Preparation of pervious concrete with 3-thiocyanatopropyltriethoxysilane modified fly ash and its use in Cd (II) sequestration

Abstract Heavy metal contamination is an important environmental issue. Heavy metal removal by cementitious materials would be an efficient method because of their large-scale exposure to rainwater and groundwater. In this study, 3-thiocyanatopropyltriethoxysilane (TCPS)-modified Fly ash (T-FA) beads were prepared and incorporated into pervious concrete. The functionalized pervious concrete was used to sequester Cd (II) from solution, utilizing the chelating property of the thiocyanate on TCPS. TCPS molecules were chemically bonded onto FA beads after alkali activation, which was confirmed by IR spectroscopy. IR shows the vibration of Si OH and the asymmetric vibrations of CH2 and CN on TCPS. In addition, 29Si NMR spectroscopy identifies a new peak at −47.22 ppm assigned to T2[RSi(OSi)2OH]. T-FA beads can efficiently remove Cd (II) when immersed and stirred in a CdCl2 solution. An equally significant sequestration capacity was demonstrated when T-FA beads were incorporated in pervious concrete. Cd (II) concentrations were reduced from 300 to 15.86 ppm when a 100 × 100 × 100 mm3 T-FA-loaded concrete specimen was exposed to a 5 L CdCl2 solution.

[1]  P. Monteiro,et al.  Microstructural and compositional change of NaOH-activated high calcium fly ash by incorporating Na-aluminate and co-existence of geopolymeric gel and C–S–H(I) , 2012 .

[2]  Á. Palomo,et al.  Characterisation of fly ashes. Potential reactivity as alkaline cements , 2003 .

[3]  C. Ha,et al.  Controlled synthesis of novel cyanopropyl polysilsesquioxane hollow spheres loaded with highly dispersed Au nanoparticles for catalytic applications. , 2012, Chemical communications.

[4]  L. Peng,et al.  Investigation of the states of water and OH groups on the surface of silica , 2009 .

[5]  R. Laine.  Nanobuilding blocks based on the [OSiO1.5]x (x= 6, 8, 10) octasilsesquioxanes , 2005 .

[6]  Xi Li,et al.  One-step synthesis of structure controlled vinyl functionalized hollow mesoporous silica nanospheres , 2015 .

[7]  A. Modarres,et al.  Durability properties of non-air entrained roller compacted concrete pavement containing coal waste ash in presence of de-icing salts , 2017 .

[8]  Min Ook Kim,et al.  Strength enhancement of alkaline activated fly ash cured at ambient temperature by delayed activation of substituted OPC , 2016 .

[9]  M. Maslehuddin,et al.  Effect of moisture, chloride and sulphate contamination on the electrical resistivity of Portland cement concrete , 1996 .

[10]  H. Im,et al.  A robust transparent protective hard-coating material using physicochemically-incorporated silica nanoparticles and organosiloxanes , 2017 .

[11]  Lu Yang,et al.  Facile preparation of photocatalytic exposed aggregate concrete with highly efficient and stable catalytic performance , 2015 .

[12]  Youssef Belmabkhout,et al.  Effect of pore expansion and amine functionalization of mesoporous silica on CO2 adsorption over a wide range of conditions , 2009 .

[13]  S. Pratsinis,et al.  OH Surface Density of SiO 2 and TiO 2 by Thermogravimetric Analysis , 2003 .

[14]  S. Yiacoumi,et al.  Characterization of metal ion interactions with chitosan by X-ray photoelectron spectroscopy , 2001 .

[15]  T. Hemalatha,et al.  A review on fly ash characteristics – Towards promoting high volume utilization in developing sustainable concrete , 2017 .

[16]  Jiyong Park,et al.  Triblock Copolymer Synthesis of Highly Ordered Large-Pore Periodic Mesoporous Organosilicas with the Aid of Inorganic Salts , 2003 .

[17]  C. Ha,et al.  Novel fluorinated polysilsesquioxane hollow spheres: synthesis and application in drug release. , 2010, Chemical communications.

[18]  P. Persson,et al.  Adsorption of glyphosate on goethite: molecular characterization of surface complexes. , 2002, Environmental science & technology.

[19]  Chitengfei Zhang,et al.  Hollow organosilica nanospheres prepared through surface hydrophobic layer protected selective etching , 2015 .

[20]  V M Malhotra,et al.  Blended Fly Ash Cements A Review , 1999 .

[21]  Sungchul Bae,et al.  Characterization of natural pozzolan-based geopolymeric binders , 2014 .

[22]  L. T. Zhuravlev.  The surface chemistry of amorphous silica. Zhuravlev model , 2000 .

[23]  S. Park,et al.  Uniform and monodisperse polysilsesquioxane hollow spheres: synthesis from aqueous solution and use in pollutant removal , 2011 .

[24]  Á. Palomo,et al.  Microstructure Development of Alkali-Activated Fly Ash Cement: A Descriptive Model , 2005 .

[25]  Wennan Hu,et al.  Vertical organic-inorganic hybrid transparent oxide TFTs gated by biodegradable electric-double-layer biopolymer , 2017 .

[26]  Fernando Pacheco-Torgal,et al.  Alkali-activated binders: A review: Part 1. Historical background, terminology, reaction mechanisms and hydration products , 2008 .

[27]  D. Macphee,et al.  Immobilization Science of Cement Systems , 1993 .