental records for input, throughflow and output waters of the Lilburn Cave system provide control on denudation rates as they respond to seasonal and spatial variability. Data suggest that maximum denudation is in the late fall and early winter. This is when non-snowmelt discharge is at its maximum. At lower discharge rates the volume of water moving through the cave system is the limiting control on the volume of denudation. During periods of snowmelt the limiting control is the rate at which the calcite dissolves. This is probably the result of water flowing through wider channels during these times. Based on instrumental measurements, there is considerable variation in terms of where denudation occurs inside the cave. The loci of dissolution change from year to year. This is to be expected in the dynamic environment of the cave where materials shift routinely. This variability should be studied over longer periods of time in order to more fully understand its extent. The relatively small area of carbonate exposure relative to the area of the drainage basin gives rise to relatively high denudation rates. The carbonate is being removed at a rate of about 5000 metric tons per year, or at about 830 mm/y. This is about five times the rate reported in the humid karst regions of Malaysia. This information indicates that the relative proportion of carbonate in the drainage basin needs to be considered when trying to estimate denudation in other areas.
    Matched MeSH terms: Calcium Carbonate/chemistry
  6. Aziz HA, Othman N, Yusuff MS, Basri DR, Ashaari FA, Adlan MN, et al.
    Environ Int, 2001 May;26(5-6):395-9.
    PMID: 11392757
    This paper discusses heavy metal removal from wastewater by batch study and filtration technique through low-cost coarse media. Batch study has indicated that more than 90% copper (Cu) with concentration up to 50 mg/l could be removed from the solution with limestone quantity above 20 ml (equivalent to 56 g), which indicates the importance of limestone media in the removal process. This indicates that the removal of Cu is influenced by the media and not solely by the pH. Batch experiments using limestone and activated carbon indicate that both limestone and activated carbon had similar metal-removal efficiency (about 95%). Results of the laboratory-scale filtration technique using limestone particles indicated that above 90% removal of Cu was achieved at retention time of 2.31 h, surface-loading rate of 4.07 m3/m2 per day and Cu loading of 0.02 kg/m3 per day. Analyses of the limestone media after filtration indicated that adsorption and absorption processes were among the mechanisms involved in the removal processes. This study indicated that limestone can be used as an alternative to replace activated carbon.
    Matched MeSH terms: Calcium Carbonate/chemistry*
  7. Al-Salihi KA, Samsudin AR
    Med J Malaysia, 2004 May;59 Suppl B:202-3.
    PMID: 15468888
    In this study the surface properties of two particulate coral and polyhydroxybutrate (PHB) were studied in order to characterize them prior to use in composite production. Coral powder and PHB particle were evaluated using scanning electron microscopy and confocal laser scanning microscopy, to measure surface porosity and pores size. The results showed that coral powder has multiple pleomorphic micropores cross each others give appearance of micro-interconnectivity. Some pore reached to 18 microm with an average porosity of 70%. PHB revealed multiple different size pores extended to the depth, with an average some times reach 25 microm and porosity 45%. These findings demonstrate that both coral and PHB have excellent pores size and porosity that facilitate bone in growth, vascular invasion and bone development. We believe that incorporation of coral powder into PHB will make an excellent composite scaffold for tissue engineering.
    Matched MeSH terms: Calcium Carbonate*
  8. Al-Salihi KA
    Med J Malaysia, 2004 May;59 Suppl B:200-1.
    PMID: 15468887
    In the present study, natural coral of porites species was used as scaffold combined with in vitro expanded bone marrow stem cell derived osteoblasts (BMSC-DO), to develop a tissue-engineered bone graft in a rat model. Coral was molded into the shape of rat mandible seeded with 5x10(6) /ml BMSC-DO subsequently implanted subcutaneously in the back of 5 week Sprague dawely rats for 3 months. Coral alone was implanted as a control. The implants were harvest and processed for gross inspection and histological observations. The results showed that newly bone grafts were successfully formed coral seeded with cells group showed smooth highly vascularized like bone tissue. Histological sections revealed mature bone formation and lots of blood vessel, the bone formation occurred in the manner resemble intramembraneous bone formation. This study demonstrates that coral can be use as a suitable scaffold material for delivering bone marrow mesenchymal stem cells in tissue engineering.
    Matched MeSH terms: Calcium Carbonate*
  9. Fadilah A, Zuki AB, Loqman MY, Zamri-Saad M, Norimah Y, Asnah H
    Med J Malaysia, 2004 May;59 Suppl B:178-9.
    PMID: 15468876
    The study was carried out to evaluate macroscopically the ability of coral to repair a large size bone defect. A total 12 adult, male sheep were used in the study. The large bone defect (2.5cm x 0.5cm x 0.5cm) was created surgically on the left proximal femur and replaced by a block of coral (Porites sp.). Radiographs were obtained immediately after surgery and at 2, 4, 8 and 12 weeks post-implantation. Ultrasonographic examinations were carried out every 2 weeks after implantation up to 12 weeks using ultrasound machine (TOSHIBA Capasee II) connected with 7MHz frequency transducer. The sheep were euthanased at 2, 4, 8, and 12 weeks post-implantation and the bone examined grossly. Both ultrasonographs and radiographs taken at 8 and 12 weeks showed that the implants had been resorbed and left the space that much reduced in size. There was no sign of implant rejection observed in all animals. The results showed that processed coral has potential to become bone substitute for reconstructive bone surgery.
    Matched MeSH terms: Calcium Carbonate/analysis*
  10. Shamsuria O, Fadilah AS, Asiah AB, Rodiah MR, Suzina AH, Samsudin AR
    Med J Malaysia, 2004 May;59 Suppl B:174-5.
    PMID: 15468874
    The aim of this study was to evaluate the in vitro cytotoxicity of biomaterials; Hydroxyapatite (HA), Natural coral (NC) and Polyhydroxybutarate (PHB). Three different materials used in this study; HA (Ca10(PO4)6(OH)2), NC (CaCO3) and PHB (Polymer) were locally produced by the groups of researcher from Universiti Sains Malaysia. The materials were separately extracted in the complete culture medium (100mg/ml) for 72h and introduced to the osteoblast cells CRL-1543. The viability of osteoblast CRL-1543 cultivated with these extraction materials after 72h incubation period was compared to negative control with neutral red assay by using spectrophotometer at 540nm. The results showed the non-cytotoxicity of the materials. After 72h of incubation period, HA showed 123% viable cells, NC was 99.43% and PHB was 176.75%. In this study, cytotoxicity test dealt mainly with the substances that leached out from the biomaterial. The results obtained showed that the materials were not toxic and also promoted cells growth in the sense of biofunctionality.
    Matched MeSH terms: Calcium Carbonate/toxicity*
  11. Fadilah A, Zuki AB, Loqman MY, Zamri-Saad M, Al-Salihi KA, Norimah Y, et al.
    Med J Malaysia, 2004 May;59 Suppl B:127-8.
    PMID: 15468851
    The study was carried out with the aim to evaluate natural coral (Porites spp.) implanted in sheep femur microscopically. Twelve adult, male sheep were used in this study. The defect area was implanted with coral and monitored for up to 12 weeks. The sheep were euthanased at 2,4,8, and 12 weeks post-implantation. Microscopically, natural coral implanted into bone tissue have shown gradual resorption and progressively replaced by new bone. At 12 weeks post-implantation, the implanted site was almost completely surrounded by mature bone. The results showed that natural coral was found to be a biodegradable and osteo-conductive biomaterial, which acted as a scaffold for a direct osteoblastic apposition.
    Matched MeSH terms: Calcium Carbonate*
  12. Hashim N, Sabudin S, Ibrahim S, Zin NM, Bakar SH, Fazan F
    Med J Malaysia, 2004 May;59 Suppl B:103-4.
    PMID: 15468839
    Hydroxyapatite (HA; Ca10(PO4)6(OH)2), is one of the significant implant materials used in Orthopaedics and Dental applications. However, synthetically produced HA may not be stable under ionic environment, which it will unavoidably encounter during its applications. In this paper, the in vitro effects of three HA materials derived from different resources, i.e. commercial HA (HAC), synthesised HA from pure chemicals (HAS) and synthesised HA from kapur sireh; derived traditionally from natural limestone (HAK), were studied. The HA disc samples were prepared and immersed in simulated body fluid (SBF) for 31-day period. The evaluation conducted focuses on the changes of the pH and the Calcium ion (Ca-ion) and Phosphate ion (P-ion) concentrations in the SBF solution, as well as the XRD and SEM data representing the reactions on the HA materials. From the XRD, it was found that HAK has the smallest crystallite sizes, which in turn affect the pH of the SBF during immersion. The Ca and P-ion concentrations generally decrease over time at different rates for different HA. Upon 1-day immersion in SBF, apatite growth was observed onto all three surfaces, which became more pronounced after 3-day immersion. However, the appetites formed were observed to be different in shapes and sizes. The reasons for the difference in the apatite-crystals and their subsequent effects on cells are still being investigated.
    Matched MeSH terms: Calcium Carbonate
  13. Najafpour HD, Suzina AH, Nizam A, Samsudin AR
    Med J Malaysia, 2004 May;59 Suppl B:121-2.
    PMID: 15468848
    There was a significant increased in Absolute Contact Length measurements of endosteal bone growth along the Nickel-Titanium (NiTi) implant coated with the natural coral powder and Hydroxyapatite (HA) compared to the non-calcium coated implants. This study demonstrated that coated implants seemed to show earlier and higher osseointergration phenomena compared to non coated ones. Furthermore, there was significantly greater bone-to-implant contact at the apical 1/3rd of the coated implants.
    Matched MeSH terms: Calcium Carbonate*
  14. Rosdan S, Al-Salihi KA, Suzina AH, Samsudin AR
    Med J Malaysia, 2004 May;59 Suppl B:111-2.
    PMID: 15468843
    The main objective of the study was to determine the biodegradability, resorption and osteoconductivity potency of coral implant. Coral blocks (CORAGRAF) were prepared from sea coral Porites species. The blocks were implanted in the right mandible of rabbit model. Implants were harvested at 2 and 4 weeks intervals and subjected for light and scanning electron microscopy. Dense hydroxyapatite (DHA) was implanted in the left mandible as a control. The results of this study demonstrated that CORAGRAF is a good implant material that can accelerates bone healing and be resorbed in an acceptable time. The mechanisms of the resorption seemed to be the same (crumbling process), a first step where the edge of the coral become powdery then a second step which could be phagocytosis and dissolution in extracellular fluid.
    Matched MeSH terms: Calcium Carbonate*
  15. Suzina AH, Azlina A, Shamsuria O, Samsudin AR
    Med J Malaysia, 2004 May;59 Suppl B:105-6.
    PMID: 15468840
    Mutagenicity of CORAGRAF (natural coral) and REKAGRAF (hydroxyapatite) was tested in Ames test with and without an external metabolic activation system (S9). The test revealed no mutagenic activity of both locally produced osseous substitutes.
    Matched MeSH terms: Calcium Carbonate/toxicity*
  16. Abu Bakar SH, Hussein Z, Hee SL, Fazan F
    Med J Malaysia, 2004 May;59 Suppl B:81-2.
    PMID: 15468829
    Hydroxyapatite, (HA; Ca1O(PO4)6(OH)2) has been successfully applied in medical and dental applications for several years due to its excellent biocompatibility. The usage of HA in Malaysia, however, is limited due to the lack of availability. Therefore the aim of this work is to produce HA materials from both pure chemicals and from Malaysian natural limestone precursors, and to compare their bulk properties. However, parts of Malaysian natural limestone deposits actually consist of a combination of Ca(OH)2 and CaCO3. In order to utilise the limestone to produce HA material, the combination of these commercially pure chemicals as HA precursors should still work. In order to test this hypothesis, two HAs were produced by wet synthesis technique utilising (a) combination of Ca(OH)2 + CaCO3 from pure commercial chemicals [WCC] and (b) a local natural limestone [WL] precursors. The HAs produced; WCC and WL, were compacted into discs and sintered at 1250 degrees C. The characterisations and evaluations conducted were XRD, SEM-EDX, FTIR and shrinkage factor. The results indicate that WL gives slightly better bulk properties compared to WCC.
    Matched MeSH terms: Calcium Carbonate/analysis; Calcium Carbonate/chemical synthesis*
  17. Al-Salihi KA, Samsudin AR
    Med J Malaysia, 2004 May;59 Suppl B:45-6.
    PMID: 15468811
    This study was designed to evaluate the ability of natural coral implant to provide an environment for marrow cells to differentiate into osteoblasts and function suitable for mineralized tissue formation. DNA content, alkaline phosptatase (ALP) activity, calcium (Ca) content and mineralized nodules, were measured at day 3, day 7 and day 14, in rat bone marrow stromal cells cultured with coral discs glass discs, while cells alone and coral disc alone were cultured as control. DNA content, ALP activity, Ca content measurements showed no difference between coral, glass and cells groups at 3 day which were higher than control (coral disc alone), but there were higher measurement at day 7 and 14 in the cell cultured on coral than on glass discs, control cells and control coral discs. Mineralized nodules formation (both in area and number) was more predominant on the coral surface than in control groups. These results showed that natural coral implant provided excellent and favorable situation for marrow cell to differentiate to osteoblasts, lead to large amount of mineralized tissue formation on coral surface. This in vitro result could explain the rapid bone bonding of coral in vivo.
    Matched MeSH terms: Calcium Carbonate*
  18. Aziz HA, Adlan MN, Zahari MS, Alias S
    Waste Manag Res, 2004 Oct;22(5):371-5.
    PMID: 15560441
    The presence of ammoniacal nitrogen (N-NH3) in leachate is one of the problems normally faced by landfill operators. Slow leaching of wastes producing nitrogen and no significant mechanism for transformation of N-NH3 in the landfills causes a high concentration of ammoniacal nitrogen in leachate over a long period of time. A literature review showed that the removal of ammoniacal nitrogen from leachate was not well documented and to date, there were limited studies in Malaysia on this aspect, especially in adsorption treatment. The main objective of the present study was to investigate the suitability of activated carbon, limestone and a mixture of both materials as a filtering medium, in combination with other treatments capable of attenuating ammoniacal nitrogen which is present in significant quantity (between 429 and 1909 mg L(-1)) in one of the landfill sites in Malaysia. The results of the study show that about 40% of ammoniacal nitrogen with concentration of more than 1000 mg L(-1) could be removed either by activated carbon or a mixture of carbon with limestone at mixture ratio of 5:35. This result shows that limestone is potentially useful as a cost-effective medium to replace activated carbon for ammoniacal nitrogen removal at a considerably lower cost.
    Matched MeSH terms: Calcium Carbonate/chemistry
  19. Aziz HA, Yusoff MS, Adlan MN, Adnan NH, Alias S
    Waste Manag, 2004;24(4):353-8.
    PMID: 15081062
    Limestone has been proven effective in removing metals from water and wastewater. A literature review indicated that limestone is capable of removing heavy metals such as Cu, Zn, Cd, Pb, Ni, Cr, Fe and Mn are through a batch process or by filtration technique. The removal capability is reported at up to 90%. However, to date most of the studies have been focused on synthetic wastewater. The present study attempts to investigate the suitability of limestone to attenuate total iron (Fe) from semi aerobic leachate at Pulau Burung Landfill Site in Penang, Malaysia. Iron was found in significant quantities at the landfill site. The study also aims to establish the Fe isotherm and breakthrough time of the proposed limestone filter for post-treatment to the migrating landfill leachate before its release to the environment. The Fe isotherms were established using a batch equilibrium test, while the breakthrough characteristics were determined using continuous flow permeating through a limestone column. The latter was used in order to simulate the continuous flow of leachate that would occur in the proposed limestone filter. The limestone media used in the experiment contain more than 90% CaCO3 with particle sizes ranging from 2 to 4 mm. Four filter columns (each 150 mm in diameter and 1000 mm depth) were installed at the landfill site. Metal loadings were kept below 0.5 kg /m3 day and the experiment was run continuously for 30 days. Initial results indicated that 90% of Fe can be removed from the leachate based on retention time of 57.8 min and surface loading of 12.2 m3/m2 day. For the batch study on the Fe isotherm, the results indicated that limestone is potentially useful as an alternative leachate treatment system at a relatively low cost.
    Matched MeSH terms: Calcium Carbonate/chemistry*
  20. Hussain S, Aziz HA, Isa MH, Adlan MN, Asaari FA
    Bioresour Technol, 2007 Mar;98(4):874-80.
    PMID: 16716587
    The purpose of the present study was to examine the removal of ammoniacal nitrogen (NH4-N) from synthetic wastewater using limestone (LS) and granular activated carbon (GAC) mixture as low cost adsorbent. In batch study, optimum shaking and settling times were 150 and 120 min, respectively. The LS-GAC mixture ratio of 25:15 removed about 58% NH4-N. The smaller particle size of medium yielded higher adsorption capacity. The equilibrium adsorption data followed the Freundlich isotherm (R2 > 0.98) but it showed weak bond. Adsorption kinetics were well described by the pseudo second-order rate model (R2 > 0.93). The upflow column showed that higher flow rate and initial concentration resulted in shorter column saturation time. The study showed that the usage of GAC could be reduced by combining GAC with LS for the removal of NH4-N from wastewater; thus reducing the cost of treatment.
    Matched MeSH terms: Calcium Carbonate*
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