- Sung-Yong Kim 1 , Varsha Khare 2, † , Ji-Hyeon Song 1 , Shiva Raj Poudel 1 and Sung-Hoon Ahn 1,2,3,† 1 Department of Mechanical and Aerospace Engineering, Seoul National University 2 Institute of Advanced Machinery and Design, Seoul National University 3 Department of Mechanical Engineering, University of Washington International Symposium on Green Manufacturing and Applications 2014, June 24 – 28, Busan, Korea INNOVATIVE DESIGN AND INTEGRATED MANUFACTURING LAB., SEOUL NATIONAL UNIVERSITY Multiscale Water Filtration Using Novel Coated Sand Material in a Column Bed Reactor # Varsha Khare / E-mail: [email protected], Sung-Hoon Ahn / E-mail: [email protected] 2 theta (degree) Intensity (counts) Conclusions and future works - Conclusions Large coverage area Coated sand was well synthesized by reactive method Hybrid column bed reactor was well designed as a new type of filtration setup Heavy metal absorption efficiency of hybrid materials were measured by UV-vis, ICPAES The effect of adsorption is visible by UV-vis spectroscopy indicating almost 100% absorption/adsorption of As - Future works Further optimized design with optimized hybrid materials will be transferred as part of knowledge to use for industrial applications Experimental results - Absorption rate of each hybrid materials Various combination of IL, GO, FGR, etc has been applied to coated sand Here has been presented just with 2-hydroxyethyl ammonium formate Absorption test was done for hybrid materials with each of the heavy metal stock solution Acknowledgements: ( NRF-2012R1A2A2A01047189, 2012R1A1A2008196 and 2010-0029227 ) Introduction - Rising concerns on water pollution and environmental effects Contaminated water and soil are rapidly becoming global environmental issues Water purification and soil remediation are important problems To find a green method of water purification is in need - Coated sand Coating sand with hybrid materials - Wet contact method : mix sand and synthesized hybrid material - Reactive method : mix sand, IL, GO, Ferric Green Rust (FGR)/Fe 3 O 4 altogether Research objectives ① To design a new filtration setup which can control the parameters affecting filtration efficiency ② To figure out filtration efficiency of each hybrid material ③ To characterize the effect of coated sand and Column Bed Reactor Eexperimental setup Cumulative number of SCI-indexed publications on nanotechnology and water pollution (T. A. Kurniawan et al. 2012) - Multiscale filtration Two stages for water filtration were applied to Column Bed Reactor Micro-filtration using coated sand, Nano- filtration using nano hybrid material Heavy metal absorption on the coated sand surface Washed sand Wet contact method Reactive method - Column Bed Reactor One cell for micro-filtration using coated sand Another cell for nano-filtration using hybrid nanomaterials Heavy metal solutions such as As was used as contaminated stock solutions Concentration of As stock solution : Sodium Arsenate 1.7339 g/L SUS mesh and Nylon mesh as a physical barrier System condition : Feed rates 100ml/min Hardware configurations of Column Bed Reactor system Sampling reservoir Coated sand Hybrid nanomaterial Contaminated solution Sampling Valve Physical barrier Electro- manometer Electro- manometer Sampling Valve Sampling reservoir Contaminated solution reservoir Peristaltic pump Flow control valve Coated sand Hybrid nanomaterial Outlet Physical barrier Schematic diagram of Column Bed Reactor system Heavy metal absorption efficiency of hybrid material IL + rGO hybrid material shows 40% absorption rate by ICPAES Raman graph shows the presence of rGO Band D means large number of defects No splitting of 2D band indicates 4~5 layered graphene IL + rGO hybrid material shows 100% absorption rate by UV-visible spectroscopy - Preparation of coated sand IL + rGO + FGR as a hybrid material IL : 2-hydroxyethyl ammonium formate Sonication for dispersion of graphene Stirring with hybrid material and sand Repeat the coating process until it has proper dark coating Energy efficient, low cost, green : no use of reducing agent Image of multiple coated sand Cu ions adsorption on MCS at different initial copper concentrations (Rachmawati et al. 2012) Global reverse osmosis/nanofiltration membrane market forecast to 2016 (Global water intelligence. August 2009) - UV-visible As(V) Absorption experiment using Column Bed Reactor and coated sand was conducted Before and after sample of absorption test was analyzed for UV-visible 300 400 500 600 700 After absorption stock solution Absorption (65%)/Adsorption rGO As(V) Absorption by coated sand in Column 300 400 500 600 700 Complete Absorption/Adsorption After absorption Stock solution As(V) Absorption by coated sand As(V) absorption test in a Column has 65% absorption ratio As(V) absorption test using coated sand without Column has complete absorption ratio UV-visible data of As(V) absorption test w/ and w/o column bed reactor 0.00 10.00 20.00 30.00 40.00 50.00 60.00 8mg 4mg 1mg absorption efficiency [%] Hybrid material of 2-OH NH 4 formate in 20ml of heavy metal solution Pb Hg As ① Hybrid material ① Coated sand Raman data of graphene (b) (a) (c) (d) SEM image of coated sand - SEM image Surface modified coated sand (a), (b) (b) shows well coated surface without FGR (c) and (d) show difference between presence of FGR in hybrid material and surface of sand (d) has well coated surface containing FGR 1time 2time 3time D G D’ 2D Raman shift (cm -1 ) Intensity (a.u) WAXS data of graphene Wavelength (nm) Normalized absorption Complete absorption As(V) absorption by hybrid material Wavelength (nm) Normalized absorption Wavelength (nm) Normalized absorption