Displaying publications 61 - 80 of 137 in total

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  1. Effects of atmospheric deposition nitrogen flux and its composition on soil solution chemistry from a red soil farmland, southeast China
    Cui J, Zhou J, Peng Y, Chan A, Mao J
    Environ Sci Process Impacts, 2015 Dec;17(12):2082-91.
    PMID: 26515781 DOI: 10.1039/c5em00383k
    A detailed study on the solution chemistry of red soil in South China is presented. Data are collected from two simulated column-leaching experiments with an improved setup to evaluate the effects of atmospheric N deposition (ADN) composition and ADN flux on agricultural soil acidification using a (15)N tracer technique and an in situ soil solution sampler. The results show that solution pH values decline regardless of the increase of the NH4(+)/NO3(-) ratio in the ADN composition or ADN flux, while exchangeable Al(3+), Ca(2+), Mg(2+), and K(+) concentrations increase at different soil depths (20, 40, and 60 cm). Compared with the control, ADN (60 kg per ha per year N, NH4(+)/NO3(-) ratio of 2 : 1) decreases solution pH values, increases solution concentrations of NO3(-)-N, Al(3+), Ca(2+) and Mg(2+) at the middle and lower soil depths, and promotes their removal. NH4(+)-N was not detected in red soil solutions of all the three soil layers, which might be attributed to effects of nitrification, absorption and fixation in farmland red soil. Some of the NO3(-)-N concentrations at 40-60 cm soil depth exceed the safe drinking level of 10 mg L(-1), especially when the ADN flux is beyond 60 kg ha(-1) N. These features are critical for understanding the ADN agro-ecological effects, and for future assessment of ecological critical loads of ADN in red soil farmlands.
    Matched MeSH terms: Nitrates/analysis
  2. Nutrient removal in a pilot and full scale constructed wetland, Putrajaya city, Malaysia
    Sim CH, Yusoff MK, Shutes B, Ho SC, Mansor M
    J Environ Manage, 2008 Jul;88(2):307-17.
    PMID: 17467147
    Putrajaya Wetlands in Malaysia, a 200ha constructed wetland system consisting of 24 cells, was created in 1997-1998 to treat surface runoff caused by development and agricultural activities from an upstream catchment before entering Putrajaya Lake (400ha). It was designed for stormwater treatment, flood control and amenity use. The water quality improvement performance of a section of the wetland cells is described. The nutrient removal performance was 82.11% for total nitrogen, 70.73% for nitrate-nitrogen and 84.32% for phosphate, respectively, along six wetland cells from Upper North UN6 to UN1 from April to December 2004. Nutrient removal in pilot scale tank systems, simulating a constructed wetland and planted with examples of common species at Putrajaya, the Common Reed Phragmites karka and Tube Sedge Lepironia articulata, and the capacity of these species to retain nutrients in above and below-ground plant biomass and substrate is reported. The uptake of nutrients by the Common Reed and Tube Sedge from the pilot tank system was 42.1% TKN; 28.9% P and 17.4% TKN; 26.1% P, respectively. The nutrient uptake efficiency of the Common Reed was higher in above-ground than in below-ground tissue. The results have implications for plant species selection in the design of constructed wetlands in Malaysia and for optimizing the performance of these systems.
    Matched MeSH terms: Nitrates/chemistry
  3. Fulltext Characteristics of Glycerolized Chitosan: NH4NO3-Based Polymer Electrolyte for Energy Storage Devices with Extremely High Specific Capacitance and Energy Density Over 1000 Cycles
    Aziz SB, Brza MA, Brevik I, Hamsan MH, Abdulwahid RT, Majid SR, et al.
    Polymers (Basel), 2020 Nov 17;12(11).
    PMID: 33212879 DOI: 10.3390/polym12112718
    In this work, plasticized polymer electrolyte films consisting of chitosan, ammonium nitrate (NH4NO3) and glycerol for utilization in energy storage devices was presented. Various microscopic, spectroscopic and electrochemical techniques were used to characterize the concerned electrolyte and the electrical double-layer capacitor (EDLC) assembly. The nature of complexation between the polymer electrolyte components was examined via X-ray diffraction analysis. In the morphological study, field emission scanning electron microscopy (FESEM) was used to investigate the impact of glycerol as a plasticizer on the morphology of films. The polymer electrolyte (conducting membrane) was found to have a conductivity of 3.21 × 10-3 S/cm. It is indicated that the number density (n), mobility (μ) and diffusion coefficient (D) of ions are increased with the glycerol amount. The mechanism of charge storing was clarified, which implies a non-Faradaic process. The voltage window of the polymer electrolyte is 2.32 V. It was proved that the ion is responsible for charge-carrying via measuring the transference number (TNM). It was also determined that the internal resistance of the EDLC assembly lay between 39 and 50 Ω. The parameters associated with the EDLC assembly are of great importance and the specific capacitance (Cspe) was determined to be almost constant over 1 to 1000 cycles with an average of 124 F/g. Other decisive parameters were found: energy density (18 Wh/kg) and power density (2700 W/kg).
    Matched MeSH terms: Nitrates
  4. Note on the effects of nitrate and nitrite upon ascorbic acid in acid solutions
    Lugg JWH
    Med J Malaya, 1950;5.
    1. It is shown that in contradistinction to the marked stability of ascorbic acid in acid solution towards nitrate is its sensitiveness towards nitrite. 2. The primary major product of the action of the nitrite is dehydroascorbic acid, which appears to be relatively stable towards the nitrite. 3. The nutritional and other physiological implications of these findings are discussed.
    Matched MeSH terms: Nitrates
  5. Prevalence of nitrite and nitrate contents and its effect on edible bird nest's color
    Paydar M, Wong YL, Wong WF, Hamdi OA, Kadir NA, Looi CY
    J Food Sci, 2013 Dec;78(12):T1940-7.
    PMID: 24279333 DOI: 10.1111/1750-3841.12313
    Edible bird nests (EBNs) are important ethnomedicinal commodity in the Chinese community. Recently, But and others showed that the white EBNs could turn red by vapors from sodium nitrite (NaNO2) in acidic condition or from bird soil, but this color-changing agent remained elusive. The aim of this study was to determine the prevalence of nitrite and nitrate contents and its affects on EBN's color. EBNs were collected from swiftlet houses or caves in Southeast Asia. White EBNs were exposed to vapor from NaNO2 in 2% HCl, or bird soil. The levels of nitrite (NO2-) and nitrate (NO3-) in EBNs were determined through ion chromatography analysis. Vapors from NaNO2 in 2% HCl or bird soil stained white bird nests to brown/red colors, which correlated with increase nitrite and nitrate levels. Moreover, naturally formed cave-EBNs (darker in color) also contained higher nitrite and nitrate levels compared to white house-EBNs, suggesting a relationship between nitrite and nitrate with EBN's color. Of note, we detected no presence of hemoglobin in red "blood" nest. Using infrared spectra analysis, we demonstrated that red/brown cave-EBNs contained higher intensities of C-N and N-O bonds compared to white house-EBNs. Together, our study suggested that the color of EBNs was associated with the prevalence of the nitrite and nitrate contents.
    Matched MeSH terms: Nitrates/analysis; Nitrates/toxicity*
  6. Differential regulation of fatty acid biosynthesis in two Chlorella species in response to nitrate treatments and the potential of binary blending microalgae oils for biodiesel application
    Cha TS, Chen JW, Goh EG, Aziz A, Loh SH
    Bioresour Technol, 2011 Nov;102(22):10633-40.
    PMID: 21967717 DOI: 10.1016/j.biortech.2011.09.042
    This study was undertaken to investigate the effects of different nitrate concentrations in culture medium on oil content and fatty acid composition of Chlorella vulgaris (UMT-M1) and Chlorella sorokiniana (KS-MB2). Results showed that both species produced significant higher (p<0.05) oil content at nitrate ranging from 0.18 to 0.66 mM with C. vulgaris produced 10.20-11.34% dw, while C. sorokiniana produced 15.44-17.32% dw. The major fatty acids detected include C16:0, C18:0, C18:1, C18:2 and C18:3. It is interesting to note that both species displayed differentially regulated fatty acid accumulation patterns in response to nitrate treatments at early stationary growth phase. Their potential use for biodiesel application could be enhanced by exploring the concept of binary blending of the two microalgae oils using developed mathematical equations to calculate the oil mass blending ratio and simultaneously estimated the weight percentage (wt.%) of desirable fatty acid compositions.
    Matched MeSH terms: Nitrates/pharmacology*
  7. Fulltext Phase formation study of CuAlO2 transparent conductive oxide thin films
    Hutagalung, Sabar D., Woon, Wu S., Khatijah A. Yaacob, Lockman, Zainovia
    Journal of Nuclear and Related Technologies, 2007;2007(1):165-170.
    MyJurnal
    P-type transparent conductive oxide of copper aluminum oxide (CuAlO2) thin films were prepared by using sol-gel method with nitrate solutions as starting precursor. Copper nitrate and aluminum nitrate were selected as raw materials that provide the copper and aluminum source. The CuAlO2 thin films were deposited on pre-cleaned silicon substrate by spin-coating technique. To study of phase formation of CuAlO2, as prepared sample was dried and subjected to heat treatment at various temperatures. The heat-treated samples were characterized by x-ray diffraction (XRD) and energy dispersive x-ray (EDX). From XRD analysis result found that CuAlO2 phase was formed after annealing at 1100 o C for 4 hrs. EDX result of annealed sample at 1100 o C shows composition of Cu and Al that indicate the possibility of forming CuAlO2.
    Matched MeSH terms: Nitrates
  8. Fulltext Proximate Analysis and Safety Profile of Farmed Edible Bird's Nest in Malaysia and Its Effect on Cancer Cells
    Tan SN, Sani D, Lim CW, Ideris A, Stanslas J, Lim CTS
    Evid Based Complement Alternat Med, 2020;2020:8068797.
    PMID: 32051689 DOI: 10.1155/2020/8068797
    Edible bird's nest (EBN) which is solidified swiftlet's saliva contains high nutritional value. It is widely consumed in countries like Malaysia, Indonesia, and Thailand. However, previous proximate analysis of Malaysia EBN was not representative of all the regions in Malaysia. In recent years, safety issues such as high nitrate and nitrite contents, presence of heavy metal, adulteration, fungal infection, and cancer cell stimulation were associated with EBN. Hence, this study aimed to determine the proximate analysis, safety profile during normal weather and hazy periods, and its effect on cancer cells stimulation in Malaysia-farmed EBN. Seven raw cleaned EBN samples were sourced from 6 different regions in Malaysia. Proximate analysis and safety profile were performed using official AOCA methods and Malaysian Standard. High protein (53.03-56.37%) and carbohydrate content (27.97-31.68%) with an acceptable level of moisture (10.8-14.04%) and ash (2.22-3.38%) were reported. A good safety profile was obtained with low nitrite and nitrate levels, with undetectable heavy metals and no significant growth of pathogenic microorganism except mould. Epidermal growth factor was detected but below the quantification level with the chicken EGF ELISA kit. The microculture tetrazolium (MTT) assay was performed for growth stimulation assessment comparing human EGF and EBN. There was no significant cell growth observed in cancer cells after EBN treatment. In conclusion, EBN Malaysia has a good nutritional profile, free of heavy metals, and an acceptable level of nitrate, nitrite, and microorganism profile except for mould contents. Furthermore, the in vitro study indicated that EBN was not associated with cancer cell growth.
    Matched MeSH terms: Nitrates
  9. Nitrate sources and processes in the surface water of a tropical reservoir by stable isotopes and mixing model
    Fadhullah W, Yaccob NS, Syakir MI, Muhammad SA, Yue FJ, Li SL
    Sci Total Environ, 2020 Jan 15;700:134517.
    PMID: 31629263 DOI: 10.1016/j.scitotenv.2019.134517
    Nitrate is one of the primary nutrients associated with sedimentation and fuels eutrophication in reservoir systems. In this study, water samples from Bukit Merah Reservoir (BMR) were analysed using a combination of water chemistry, water stable isotopes (δ2H-H2O and δ18O-H2O) and nitrate stable isotopes (δ15N-NO3- and δ18O-NO3-). The objective was to evaluate nitrate sources and processes in BMR, the oldest man-made reservoir in Malaysia. The δ15N-NO3- values in the river and reservoir water samples were in the range +0.4 to +14.9‰ while the values of δ18O-NO3- were between -0.01 and +39.4‰, respectively. The dual plots of δ15N-NO3- and δ18O-NO3- reflected mixing sources from atmospheric deposition (AD) input, ammonium in fertilizer/rain, soil nitrogen, and manure and sewage (MS) as the sources of nitrate in the surface water of BMR. Nitrate stable isotopes suggested that BMR undergoes processes such as nitrification and mixing. Denitrification and assimilation were not prevalent in the system. The Bayesian mixing model highlighted the dominance of MS sources in the system while AD contributed more proportion in the reservoir during both seasons than in the river. The use of δ13C, δ15N, and C:N ratios enabled the identification of terrestrial sources of the organic matter in the sediment, enhancing the understanding of sedimentation associated with nutrients previously reported in BMR. Overall, the nitrate sources and processes should be considered in decision-making in the management of the reservoir for irrigation, Arowana fish culture and domestic water supply.
    Matched MeSH terms: Nitrates
  10. Pyrus pyrifolia fruit peel as sustainable source for spherical and porous network based nanocellulose synthesis via one-pot hydrolysis system
    Chen YW, Hasanulbasori MA, Chiat PF, Lee HV
    Int J Biol Macromol, 2019 Feb 15;123:1305-1319.
    PMID: 30292586 DOI: 10.1016/j.ijbiomac.2018.10.013
    In the present study, we attempted revalorization of pear (Pyrus pyrifolia L.) peel residue into high value-added nanomaterials. A green and facile one-pot isolation procedure was designed to simplify the isolation process of nanocellulose directly from pear peel residue. The one-pot approach employed in this work is interesting as the reaction involved less harmful chemicals usage and non-multiple steps. The reaction was carried out by adding hydrogen peroxide as an oxidant and chromium (III) nitrate as catalyst in the acidic medium under mild process conditions. FTIR spectroscopy proved that the pear peel derived nanocellulose was purely cellulose phases without the presence of non-cellulosic layer. XRD study indicated that the isolated nanocellulose possessed of cellulose I polymorph with high crystallinity index of 85.7%. FESEM analysis clearly revealed that the considerable size reduction during one-pot process. Remarkably, TEM analysis revealed that the isolated nanocellulose consisted of network-liked nature and spherical shaped morphologies with high aspect ratio of 24.6. TGA showed nanocellulose has lower thermal stability compared to pear peel residue. This study provided a cost-effective method and straightforward one-pot process for fabrication of nanocellulose from pear peel residue. This is the first investigation on the nanocellulose extraction from pear fruit.
    Matched MeSH terms: Nitrates
  11. Distribution and behaviour of nitrogen compounds in the surface water of the Sungai Terengganu estuary, southern waters of South China sea, Malaysia
    Suhaimi Suratman, Azyyati Abdul Aziz, Norhayati Mohd Tahir, Lee HL
    Sains Malaysiana, 2018;47:651-659.
    A study was carried out to determine the distribution and behaviour of nitrogen (N) compounds (nitrite, nitrate, ammonia,
    dissolved and particulate organic nitrogen) in Sungai Terengganu estuary (TRE). Surface water samples were collected
    during ebb neap and spring tides for the longitudinal survey along the salinity gradient. The results indicated that all N
    compounds behave non-conservatively with addition during both tidal cycles, except for nitrate which exhibited removal
    behaviour during spring tide. In general, higher concentration of N compounds was observed during spring tide compared
    to neap tide. It is suggested that during spring tide, stronger water turbulence resulted in resuspension of nutrients in
    bottom sediment and lead to the increase in N compounds concentrations in the surface water. The diurnal survey for the
    freshwater station showed that the concentrations of N compounds follow the ebb and flood variations, whereas for the
    coastal station the reverse trend was observed. Comparisons with a previous study under similar tidal conditions show
    there was an increase in nitrite and ammonia concentrations in TRE, which was probably due to increase in discharge
    from the rapid development activities around this area. In addition, the presence of a breakwater at the lower part of
    the estuary may also contribute to the high nutrient content in the estuary due to restricted outflow of nutrients to the
    coastal area. Overall, the results from this study highlighted the importance of monitoring the N compounds for future
    protection of the estuary.
    Matched MeSH terms: Nitrates
  12. Assessment of Pb uptake, translocation and immobilization in kenaf (Hibiscus cannabinus L.) for phytoremediation of sand tailings
    Ho WM, Ang LH, Lee DK
    J Environ Sci (China), 2008;20(11):1341-7.
    PMID: 19202874
    The potential of kenaf (Hibiscus cannabinus L.) for phytoremediation of lead (Pb) on sand tailings was investigated. A pot experiment employing factorial design with two main effects of fertilizer and lead was conducted in a nursery using sand tailings from an ex-tin mine as the growing medium. Results showed that Pb was found in the root, stem, and seed capsule of kenaf but not in the leaf. Application of organic fertilizer promoted greater biomass yield as well as higher accumulation capacity of Pb. In Pb-spiked treatments, roots accumulated more than 85% of total plant Pb which implies that kenaf root can be an important sink for bioavailable Pb. Scanning transmission electron microscope (STEM) X-ray microanalysis confirmed that electron-dense deposits located along cell walls of kenaf roots were Pb precipitates. The ability of kenaf to tolerate Pb and avoid phytotoxicity could be attributed to the immobilization of Pb in the roots and hence the restriction of upward movement (translocation factor < 1). With the application of fertilizer, kenaf was also found to have higher biomass and subsequently higher bioaccumulation capacity, indicating its suitability for phytoremediation of Pb-contaminated site.
    Matched MeSH terms: Nitrates
  13. Physiological and transcriptional responses to inorganic nutrition in a tropical Pacific strain of Alexandrium minutum: Implications for the saxitoxin genes and toxin production
    Hii KS, Lim PT, Kon NF, Takata Y, Usup G, Leaw CP
    Harmful Algae, 2016 06;56:9-21.
    PMID: 28073499 DOI: 10.1016/j.hal.2016.04.005
    Saxitoxins (STXs) constitute a family of potent sodium channel blocking toxins, causative agents of paralytic shellfish poisoning (PSP), and are produced by several species of marine dinoflagellates and cyanobacteria. Two STX-core genes, sxtA and sxtG, have been well elucidated in Alexandrium but the expression of these genes under various nutritional modes in tropical species remains unclear. This study investigates the physiological responses of a tropical Pacific strain of Alexandrium minutum growing with nitrate or ammonium, and with various nitrogen to phosphorus (N:P) supply ratios. The transcriptional responses of the sxt genes were observed. Likewise, a putative sxtI encoding O-carbamoyltransferase (herein designated as AmsxtI) was recovered from the transcriptomic data, and its expression was investigated. The results revealed that the cellular toxin quota (Qt) was higher in P-depleted, nitrate-grown cultures. With cultures at similar N:P (<16), cells grown with excess ammonium showed a higher Qt than those grown with nitrate. sxtA1 was not expressed under any culture conditions, suggesting that this gene might not be involved in STX biosynthesis by this strain. Conversely, sxtA4 and sxtG showed positive correlations with Qt, and were up-regulated in P-depleted, nitrate-grown cultures and with excess ambient ammonium. On the other hand, AmsxtI was expressed only when induced by P-depletion, suggesting that this gene may play an important role in P-recycling metabolism, while simultaneously enhancing toxin production.
    Matched MeSH terms: Nitrates/metabolism
  14. Transcriptional and physiological responses to inorganic nutrition in a tropical Pacific strain of Alexandrium minutum: Implications for nutrient uptakes and assimilation
    Hii KS, Lim PT, Kon NF, Usup G, Gu H, Leaw CP
    Gene, 2019 Aug 30;711:143950.
    PMID: 31255736 DOI: 10.1016/j.gene.2019.143950
    The marine dinoflagellate Alexandrium minutum is known to produce saxitoxins that cause paralytic shellfish poisoning in human worldwide through consumption of the contaminated shellfish mollusks. Despite numerous studies on the growth physiology and saxitoxin production of this species, the knowledge on the molecular basis of nutrient uptakes in relation to toxin production in this species is limited. In this study, relative expressions of the high-affinity transporter genes of nitrate, ammonium, and phosphate (AmNrt2, AmAmt1 and AmPiPT1) and the assimilation genes, nitrate reductase (AmNas), glutamine synthase (AmGSIII) and carbamoyl phosphate synthase (AmCPSII) from A. minutum were studied in batch clonal culture condition with two nitrogen sources (nitrate: NO3- or ammonium: NH4+) under different N:P ratios (high-P: N:P of 14 and 16, and low-P: N:P of 155). The expression of AmAmt1 was suppressed in excess NH4+-grown condition but was not observed in AmNrt2 and AmNas. Expressions of AmAmt1, AmNrt2, AmNas, AmGSIII, AmCPSII, and AmPiPT1 were high in P-deficient condition, showing that A. minutum is likely to take up nutrients for growth under P-stress condition. Conversely, relative expression of AmCPSII was incongruent with cell growth, but was well correlated with toxin quota, suggesting that the gene might involve in arginine metabolism and related toxin production pathway. The expression of AmGSIII is found coincided with higher toxin production and is believed to involve in mechanism to detoxify the cells from excess ammonium stress. The gene regulation observed in this study has provided better insights into the ecophysiology of A. minutum in relation to its adaptive strategies in unfavorable environments.
    Matched MeSH terms: Nitrates/metabolism
  15. Fulltext Heart failure in patients presenting with dyspnoea to the emergency department in the Asia Pacific region: an observational study
    Keijzers G, Kelly AM, Cullen L, Klim S, Graham CA, Craig S, et al.
    BMJ Open, 2017 02 28;7(2):e013812.
    PMID: 28246137 DOI: 10.1136/bmjopen-2016-013812
    OBJECTIVES: To describe demographic features, assessment, management and outcomes of patients who were diagnosed with heart failure after presenting to an emergency department (ED) with a principal symptom of dyspnoea.

    DESIGN: Planned substudy of the prospective, descriptive cohort study: Asia, Australia and New Zealand Dyspnoea in Emergency Departments (AANZDEM).

    SETTING: 46 EDs in Australia, New Zealand, Singapore, Hong Kong and Malaysia collected data over 3 72-hour periods in May, August and October 2014.

    PARTICIPANTS: Patients with an ED diagnosis of heart failure.

    OUTCOME MEASURES: Outcomes included patient epidemiology, investigations ordered, treatment modalities used and patient outcomes (hospital length of stay (LOS) and mortality).

    RESULTS: 455 (14.9%) of the 3044 patients had an ED diagnosis of heart failure. Median age was 79 years, half were male and 62% arrived via ambulance. 392 (86%) patients were admitted to hospital. ED diagnosis was concordant with hospital discharge diagnosis in 81% of cases. Median hospital LOS was 6 days (IQR 4-9) and in-hospital mortality was 5.1%. Natriuretic peptide levels were ordered in 19%, with lung ultrasound (<1%) and echocardiography (2%) uncommonly performed. Treatment modalities included non-invasive ventilation (12%), diuretics (73%), nitrates (25%), antibiotics (16%), inhaled β-agonists (13%) and corticosteroids (6%).

    CONCLUSIONS: In the Asia Pacific region, heart failure is a common diagnosis among patients presenting to the ED with a principal symptom of dyspnoea. Admission rates were high and ED diagnostic accuracy was good. Despite the seemingly suboptimal adherence to investigation and treatment guidelines, patient outcomes were favourable compared with other registries.

    Matched MeSH terms: Nitrates/therapeutic use
  16. Fulltext Assessment of Aqueous Extraction Methods on Extractable Organic Matter and Hydrophobic/Hydrophilic Fractions of Virgin Forest Soils
    Wan Mohd Zamri WMI, Sjahrir F, Yaacob NS, Dzulkafli NF, Ahmad MF, Abdullah H, et al.
    Molecules, 2021 Apr 23;26(9).
    PMID: 33922872 DOI: 10.3390/molecules26092480
    The assessment of water-extractable organic matter using an autoclave can provide useful information on physical, chemical, and biological changes within the soil. The present study used virgin forest soils from Chini Forest Reserve, Langkawi Island, and Kenyir Forest Reserve (Malaysia), extracted using different extraction methods. The dissolved organic carbon (DOC), total dissolved nitrogen (TDN), total dissolved phosphorus (TDP), and ammonium-nitrate content were higher in the autoclave treatments, up to 3.0, 1.3, 1.2, and 1.4 times more than by natural extraction (extracted for 24 h at room temperature). Overall, the highest extractable DOC, TDN, TDP, ammonium and nitrate could be seen under autoclaved conditions 121 °C 2×, up to 146.74 mg C/L, 8.97 mg N/L, 0.23 mg P/L, 5.43 mg N mg/L and 3.47 N mg/L, respectively. The soil extracts became slightly acidic with a higher temperature and longer duration. Similar trends were observed in the humic and nonhumic substances, where different types of soil extract treatments influenced the concentrations of the fractions. Different soil extraction methods can provide further details, thus widening the application of soil extracts, especially in microbes.
    Matched MeSH terms: Nitrates
  17. Dual function of Lemna minor and Azolla pinnata as phytoremediator for Palm Oil Mill Effluent and as feedstock
    Kadir AA, Abdullah SRS, Othman BA, Hasan HA, Othman AR, Imron MF, et al.
    Chemosphere, 2020 Nov;259:127468.
    PMID: 32603966 DOI: 10.1016/j.chemosphere.2020.127468
    In this study, two native duckweeds (Lemna minor and Azolla pinnata) were cultivated in Palm Oil Mill Effluent (POME) to extract nutrients from the effluent. Five grams of A. pinnata and 2 g of L. minor were transferred to 2 L POME (Initial concentrations: 198 mg/L COD, 4.3 mg/L nitrates, pH 9.53, 4 mg/L phosphate, 2.98 mg/L ammonia) with four different dilutions (2.5%, 5%, 10%, 15%) under greenhouse conditions. Samples of POME were taken every two days up to 10 days. Growth parameter, phosphate, ammonia, nitrates, pH, and COD were monitored within 10 days to select the most suitable growth medium for both plants. Results showed that 2.5% POME dilution had positive effect on L. minor growth and A. pinnata (wet weight increased by 8.7 g and 9.8 g, respectively), with all plants able to survive until the final day of exposure. The highest removal of ammonia was accomplished in 5% POME dilution by A. pinnata (98%) and L. minor (95.5%). The maximum phosphate removal was obtained in 10% POME dilution with 93.3% removal by A. pinnata and 86.7% by L. minor. Significant COD removal in 15% POME was obtained by L. minor (78%) and A. pinnata (66%). Both plants responded positively to the phytoremediation process, especially for A. pinnata which showed significant decreases in all parameters. The nutrient extraction by both plants from POME showed a positive effect on growth parameter, which has further promising potential to be used as animal feedstock.
    Matched MeSH terms: Nitrates
  18. Effect of the number of Cyperus rotundus and medium height on the performance of batch-constructed wetland in treating aquaculture effluent
    Imron MF, Hestianingsi WOA, Putranto TWC, Citrasari N, Abdullah SRS, Hasan HA, et al.
    Chemosphere, 2024 Apr;353:141595.
    PMID: 38438021 DOI: 10.1016/j.chemosphere.2024.141595
    Increasing aquaculture cultivation produces large quantities of wastewater. If not handled properly, it can have negative impacts on the environment. Constructed wetlands (CWs) are one of the phytoremediation methods that can be applied to treat aquaculture effluent. This research was aimed at determining the performance of Cyperus rotundus in removing COD, BOD, TSS, turbidity, ammonia, nitrate, nitrite, and phosphate from the batch CW system. Treatment was carried out for 30 days with variations in the number of plants (10, 15, and 20) and variations in media height (10, 12, and 14 cm). The result showed that aquaculture effluent contains high levels of organic compounds and nutrients, and C. rotundus can grow and thrive in 100% of aquaculture effluent. Besides that, the use of C. rotundus in CWs with the effect of numbers of plants and media height showed performance of COD, BOD, TSS, turbidity, ammonia, nitrate, nitrite, and phosphate with 70, 79, 90, 96, 64, 82, 92, and 48% of removal efficacy, respectively. There was no negative impact observed on C. rotundus growth after exposure to aquaculture effluent, as indicated by the increase in wet weight, dry weight, and growth rate when compared to the control. Thus, adding aquaculture effluent to CWs planted with C. rotundus supports the growth and development of plants while also performing phytoremediation.
    Matched MeSH terms: Nitrates
  19. Fulltext Morphology tuning of ZnO nanostructures grown on zinc foil using facile and low temperature hydrothermal method
    Daud, S.N.H., Chiu, W.S., Aspanut, Z., Khiew, P.S.
    Malaysian Journal of Microscopy, 2015;11(1):50-55.
    MyJurnal
    Current study report the growth of Zinc Oxide (ZnO) nanorods (NRs) by a facile and low temperature method on Zinc (Zn) foil in deionized (DI) water. These ZnO NRs have a typical length of 500-700 nm and average diameter of 50-70 nm. By using different volume of DI water, the morphology of ZnO nanostructures are tunable from rod-like to flower-like structures. Under the presence of Zn nitrate precursor, mixture of rod/wall-like structures are formed. Both of ZnO NRs and combined nanorods/nanowalls render higher diffraction for the (002) peak reveals, which implies preferred orientation growth along c-axis take place. However, photoluminescence (PL) study indicates that ZnO NRs have strong emission located at ~380 nm if compared to that of combined ZnO nanorods/nanowalls. This shows that ZnO NRs have higher-densities of defects.
    Matched MeSH terms: Nitrates
  20. Assessment of groundwater nitrate contamination hazard in a semi-arid region by using integrated parametric IPNOA and data-driven logistic regression models
    Rizeei HM, Azeez OS, Pradhan B, Khamees HH
    Environ Monit Assess, 2018 Oct 04;190(11):633.
    PMID: 30288624 DOI: 10.1007/s10661-018-7013-8
    Groundwater hazard assessments involve many activities dealing with the impacts of pollution on groundwater, such as human health studies and environment modelling. Nitrate contamination is considered a hazard to human health, environment and ecosystem. In groundwater management, the hazard should be assessed before any action can be taken, particularly for groundwater pollution and water quality. Thus, pollution due to the presence of nitrate poses considerable hazard to drinking water, and excessive nutrient loads deteriorate the ecosystem. The parametric IPNOA model is one of the well-known methods used for evaluating nitrate content. However, it cannot predict the effect of soil and land use/land cover (LULC) types on calculations relying on parametric well samples. Therefore, in this study, the parametric model was trained and integrated with the multivariate data-driven model with different levels of information to assess groundwater nitrate contamination in Saladin, Iraq. The IPNOA model was developed with 185 different well samples and contributing parameters. Then, the IPNOA model was integrated with the logistic regression (LR) model to predict the nitrate contamination levels. Geographic information system techniques were also used to assess the spatial prediction of nitrate contamination. High-resolution SPOT-5 satellite images with 5 m spatial resolution were processed by object-based image analysis and support vector machine algorithm to extract LULC. Mapping of potential areas of nitrate contamination was examined using receiver operating characteristic assessment. Results indicated that the optimised LR-IPNOA model was more accurate in determining and analysing the nitrate hazard concentration than the standalone IPNOA model. This method can be easily replicated in other areas that have similar climatic condition. Therefore, stakeholders in planning and environmental decision makers could benefit immensely from the proposed method of this research, which can be potentially used for a sustainable management of urban, industrialised and agricultural sectors.
    Matched MeSH terms: Nitrates/analysis*
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