title: Preparation and application of oyster shell supported zero valent nano scale iron for removal of natural organic matter from aqueous solutions.
abstract: BACKGROUND
  In this Research, oyster shell supported zero valent iron nanoparticles were prepared and applied for the removal of natural organic matters (NOMs) from aqueous solutions under different experimental conditions.
  
  
  METHODS
  The nanoadsorbents prepared by wet impregnation method, then characterized using Scanning Electron Microscopy, Energy Dispersive Spectroscopy, X-Ray Fluorescence and BET analysis. Adsorption test was done in a batch reactor and the effects of different parameters such as initial adsorbate concentration, adsorbent dose, adsorption kinetic, pH, and temperature on removal of NOMs (humic acid as the indicator) were studied.
  
  
  RESULTS
  Results showed that particle size of nanoadsorbent was in the range of 60-83 nm, and surface area and micropore volume as 16.85 m(2)/g and 0.021 m(3)/g, respectively; the main elements of adsorbent were Ca, O, Fe and Na and lime, as high as about 94.25% was the main structural component of the total weight. Produced nanoadsorbent was not soluble in water. It was also shown that by increasing the nanoadsorbent dose from 0.5 to 5 g/100 ml, the removal of humic acid increased from 62.3% to 97.4%. An inverse relationship was found between initial concentration and adsorption capacity, so that a decreasing rate of 33% for humic acid removal was observed by increasing pH from 5 to 10. Temperature increase from 25°C to 40°C, resulted in an increase in humic acid removal from 76.8% to 91.4% and its adsorption on the adsorbent could be better described by Freundlich isotherm (n = 0.016, Kf = 0.013 and R(2) = 0.74). The most fitted adsorption kinetic model was pseudo-second order model.
  
  
  CONCLUSIONS
  The chemical structure of nanoadsorbent was proper and free from harmful substances. Despite the relative good condition of the effective surface, due to the large size of the shell, the overall micropore volume was low. Hence the qualitative characteristics the adsorbent caused the absorption capacity of humic acid to be low (0.96 mg/g).
authors: Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
authors: Vali
authors: V
authors: Alipour
authors: Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran ; Center for Water Quality Research (CWQR), Institute for Environmental Research (IER), Tehran University of Medical Sciences, Tehran, Iran.
authors: Simin
authors: S
authors: Nasseri
authors: Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran ; Center for Water Quality Research (CWQR), Institute for Environmental Research (IER), Tehran University of Medical Sciences, Tehran, Iran.
authors: Ramin
authors: R
authors: Nabizadeh Nodehi
authors: Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran ; Center for Water Quality Research (CWQR), Institute for Environmental Research (IER), Tehran University of Medical Sciences, Tehran, Iran.
authors: Amir Hossein
authors: AH
authors: Mahvi
authors: Nanotechnology Research Center, Research Institute of Petroleum Industry (RIPI), Tehran, Iran.
authors: Alimorad
authors: A
authors: Rashidi
keywords: Adsorption; Humic acid; Iron supported oyster shell; Isotherm; Nanoadsorbent; Natural organic matters
references: Water Res. 2001 Dec;35(18):4435-43
references: 11763046
references: J Colloid Interface Sci. 2011 Dec 15;364(2):279-87
references: 21924733
references: J Hazard Mater. 2013 Oct 15;261:295-306
references: 23959249
references: Water Sci Technol. 2005;51(6-7):241-8
references: 16003983
references: J Hazard Mater. 2005 Sep 30;124(1-3):74-80
references: 15975712
references: Environ Sci Technol. 2007 Mar 15;41(6):2022-7
references: 17410800
references: Water Res. 2008 Nov;42(18):4591-602
references: 18804836
references: Environ Sci Technol. 2003 Mar 15;37(6):1208-18
references: 12680677
references: Int J Biol Macromol. 2004 Jun;34(3):155-61
references: 15225987
references: Water Res. 2002 Dec;36(20):5057-65
references: 12448554
references: J Colloid Interface Sci. 2009 Dec 15;340(2):131-41
references: 19800631
references: Water Res. 2005 Sep;39(15):3668-74
references: 16084557
references: J Hazard Mater. 2010 Dec 15;184(1-3):724-30
references: 20855161
references: J Hazard Mater. 2010 Jun 15;178(1-3):171-9
references: 20129731
references: Water Res. 2003 Sep;37(15):3541-50
references: 12867320