Applications of Fenton and Fenton-like Reactions with
Subsequent Hydroxide Precipitation for Derusting
Wastewater Treatment
Piseth Som
Master Program in Chemical and
Environmental Engineering
07 January 2014
Outline
• Background and Problems
• Rational and Importance
• Theoretical and Empirical Reviews
• Materials and Experiment
2
Background and Problem
• Cleaning operations of pipes and boilers
Rust (Fe2O3)
• To dissolve rust
– hydrochloric acid or Alkali
Flushing
– Hot and cold water flushing
– Ammoniated Ethylene Diamine
Tetraacetic Acid (EDTA) Pickling
– Pasivative agent (Sodium Nitrite)
– Ammonia rinsing
(Bansal, 2012)
www.fourquest.com/chemicalcleaning
3
Background and Problem
Generation of Complex Wastewater
• High content of metal and organic
chelating agent
– 5000-10000 mg/L of iron
– <100 mg/L of Copper (Huang et al.,
2000)
Kation Power (2010)
• Organic acid (EDTA and Citric Acid)
cause metal-complexation (Fu et
al., 2012; Chitra et al., 2011 )
www.chemicool.com/defination/ligand
4
Rational and Importance
Ability of Fenton reaction for organic degradation and
industrial wastewater treatment (Buatista et al., 2008)
• Metal-EDTA
Complex
(Fe-EDTA)
Derusting
Wastewater
Fenton , Fentonlike Reactions
• Destroy EDTA
compound
• Fee iron
molecule
• M(OH)n
• Fe(OH)3
Precipitation
5
Rational and Importance
• Fenton and Fenton-like reactions for derusting
wastewater is not well documented
• Feasibility for NiEDTA and CuEDTA treatment, so they
may do for FeEDTA (Fu et a., 2009, and Lan et al., 2012)
• Originated Iron (Fe2+/Fe3+ ) and iron oxide (Fe2O3) in
wastewater could be used as catalyst for Fenton-like
reaction (Lan et al. 2012)
6
Objectives
1. To determine optimum initial parameters of Fenton
and Fenton-like reactions (initial pH, [Fe2+ ], and [H2O2])
for treatment of derusting wastewater
2. To determine the optimum reaction time and reaction
kinetics
3. To determine the optimum precipitation pH for
Fenton and Fenton-like reactions
4. To investigate the effects of Fenton and Fenton-like
reactions on ammonia, nitrate and nitrite removal
7
Scope and Limitation
• Real derusting wastewater is used in the study
• Jar Test apparatus is conducted at laboratory room
temperature at DChE, BUU
• Objective Parameters: TCOD, SCOD, Total Iron, Soluble Iron,
Fe2+, Fe3+, Ammonium, Nitrate, Nitrate, TDS
• Kinetic degradation organic chelating agents are monitored
in term of COD
• Oxidation Products or intermediate are NOT monitored
8
Theoretical Reviews
• Fenton Reactions as Advanced Oxidation Processes (AOP)
using hydroxyl radical (OH•) (E0 = 2.8V) (Neyens &
Baeyens, 2003)
pH ~ 3 - 4
Fe3+ + OH• + OH−
H2O2 + Fe2+
H2O2 + Fe3+
H2O2 + Fe2+
pH ~ 3 - 4
pH ~ 3 - 4
Fe2+ + HO2• + OH−
(Fenton)
(Fenton-like)
Fe3+ + OH• + OH−
pH ~ 3 - 4
Fe2+ + H2
Feo(ZVI)+ 2H+
H2O2 +
Fe2+
pH ~ 3 - 4
Fe3+
+
OH•
+
OH−
(Fenton-like)
OH • + Organic Compound  Oxidized Products
9
Theoretical Reviews (Cont’)
Reaction Mechanism Pathways
(Hydroxyl Radical Addition)
RH + •OH
→ (OH)RH•
(Matthew Tarr, 2003)
(Hydrogen Abstraction)
RH +
•OH
→ R• + H2O
(Neyens & Baeyens, 2003)
(Direct Electron Transfer)
RH +
•OH
→ (RH)• + + OH−
(Munter, 2001)
R•
+ Fe3+ -oxidation → R+ + Fe2+ (Fe2+/3+ inducing)
R•
+ Fe2+ -reduction → R− + Fe3+ (Kim et al., 2010)
10
Empirical Reviews
Huang et al.,
(2000)
Kim et al.,
(2010)
Fu et al.,
(2009, 2012)
Electro
UV/H2O2/Fe2+
-chemical
UV/H2O2
treatment
H2O2 /Fe2+
Fenton and
Fenton-like
reaction for
NiEDTA
complex
EDTA recovery
UV/H2O2/Fe3+
> 92.8% of Ni
removal
94.16% of
metal removed
Citric Acid
degraded
78.8% COD
removal
15.5 mA/Cm2
93% COD
removal
Residual Fe =
0.04 mg/L
Lan et al.,
(2012)
Interior Micro
electrolysis –
Fenton –
Coagulation
(IM-FOC) for
CuEDTA
complete
removal of Cu
87% COD
removal
11
Materials and Experiment
Derusting Wastewater
– Boilers cleaning processes
– Kation Power Company located in Rayong Province
12
Materials and Experiment
Parameters
Value
Limited effluent**
pH
10
6.5-8.5
COD (mg/L)
< 400
Total Iron (mg/L)
15334
7668
Ferric (Fe3+) (mg/L)
6919
NA
TDS (mg/L)
25190
< 5000
TSS (mg/L)
0.006
< 150
Conductivity (µS/cm)
30150
NA
Ammonia Nitrogen (mg/L)
6990
< 1.1
Nitrite nitrogen (mg/L)
2000
< 45
Nitrate Nitrogen (mg/L)
1600
NA
**Pollution
< 0.5
Control Department, PCD at www.pcd.go.th
13
Materials and Experiment
Materials
•
•
•
•
•
•
•
•
•
Jar Test Apparatus
pH meter
Portable TSD meter
Multiple parameters
Photometer
Hotplate
UV-Vis spectrophotometer
Drying Oven
Centrifugal Machine
supporting glassware
14
Materials and Experiment
Chemicals for Fenton and Fenton-like reaction
•
•
•
•
•
H2O2 – 35% w/w (AR Grade)
FeSO4 7H2O (AR Grade)
H2SO4 , HCl and HNO3 Conc.
NaOH – 10 N
H2SO4 – 5N
Chemicals for parameters analysis
•
•
•
•
•
Ferrous Ammonium Sulfate (Fe(NH4 )2(SO4)2·6H2O)
Sodium acetate (NaC2H3O23H2O)
Hydroxylamine(NH2OH-HCl)
1,10-pehnanthroline (C12H8N23H2O )
Potassium Permanganate (KMnO4)
15
Materials and Experiment
Add Fe2+ under mixing 150
rpm for 10 min
Fill 500 mL of sample
adjust
pH= 3
Analysis of
Objective
Parameters
adjust
pH =8
Settling for 30 min
Add H2O2 under
mixing 50 rpm for
60 min
16
Materials and Experiment
Input
Processes
initial pH: 2-7
[Fe2+] : 0.0050.15 M
[H2O2]: 1-3.5 M
Reaction Time
20-120 min
Precipitation
pH: 6-11
Control
variables
Output
TCOD, SCOD
Fenton-like
Reaction
(Add H2O2 only)
Total Iron,
Soluble Iron,
Fe2+, Fe3+
Fenton Reaction
(Fe2+ + H2O2)
Ammonium,
Nitrate, Nitrate
TDS
room temperature (28 0C ), mixing at 150 rpm and 80 rpm
17
Materials and Experiment
2
Varying initial pH
4
Fenton-like
reaction
Add H2O2
only
RT= 60 min
6
H2O2=2 M
Initial pH
8
pH=2
pH=4
pH=6
pH=8
pH=10
pH=12
10
12
Repeat with pH: 2, 3, 4, 5, 6 7  Best pH
18
Materials and Experiment
Varying [H2O2] 1M
1.5M
2M
2.5M
3M 3.5M
Best [H2O2]
Varying RT (min)
20
40
60
80
100
120
Best RT (min)
Precipitation pH
6
7
8
9
10
11
19
Materials and Experiment
2
3
Fenton
Reaction
RT= 60 min
4
Fe2+=0.05M
H2O2=2M
Initial pH
5
6
7
Repeat experiment with initial pH around the suitable pH to
obtain the best initial pH for Fenton reaction
20
Materials and Experiment
Varying [Fe2+] 0.005M 0.01M 0.05M 0.08M 0.1M 0.12M
Varying [H2O2] 1M
1.5M
Varying RT (min)
20
40
Precipitation pH
6
7
2M
60
8
2.5M
3M 3.5M
80
100
120
9
10
11
Optimum Condition, Impacts of each parameters, Kinetics
21
Materials and Experiment
• TCOD and SCOD are determined by close reflux titrimetric
method (Method, 5520)
• Total iron , ferric and ferrous concentration are measure by
Phenanthroline method (Method, 3500)
• pH is measured by pH meter (EUTECH)
• TSS is measured according to standard method (Method, 2540)
• TDS is measured by portable TDS meter (OHAUS Starter 300C)
• Ammonium nitrogen, Nitrate and Nitrite are measured by
Multiple parameters Photometer (Hana HI 83205-2008)
22
Outlook
Fenton and Fentonlike Reactions
Fe2+?
H2O2?
Initial pH?
Reaction Time (min)?
Hydroxide
Precipitation
precipitation pH?
Removal Efficiency
COD?
Total Iron?
TDS/TSS?
Ammonia, Nitrite
and Nitrate
23
Outlook
24
Activity Plan
25
Thank You for Your Attention !
Q & A?
26
Materials and Experiment
• Hydroxide Precipitation of Iron Before Fenton and
Fenton-like Reaction
pH=6
pH=7
pH=8
pH=9
pH=10
pH=11
Mixing at 50
rpm for 15 min
Settling down
for 30 min
Does Iron precipitate?  Hypothesis 1
27
Materials and Experiment
• Kinetic Study of COD degradation
Organic Matter (COD )+
OH•
Oxidized product (P) +
CO2 + H20
• Rate Equation (r)
dCOD
r
 k[OH  ]COD
dt
dCOD
r
 k appCOD
dt
ln
CODt
  k app t )
COD0
Second Order Reaction
Pseudo-first order Reaction
Integrated Equation
Skoog and West , 2004 ; Lucas and Peres , 2007 and Samet et
al., 2011
28
Digestion
Extraction
Reagent
adding
Iron
determination
Calibration
Curve
UV-Visible
Spectro.
29
1
y = 0.002x - 0.0005
R² = 1
Absorbance
0.8
0.6
0.4
0.2
0
0
50 100 150 200 250 300 350 400 450 500
Fe (µg in 100 mL)
μg Fe (in 100 mL final volume)
100
mg Fe/L 

mL sample
mL portion
30