Piseth Som

Master Program in Chemical and Environmental Engineering

07 January 2014

Applications of Fenton and Fenton-like Reactions with Subsequent Hydroxide Precipitation for Derusting

Wastewater Treatment

Outline

• Background and Problems

• Rational and Importance

• Theoretical and Empirical Reviews

• Materials and Experiment

2

Background and Problem

• Cleaning operations of pipes and boilers

3

• 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

Rust (Fe2O3)

Background and Problem

• High content of metal and organic chelating agent– 5000-10000 mg/L of iron – <100 mg/L of Copper (Huang et al.,

2000)

4

Kation Power (2010)

• Organic acid (EDTA and Citric Acid) cause metal-complexation (Fu et al., 2012; Chitra et al., 2011 )

Generation of Complex Wastewater

www.chemicool.com/defination/ligand

Rational and Importance

5

• Metal-EDTA Complex (Fe-EDTA)

Derusting Wastewater

Ability of Fenton reaction for organic degradation and industrial wastewater treatment (Buatista et al., 2008)

Rational and Importance

6

• 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)

Objectives

7

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

Scope and Limitation

8

• 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

Theoretical Reviews

9

• Fenton Reactions as Advanced Oxidation Processes (AOP) using hydroxyl radical (OH•) (E0

= 2.8V) (Neyens & Baeyens, 2003)

OH • + Organic Compound Oxidized Products

H2O2 + Fe2+pH ~ 3 - 4

Fe3+ + OH• + OH− (Fenton)

H2O2 + Fe3+pH ~ 3 - 4

Fe2+ + HO2• + OH−

H2O2 + Fe2+pH ~ 3 - 4

Fe3+ + OH• + OH− (Fenton-like)

Feo(ZVI)+ 2H+ pH ~ 3 - 4

Fe2+ + H2

H2O2 + Fe2+pH ~ 3 - 4

Fe3+ + OH• + OH− (Fenton-like)

Theoretical Reviews (Cont’)

10

Reaction Mechanism Pathways

RH + •OH → (OH)RH•

(Hydroxyl Radical Addition)(Matthew Tarr, 2003)

RH + •OH → R• + H2O(Hydrogen Abstraction)(Neyens & Baeyens, 2003)

RH + •OH → (RH)• + + OH−

(Direct Electron Transfer)(Munter, 2001)

R• + Fe3+ -oxidation → R+ + Fe2+ R• + Fe2+ -reduction → R− + Fe3+

(Fe2+/3+ inducing) (Kim et al., 2010)

Empirical Reviews

11

Huang et al., (2000)

Electro-chemicaltreatment

EDTA recovery94.16% of metal removed

15.5 mA/Cm2

Materials and Experiment

12

Derusting Wastewater – Boilers cleaning processes– Kation Power Company located in Rayong Province

Materials and Experiment

13

Parameters Value Limited effluent**

pH 10 6.5-8.5COD (mg/L) 15334 < 400

Total Iron (mg/L) 7668 < 0.5 Ferric (Fe3+) (mg/L) 6919 NA

TDS (mg/L) 25190 < 5000TSS (mg/L) 0.006 < 150

Conductivity (µS/cm) 30150 NA

Ammonia Nitrogen (mg/L) 6990 < 1.1Nitrite nitrogen (mg/L) 2000 < 45

Nitrate Nitrogen (mg/L) 1600 NA

**Pollution Control Department, PCD at www.pcd.go.th

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

15

Chemicals for parameters analysis • Ferrous Ammonium Sulfate (Fe(NH4 )2(SO4)2·6H2O)

• Sodium acetate (NaC2H3O23H2O)

• Hydroxylamine(NH2OH-HCl)

• 1,10-pehnanthroline (C12H8N23H2O )

• Potassium Permanganate (KMnO4)

Materials and Experiment

16

Add Fe2+ under mixing 150 rpm for 10 min

adjust pH= 3

Settling for 30 min

adjust pH =8

Add H2O2 under mixing 50 rpm for

60 min

Analysis of Objective

Parameters

Fill 500 mL of sample

Materials and Experiment

17

initial pH: 2-7

[Fe2+] : 0.005-0.15 M

[H2O2]: 1-3.5 M

Reaction Time 20-120 min

Precipitation pH: 6-11

Input

Fenton-like Reaction

(Add H2O2 only)

Fenton Reaction(Fe2+ + H2O2)

ProcessesTCOD, SCOD

Total Iron, Soluble Iron,

Fe2+, Fe3+

Ammonium, Nitrate, Nitrate

TDS

Output

room temperature (28 0C ), mixing at 150 rpm and 80 rpmControl variables

Materials and Experiment

18

Fenton-like reaction

Add H2O2 only

RT= 60 min

H2O2=2 M

Initial pH

2

4

6

8

10

12

pH=2 pH=4 pH=6 pH=8 pH=10 pH=12

Repeat with pH: 2, 3, 4, 5, 6 7 Best pH

Varying initial pH

Materials and Experiment

19

1M 1.5M 2M 2.5M 3M 3.5MVarying [H2O2]

Best [H2O2]

20 40 60 80 100 120Varying RT (min)

Best RT (min)

6 7 8 9 10 11 Precipitation pH

Materials and Experiment

20

Fenton ReactionRT= 60 min

Fe2+=0.05M

H2O2=2M

Initial pH

2

3

4

5

6

7

Repeat experiment with initial pH around the suitable pH to obtain the best initial pH for Fenton reaction

Materials and Experiment

21

0.005M 0.01M 0.05M 0.08M 0.1M 0.12MVarying [Fe2+]

1M 1.5M 2M 2.5M 3M 3.5MVarying [H2O2]

20 40 60 80 100 120Varying RT (min)

6 7 8 9 10 11 Precipitation pH

Optimum Condition, Impacts of each parameters, Kinetics

Materials and Experiment

22

• 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)

Outlook

23

Fenton and Fenton-like Reactions

Fe2+?

H2O2?

Initial pH?

Reaction Time (min)?

Outlook

24

Activity Plan

25

26

Thank You for Your Attention !

Q & A?

Materials and Experiment

• Hydroxide Precipitation of Iron Before Fenton and Fenton-like Reaction

27

pH=6 pH=7 pH=8 pH=9 pH=10 pH=11Mixing at 50

rpm for 15 min

Settling down for 30 min

Does Iron precipitate? Hypothesis 1

Materials and Experiment

28

• Kinetic Study of COD degradation

• Rate Equation (r)

Organic Matter (COD )+ OH• Oxidized product (P) + CO2 + H20

CODOHkdt

dCODr ][ Second Order Reaction

CODkdt

dCODr app Pseudo-first order Reaction

)ln0

tkCODCOD

appt Integrated Equation

Skoog and West , 2004 ; Lucas and Peres , 2007 and Samet et al., 2011

29

Digestion Extraction

Reagent adding

UV-Visible Spectro.

Calibration Curve

Iron determination

30

0 50 100 150 200 250 300 350 400 450 5000

0.2

0.4

0.6

0.8

1f(x) = 0.00197419748079877 x − 0.000456190476190277R² = 0.999995281575467

Fe (µg in 100 mL)

Abso

rban

ce

portion mL100

sample mLvolume) final mL 100 (in Fe μg Fe/L mg