X 2008 Synthesis and Application of Manganese Dioxide Coated Magnetite for Removal of Trace Contaminants from Water Carla Calderon, Wolfgang H. Höll Institute for Technical Chemistry, Water and Geotechnology Research Center Karlsruhe GmbH la Calderon 10.07.2008 KIT die Kooperation von Forschungszentrum Karlsruhe GmbH und Universität Karlsruhe (TH)
utline Introduction Sorbents Hydrous manganese dioxide Magnetic Micro Sorbents Magnetic Micro Sorbent MMS Magnetic Micro Sorbent MMS Preparation Characterization Magnetic separation Adsorption performance Adsorption performance Kinetics Equilibrium Conclusions la Calderon 10.07.2008
troduction Ground Waters Surface Waters Processes Waters Wastewaters Hazardous inorganic trace components Sorption selectivity capacity low cost la Calderon 10.07.2008
troduction - Sorbents Sorbents Polymeric materials Zeolites Hydrous metal oxides MnO 2 Activated carbon Clay minerals Biosorbents la Calderon 10.07.2008
troduction Hydrous manganese dioxide MnO 2 β-mno 2 MnO 1.7 to MnO <2 Highly crystalline Nearly amorphous Least reactive Much more reactive Sorption affinityand and ionic-exchange capabilities la Calderon 10.07.2008
troduction MnO 2 and MMS Manganese dioxide MnCl 2 + KMnO 4 + KOH MnO 2 MnCl 2 + KMnO 4 + KOH MnO 2 Magnetic Micro Sorbent + Mn 2+ MnO 4 - Fe 3 O 4 ph MMS la Calderon 10.07.2008
utline Introduction Adsorbents Hydrous manganese dioxide Magnetic Micro Sorbents Magnetic Micro Sorbent MMS Magnetic Micro Sorbent MMS Preparation Characterization Magnetic separation Adsorption performance Adsorption performance Kinetics Equilibrium Conclusions la Calderon 10.07.2008
agnetic Micro Sorbent preparation SET UP MnCl 2 1mol/L = 7 ml KMnO 4 0.2 mol/l = 23 ml KOH 1 mol/l = 14 ml Fe 3 O 4 Bayoxide m = 1g V H2O = 500 ml 3MnCl 2 + 2KMnO 4 + 4OH - 5MnO 2 + 2H 2 O + 2K + 6Cl - la Calderon 10.07.2008
agnetic Micro Sorbent preparation Magnetite suspended in alkaline solution of KMnO 4 Addition of MnCl 2 Precipitation of MnO 2 Solid/ Liquid separation by means of a magnet la Calderon 10.07.2008
agnetic Micro Sorbent characterization Fe 3 0 4 MnO 2 MMS Mn 2+ (g/g MMS) - - 0.47 BET Surface area 5 240* 92 (m² g -1 ) Magnetic saturation (Am²/kg) 90-95 0.3 0.4 36-40 ph (PZC) 6.5 2.1 3.5 content, Magnetization, ph (PZC) and BET surface area measurements. Driehaus, Arsenentfernung mit Mangandioxid und Eisenhydroxid in der Trinkwasseraufbereitung
agnetic Micro Sorbent characterization
agnetic Micro Sorbent separation t = 0 s t = 10 s t = 30 s t = 2 min = 10 ml, m MMS = 4.9 mg
utline Introduction Adsorbents Hydrous manganese dioxide Magnetic Micro Sorbents Magnetic Micro Sorbent MMS Magnetic Micro Sorbent MMS Preparation Characterization Magnetic separation Adsorption performance Adsorption performance Kinetics Equilibrium Conclusions
dsorption performance SET UP Kinetics C i, Cd = 1 mg/l m MSS = 92 mg V o = 1 L r.p.m. = 300 t =0 t = 90 min SET UP Equilibrium Study C i, Cd = 0.08 0.5 mg/l V o = 500 ml m MSS = 3 mg r.p.m. = 250 t = 90 min CH 3 COONa = 0.01 mol/l
dsorption performance - Kinetics c (Cd 2+ ), mg/l 1 0,9 0,8 0,7 0,6 0,5 0,4 0,3 0,2 0,1 0 c (Cd 2+ ), mg/l 1 0.8 0.6 0.4 0.2 0 V 0 C i,cd = 1L = 1mg/L m MMS = 92 mg 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 Time, min > 90% adsorption 0 10 20 30 40 50 60 70 80 90 Time, min
dsorption performance equilibrium study ph effect q eq, mg/g 45 40 35 30 25 20 15 10 5 ph 6 ph 5 ph 4 0 0.0 0.1 0.2 0.3 0.4 0.5 c eq (Cd), mg/l V = 500 ml, m MMS = 3 mg, C i, Cd = 0.08 to 0.5 mg/l
dsorption performance equilibrium study Competition: Addition of CaCl 2 q eq, mg/g 45 40 35 30 25 20 15 10 5 0 0 mg/l Ca 2+ 50 mg/l Ca 2+ 100 mg/l Ca 2+ 0.0 0.1 0.2 0.3 0.4 0.5 c eq (Cd ), mg/l V = 500 ml, m MMS = 3 mg, C i, Cd = 0.08 to 0.5 mg/l
dsorption performance equilibrium study Ionic strength : Addition of NaCl 0.01 mol/l qeq, mg/g 45 40 35 30 25 20 15 10 5 0 NaCl 0.01 mol/l 0.0 0.1 0.2 0.3 0.4 0.5 c eq (Cd), mg/l V = 500 ml, m MMS = 3 mg, C i, Cd = 0.08 to 0.5 mg/l
dsorption performance Cd speciation Cd 2+,% CdCl +, % CdCl 2 100-50 mg/l CaCl 2 80 20 100 mg/l CaCl 2 67 33 0.01M NaCl, 50 mg/l CaCl 2 45 53 0.01M NaCl, 100 mg/l CaCl 2 40 58 odelling with MINEQL, C Cd = 0.08 mg/l
utline Introduction Adsorbents Hydrous manganese dioxide Magnetic Micro Sorbents Magnetic Micro Sorbent MMS Magnetic Micro Sorbent MMS Preparation Characterization Magnetic separation Adsorption performance Adsorption performance Kinetics Equilibrium Conclusions
onclusions Magnetic manganese oxide adsorbents can easily be produced from magnetite and manganese salts. Magnetic properties of magnetic micro sorbents allow simple solid-liquid separation applying a magnetic field. Divalent heavy metals like cadmium can be well adsorbed. Fast adjustment of sorption equilibria is obtained by using MMS in the conditions applied.
X 2008 Synthesis and Application of Manganese Dioxide Coated Magnetite for Removal of Trace Contaminants from Water Carla Calderon, Wolfgang H. Höll Institute for Technical Chemistry, Water and Geotechnology Research Center Karlsruhe GmbH KIT die Kooperation von Forschungszentrum Karlsruhe GmbH und Universität Karlsruhe (TH)