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River Dell HS (RDHSB) Event #2 Presented by: HyoungBin Lee Oradell, NJ Team B Kaitlyn Dantoni Coach: Mrs. C. Jacobus Michelle Hao. Environmental Research: Activated Charcoal and Water Filtration. Chemistry of Activated Carbon. Physisorption
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River Dell HS (RDHSB) Event #2 Presented by: HyoungBin LeeOradell, NJ Team B KaitlynDantoniCoach: Mrs. C. Jacobus Michelle Hao Environmental Research:Activated Charcoaland Water Filtration
Chemistry of Activated Carbon Physisorption Intermolecular forces (IMF)) Van Der Waals (London dispersion force, LDF) Chemisorption Formation of chemical bond Complex ion (ligands) Adsorption equilibrium Rate of adsorption = rate of desorption
Hypothesis &Experimental Method Hypothesis Activated charcoal will decrease acidity more efficiently than pure charcoal. Experimental Methods Overview - Filtration - column, regular - Titration to determine pH - higher pH = better adsorption
Development of Procedure • Two systems of activated charcoal in 0.40M HAc against wet and dry charcoal, pH then measured • No significant difference between types • Granular charcoal was more effective than ground • Stirring method more efficient than column filtration • Granular vs Ground; experiment performed via column filtration (see Fig. 1) Fig. 1 • National Institute of Environmental Health Sciences. Cleaner Air on the Fly: EHP Student Edition, [Online] August 2006, p. A277 http://www.niehs.nih.gov/health/assets/docs_a_e/ehp_student_edition_lesson_cleaner_air_and_water_on_the_fly.pdf (accessed April 21, 2013)
Development of Procedure Cont. Minimum time for adsorption process to reach equilibrium determined with 2.00 g AC in 50 mL ~0.4 M HAc • Reaction ran under 6 different time intervals in increments of 30 minutes • pH then measured
Set Up 200mL solutions of various concentrations (0.05M-5M) of HAc, one labeled each for pure carbon and activated carbon.
Procedure Stir Method vs Column Filtration to Reach Equilibrium 50 mL HAc column filtrated through ground carbon Set the stir value of the magnetic stirrer to 360 RPM, let the process run for 2 hours
Procedure Cont. Filtration Filtered pure and activated carbon from acid after two hours of being stirred.
Procedure Cont. pH and Titrations Left:pH test after filtering acetic acid from charcoal Right:Titrations to determine change in # moles
pH and Le Chatelier’sPrinciple Activated Charcoal: uses LDF >molecular size = >polarizability= >LDF C2H3O2-is greater in size than H+ ∴ more C2H3O2- adsorbed than H+ Le Chatelier’sprinciple C2H3O2- is adsorbed, equilibrium shifts to products, increasing [H+] ∴ pH decrease HC2H3O2 ⇌ H+ + C2H3O2-
Conclusion Binding Capacity AC = 0.00336 C = 0.00115 • Hypothesis supported As [H+] inc, chance of adsorption increases