environmental research: activated charcoal and water filtration
DESCRIPTION
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 - PowerPoint PPT PresentationTRANSCRIPT
Environmental Research:Activated Charcoal
and Water Filtration
River Dell HS (RDHSB) Event #2 Presented by: HyoungBin LeeOradell, NJ Team B Kaitlyn DantoniCoach: Mrs. C. Jacobus Michelle Hao
Chemistry of Activated CarbonPhysisorption• 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 MethodHypothesisActivated 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)
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)
Wet Charcoal Dried CharcoalInitial pH 2.16 2.16pH after 30 min 2.55 2.61pH after 1 hr 2.60 2.62pH after 1hr and 30min 2.62 2.63
Fig. 1
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
Time(minutes)
0 30 60 90 120 150
pH value 2.23 2.58 2.60 2.63 2.65 2.66
Set Up
200mL solutions of various concentrations (0.05M-5M) of HAc, one labeled each for pure carbon and activated
carbon.
ProcedureStir Method vs Column Filtration to Reach Equilibrium
Set the stir value of the magnetic stirrer to 360 RPM, let the process run
for 2 hours
50 mL HAc column filtrated through ground carbon
Procedure Cont.Filtration
Filtered pure and activated carbon from acid after two hours of being stirred.
Procedure Cont.
Left:pH test after filtering acetic acid from charcoal
Right:Titrations to
determine change in #
moles
pH and Titrations
Molarity Calculations
0.05M HAc
0.2M HAc
0.3M HAc
0.4M HAc
0.5M HAc
Starting NaOH (mL) 44.5 40.0 36.0 31.0 41.0
Ending NaOH (mL) 44.0 42.65 39.55 36.0 47.2
Used NaOH (mL) 0.50 2.65 3.55 5.00 6.20
Molarity (mol/L) 0.0407 0.215 0.289 0.407 0.5041
ORIGINAL SOLUTION
Molarity Calculations Cont.
0.05M HAc
0.2M HAc
0.3M HAc
0.4M HAc
0.5M HAc
Starting NaOH (mL) 0.1 0.2 2.0 4.7 9.0
Ending NaOH (mL) 0.2 1.95 4.65 8.6 13.85
Used NaOH (mL) 0.10 1.75 2.65 3.90 4.85Molarity (mol/L) 0.0081 0.142 0.215 0.317 0.3943
FILTERED WITH ACTIVATED CARBON
0.05M HAc
0.2M HAc
0.3M HAc
0.4M HAc
0.5M HAc
Starting NaOH (mL) 14.0 14.5 17.0 20.5 25.0
Ending NaOH (mL) 14.5 16.9 20.25 25.0 30.6
Used NaOH (mL) 0.50 2.40 3.25 4.50 5.60Molarity (mol/L) 0.0407 0.195 0.264 0.366 0.4553
FILTERED WITH PURE CARBON
0 0.5 1 1.5 2 2.50
0.02
0.04
0.06
0.08
0.1
0.12
0.14
0.16
f(x) = 0.0136132320665448 ln(x) + 0.0465382601179672
f(x) = 0.0294823165874894 ln(x) + 0.124112265370178
[H+] adsorbedActivated Charcoal (AC) vs. Pure Carbon (C)
Activated CharcoalLogarithmic (Ac-tivated Char-coal)Pure CarbonLogarithmic (Pure Carbon)
Initial concentration of H+ in the solution (M)
conc
entr
atio
n of
H+
ads
orbe
d ()
M
0 0.5 1 1.5 2 2.50
10
20
30
40
50
60
70
80
90f(x) = 12.7315883313048 x^-0.621832257405741R² = 0.968599706805737
% [H+] adsorbedActivated Charcoal (AC) vs. Pure Carbon (C)
Activated CharcoalPower (Activated Charcoal)Pure Carbon
Concentration of initial solution of HAc
%[H
+]
adso
rbed
pH and Le Chatelier’s Principle
• Activated Charcoal: uses LDF• >molecular size = >polarizability = >LDF• C2H3O2
- is greater in size than H+
∴ more C2H3O2- adsorbed than H+
• Le Chatelier’s principle C2H3O2- is adsorbed,
equilibrium shifts to products, increasing [H+]∴ pH decrease
0.05M
HAc
0.2M HAc
0.3M HAc
0.4M HAc
0.5M HAc
Activated
charcoal
3.87
2.71 2.60 2.25 2.19
Pure Charco
al3.44
2.80 2.70 2.63 2.71HC2H3O2 ⇌ H+ + C2H3O2-
0 0.1 0.2 0.3 0.4 0.5 0.600.5
11.5
22.5
33.5
44.5
f(x) = 2.42057751698073 x^-0.106062324875398R² = 0.942764045370073
f(x) = 1.89155119761874 x^-0.2265446598324R² = 0.987642695417233
pH of the solutionSeries1
PH of Acti-vated charcoal
Series3
pH of Charcoal
Series5
initial pH
concentration of initial solution (M)
pH o
f re
mai
ng s
olut
ion
ConclusionBinding Capacity• AC = 0.00336 • C = 0.00115
• Hypothesis supported
• As [H+] inc, chance of adsorption increases