The Experts below are selected from a list of 201 Experts worldwide ranked by ideXlab platform

Natrayasamy Viswanathan - One of the best experts on this subject based on the ideXlab platform.

  • hydrothermal fabrication of zirconium oxyhydroxide capped chitosan kaolin framework for highly selective nitrate and phosphate retention
    Industrial & Engineering Chemistry Research, 2018
    Co-Authors: Ilango Aswin Kumar, Natrayasamy Viswanathan
    Abstract:

    In recent years, hydrothermal technology has been paid more attention because of its unique advantages like large surface area and high porous nature. In the present study, chitosan (CS) embedded kaolin (KN) clay, namely, CSKN composite, was prepared. To enhance the sorption capacity (SC) and selectivity, zirconium oxyhydroxide (ZrO(OH)2) was coated onto CSKN composite to get Zr@CSKN composite using in situ precipitation (In situ) and hydrothermal (Hydro) methods. The developed Zr@CSKN composite was used toward nitrate and phosphate removal, which helps in the minimization of methemoglobinemia (Blue Baby Syndrome) and eutrophication. The adsorbents were characterized using FTIR, XRD, SEM, BET, and EDAX with mapping analysis. Various adsorption influencing factors like contact time, adsorbent dosage, pH, co-anions, initial ion concentration, and temperature were optimized. The experimental data was fitted with various isotherms and thermodynamic parameters to find the nature of adsorption. The reuse and fi...

  • Hydrothermal Fabrication of Zirconium Oxyhydroxide Capped Chitosan/Kaolin Framework for Highly Selective Nitrate and Phosphate Retention
    2018
    Co-Authors: Ilango Aswin Kumar, Natrayasamy Viswanathan
    Abstract:

    In recent years, hydrothermal technology has been paid more attention because of its unique advantages like large surface area and high porous nature. In the present study, chitosan (CS) embedded kaolin (KN) clay, namely, CSKN composite, was prepared. To enhance the sorption capacity (SC) and selectivity, zirconium oxyhydroxide (ZrO­(OH)2) was coated onto CSKN composite to get Zr@CSKN composite using in situ precipitation (In situ) and hydrothermal (Hydro) methods. The developed Zr@CSKN composite was used toward nitrate and phosphate removal, which helps in the minimization of methemoglobinemia (Blue Baby Syndrome) and eutrophication. The adsorbents were characterized using FTIR, XRD, SEM, BET, and EDAX with mapping analysis. Various adsorption influencing factors like contact time, adsorbent dosage, pH, co-anions, initial ion concentration, and temperature were optimized. The experimental data was fitted with various isotherms and thermodynamic parameters to find the nature of adsorption. The reuse and field studies of Zr@CSKN composite were also examined

  • Development and Reuse of Amine-Grafted Chitosan Hybrid Beads in the Retention of Nitrate and Phosphate
    2018
    Co-Authors: Ilango Aswin Kumar, Natrayasamy Viswanathan
    Abstract:

    A variety of adsorbent materials have been tried day by day to minimize the effects of Blue Baby Syndrome and eutrophication but most of them constitute academic interest because of their properties such as powder form, poor selectivity, not easily separable, and difficult regeneration; hence, they could not be used at field conditions. To overcome such technological bottle-necks, the present study has been carried out with amine-functionalized magnetic chitosan (AFMCS) composite beads which was prepared and applied for the remediation of nitrate and phosphate in batch scale. The fabricated adsorbent materials were characterized by Fourier transform infrared spectroscopy, Brunauer–Emmett–Teller analysis, transmission electron microscopy, X-ray diffraction, scanning electron microscopy, and energy dispersive X-ray analysis with mapping analysis. The numerous adsorption-influenced parameters such as contact time, adsorbent dosage, initial ions concentration, co-anions, solution pH, and temperature were optimized. The various sorption isotherm models were used to fit the equilibrium data. The feasible mechanism toward nitrate and phosphate removal was interpreted. The efficient regeneration and repeated use of AFMCS composite beads were achieved up to six cycles. The applicability of easily separable AFMCS composite beads at field conditions was checked by collecting nitrate and phosphate contaminated water sample from the nearby area of Dindigul district

Ilango Aswin Kumar - One of the best experts on this subject based on the ideXlab platform.

  • hydrothermal fabrication of zirconium oxyhydroxide capped chitosan kaolin framework for highly selective nitrate and phosphate retention
    Industrial & Engineering Chemistry Research, 2018
    Co-Authors: Ilango Aswin Kumar, Natrayasamy Viswanathan
    Abstract:

    In recent years, hydrothermal technology has been paid more attention because of its unique advantages like large surface area and high porous nature. In the present study, chitosan (CS) embedded kaolin (KN) clay, namely, CSKN composite, was prepared. To enhance the sorption capacity (SC) and selectivity, zirconium oxyhydroxide (ZrO(OH)2) was coated onto CSKN composite to get Zr@CSKN composite using in situ precipitation (In situ) and hydrothermal (Hydro) methods. The developed Zr@CSKN composite was used toward nitrate and phosphate removal, which helps in the minimization of methemoglobinemia (Blue Baby Syndrome) and eutrophication. The adsorbents were characterized using FTIR, XRD, SEM, BET, and EDAX with mapping analysis. Various adsorption influencing factors like contact time, adsorbent dosage, pH, co-anions, initial ion concentration, and temperature were optimized. The experimental data was fitted with various isotherms and thermodynamic parameters to find the nature of adsorption. The reuse and fi...

  • Development and Reuse of Amine-Grafted Chitosan Hybrid Beads in the Retention of Nitrate and Phosphate
    2018
    Co-Authors: Ilango Aswin Kumar, Natrayasamy Viswanathan
    Abstract:

    A variety of adsorbent materials have been tried day by day to minimize the effects of Blue Baby Syndrome and eutrophication but most of them constitute academic interest because of their properties such as powder form, poor selectivity, not easily separable, and difficult regeneration; hence, they could not be used at field conditions. To overcome such technological bottle-necks, the present study has been carried out with amine-functionalized magnetic chitosan (AFMCS) composite beads which was prepared and applied for the remediation of nitrate and phosphate in batch scale. The fabricated adsorbent materials were characterized by Fourier transform infrared spectroscopy, Brunauer–Emmett–Teller analysis, transmission electron microscopy, X-ray diffraction, scanning electron microscopy, and energy dispersive X-ray analysis with mapping analysis. The numerous adsorption-influenced parameters such as contact time, adsorbent dosage, initial ions concentration, co-anions, solution pH, and temperature were optimized. The various sorption isotherm models were used to fit the equilibrium data. The feasible mechanism toward nitrate and phosphate removal was interpreted. The efficient regeneration and repeated use of AFMCS composite beads were achieved up to six cycles. The applicability of easily separable AFMCS composite beads at field conditions was checked by collecting nitrate and phosphate contaminated water sample from the nearby area of Dindigul district

Mark A. Underwood - One of the best experts on this subject based on the ideXlab platform.

  • Intestinal microbiota and Blue Baby Syndrome: probiotic therapy for term neonates with cyanotic congenital heart disease.
    Gut microbes, 2010
    Co-Authors: Collin L. Ellis, John C. Rutledge, Mark A. Underwood
    Abstract:

    Necrotizing enterocolitis (NEC) is the most common intestinal emergency among premature infants. Risk factors in premature infants include immature intestinal immunity and an intestinal microbiota dominated by hospital-acquired bacteria. Some probiotics have been shown to decrease the incidence of NEC in premature infants. Among term infants, NEC is rare. However, among term infants with cyanotic congenital heart disease (CCHD), the incidence of NEC is similar to that of premature infants but with even greater mortality rates. Mechanisms by which NEC occurs in term infants with CCHD are unknown. Of central interest is the potential role of changes in the intestinal microbiota and whether these can be modified with probiotic bacteria; accordingly, we review the literature, propose hypotheses and present the rationale for future studies involving preliminary probiotic clinical trials.

Collin L. Ellis - One of the best experts on this subject based on the ideXlab platform.

  • Intestinal microbiota and Blue Baby Syndrome: probiotic therapy for term neonates with cyanotic congenital heart disease.
    Gut microbes, 2010
    Co-Authors: Collin L. Ellis, John C. Rutledge, Mark A. Underwood
    Abstract:

    Necrotizing enterocolitis (NEC) is the most common intestinal emergency among premature infants. Risk factors in premature infants include immature intestinal immunity and an intestinal microbiota dominated by hospital-acquired bacteria. Some probiotics have been shown to decrease the incidence of NEC in premature infants. Among term infants, NEC is rare. However, among term infants with cyanotic congenital heart disease (CCHD), the incidence of NEC is similar to that of premature infants but with even greater mortality rates. Mechanisms by which NEC occurs in term infants with CCHD are unknown. Of central interest is the potential role of changes in the intestinal microbiota and whether these can be modified with probiotic bacteria; accordingly, we review the literature, propose hypotheses and present the rationale for future studies involving preliminary probiotic clinical trials.

Peake Barrie - One of the best experts on this subject based on the ideXlab platform.

  • Nitrogen species distribution in the Taieri Plain aquifer, New Zealand
    2011
    Co-Authors: Kensington Christopher, Richards Katrina, Murray Dave, Peake Barrie
    Abstract:

    Nitrogen contamination of drinking water has been linked to health risks including ‘Blue Baby Syndrome’. In New Zealand, up to 51% of people use at least some groundwater for drinking, and there is growing concern that the rapid growth of intensive dairying may lead to aquifer contamination. The distribution of nitrogen species nitrate (NO3-), ammonium (NH4+), nitrite (NO2-) and organic nitrogen were measured in groundwater bores in the Taieri Plain aquifer, New Zealand, during March-November 2002. There was significant spatial variation in the concentration of nitrate and ammonium across the aquifer. Concentrations of nitrate were low in the confined aquifer in West Taieri, but high in unconfined bores in East Taieri and in bores in alluvial fans, i.e. where infiltration of surface runoff can occur. Ammonium showed the reverse pattern, i.e. low concentrations in the unconfined aquifer, and high concentrations in parts of the confined aquifer. Nitrite concentrations were low everywhere. Mean nitrate concentrations for confined and unconfined bores were well below the maximum limit for drinking water in New Zealand (11.3 ppm NO3-N), but in the unconfined zone some individual measurements approached or slightly exceeded this limit. Some individual measurements for ammonium species exceeded the aesthetic guideline for drinking water (1.2 ppm NH4-N). No temporal variations were seen in species concentrations over the relatively short time scale of the study, and there was little correlation between concentrations and bore depth. Fortuitously, the Waihola silt-sand unit protects the underlying aquifer and mitigates the potential for contamination in the areas where intensive dairying occurs on the Taieri Plain. The unconfined/semiconfined aquifer in East Taieri, and alluvial fan areas, are far more vulnerable to contamination from nitrogen species. Ideally, conditions and land use practices in these areas should be closely monitored and, perhaps, regulated.PublishedNon Peer ReviewedAmerican Public Health Association (APHA) (1998) Standard Methods for the Examination of Water and Wastewater. Clesceri, L.S., A.E. Greenberg and A.D. Eaton (eds.) United Book Press, Maryland. Avery, A.A. (1999) Infantile Methaemoglobinaemia: Re-examining the role of drinking water nitrates. Environmental Health Perspectives, 107:7, pp. 583-586. Barrell, D.J.A., P.J. Forsyth, N.J. Litchfield and L.J. Brown. (1999) Quaternary stratigraphy of the Lower Taieri Plain, Otago, New Zealand. Institute of Geological and Nuclear Sciences Science Report, 99:15. Burden, R.J. (1982) Nitrate contamination of New Zealand aquifers: a review. New Zealand Journal of Science, 25, pp. 205-220. Canter, L.W. (1997) Nitrates in Groundwater. Lewis Publishers, USA. Close, M.E., M.R. Rosen, and V.R. Smith (2001) Fate and transport of nitrates and pesticides in New Zealand’s aquifers. In: Groundwaters of New Zealand, Rosen, M.R. and P.A. White (eds). New Zealand Hydrological Society, Wellington, pp. 185-220. Downes, C.J. (1980) Chemistry of the Hutt Valley underground waters. Department of Scientific and Industrial Research, Chemistry Division Report, pp. 55-56. Gallegos, E., A. Warren, E. Robles, E. Campoy, A. Calderon, M.G. Sainz, P. Bonilla and O. Escolero. (1999) The effects of wastewater irrigation on groundwater quality in Mexico. Water Science Technology, 40: 2, pp. 45-52. Hallberg, G.R. (1989) Nitrate in groundwater in the United States. In: Follett, R.F. (ed.) Nitrogen Management and Groundwater Protection. Elsevier, Amsterdam, pp. 35-74. International Organization for Standardization (ISO) (1997) Method 11732: Water quality - Determination of ammonium nitrogen by flow analysis (CFA and FIA) and spectrometric detection. Web site http://www.iso.ch/iso/en/CatalogueDetailPage.CataloguDetail (accessed 2002) IRRICON (1994) Lower Taieri Groundwater Report, Preliminary Study, for Otago Regional Council, Dunedin. IRRICON (1997) Lower Taieri Groundwater Study, for Otago Regional Council, Dunedin. Kensington, C.G. (2003) Distribution of Nitrogen Species in Groundwater in the Taieri Plain Aquifer, New Zealand. Unpublished MSc thesis. University of Otago, Dunedin, New Zealand. Mariotti, A., A. Landreau and B. Simon (1988) 15N isotope biogeochemistry and natural denitrification process in groundwater: Application to the chalk aquifer of northern France. Geochimica et Cosmochimica Acta, 52, pp. 1869-1878. McLarin, W., G. Bekesi, L. Brown and J. McConchie (1999) Nitrate contamination of the unconfined aquifer, Manakau, Horowhenua, New Zealand. Journal of Hydrology (NZ), 38: 2, pp. 211-235. Ministry of Health (1995) Drinking Water Standards for New Zealand 1995. Ministry of Health, Wellington. Otago Regional Council (1999) Taieri River Catchment Monitoring Report. Unpublished internal report housed in the Otago Regional Council library, Dunedin. Selvarajah, N., G.R. Maggs, J.R. Crush and S.F. Ledgard (1994) Nitrate in ground water in the Waikato region. In: The Efficient Use of Fertilisers in a Changing Environment: Reconciling Productivity with Sustainability. Proceedings of the 7th Annual Workshop (Feb, 1994), Fertiliser and Lime Research Centre, Massey University, Palmerston North. Wassenaar, L.I. (1995) Evaluation of the origin and fate of nitrate in the Abbotsford aquifer using the isotopes of 15N and 18O in NO3-. Applied Geochemistry, 10, pp. 391-340