Displaying publications 41 - 60 of 137 in total

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  1. Development of a multiplex real-time PCR assay using SYBR Green 1 chemistry for simultaneous detection and subtyping of H9N2 influenza virus type A
    Ong WT, Omar AR, Ideris A, Hassan SS
    J Virol Methods, 2007 Sep;144(1-2):57-64.
    PMID: 17512062
    Avian influenza viruses are pathogens of economical and public health concerns. However, infections caused by low pathogenic avian influenza particularly H9N2 subtype are not associated with clear clinical features. Hence, rapid detection and subtyping of the virus will enable immediate measures to be implemented for preventing widespread transmission. This study highlights the development of a multiplex real-time reverse-transcriptase polymerase chain reaction (RRT-PCR) assay using SYBR Green 1 chemistry for universal detection of avian influenza viruses and specific subtyping of H9N2 isolates based on melting temperatures (T(m)) discriminations. Three melting peaks generated simultaneously at temperatures 85.2+/-1.0, 81.9+/-0.9 and 78.7+/-0.9 degrees C represent NP, H9 and N2 gene products, respectively. The RRT-PCR assay was about 10-100-fold more sensitive when compared to the conventional RT-PCR method using reference H9N2 isolate. In addition, the RRT-PCR assay was 100% sensitive as well as 92% specific according to the standard virus isolation method in detecting experimentally infected specific-pathogen-free (SPF) chickens.
    Matched MeSH terms: Organic Chemicals
  2. Development of a quantitative real-time RT-PCR for kinetic analysis of immediate-early transcripts of rat cytomegalovirus
    Loh HS, Mohd-Azmi ML
    Acta Virol., 2009;53(4):261-9.
    PMID: 19941390
    One-step real-time RT-PCR assay was developed for quantification of the immediate-early (IE), namely IE1 and IE2 transcripts of Rat cytomegalovirus (RCMV), strain ALL-03 in rat embryonic fibroblast cells (REF). This in-house SYBR Green I based RT-PCR was shown to have higher amplification efficiency and detection limit as compared to a commercially available real-time RT-PCR kit in quantifying these two transcripts. The quantification histogram revealed the divergence of transcription activities of the two IE genes. The IE1 transcript had a concentration peak at 7 hrs post infection (p.i.), whereas IE2 transcript at 20 hrs p.i. Regulation of IE expression is critical for determination, whether the infection is going to be abortive, lytic or latent. Therefore, this in-house developed quantitative RT-PCR assay offers an alternative for diagnosis and monitoring of the acute cytomegalovirus (CMV) infection directed at IE transcript detection.
    Matched MeSH terms: Organic Chemicals
  3. Duplex real-time PCR assay using SYBR Green to detect and quantify Malayan box turtle (Cuora amboinensis) materials in meatballs, burgers, frankfurters and traditional Chinese herbal jelly powder
    Asing, Ali E, Hamid SB, Hossain M, Ahamad MN, Hossain SM, et al.
    Food Addit Contam Part A Chem Anal Control Expo Risk Assess, 2016 Nov;33(11):1643-1659.
    PMID: 27643977
    The Malayan box turtle (Cuora amboinensis) (MBT) is a vulnerable and protected species widely used in exotic foods and traditional medicines. Currently available polymerase chain reaction (PCR) assays to identify MBT lack automation and involve long targets which break down in processed or denatured tissue. This SYBR Green duplex real-time PCR assay has addressed this research gap for the first time through the combination of 120- and 141-bp targets from MBT and eukaryotes for the quantitative detection of MBT DNA in food chain and herbal medicinal preparations. This authentication ensures better security through automation, internal control and short targets that were stable under the processing treatments of foods and medicines. A melting curve clearly demonstrated two peaks at 74.63 ± 0.22 and 78.40 ± 0.31°C for the MBT and eukaryotic products, respectively, under pure, admixed and commercial food matrices. Analysis of 125 reference samples reflected a target recovery of 93.25-153.00%, PCR efficiency of 99-100% and limit of detection of 0.001% under various matrices. The quantification limits were 0.00001, 0.00170 ± 0.00012, 0.00228 ± 0.00029, 0.00198 ± 0.00036 and 0.00191 ± 0.00043 ng DNA for the pure meat, binary mixtures, meatball, burger and frankfurter products, respectively. The assay was used to screen 100 commercial samples of traditional Chinese herbal jelly powder from eight different brands; 22% of them were found to be MBT-positive (5.37 ± 0.50-7.00 ± 0.34% w/w), which was reflected through the Ct values (26.37 ± 0.32-28.90 ± 0.42) and melting curves (74.63-78.65 ± 0.22°C) of the amplified MBT target (120 bp), confirming the speculation that MBT materials are widely used in Chinese herbal desserts, exotic dishes consumed with the hope of prolonging life and youth.
    Matched MeSH terms: Organic Chemicals/analysis*
  4. Fulltext Effect of Preparation Methods on the Tensile, Morphology and Solar Energy Conversion Efficiency of RGO/PMMA Nanocomposites
    Kee SY, Munusamy Y, Ong KS, Lai KC
    Polymers (Basel), 2017 Jun 18;9(6).
    PMID: 30970908 DOI: 10.3390/polym9060230
    In this study, reduced graphene oxide (RGO)/polymethyl methacrylate (PMMA) nanocomposites were prepared by employing in situ polymerization and solution blending methods. In terms of mechanical properties, RGO loading increased the Young's modulus but decreased the elongation at break for RGO/PMMA nanocomposites. Tensile strength for solution blended RGO/PMMA nanocomposites increased after adding 0.5 wt % RGO, which was attributed to the good dispersion of RGO in the nanocomposites as evidenced from SEM and TEM. Solar energy conversion efficiency measurement results showed that the optimum concentration of RGO in the RGO/PMMA nanocomposites was found to be 1.0 wt % in order to achieve the maximum solar energy conversion efficiency of 25%. In the present study, the solution blended nanocomposites exhibited better overall properties than in situ polymerized nanocomposites owing to the better dispersion of RGO in solution blending. These findings would contribute to future work in search of higher conversion efficiency using nanocomposites.
    Matched MeSH terms: Organic Chemicals
  5. Effect of TMAH etching duration on the formation of silicon nanowire transistor patterned by AFM nanolithography
    Hutagalung SD, Lew KC
    Sains Malaysiana, 2012;41:1023-1028.
    Atomic force microscopy (AFM) lithography was applied to produce nanoscale pattern for silicon nanowire transistor fabrication. This technique takes advantage of imaging facility of AFM and the ability of probe movement controlling over the sample surface to create nanopatterns. A conductive AFM tip was used to grow the silicon oxide nanopatterns on silicon on insulator (SOI) wafer. The applied tip-sample voltage and writing speed were well controlled in order to form pre-designed silicon oxide nanowire transistor structures. The effect of tetra methyl ammonium hydroxide (TMAH) etching duration on the oxide covered silicon nanowire transistor structure has been investigated. A completed silicon nanowire transistor was obtained by removing the oxide layer via hydrofluoric acid etching process. The fabricated silicon nanowire transistor consists of a silicon nanowire that acts as a channel with source and drain pads. A lateral gate pad with a nanowire head was fabricated very close to the channel in the formation of transistor structures.
    Matched MeSH terms: Organic Chemicals
  6. Effect of agitation and aeration on bioconversion of domestic wastewater sludge in a batch fermenter
    Alam MZ, Fakhru'l-Razi A
    J Environ Sci Health A Tox Hazard Subst Environ Eng, 2002;37(6):1087-97.
    PMID: 12090282
    Effects of agitation and aeration rate on microbial treatment of domestic wastewater sludge were investigated in a batch fermenter using mixed culture of Penicillium corylophilum and Aspergillus niger. It was found that liquid state bioconversion (LSB) of wastewater sludge was highly influenced by the effects of agitation and aeration. The maximum production of sludge cake and reduction of organic substances in treated sludge were recorded at 150-200 rpm of agitation speed and 0.5 vvm of aeration rate after 72 h of treatment. No effective results were observed at higher rate of agitation (300 rpm) and aeration (1.5 vvm) as compared to optimum values. The results showed that the minimum level of air saturation (pO2) was adequate to maintain the bioconversion process.
    Matched MeSH terms: Organic Chemicals/metabolism
  7. Effect of culture media on expansion properties of human umbilical cord matrix-derived mesenchymal cells
    Salehinejad P, Alitheen NB, Nematollahi-Mahani SN, Ali AM, Omar AR, Janzamin E, et al.
    Cytotherapy, 2012 Sep;14(8):948-53.
    PMID: 22587592 DOI: 10.3109/14653249.2012.684377
    BACKGROUND AIMS: Mesenchymal stromal cells (MSC) have been isolated from a number of different tissues, including umbilical cord. Because of the lack of a uniform approach to human umbilical cord matrix-derived mesenchymal (hUCM) cell expansion, we attempted to identify the optimum conditions for the production of a high quantity of hUCM cells by comparing two media.

    METHODS: We compared the ability of Dulbecco's Modified Eagle's Medium/F12 (DMEM/F12) and Alpha Minimum Essential Medium (α-MEM) with Glutamax (GL) (α-MEM/GL) to expand hUCM cells. For this purpose, hUCM cells were cultured in plates containing different culture media supplemented with 10% fetal bovine serum (FBS). Culture dishes were left undisturbed for 10-14 days to allow propagation of the newly formed hUCM cells. The expansion properties, CD marker expression, differentiation potential, population doubling time (PDT) and cell activity were compared between the two groups.

    RESULTS: The hUCM cells harvested from each group were positive for MSC markers, including CD44, CD90 and CD105, while they were negative for the hematopoietic cell surface marker CD34. Differentiation into adipogenic and osteogenic lineages was confirmed for both treatments. Cell activity was higher in the α-MEM/GL group than the DMEM/F12 group. PDT was calculated to be 60 h for the DMEM/F12 group, while for the α-MEM/GL group it was 47 h.

    CONCLUSIONS: Our data reveal that α-MEM/GL with 10% FBS supports hUCM cell growth more strongly than DMEM/F12 with 10% FBS.

    Matched MeSH terms: Organic Chemicals
  8. Effects of aeration rate on degradation process of oil palm empty fruit bunch with kinetic-dynamic modeling
    Talib AT, Mokhtar MN, Baharuddin AS, Sulaiman A
    Bioresour Technol, 2014 Oct;169:428-38.
    PMID: 25079208 DOI: 10.1016/j.biortech.2014.07.033
    The effect of different aeration rates on the organic matter (OM) degradation during the active phase of oil palm empty fruit bunch (EFB)-rabbit manure co-composting process under constant forced-aeration system has been studied. Four different aeration rates, 0.13 L min(-1) kg(DM)(-1),0.26 L min(-1) kg(DM)(-1),0.49 L min(-1) kg(DM)(-1) and 0.74 L min(-1) kg(DM)(-1) were applied. 0.26 L min(-1) kg(DM)(-1) provided enough oxygen level (10%) for the rest of composting period, showing 40.5% of OM reduction that is better than other aeration rates. A dynamic mathematical model describing OM degradation, based on the ratio between OM content and initial OM content with correction functions of moisture content, free air space, oxygen and temperature has been proposed.
    Matched MeSH terms: Organic Chemicals/isolation & purification
  9. Fulltext Effects of pH on Phosphorus Recovery from Different Composition of Food Waste Using Anaerobic Batch Digestion
    Selaman, R., Newati Wid
    Borneo Journal of Medical Sciences, 2018;12(101):63-64.
    MyJurnal
    Anaerobic digestion is a process by which microorganisms break down biodegradable material in the absence of oxygen. The process involves hydrolysis, acidogenesis and methanogenesis stages. Anaerobic digestion of food waste has been widely investigated for biogas recovery but limited study was performed on phosphorus recovery, which is reported depleting. Food waste is produced every day and dumped on landfill for final disposal which may lead to environmental issues such as odour problems and greenhouse gases release, due to decomposing of food waste, hence impacts global climate change. In anaerobic digestion pH is a very crucial parameter in an attempt to recover phosphorus as it highly influences the production of organic acids during acidogenesis.
    Matched MeSH terms: Organic Chemicals
  10. Electrical behaviour of MEH-PPV based diode and transistor
    Reshak AH, Shahimin MM, Juhari N, Suppiah S
    Prog Biophys Mol Biol, 2013 Nov;113(2):289-94.
    PMID: 24080185 DOI: 10.1016/j.pbiomolbio.2013.09.002
    The potential of organic semiconductor based devices for light generation is demonstrated by the commercialisation of display technologies using organic light emitting diode (OLED). In OLED, organic materials plays an important role of emitting light once the current is passed through. However OLED have drawbacks whereby it suffers from photon loss and exciton quenching. Organic light emitting transistor (OLET) emerged as a new technology to compensate the efficiency and brightness loss encountered in OLED. The structure has combinational capability to switch the electronic signal such as the field effect transistor (FET) as well as to generate light. Different colours of light could be generated by using different types of organic material. The light emission could also be tuned and scanned in OLET. The studies carried out in this paper focuses on investigation of fabricated MEH-PPV based OLED and also OLET via current voltage characteristics. These studies will continue with a view to develop an optimised MEH-PPV based OLET.
    Matched MeSH terms: Organic Chemicals/chemistry*
  11. Eliminating xenobiotics organic compounds from greywater through green synthetic nanoparticles
    Heshammuddin NA, Al-Gheethi A, Saphira Radin Mohamed RM, Bin Khamidun MH
    Environ Res, 2023 Apr 01;222:115316.
    PMID: 36669587 DOI: 10.1016/j.envres.2023.115316
    Xenobiotic Organic Compounds (XOCs) have been widely considered to be pollutant compounds due to their harmful impacts on aquatic life. However, there have been few rigorous studies of cutting-edge technology used to eradicate XOCs and their presence in bathroom greywater. The present review provides a comprehensive examination of current methodologies used for removing XOCs by photocatalysis of green nanoparticles. It was appeared that zinc oxide nanoparticles (ZnO NPs) have high efficiency (99%) in photocatalysis process. Green synthesis provides proven processes that do not require dangerous chemicals or expensive equipment, making photocatalysis a potential solution for the status quo. XOCs residue was decomposed, and pollutants were eliminated with varied degrees of efficiency using green synthesis ZnO nanoparticles. It is hypothesized that the utilization of photocatalysis can create a greywater treatment system capable of degrading the toxic XOCs in greywater while increasing the pace of production. Hence, this review will be beneficial in improving greywater quality and photocatalysis using green nanoparticles can be an immediate platform in solving the issue regarding the existence of XOCs in greywater in Malaysia. Researchers in the future may benefit from focusing on optimizing photocatalytic degradation using green-synthesis ZnO. It might also help with the creativity and productivity of the next generation of authoritative concerns, notably water conservation.
    Matched MeSH terms: Organic Chemicals
  12. Enhanced mechanical properties of chitosan/EDTA-GO nanocomposites thin films
    Syuhada N, Huang N, Vijay Kumar S, Lim H, Rahman S, Thien G, et al.
    Sains Malaysiana, 2014;43:851-859.
    Nanocomposite thin films of chitosanlgraphene oxide (cs/Go) and chitosanl EDTA-GO (CSIEDTA-GO) were prepared by environmental friendly method and the properties were compared. The experimental results showed fine dispersion of GO and EDTA-GO in CS matrix and some interaction occur between the filler and the CS matrix that leads to better distribution of stress transfer. At 0.5 wt. %, both CSIGO and CSIEDTA-GO experienced maximum tensile stress by 51 and 71% compared with CS. Moreover, the elongation at break for both nanocomposites increases and the amount of filler increases.
    Matched MeSH terms: Organic Chemicals
  13. Fulltext Evaluation of potential carcinogenicity of organic chemicals in synthetic turf crumb rubber
    Perkins AN, Inayat-Hussain SH, Deziel NC, Johnson CH, Ferguson SS, Garcia-Milian R, et al.
    Environ Res, 2019 02;169:163-172.
    PMID: 30458352 DOI: 10.1016/j.envres.2018.10.018
    Currently, there are >11,000 synthetic turf athletic fields in the United States and >13,000 in Europe. Concerns have been raised about exposure to carcinogenic chemicals resulting from contact with synthetic turf fields, particularly the infill material ("crumb rubber"), which is commonly fabricated from recycled tires. However, exposure data are scant, and the limited existing exposure studies have focused on a small subset of crumb rubber components. Our objective was to evaluate the carcinogenic potential of a broad range of chemical components of crumb rubber infill using computational toxicology and regulatory agency classifications from the United States Environmental Protection Agency (US EPA) and European Chemicals Agency (ECHA) to inform future exposure studies and risk analyses. Through a literature review, we identified 306 chemical constituents of crumb rubber infill from 20 publications. Utilizing ADMET Predictor™, a computational program to predict carcinogenicity and genotoxicity, 197 of the identified 306 chemicals met our a priori carcinogenicity criteria. Of these, 52 chemicals were also classified as known, presumed or suspected carcinogens by the US EPA and ECHA. Of the remaining 109 chemicals which were not predicted to be carcinogenic by our computational toxicology analysis, only 6 chemicals were classified as presumed or suspected human carcinogens by US EPA or ECHA. Importantly, the majority of crumb rubber constituents were not listed in the US EPA (n = 207) and ECHA (n = 262) databases, likely due to an absence of evaluation or insufficient information for a reliable carcinogenicity classification. By employing a cancer hazard scoring system to the chemicals which were predicted and classified by the computational analysis and government databases, several high priority carcinogens were identified, including benzene, benzidine, benzo(a)pyrene, trichloroethylene and vinyl chloride. Our findings demonstrate that computational toxicology assessment in conjunction with government classifications can be used to prioritize hazardous chemicals for future exposure monitoring studies for users of synthetic turf fields. This approach could be extended to other compounds or toxicity endpoints.
    Matched MeSH terms: Organic Chemicals
  14. Evaluation of thermochemical pretreatment and continuous thermophilic condition in rice straw composting process enhancement
    Hosseini SM, Abdul Aziz H
    Bioresour Technol, 2013 Apr;133:240-7.
    PMID: 23428821 DOI: 10.1016/j.biortech.2013.01.098
    The effects of thermochemical pretreatment and continuous thermophilic conditions on the composting of a mixture of rice straw residue and cattle manure were investigated using a laboratory-scale composting reactor. Results indicate that the composting period of rice straw can be shortened to less than 10 days by applying alkali pre-treatment and continuous thermophilic composting conditions. The parameters obtained on day 9 of this study are similar to the criteria level published by the Canadian Council of Ministers of the Environment. The moisture content, organic matter reduction, pH level, electrical conductivity, total organic carbon reduction, soluble chemical oxygen demand reduction, total Kjeldahl nitrogen, carbon-to-nitrogen ratio, and germination index were 62.07%, 16.99%, 7.30%, 1058 μS/cm, 17.00%, 83.43%, 2.06%, 16.75%, and 90.33%, respectively. The results of this study suggest that the application of chemical-biological integrated processes under thermophilic conditions is a novel method for the rapid degradation and maturation of rice straw residue.
    Matched MeSH terms: Organic Chemicals/analysis
  15. Fulltext Experimental Investigation and Performance Evaluation of Modified Viscoelastic Surfactant (VES) as a New Thickening Fracturing Fluid
    Chieng ZH, Mohyaldinn ME, Hassan AM, Bruining H
    Polymers (Basel), 2020 Jun 30;12(7).
    PMID: 32629958 DOI: 10.3390/polym12071470
    In hydraulic fracturing, fracturing fluids are used to create fractures in a hydrocarbon reservoir throughout transported proppant into the fractures. The application of many fields proves that conventional fracturing fluid has the disadvantages of residue(s), which causes serious clogging of the reservoir's formations and, thus, leads to reduce the permeability in these hydrocarbon reservoirs. The development of clean (and cost-effective) fracturing fluid is a main driver of the hydraulic fracturing process. Presently, viscoelastic surfactant (VES)-fluid is one of the most widely used fracturing fluids in the hydraulic fracturing development of unconventional reservoirs, due to its non-residue(s) characteristics. However, conventional single-chain VES-fluid has a low temperature and shear resistance. In this study, two modified VES-fluid are developed as new thickening fracturing fluids, which consist of more single-chain coupled by hydrotropes (i.e., ionic organic salts) through non-covalent interaction. This new development is achieved by the formulation of mixing long chain cationic surfactant cetyltrimethylammonium bromide (CTAB) with organic acids, which are citric acid (CA) and maleic acid (MA) at a molar ratio of (3:1) and (2:1), respectively. As an innovative approach CTAB and CA are combined to obtain a solution (i.e., CTAB-based VES-fluid) with optimal properties for fracturing and this behaviour of the CTAB-based VES-fluid is experimentally corroborated. A rheometer was used to evaluate the visco-elasticity and shear rate & temperature resistance, while sand-carrying suspension capability was investigated by measuring the settling velocity of the transported proppant in the fluid. Moreover, the gel breaking capability was investigated by determining the viscosity of broken VES-fluid after mixing with ethanol, and the degree of core damage (i.e., permeability performance) caused by VES-fluid was evaluated while using core-flooding test. The experimental results show that, at pH-value ( 6.17 ), 30 (mM) VES-fluid (i.e., CTAB-CA) possesses the highest visco-elasticity as the apparent viscosity at zero shear-rate reached nearly to 10 6 (mPa·s). Moreover, the apparent viscosity of the 30 (mM) CTAB-CA VES-fluid remains 60 (mPa·s) at (90 ∘ C) and 170 (s - 1 ) after shearing for 2-h, indicating that CTAB-CA fluid has excellent temperature and shear resistance. Furthermore, excellent sand suspension and gel breaking ability of 30 (mM) CTAB-CA VES-fluid at 90 ( ∘ C) was shown; as the sand suspension velocity is 1.67 (mm/s) and complete gel breaking was achieved within 2 h after mixing with the ethanol at the ratio of 10:1. The core flooding experiments indicate that the core damage rate caused by the CTAB-CA VES-fluid is ( 7.99 % ), which indicate that it does not cause much damage. Based on the experimental results, it is expected that CTAB-CA VES-fluid under high-temperature will make the proposed new VES-fluid an attractive thickening fracturing fluid.
    Matched MeSH terms: Organic Chemicals
  16. Experimental chemotherapy of lymphatic filariasis. A review
    Mak JW, Navaratnam V, Ramachandran CP
    Ann Trop Med Parasitol, 1991 Feb;85(1):131-7.
    PMID: 1888210
    An intense global collaborative effort under the leadership of the Steering Committee of the Filariasis Scientific Working Group of the Tropical Diseases Research Programme, World Health Organization, has brought together researchers, pharmaceutical chemists and clinicians in the development and search for antifilarial compounds which are more effective and more convenient to administer than diethylcarbamazine citrate, the current drug of choice for lymphatic filariasis. The Brugia spp.-rodent model has been used extensively for the primary screening and B. pahangi infections in the dog or cat for the secondary screening, of potential filaricides. Recently, the leaf-monkey (Presbytis spp.) infected with subperiodic B. malayi or Wuchereria kalimantani has been used for the tertiary evaluation and pharmacokinetic studies of compounds which have shown effectiveness in the primary and secondary screens. Both P. cristata and P. melalophos are extremely susceptible to subperiodic B. malayi infection, but the former is a better host as a higher peak microfilaremia and adult worm recovery rate were obtained. Although more than 30 potential filaricides have been evaluated in the tertiary screen, only a few compounds have shown some promise against lymphatic filariasis. CGP 20376, a 5-methoxyl-6-dithiocarbamic-S-(2-carboxy-ethyl) ester derivative of benzothiazole, had complete adulticidal and microfilaricidal activities against the parasite at a single oral dose of 20 mg kg-1. However, as the compound or its metabolites caused hepatotoxicity, its clinical use in the present formulation is not recommended.(ABSTRACT TRUNCATED AT 250 WORDS)
    Matched MeSH terms: Organic Chemicals
  17. Fulltext Factorial Design and Optimization of Landfill Leachate Treatment Using Tannin-Based Natural Coagulant
    Banch TJH, Hanafiah MM, Alkarkhi AFM, Abu Amr SS
    Polymers (Basel), 2019 Aug 14;11(8).
    PMID: 31416151 DOI: 10.3390/polym11081349
    In this study, tannin-based natural coagulant was used to treat stabilized landfill leachate. Tannin modified with amino group was utilized for the treatment process. Central composite design (CCD) was used to investigate and optimize the effect of tannin dosage and pH on four responses. The treatment efficiency was evaluated based on the removal of four selected (responses) parameters; namely, chemical oxygen demand (COD), color, NH3-N and total suspended solids (TSS). The optimum removal efficiency for COD, TSS, NH3-N and color was obtained using a tannin dosage of 0.73 g at a pH of 6. Moreover, the removal efficiency for selected heavy metals from leachate; namely, iron (Fe2+), zinc (Zn2+), copper (Cu2+), chromium (Cr2+), cadmium (Cd2+), lead (Pb2+), arsenic (As3+), and cobalt (Co2+) was also investigated. The results for removal efficiency for COD, TSS, NH3-N, and color were 53.50%, 60.26%, and 91.39%, respectively. The removal of selected heavy metals from leachate for Fe2+, Zn2+, Cu2+, Cr2+, Cd2+, Pb2+, As3+ and cobalt Co2+ were 89.76%, 94.61%, 94.15%, 89.94%, 17.26%, 93.78%, 86.43% and 84.19%, respectively. The results demonstrate that tannin-based natural coagulant could effectively remove organic compounds and heavy metals from stabilized landfill leachate.
    Matched MeSH terms: Organic Chemicals
  18. Fluorescence technique for the characterization of natural organic matter in river water
    Ahmad UK, Ulang Z, Yusop Z, Fong TL
    Water Sci Technol, 2002;46(9):117-25.
    PMID: 12448460
    The complex nature of natural organic matter (NOM), and the impact of this matter on drinking water quality have necessitated the characterization studies of NOM. A fluorescence technique for the characterization of NOM in Malaysian river water is reported. Water samples from several river sampling sites were collected and concentrated using a low-pressure reverse osmosis (LPROM). Solid phase extraction (SPE) using C18 extraction cartridges were used to fractionate the water samples into humic and non-humic fractions. To differentiate and classify various types of humic substances, fluorescence was applied in emission, excitation and in synchronous-scan modes. A synchronous spectral profile was found to be able to differentiate humic and fulvic acids better than the emission or excitation spectra. Synchronous excitation spectra showed different spectral patterns for the water samples due to different origin. All water samples showed the presence of both fulvic and humic acids.
    Matched MeSH terms: Organic Chemicals/analysis
  19. Formation, modeling and validation of trihalomethanes (THM) in Malaysian drinking water: a case study in the districts of Tampin, Negeri Sembilan and Sabak Bernam, Selangor, Malaysia
    Abdullah MP, Yew CH, Ramli MS
    Water Res, 2003 Nov;37(19):4637-44.
    PMID: 14568050
    A modeling procedure that predicts trihalomethane (THM) formation from field sampling at the treatment plant and along its distribution system using Tampin district, Negeri Sembilan and Sabak Bernam district, Selangor as sources of data were studied and developed. Using Pearson method of correlation, the organic matter measured as TOC showed a positive correlation with formation of THM (r=0.380,P=0.0001 for Tampin and r=0.478,P=0.0001 for Sabak Bernam). Similar positive correlation was also obtained for pH in both districts with Tampin (r=0.362,P=0.0010) and Sabak Bernam (r=0.215,P=0.0010). Chlorine dosage was also found to have low correlation with formation of THM for the two districts with Tampin (r=0.233,P=0.0230) and Sabak Bernam (r=0.505,P=0.0001). Distance from treatment plant was found to have correlation with formation of THM for Tampin district with r=0.353 and P=0.0010. Other parameters such as turbidity, ammonia, temperature and residue chlorine were found to have no correlation with formation of THM. Linear and non-linear models were developed for these two districts. The results obtained were validated using three different sets of field data obtained from own source and district of Seremban (Pantai and Sg. Terip), Negeri Sembilan. Validation results indicated that there was significant difference in the predictive and determined values of THM when two sets of data from districts of Seremban were used with an exception of field data of Sg. Terip for non-linear model developed for district of Tampin. It was found that a non-linear model is slightly better than linear model in terms of percentage prediction errors. The models developed were site specific and the predictive capabilities in the distribution systems vary with different environmental conditions.
    Matched MeSH terms: Organic Chemicals
  20. Fulltext Fractionation of as, co, cu and zn by sequential extraction in surface sediment of Kuala Terengganu river estuary
    Muhammad Nazirul Mubin Abd Halim Shah, Lee, Siang Hing, Mohd Yusoff Nurulnadia, Meng, Chuan Ong
    Malaysian Journal of Applied Sciences, 2020;5(2):57-68.
    MyJurnal
    Development and urbanization processes around Terengganu River estuary are expected to release a significant amount of heavy metals into the existing surface sediment. However, information on how and why these metals are attached into specific fraction of sediments is still lacking. Therefore, this study aimed to explain the heavy metal concentration distribution in each available fraction in Terengganu River estuary. In this study, nine surface sediments originated from various human activities area in Terengganu River estuary were collected during four different sampling sessions in 2017. Heavy metal content from the collected sediments were extracted using 3-steps BCR sequential extraction method followed by detection using Inductively Coupled Plasma Mass-Spectrometer (ICP-MS) and we discovered that the total concentration of arsenic (As), cobalt (Co), copper (Cu), and zinc (Zn) ranged from 2.18 to 17.48 mg/kg dry wt., 2.53 to 20.53 mg/kg dry wt., 1.01 to 13.13 mg/kg dry wt., and 6.10 to 65.71 mg/kg dry wt., respectively. Dominance of metals in each fraction can be arranged as follows: As: residual > reducible > exchangeable > oxidizable; Co: residual > exchangeable > reducible > oxidizable; Cu: residual > oxidizable > reducible > exchangeable; Zn: residual > exchangeable > reducible > oxidizable. Availability of metals in the sediment at Terengganu River estuary is limited since that majority of metals resides in non-mobilisable fraction of the sediment. In essence, the sequential extraction provides information regarding the metals’ fractionation, availability and mobility, which could be used in assessing the environmental contamination in the area.
    Matched MeSH terms: Organic Chemicals
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