Oviedo, 4-5 de julio de 2019

Angel Fernández Mohedano

UNIVERSIDAD AUTONOMA DE MADRID

Industrial wastewater treatment through combined processes

INDUSTRIAL WASTEWATER TREATMENTTechnical Workshop

PhenolsChlorophenols

MetalsSolvents

DrugsPersonal care

products

HerbicidesPesticides

Priority and Emerging Contaminants

Industrial wastewater Wastewater derived from any industrial or commercialactivity, not directly related to sanitary uses (washbasins,toilets, showers).

Non destructive Destructive

Stripping

Coagulation

Floculation

Sedimentation

Filtration

Adsorption

Chemical Oxidation

WAO

CWAO

AOPs

AC

Agricultural wastesSludge biosolids

ChitosanMineral clays

OzonationPhotocatalysis

UltrasoundsElectrochemical

FentonPhoto-Fenton

Biological

Anaerobic

Aerobic

CASSBRMBR

Mild P and T ·OH

Refractoryintermediates

Recalcitrantcompounds

Cost

AOPs

Biological

High toxicity Low biodegradability

Biodegradable organic matter Recalcitrant compounds

(non toxic)

OPTIMIZATION

Intermediates

ToxicityBiodegradability

Advanced Oxidation Processes (AOPs)

Photocatalysis

High cost AOPs as treatment to enhance biodegradabilityand reduce toxicity

Fenton oxidation

h+

e-

Conduction band

Valence band

Eg

O2

O2•-

Photo-reduction

Photo-oxidation

H2O

HO•

TiO2hv

Biological Oxidation (SBR)

OLR 0.15-0.3 kg COD kg-1 SSV d-1

Biomass concentration: 2-4 g VSS L-1

Cellular retention time: 25 d

Hydraulic residence time: 6 d

Cycle: 6-8 h

Anoxic filling (0.5 h)

Aerated reaction (4.75-7 h)

Settle and draw (0.5-0.75 h)

Second generationNeonicotinoids

Source ofwater

contamination

Beepopulationdeclination

Bio-recalcitrant

High toxicitymicroorganism

Widespreaduse and

goodstability

Broadspectrum

insecticidalactivity

European Union expands ban of three neonicotinoid pesticides (2018)Imidacloprid, clothianidin and thiamethoxam

Time course of TMX concentration, COD removal,

H2O2 and TOC conversion in the Fenton-like

oxidation of pure TMX (a) and its commercial

formulation (b) with a stoichiometric H2O2 dose.

[TMX] = 100 mg L-1

pH = 3700 rpm

50ºCt = 4 h

0 40 80 120 160 200 240 280

0

20

40

60

80

100

TMX

XTOC

XH2O2

b

TM

X (

mg L

-1),

XT

OC (

%),

XH

2O

2 (

%)

T

MX

(m

g L

-1),

XT

OC (

%),

XH

2O

2 (

%)

Time (min)

a

0 50 100 150 200 250 300

0

20

40

60

80

100

TMX

XTOC

XH2O2

Time (min)

0,0

0,2

0,4

0,6

0,8

1,0

COD

0,0

0,2

0,4

0,6

0,8

1,0

COD

CO

D (m

g L

-1)

CO

D (m

g L

-1)

H2O2(%)

TMX (commercial) TMX (pure)

XH2O2 XTMX XTOC XCOD XH2O2 XTMX XTOC XCOD

100 > 99 > 99 60.5 63.2 > 99 > 99 49.09 69.47

75 > 99 > 99 60.0 59.7 > 99 > 99 45.58 66.71

50 > 99 > 99 52.6 52.5 > 99 > 99 42.26 69.13

25 > 99 76.25 49.9 43.9

TMX, TOC conversion and COD removal (%) upon Fenton oxidation at

different H2O2 doses

50-100 %≈ COD-TOC removal

(%) H2O2 dose

m/z = 278

m/z = 265

m/z = 274

m/z = 232

m/z = 247 m/z = 205

m/z = 205

m/z = 173

m/z = 116

m/z = 177

m/z = 115m/z = 149

m/z = 74

m/z = 75

Identified by-products for Thiamethoxam oxidation

0 25 50 75 1000

10

20

30

40

50

60

0

10

20

30

40

50

60

TOCTMX

TOCacids

TOCunidentified

TN

(m

g L

-1)

TO

C (m

g L-

1 )

H2O

2 Dose (%)

TNTMX

TNN-NO

-

2,N-NO

-

3

TNunidentified

Measured and unidentified TN and TOC

balance closure from Fenton oxidation.

0

30

60

90

120

150

180

0,0

0,1

0,2

0,3

0,4

0,5

0,6

0 50 100

Ecoto

xic

ity (T

U)

BO

D5/C

OD

H2O2 dose (%)

Variation of Ecotoxicity (TU) and

BOD5/COD ratio.

Effluents from Fenton oxidation with H2O2 doses of 50% and 75% from stoichiometric were selected for a subsequent biological treatment

OLR: 0.15-0.3 kgCOD kg-1

VSS d-1

0

10

20

30

40

50

60

70

80

0 5 10 15 20 25 30 35

TOC

, COD

(mg

L-1)

Time (d)

0

10

20

30

40

50

60

70

80

0 5 10 15 20 25 30 35Time (d)

Accl.Accl. ORL 0.15ORL 0.15 ORL 0.30 ORL 0.30

0.5 h 4.75 h 0.75 h

Anoxicfilling Aerobic stage Settling and Draw

SBR: 6-hours cycle

XTOC =↑20 %

H2O2 H2O2

0.5 h 4.75 h 0.75 h

Anoxicfilling Aerobic stage Settling and Draw

SBR: 6-hours cycle

75 %

H2O

250 %

H2O

2

Time-course over a 6-h SBR cycle.

Coupling Fenton and biological oxidation is an adequate alternativefor TMX removal, according to the TOC conversion and CODremoval above 80% for the combined treatment.

IONIC LIQUIDS (ILs)

Alternative

to VOCs

o Negligible vapor pressure

o High solvent capacity

o Non – flammability

o Thermal stability

“Design” products

“GREEN” compounds

BmpyrCl HmimCl

1-butyl-4-methylpyridinium 1-hexyl-3-methylimidazolium

0

0,2

0,4

0,6

0,8

1

0

0,2

0,4

0,6

0,8

1

0 200 400 600 800 1000 1200 1400

XC

OD, X

CO

T

C/C

0

Time (min)

0

0,2

0,4

0,6

0,8

1

0

0,2

0,4

0,6

0,8

1

0 200 400 600 800 1000 1200 1400

XC

OD

, X

CO

T

C/C

0

Time (min)

Photolysis Photocatalysis Adsorption XCOD XTOC

BmpyrCl HmimCl

[IL] = 0.35 g L-1

[TiO2] = 0.25 g L-1

24 h

Xe lamp = 600 W m-2

35 ºC

Sunset solar simulator

TiO2

0

50

100

150

200

250

300

0 10 20 30

TO

C,

CO

D,

TN

(m

g L

-1)

Time (d)

TOC TOCi COD CODi TN TNi

BmpyrCl HmimCl

0

50

100

150

200

250

0 5 10 15 20 25 30 35

TO

C,

CO

D,

TN

(m

g L

-1)

Time (d)

Sludge

Acclimat.

Sludge

Acclimat.

0

20

40

60

80

100

120

140

160

0 100 200 300 400 500

TO

C,

CO

D,

Co

nce

ntr

ati

on

(mg

L-1

)

Time (min)

0

20

40

60

80

100

120

140

160

0 100 200 300 400 500

TO

C,

CO

D,

Co

nce

ntr

ati

on

(m

g L

-1)

Time (min)

TOC COD AcidsShort-chain

acids

• Fenton oxidation and solar photocatalysis generatedeffluents with low ecotoxicity values and highbiodegradability index.

• Working at 75 and 50% of the stoichiometric doseof H2O2 in Fenton oxidation gave rise to suitableeffluents for the combined treatment.

• Coupling Fenton/solar photocatalysis and biologicaloxidation is an adequate alternative for TMX or ILsremoval, according to TOC conversion and CODremoval values, higher than 80% for the combinedtreatment.

ACKNOWLEDGEMENTS

Spanish MCI (CTM2016-76564-R)

THANK YOU

Madrid’s Regional Government

(S2013/MAE-2716)

UAM-Santander (CEAL-AL/2015-08)