Displaying publications 1 - 20 of 37 in total

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  1. Environmental surveillance of SARS-CoV-2 in municipal wastewater to monitor COVID-19 status in urban clusters in Malaysia
    Aziz MA, Norman S, Mohamed Zaid S, Simarani K, Sulaiman R, Mohd Aris A, et al.
    Arch Microbiol, 2023 Jan 28;205(2):76.
    PMID: 36708390 DOI: 10.1007/s00203-023-03417-y
    Wastewater monitoring for SARS-CoV-2 has attracted considerable attention worldwide to complement the existing clinical-based surveillance system. In this study, we report our first successful attempt to prove the circulation of SARS-CoV-2 genes in Malaysian urban wastewater. A total of 18 wastewater samples were obtained from a regional sewage treatment plant that received municipal sewage between February 2021 and May 2021. Using the quantitative PCR assay targeting the E and RdRp genes of SARS-CoV-2, we confirmed that both genes were detected in the raw sewage, while no viral RNA was found in the treated sewage. We were also able to show that the trend of COVID-19 cases in Kuala Lumpur and Selangor was related to the changes in SARS-CoV-2 RNA levels in the wastewater samples. Overall, our study highlights that monitoring wastewater for SARS-CoV-2 should help local health professionals to obtain additional information on the rapid and silent circulation of infectious agents in communities at the regional level.
  2. Multivariate and Geoaccumulation Index evaluation in mangrove surface sediment of Mengkabong lagoon, Sabah
    Praveena SM, Ahmed A, Radojevic M, Abdullah MH, Aris AZ
    Bull Environ Contam Toxicol, 2008 Jul;81(1):52-6.
    PMID: 18506379 DOI: 10.1007/s00128-008-9460-3
    Spatial variations in estuarine intertidal sediment have been often related to such environmental variables as salinity, sediment types, heavy metals and base cations. However, there have been few attempts to investigate the difference condition between high and low tides relationships and to predict their likely responses in an estuarine environment. This paper investigates the linkages between environmental variables and tides of estuarine intertidal sediment in order to provide a basis for describing the effect of tides in the Mengkabong lagoon, Sabah. Multivariate statistical technique, principal components analysis (PCA) was employed to better interpret information about the sediment and its controlling factors in the intertidal zone. The calculation of Geoaccumulation Index (I(geo)) suggests the Mengkabong mangrove sediments are having background concentrations for Al, Cu, Fe, and Zn and unpolluted for Pb. Extra efforts should therefore pay attention to understand the mechanisms and quantification of different pathways of exchange within and between intertidal zones.
  3. Influence of static mixer on the development of aerobic granules for the treatment of low-medium strength domestic wastewater
    We ACE, Aris A, Zain NAM, Muda K, Sulaiman S
    Chemosphere, 2021 Jan;263:128209.
    PMID: 33297168 DOI: 10.1016/j.chemosphere.2020.128209
    The present work investigates the feasibility of aerobic granulation for the treatment of low-medium strength domestic wastewater for long-term operation and effects of a static mixer on the properties and removal performances of the aerobic granules formed. The static mixer was installed in a sequential batch reactor to provide higher hydrodynamic shear force in enhancing the formation of the aerobic granules. Aerobic granules were successfully formed in the domestic wastewater, and the granulation treatment system was sustained for a period of 356 days without granules disintegration. Subsequent to the installation, aerobic granules with a low SVI30 of 41.37 mL/gTSS, average diameter 1.11 mm, granular strength with integrity coefficient 10.4% and regular shape with minimum filamentous outgrowth were formed. Mineral concentrations such as Fe, Mg, Ca and Na as well as composition of protein and polysaccharide in tightly bound-extracellular polymeric substance of the aerobic granules were found to be higher under the effect of the static mixer. However, no significant improvement was observed on the TCOD, NH4+-N and TSS removal performance. Good TCOD and TSS removal performance of above 85% and 90%, respectively and moderate NH4+-N removal performance of about 60% were observed throughout the study. Higher simultaneous nitrification and denitrification (SND) efficiency of 56% was observed after the installation of the static mixer, as compared to 21% prior. Therefore, it may be concluded that the installation of the static mixer significantly improved the properties of aerobic granules formation and SND efficiency but not the TCOD, NH4+-N and TSS removal performance.
  4. Type 2 diabetes risk among university students in Malaysia
    Aris A, Khalid MZM, Yahaya H, Yoong LO, Ying NQ
    Curr Diabetes Rev, 2020;16(4):387-394.
    PMID: 31433762 DOI: 10.2174/1573399815666190712192527
    BACKGROUND: Type 2 diabetes (T2D) is a preventable condition. Targeting those who are at risk of getting this disease is essential.

    OBJECTIVE: To examine T2D risk among university students in Malaysia and determine its relationship with socio-demographic characteristics and physical activity.

    METHODS: The study was conducted cross-sectionally on 390 students selected using quota sampling method from 13 faculties in Universiti Kebangsaan Malaysia. A short form of the International Physical Activity Questionnaire and Finnish Diabetes Risk Score were used to measure the physical activity and T2D risk.

    RESULTS: The T2D risk was found to be low (M = 5.23, SD = 3.32) with more than two-third of the student population at the low risk level while a significant proportion of 23.8%, 5.6% and 0.3% having slightly elevated, moderate and high risk respectively. The T2D risk was significantly related to their age (rho = 0.197, p < 0.000), gender (U = 12641, p = 0.011), ethnic group (Χ2 = 18.86, p < 0.000), marital status (Χ2 = 6.597, p = 0.037), residence (U = 10345, p = 0.008), academic year (Χ2 = 14.24, p = 0.007) and physical activity (rho = -0.205, p < 0.000 and Χ2 = 13.515, p = 0.001). Of these, only age (β=0.130) and physical activity (β=-0.159) remained significant in the regression analysis.

    CONCLUSION: The findings call for a radical change in the nursing practice to target the amendable factors that are significant in order to prevent the progression of the risk towards type 2 diabetes.
  5. The influence of music therapy on mental well-being among postoperative patients of total knee arthroplasty (TKA)
    Aris A, Sulaiman S, Che Hasan MK
    Enferm Clin, 2019 09;29 Suppl 2:16-23.
    PMID: 31208927 DOI: 10.1016/j.enfcli.2019.04.004
    OBJECTIVE: The objective of this study was to investigate whether music therapy affects immediate postoperative well-being among patients who had undergone TKA surgery in the recovery unit.

    METHOD: A randomized controlled trial was conducted recruiting patients from Hospital Melaka, Malaysia. Postoperative TKA patients with good hearing and visual acuity, fully conscious and prescribed with patients controlled analgesia (PCA) were randomized to either intervention or control groups using a sealed envelope. Patients in the intervention group received usual care with additional music therapy during recovery, while patients in the control group received the usual care provided by the hospital. Two factors identified affecting mental well-being were the pain (measured using numerical rating scale) and anxiety (measured using a visual analog scale) at five different minutes' points (0, 10, 20, 30, and 60).

    RESULTS: A total of 56 (control: 28, intervention: 28) postoperative TKA patients consented in the study. There was no difference in baseline characteristics between the two groups (p>0.05). Using Mann-Whitney U tests, patients in music therapy group showed significantly lower numerical pain score at 60min (p=0.045) whereas there was no significant difference between the two groups at all time points for anxiety scores (p>0.05). In the intervention group, Friedman tests showed that there was a significant difference in numerical pain (χ2=36.957, df=4, p<0.001) and anxiety score across times (χ2=18.545, p=0.001).

    CONCLUSIONS: This study found that pain score decreases over time among patients in the music therapy group while no effect is seen for anxiety. It is suggested that music therapy could not affect postoperative TKA patients' mental well-being. Nonetheless, patients reported better pain score despite the small sample.

  6. Effects of music therapy on physiological outcomes for post-operative total knee arthroplasty (TKA) patients
    Aris A, Sulaiman S, Che Hasan MK
    Enferm Clin, 2021 04;31 Suppl 2:S10-S15.
    PMID: 33849138 DOI: 10.1016/j.enfcli.2020.10.006
    This study aimed to investigate the effects of music on physiological outcomes for post-operative TKA patients in the recovery unit. Fifty-six patients from Hospital Melaka were randomized equally into intervention (IG) and control groups (CG). IG received the usual care and listened to selected music for 60min, while the CG received only the usual care. Systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), respiration rate (RR) and oxygen saturation (SpO2) were measured on arrival and after 10, 20, 30, and 60min in the recovery unit. A significant difference between groups was observed in RR upon arrival (U=276.5, p=0.029) and after 10min (U=291, p=0.45). Meanwhile, there were significant differences in DBP (F=3.158, p=0.032), RR (χ2=15.956, p=0.003) and SpO2 (χ2=14.084, p=0.007) over time in the IG. Overall, listening to music immediately after TKA has an effect on DBP, RR, and SpO2.
  7. Status, source identification, and health risks of potentially toxic element concentrations in road dust in a medium-sized city in a developing country
    Praveena SM, Aris AZ
    Environ Geochem Health, 2018 Apr;40(2):749-762.
    PMID: 28929262 DOI: 10.1007/s10653-017-0021-8
    This study aims to determine the status of potentially toxic element concentrations of road dust in a medium-sized city (Rawang, Malaysia). This study adopts source identification via enrichment factor, Pearson correlation analysis, and Fourier spectral analysis to identify sources of potentially toxic element concentrations in road dust in Rawang City, Malaysia. Health risk assessment was conducted to determine potential health risks (carcinogenic and non-carcinogenic risks) among adults and children via multiple pathways (i.e., ingestion, dermal contact, and inhalation). Mean of potentially toxic element concentrations were found in the order of Pb > Zn > Cr(IV) > Cu > Ni > Cd > As > Co. Source identification revealed that Cu, Cd, Pb, Zn, Ni, and Cr(IV) are associated with anthropogenic sources in industrial and highly populated areas in northern and southern Rawang, cement factories in southern Rawang, as well as the rapid development and population growth in northwestern Rawang, which have resulted in high traffic congestion. Cobalt, Fe, and As are related to geological background and lithologies in Rawang. Pathway orders for both carcinogenic and non-carcinogenic risks are ingestion, dermal contact, and inhalation, involving adults and children. Non-carcinogenic health risks in adults were attributed to Cr(IV), Pb, and Cd, whereas Cu, Cd, Cr(IV), Pb, and Zn were found to have non-carcinogenic health risks for children. Cd, Cr(IV), Pb, and As may induce carcinogenic risks in adults and children, and the total lifetime cancer risk values exceeded incremental lifetime.
  8. Bioavailability and mobility of arsenic, cadmium, and manganese in gold mine tailings amended with rice husk ash and Fe-coated rice husk ash
    Tariq FS, Samsuri AW, Karam DS, Aris AZ, Jamilu G
    Environ Monit Assess, 2019 Mar 21;191(4):232.
    PMID: 30900076 DOI: 10.1007/s10661-019-7359-6
    This study was conducted to determine the effects of rice husk ash (RHA) and Fe-coated rice husk ash (Fe-RHA) on the bioavailability and mobility of As, Cd, and Mn in mine tailings. The amendments were added to the tailings at 0, 5, 10, or 20% (w/w) and the mixtures were incubated for 0, 7, 15, 30, 45, and 60 days. The CaCl2 extractable As, Cd, and Mn in the amended tailings were determined at each interval of incubation period. In addition, the tailings mixture was leached with simulated rain water (SRW) every week from 0 day (D 0) until day 60 (D 60). The results showed that both RHA and Fe-RHA application significantly decreased the CaCl2-extractable Cd and Mn but increased that of As in the tailings throughout the incubation period. Consequently, addition of both RHA and Fe-RHA leached out higher amount of As from the tailings but decreased Cd and Mn concentration compared to the controls. The amount of As leached from the Fe-RHA-amended tailings was less than that from RHA-amended tailings. Application of both RHA and Fe-RHA could be an effective way in decreasing the availability of cationic heavy metals (Cd and Mn) in the tailings but these amendments could result in increasing the availability of anionic metalloid (As). Therefore, selection of organic amendments to remediate metal-contaminated tailings must be done with great care because the outcomes might be different among the elements.
  9. Application of zeolite-activated carbon macrocomposite for the adsorption of Acid Orange 7: isotherm, kinetic and thermodynamic studies
    Lim CK, Bay HH, Neoh CH, Aris A, Abdul Majid Z, Ibrahim Z
    Environ Sci Pollut Res Int, 2013 Oct;20(10):7243-55.
    PMID: 23653315 DOI: 10.1007/s11356-013-1725-7
    In this study, the adsorption behavior of azo dye Acid Orange 7 (AO7) from aqueous solution onto macrocomposite (MC) was investigated under various experimental conditions. The adsorbent, MC, which consists of a mixture of zeolite and activated carbon, was found to be effective in removing AO7. The MC were characterized by scanning electron microscopy (SEM), energy dispersive X-ray, point of zero charge, and Brunauer-Emmett-Teller surface area analysis. A series of experiments were performed via batch adsorption technique to examine the effect of the process variables, namely, contact time, initial dye concentration, and solution pH. The dye equilibrium adsorption was investigated, and the equilibrium data were fitted to Langmuir, Freundlich, and Tempkin isotherm models. The Langmuir isotherm model fits the equilibrium data better than the Freundlich isotherm model. For the kinetic study, pseudo-first-order, pseudo-second-order, and intraparticle diffusion model were used to fit the experimental data. The adsorption kinetic was found to be well described by the pseudo-second-order model. Thermodynamic analysis indicated that the adsorption process is a spontaneous and endothermic process. The SEM, Fourier transform infrared spectroscopy, ultraviolet-visible spectral and high performance liquid chromatography analysis were carried out before and after the adsorption process. For the phytotoxicity test, treated AO7 was found to be less toxic. Thus, the study indicated that MC has good potential use as an adsorbent for the removal of azo dye from aqueous solution.
  10. Biosorption and biodegradation of Acid Orange 7 by Enterococcus faecalis strain ZL: optimization by response surface methodological approach
    Lim CK, Bay HH, Aris A, Abdul Majid Z, Ibrahim Z
    Environ Sci Pollut Res Int, 2013 Jul;20(7):5056-66.
    PMID: 23334551 DOI: 10.1007/s11356-013-1476-5
    Reactive dyes account for one of the major sources of dye wastes in textile effluent. In this study, decolorization of the monoazo dye, Acid Orange 7 (AO7) by the Enterococcus faecalis strain ZL that isolated from a palm oil mill effluent treatment plant has been investigated. Decolorization efficiency of azo dye is greatly affected by the types of nutrients and the size of inoculum used. In this work, one-factor-at-a-time (method and response surface methodology (RSM) was applied to optimize these operational factors and also to study the combined interaction between them. Analysis of AO7 decolorization was done using Fourier transform infrared (FTIR) spectroscopy, desorption study, UV-Vis spectral analysis, field emission scanning electron microscopy (FESEM), and high performance liquid chromatography (HPLC). The optimum condition via RSM for the color removal of AO7 was found to be as follows: yeast extract, 0.1% w/v, glycerol concentration of 0.1% v/v, and inoculum density of 2.5% v/v at initial dye concentration of 100 mg/L at 37 °C. Decolorization efficiency of 98% was achieved in only 5 h. The kinetic of AO7 decolorization was found to be first order with respect to dye concentration with a k value of 0.87/h. FTIR, desorption study, UV-Vis spectral analysis, FESEM, and HPLC findings indicated that the decolorization of AO7 was mainly due to the biosorption as well as biodegradation of the bacterial cells. In addition, HPLC analyses also showed the formation of sulfanilic acid as a possible degradation product of AO7 under facultative anaerobic condition. This study explored the ability of E. faecalis strain ZL in decolorizing AO7 by biosorption as well as biodegradation process.
  11. A review of antibiotic removal from domestic wastewater using the activated sludge process: removal routes, kinetics and operational parameters
    Chen CX, Aris A, Yong EL, Noor ZZ
    Environ Sci Pollut Res Int, 2022 Jan;29(4):4787-4802.
    PMID: 34775565 DOI: 10.1007/s11356-021-17365-x
    Many advanced technologies have shown encouraging results in removing antibiotics from domestic wastewater. However, as activated sludge treatment is the most common sewage treatment system employed worldwide, improving its effect on antibiotic removal would be more desirable. Understanding the removal mechanisms, kinetics and factors that affect antibiotic removal in the activated sludge process is important as it would allow us to improve the treatment performance. Although these have been discussed in various literature covering different types of antibiotics and wastewater, a specific review on antibiotics and domestic wastewater is clearly missing. This review paper collates, discusses and analyses the removal of antibiotics from sewage in the activated sludge process along with the removal mechanisms and kinetics. The antibiotics are categorised into six classes: β-lactam, dihydrofolate reductase inhibitor, fluoroquinolone, macrolide, sulfonamides and tetracycline. Furthermore, the factors affecting the system performance with regard to antibiotic removal are examined.
  12. Influence of initial dissolved oxygen concentration on Fenton's reagent degradation
    Aris A, Sharratt PN
    Environ Technol, 2006 Oct;27(10):1153-61.
    PMID: 17144264
    The effect of initial dissolved oxygen concentration (IDOC) on Fenton's reagent degradation of a dyestuff, Reactive Black 5 was explored in this study. The study was designed, conducted and analysed based on Central Composite Rotatable Design using a 3-1 lab-scale reactor. The participation of O2 in the process was experimentally observed and appears to be affected by the dosage of the reagents used in the study. The IDOC was found to have a significant influence on the process. Reducing the IDOC from 7.5 mg l(-1) to 2.5 mg l(-1) increased the removal of TOC by an average of about 10%. Reduction of IDOC from 10 mg l(-1) to 0 mg l(-1) enhanced the TOC removal by about 30%. The negative influence of IDOC is likely to be caused by the competition between the O2 and the reagents for the organoradicals. A model describing the relationship between initial TOC removal, reagent dosage and IDOC has also been developed.
  13. Mass transfer kinetics of biosorption of nitrogenous matter from palm oil mill effluent by aerobic granules in sequencing batch reactor
    Fulazzaky MA, Nuid M, Aris A, Muda K
    Environ Technol, 2018 Sep;39(17):2151-2161.
    PMID: 28675960 DOI: 10.1080/09593330.2017.1351494
    Understanding of mass transfer kinetics is important for biosorption of nitrogen compounds from palm oil mill effluent (POME) to gain a mechanistic insight into future biological processes for the treatment of high organic loading wastewater. In this study, the rates of global and sequential mass transfer were determined using the modified mass transfer factor equations for the experiments to remove nitrogen by aerobic granular sludge accumulation in a sequencing batch reactor (SBR). The maximum efficiencies as high as 97% for the experiment run at [kLa]g value of 1421.8 h-1 and 96% for the experiment run at [kLa]g value of 9.6 × 1037 h-1 were verified before and after the addition of Serratia marcescens SA30, respectively. The resistance of mass transfer could be dependent on external mass transfer that controls the transport of nitrogen molecule along the experimental period of 256 days. The increase in [kLa]g value leading to increased performance of the SBR was verified to contribute to the future applications of the SBR because this phenomenon provides new insight into the dynamic response of biological processes to treat POME.
  14. Health Risk Assessment using in vitro digestion model in assessing bioavailability of heavy metal in rice: A preliminary study
    Omar NA, Praveena SM, Aris AZ, Hashim Z
    Food Chem, 2015 Dec 1;188:46-50.
    PMID: 26041162 DOI: 10.1016/j.foodchem.2015.04.087
    Little is known about the bioavailability of heavy metal contamination and its health risks after rice ingestion. This study aimed to determine bioavailability of heavy metal (As, Cd, Cu, Cr, Co, Al, Fe, Zn and Pb) concentrations in cooked rice and human Health Risk Assessment (HRA). The results found Zn was the highest (4.3±0.1 mg/kg), whereas As showed the lowest (0.015±0.001 mg/kg) bioavailability of heavy metal concentration in 22 varieties of cooked rice. For single heavy metal exposure, no potential of non carcinogenic health risks was found, while carcinogenic health risks were found only for As. Combined heavy metal exposures found that total Hazard Quotient (HQtotal) values for adult were higher than the acceptable range (HQTotal<1), whereas total Lifetime Cancer Risk (LCRTotal) values were higher than the acceptable range (LCRTotal values >1×10(-4)) for both adult and children. This study is done to understand that the inclusion of bioavailability heavy metal into HRA produces a more realistic estimation of human heavy metal exposure.
  15. Fulltext Bioavailability of heavy metal in rice using in vitro digestion model
    Omar, N. A., Praveena, S. M., Hashim, Z., Aris, A. Z.
    International Food Research Journal, 2013;20(6):2979-2985.
    MyJurnal
    Rice is a carbohydrate, one of the plant-based foods that can accumulate heavy metal from soil and the irrigation water. Since total heavy metal always overestimates the amount of heavy metal available in rice, bioavailability of heavy metal is always preferred. Many studies have been done and found that in vitro methods offer an appealing alternative to human and animal studies. They can be simple, rapid, low in cost and may provide insights which not achievable in the in vivo studies. In vitro digestion model for rice may differ from other in vitro digestion models applied in soil or other type of foods studies. This review aims to provide an overview of in vitro digestion model used to determine bioavailability of heavy metal in rice, summarize health risk assessment application of heavy metal in rice studies and highlight the importance of health risk assessment to be included in the studies. Future exploration of in vitro digestion model and health risk assessment application on the bioavailability of heavy metal in rice was also suggested.
  16. Biocontrol efficacy of Trichoderma asperellum-enriched coconut fibre against Fusarium wilts of cherry tomato
    Hasan ZAE, Mohd Zainudin NAI, Aris A, Ibrahim MH, Yusof MT
    J Appl Microbiol, 2020 Oct;129(4):991-1003.
    PMID: 32324939 DOI: 10.1111/jam.14674
    AIMS: Agro-based wastes were evaluated as a medium for mass micropropagule production and optimal efficacy of Trichoderma asperellum B1092 in controlling Fusarium oxysporum f. sp. lycopersici and promoting tomato growth. This study focused on biological control because pathogen persistence in the soil makes the disease difficult to control.

    METHODS AND RESULTS: Rice bran, biochar, empty fruit bunches, coconut fibres, compost, top soil and mixed soil were evaluated as media for mass multiplication of T. asperellum, which is effective in controlling plant pathogens. Yielding the most colony forming units (CFU) among the media, coconut fibre was deemed most suitable for promoting sporulation. After 120 days on the medium, T. asperellum B1902 produced 9·053 × 105  CFU per gram coconut fibre; oil palm empty fruit bunches was second highest (7·406 × 105  CFU per gram). In field tests of T. asperellum B1092 against F. oxysporum f. sp lycopersici (causing Fusarium wilt of cherry tomato), B1092 significantly promoted plant growth compared to the control. The efficacy of this formulation resulted in increased growth of roots and shoots tomato plants and total lycopene, sugar, K, N, Ca, P and Mg content after 120 days.

    CONCLUSIONS: Trichoderma asperellum B1092 showed great field potential for improving productivity and quality of tomatoes and in controlling Fusarium wilt of cherry tomato.

    SIGNIFICANCE AND IMPACT OF THE STUDY: This innovative approach using a cheap agro-waste to control the persistent soil-borne Fusarium pathogen of cherry tomato should increase soil survival rate of Trichoderma and has potential for upscaling in the field for other crops.

  17. Vibriosis in Fish: A Review on Disease Development and Prevention
    Ina-Salwany MY, Al-Saari N, Mohamad A, Mursidi FA, Mohd-Aris A, Amal MNA, et al.
    J Aquat Anim Health, 2019 03;31(1):3-22.
    PMID: 30246889 DOI: 10.1002/aah.10045
    Current growth in aquaculture production is parallel with the increasing number of disease outbreaks, which negatively affect the production, profitability, and sustainability of the global aquaculture industry. Vibriosis is among the most common diseases leading to massive mortality of cultured shrimp, fish, and shellfish in Asia. High incidence of vibriosis can occur in hatchery and grow-out facilities, but juveniles are more susceptible to the disease. Various factors, particularly the source of fish, environmental factors (including water quality and farm management), and the virulence factors of Vibrio, influence the occurrence of the disease. Affected fish show weariness, with necrosis of skin and appendages, leading to body malformation, slow growth, internal organ liquefaction, blindness, muscle opacity, and mortality. A combination of control measures, particularly a disease-free source of fish, biosecurity of the farm, improved water quality, and other preventive measures (e.g., vaccination) might be able to control the infection. Although some control measures are expensive and less practical, vaccination is effective, relatively cheap, and easily implemented. In this review, the latest knowledge on the pathogenesis and control of vibriosis, including vaccination, is discussed.
  18. Waste bones ash as an alternative source of P for struvite precipitation
    Darwish M, Aris A, Puteh MH, Jusoh MNH, Abdul Kadir A
    J Environ Manage, 2017 Dec 01;203(Pt 2):861-866.
    PMID: 26935149 DOI: 10.1016/j.jenvman.2016.02.033
    Struvite precipitation has been widely applied for the removal of ammonium-nitrogen (NH4-N) from wastewater. Due to the high cost of phosphorus (P) reagents, the current research trend was directed to find alternative sources of P, in order to maintain a sustainable NH4-N removal process. The current study investigated waste bones ashes as alternative sources of P. Different types of bones' ashes were characterized, in which the ash produced from waste fish bones was the highest in P content (17%wt.). The optimization of the factors affecting P extraction from ash by acidic leaching showed that applying 2M H2SO4 and 1.25 kg H2SO4/kg ash achieved the highest P recovery (95%). Thereafter, the recovered P was successfully used in struvite precipitation, which achieved more than 90% NH4-N removal and high purity struvite.
  19. Identification of naphthalene metabolism by white rot fungus Armillaria sp. F022
    Hadibarata T, Yusoff AR, Aris A, Kristanti RA
    J Environ Sci (China), 2012;24(4):728-32.
    PMID: 22894109
    Armillaria sp. F022, a white rot fungus isolated from tropical rain forest (Samarinda, Indonesia) was used to biodegrade naphthalene in cultured medium. Transformation of naphthalene by Armillaria sp. F022 which is able to use naphthalene, a two ring-polycyclic aromatic hydrocarbon (PAH) as a source of carbon and energy was investigated. The metabolic pathway was elucidated by identifying metabolites, biotransformation studies and monitoring enzyme activities in cell-free extracts. The identification of metabolites suggests that Armillaria sp. F022 initiates its attack on naphthalene by dioxygenation at its C-1 and C-4 positions to give 1,4-naphthoquinone. The intermediate 2-hydroxybenzaldehyde and salicylic acid, and the characteristic of the meta-cleavage of the resulting diol were identified in the long-term incubation. A part from typical metabolites of naphthalene degradation known from mesophiles, benzoic acid was identified as the next intermediate for the naphthalene pathway of this Armillaria sp. F022. Neither phthalic acid, catechol and cis,cis-muconic acid metabolites were detected in culture extracts. Several enzymes (manganese peroxidase, lignin peroxidase, laccase, 1,2-dioxygenase and 2,3-dioxygenase) produced by Armillaria sp. F022 were detected during the incubation.
  20. Simultaneous determination of three organophosphorus pesticides in different food commodities by gas chromatography with mass spectrometry
    Vijaya Bhaskar Reddy A, Yusop Z, Jaafar J, Bin Aris A, Abdul Majid Z, Umar K, et al.
    J Sep Sci, 2016 Jun;39(12):2276-83.
    PMID: 27095506 DOI: 10.1002/jssc.201600155
    A sensitive and selective gas chromatography with mass spectrometry method was developed for the simultaneous determination of three organophosphorus pesticides, namely, chlorpyrifos, malathion, and diazinon in three different food commodities (milk, apples, and drinking water) employing solid-phase extraction for sample pretreatment. Pesticide extraction from different sample matrices was carried out on Chromabond C18 cartridges using 3.0 mL of methanol and 3.0 mL of a mixture of dichloromethane/acetonitrile (1:1 v/v) as the eluting solvent. Analysis was carried out by gas chromatography coupled with mass spectrometry using selected-ion monitoring mode. Good linear relationships were obtained in the range of 0.1-50 μg/L for chlorpyrifos, and 0.05-50 μg/L for both malathion and diazinon pesticides. Good repeatability and recoveries were obtained in the range of 78.54-86.73% for three pesticides under the optimized experimental conditions. The limit of detection ranged from 0.02 to 0.03 μg/L, and the limit of quantification ranged from 0.05 to 0.1 μg/L for all three pesticides. Finally, the developed method was successfully applied for the determination of three targeted pesticides in milk, apples, and drinking water samples each in triplicate. No pesticide was found in apple and milk samples, but chlorpyrifos was found in one drinking water sample below the quantification level.
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