aops for wastewater treatment (reuse and...

Marie Skłodowska-Curie actions

TreatRec - Interdisciplinary concepts for municipal wastewater treatment and

resource recovery. Tackling future challenges

MARIE SKŁODOWSKA-CURIE ACTIONS Innovative Training Networks (ITN) Modality: EID – European Industrial Doctorate Call: H2020-MSCA-ITN-2014

AOPs for wastewater treatment (reuse and disinfection)

Dr. Pilar Fernández Ibáñez; Plataforma Solar de Almería-CIEMAT

Sustainable and Integrated Urban Water System Management

Contents

• Solar radiation and CPC photoreactors • Solar AOPs coupled to Bio-treament • Emerging contaminants removal • Solar reactors for water disinfection • Solar treated MWW reuse: case study • Concluding remarks


• PSA is an European Large Scientific Installation, being the largest and most

complete R+D center in the World devoted to solar thermal concentrating

systems. PSA is also a Singular Science and Technology Infrastructure (ICTS) of

Spain.

• Goal: R+D in potential industrial applications of concentrated solar thermal

energy and solar photochemistry.

• Location: Distributed over 103 hectares in the Tabernas desert (Almería, South-

Est of Spain).

Plataforma Solar de Almería

www.psa.es

http://www.psa.es/


1. Central receiver technology

7. Solar furnaces

4. Parabolic-trough technology (DSG)

2. Parabolic dishes + Stirling engines

3. Parabolic-trough technology (thermal oil)

8. Water desalination

9. Water photocatalysis

1

1

3

10. Passive architecture 10

8

9 7

2

4

6. Linear Fresnel Collector

6

5. Parabolic-troughs (gas) + Molten Salt TES

5

Plataforma Solar de Almería


Emerging contaminants

5

• Unknown until now.

• Commonly used.

• Emerging risks

(EDCs, antibiotics).

• Non-regulated.

Incomplete removal

in MWWTP

There is a continuous introduction of emerging contaminants into the environment

(ng-μg/L)

•These contaminants are

present in natural waters.

•Under sunlight they are

transformed also into new

contaminants.


Water microbial contamination

6 6

Reservoir Well

Water pathogens

Viruses Encephalomyocarditis Poliovirus, Rotavirus Norovirus

Protozoa Acanthamoeba polyphaga Cryptosporidium parvum Entamoeba sp. Giardia sp

Fungi Fusarium Olphidium Aspergillus

Candida

Rivers Lakes

Bacteria E. Coli Enterococcus sp Pseudomonas aeruginosa Salmonella typhi Vibrio cholera

http://www.google.es/imgres?imgurl=http://wallpapers-diq.com/wallpapers/90/Fresh_Water_Well.jpg&imgrefurl=http://wallpapers-diq.net/es_90_~_Fresh_Water_Well.html&usg=__UsEwtxN_Wsjs4iNFlLMWmp1xnVk=&h=1200&w=1600&sz=344&hl=es&start=52&sig2=cNAxp727hltlZcHmJ9y-EQ&zoom=1&itbs=1&tbnid=3FjdZ52aUdLMdM:&tbnh=113&tbnw=150&prev=/images?q=well+water&start=40&hl=es&sa=N&gbv=2&ndsp=20&tbm=isch&ei=yw-bTY7vHsm0tAbC8an5BQ


7

Solar radiation

7

O3 layer

Cosmic

rays

γ-rays X-rays Ultraviolet

C B A Visible Infrared Radio waves

http://www.google.es/imgres?imgurl=http://blogs.hoy.es/blogfiles/erasmus-en-estonia/sol1.bmp&imgrefurl=http://blogs.hoy.es/erasmus-en-estonia/2011/2/10/hoy-ha-salido-sol&usg=__AD3QwgQmVTaslfdQP_pQHRe2URI=&h=341&w=368&sz=368&hl=es&start=16&sig2=0l8HDKhvH4Pl0BOFpqZrhA&zoom=1&itbs=1&tbnid=AfVlCK6LjZpG7M:&tbnh=113&tbnw=122&prev=/images?q=sol&hl=es&sa=N&gbv=2&ndsp=20&tbs=isch:1&ei=KmKHTeuhE8_fsgbj0d2tAw


driven by solar energy

Solar Advanced Oxidation Processes

“near ambient temperature and pressure water

treatment processes driven by solar energy which involve the generation

of hydroxyl radicals in sufficient quantity to effective water purification”


Fe3+ activity, l540-580 nm

0.2 0.4 0.8 1.0 1.2 1.4

0

200

400

600

800

1000

1200I,

W/m

2

m

O3 O2

O3

H2O

H2O

CO

H2O

0.6

0

200

400

600

800

1000

1200

Wavelength, µm

O3 O2

O3

H2O

H2O

2

H2O

TiO

2ac

tivi

ty, l

39

0n

m

Wavelength, µm


10 10

Solar photocatalytic processes

22

2

2

h

2

OOe

HOHh

)he(TiOTiO

OH

TiO2/UVA (Carey et al., 1976)

Aquacomplexes Fe(III) + hn ●OH (Mazellier et al., 1997a,b; Brand et al., 1998,

2000; Mailhot et al., 1999)

Aquacomplexes Fe(II) + hn ●OH (Benkelberg and Warneck, 1995)

Fe(III)-Fe(II)/UVA

H2O2 + h 2 ●OH for l<280 nm

(Goldstein et al., 2007)

H2O2/UVA

OHHFeOHFe 2h

2

3

Photo-Fenton (several authors, early 90s)

OHOHFeOHFe 3

22

2

Fenton

(J. Chem. Soc., 1894)



Evaluation of solar energy

a) QUV: cumulative UV energy during exposure time per unit of volume of

treated water (J l-1).

b) UV Dose: UV energy received per unit surface during exposure time (J m-2).

EnergyUV = UVG,n·A· Dtn

c) UV Energy: total UV energy received during exposure time (J).

DoseUV = UVG,n· Dtn

QUV,n = QUV,n-1 +UVG,n· Dtn· A/Vt


Parameters for solar reactors design

Efficient distribution of UV radiation.

pH resistance and chemical stability of reactor components.

Flow guaranteed at minimal pressure.

Maximal homogenization.

Resistance to temperature range: 0-50ºC.

Robust and resistant to environmental conditions.

Easy handling, low operational cost.

Modular systems are desirable.

Cheap and accessible.


Collection and distribution of solar UV

From early 80’s until middle 90’s the research work on this field moved

from high-concentrating to middle- and non- concentrating systems:

•Quarz reactors without concentration (Ahmed and Ollis, 1984).

•Flat reactors (glass) with immobilized catalyst (Bahnemann, 1994;

Bockelman, 1995)

•Flat reactors (Pacheco and Sullivan, 1993-94).

•Parabolic-1 axis collectors(Pacheco and Anderson, 1991).

•Parabolic-2 axis collectors (Minero, 1993-96; Malato, 1999).

2-axis 1-axis


Optical efficiency of solar collectors at PSA

10000

20000

30000

40000

b

a

Sep Oct Nov DecMay Jun Jul AugFeb Mar AprJan

Total = 2 axis PTC, 3649 kWh m-2 (100%)

1 axis PTC E-W, 2792 kWh m-2 (76%)

1 axis PTC N-S, 3119 kWh m-2 (85%)

Da

ily

in

teg

rate

d irr

ad

ian

ce

x

c

os

(

kJ

m-2)

0

10000

20000

30000

40000

Total, 3649 kWh m-2 (100%)

0º, 1986 kWh m-2 (54%)

37º, 2556 kWh m-2 (70%)

60º, 2388 kWh m-2 (65%)

Static

collectors

Sun

tracking

PTC


15

Compound Parabolic Collectors: CPC

Concentration of direct

solar radiation

Sunlight tracking

High cost

Compound Parabolic Collector

Static

Low cost

Non-concentrating Concentrating


16

Solar Energy, 67, 317-330, 2000.

Solar Energy, 77, 513-524, 2004.

Ray tracing for CPC collectors


17

Advantages of solar CPC mirrors

1) Highly efficient use of direct and diffuse solar UV radiation without sun

tracking.

2) Low-cost systems than solar collectors used for thermal applications.

3) High optical efficiency (geometrical design).

4) Water temperatures are low (max. 50ºC).

5) Turbulent water flow can easily be maintained under low pressure.

Tubular CPC photoreactors have been demonstrated to be a good option for

solar photochemical applications like wastewater treatment for removing

hazardous chemical compounds and disinfect contaminated water. Madrid, 1999

Solar CPC collectors: 100 m2

Batch total volume: 800 L


18

CPC Manufacturing

Modular design:

• to optimize manufacturing and set-up

• to minimize dark regions

• to minimize capital and running costs


19

Materials (mirrors, tubes, etc.)

Highest UV reflectivity is given by aluminium.

Highest UV transmission is given by quartz, followed by borosilicate, PTFE

and standard glass.


20

0.0 0.1 0.2 0.30

20

40

60

80

100 Pathlength 50 mm

Pathlength 30 mm

Pathlength 10 mm

Tra

nsm

itta

nce

(8

00

nm

), %

TiO2, g/L

0.0 0.2 0.4 0.6 0.8 1.0 1.20

20

40

60

80

100

Pathlength 50 mm

Pathlength 30 mm

Pathlength 10 mm

Tra

nsm

itta

nce

(3

50

nm

), %

Fe3+

, mM

Lower catalyst load => higher reactor diameter

Reactor diameter


21

CPC orientation: energy gains and loses

Daily solar UVA-irradiance (Wh/m2)

at PSA (Spain)

Ratios of monthly mean inclined/horizontal solar

irradiation for the UV and Global spectra.

Navntoft et al., Solar Energy 86 (2012) 307-318.


22

REAL APPLICATIONS FOR WW TREATMENT


23

Solar photocatalysis demonstration projects


24

Real applications…

source: www.scopus.com, 2012

Photocatalysis

Solar-driven photocatalysis

Nevertheless, real applications for

wastewater treatment are still scarce

http://www.scopus.com/


25

Solar heterogeneous photocatalysis (TiO2)

Linearly dependent on the energy flux but only ~5% of the whole solar

spectrum is available for TiO2 band-gap.

Solar collector efficiency of 75% and 1% for the catalyst means 0.04%

original solar photons are efficiently used. This is a rather inefficient process.

Pure TiO2 can utilize only UV and new catalysts able to work with the visible

component of the solar spectrum are needed.


26

Photo-Fenton has good potential for wastewater treatment applications.

Several aspects may also contribute to market introduction:

Catalysts based on immobilized iron.

Additives which enhance the process performance, either regarding kinetics

or pH operation range.

Optimization of treatment taking into account the wastewater specific

requirements.

Ways to minimize hydrogen peroxide consumption, which is the main factor

regarding operation costs.

Photo-Fenton


AOP-BIO and BIO-AOP


WW characterization: TOC, COD, BOD, main inorganics, contaminants (LC-MS/GC-MS)

Non-toxic or partially

toxic (<50%)

TOXICITY

Toxic (>50%)

EVALUATION OF

BIODEGRADABILITY

2: Biodegradable. COD>Guideline

AOP EVALUATION OF

BIODEGRADABILITY DURING AOP

1: Partially or not biodegradable

BIOLOGICAL

TREATMENT

COD and

toxicity<Guideline

DISCHARGE

TOC<500 mg/L TOC>500 mg/L

DILUTION AND EVALUATION OF

BIODEGRADABILITY

AOP EVALUATION OF

BIODEGRADABILITY

DURING AOP BIOLOGICAL

TREATMENT

AOP

Biorecalcitrant

compounds COD and toxicity<Guideline

DISCHARGE

BIOLOGICAL

TREATMENT

AOP EVALUATION OF

BIODEGRADABILITY

DURING AOP

1

1 2

2

2

2

1

1 1 2

AOP-BIO and BIO-AOP

Science of the Total Environment, 409, 4141–4166, 2011.


29

Photocatalytic processes only make sense for hazardous non-biodegradable

pollutants.

The use of photocatalysis as a pre-treatment makes sense when the

intermediates are biodegradable.

Toxicity tests of the treated wastewater are needed when incomplete

degradation is planned.

However, if we consider that toxicity is a biological response, the values

obtained by a single toxicity assay can be insufficient. Consequently, a

battery of assays is recommended.

Toxicity results are reliable when two or more different bioassays point in the

same direction.

AOP treatment coupled to BIO (AOP-BIO)


Combined photo-Fenton and biotreatment

Biological

treatment (IBR) Solar Photo-Fenton

Industrial

wastewater

DOC0: 480

mg/L

Non-biodegradable

pesticides

Biodegradable

compounds

Decontaminated

water

DOC: 75 mg/L • 20 mg/L Fe / pH: 2.8

• 44 % mineralization

• DOCf: 270 mg/L

• 21 mM H2O2 consumed

• DOC0: 300 mg/L

• 1.5 days of biotreatment

• 75 % mineralization

• DOCresidual: 75 mg/L

0 4 8 12 16 20 24 280

20

40

60

80

100%

BIO

DE

G.

Time (days)

S1 (DOC0: 490 mg/L) S5 (DOC

0: 345 mg/L)


0: 255 mg/L)


0: 170 mg/L)


0: 145 mg/L)

Biodegradability limit

0 1 2 3 20 400

250

500

750

1000

1250

0.0

0.2

0.4

0.6

0.8

1.0

IBR

Illumination time (hours)

DOC

COD

H2O

2 consumed

C (

mg/L

)

Treatment time (hours)

Photo-Fenton

AOS

AO

S

AOP-BIO


31

Pesticides identification and quantification by LC-TOF-MS in real

wastewater

1. SPE extraction

Oasis® HLB

1 2 3 4

Imidacloprid

Dimethoate

Pyrimethanil

Thiacloprid

Carbofuran

Metalaxyl

Spinosyn a

Bupirimate

Fenamiphos

Azoxystrobin

Malathion

Tebufenozide

Pesticides identified in real wastewater

Imidacloprid

Dimethoate

Pyrimethanil

Thiacloprid

Carbofuran

Metalaxyl

Spinosyn a

Bupirimate

Fenamiphos

Azoxystrobin

Malathion

Tebufenozide

Imidacloprid

Dimethoate

Pyrimethanil

Thiacloprid

Carbofuran

Metalaxyl

Spinosyn a

Bupirimate

Fenamiphos

Azoxystrobin

Malathion

Tebufenozide

Imidacloprid

Dimethoate

Pyrimethanil

Thiacloprid

Carbofuran

Metalaxyl

Spinosyn a

Bupirimate

Fenamiphos

Azoxystrobin

Malathion

Tebufenozide

Imidacloprid

Dimethoate

Pyrimethanil

Thiacloprid

Carbofuran

Metalaxyl

Spinosyn a

Bupirimate

Fenamiphos

Azoxystrobin

Malathion

Tebufenozide

Imidacloprid

Dimethoate

Pyrimethanil

Thiacloprid

Carbofuran

Metalaxyl

Spinosyn a

Bupirimate

Fenamiphos

Azoxystrobin

Malathion

Tebufenozide

Imidacloprid

Dimethoate

Pyrimethanil

Thiacloprid

Carbofuran

Metalaxyl

Spinosyn a

Bupirimate

Fenamiphos

Azoxystrobin

Malathion

Tebufenozide

Imidacloprid

Dimethoate

Pyrimethanil

Thiacloprid

Carbofuran

Metalaxyl

Spinosyn a

Bupirimate

Fenamiphos

Azoxystrobin

Malathion

Tebufenozide

Imidacloprid

Dimethoate

Pyrimethanil

Thiacloprid

Carbofuran

Metalaxyl

Spinosyn a

Bupirimate

Fenamiphos

Azoxystrobin

Malathion

Tebufenozide

Imidacloprid

Dimethoate

Pyrimethanil

Thiacloprid

Carbofuran

Metalaxyl

Spinosyn a

Bupirimate

Fenamiphos

Azoxystrobin

Malathion

Tebufenozide

Imidacloprid

Dimethoate

Pyrimethanil

Thiacloprid

Carbofuran

Metalaxyl

Spinosyn a

Bupirimate

Fenamiphos

Azoxystrobin

Malathion

Tebufenozide

Imidacloprid

Dimethoate

Pyrimethanil

Thiacloprid

Carbofuran

Metalaxyl

Spinosyn a

Bupirimate

Fenamiphos

Azoxystrobin

Malathion

Tebufenozide

Mezcua et al., Anal. Chem. 81, 2009.

2. LC-TOF-MS 3. Automatic screening using a pesticide accurate

mass-database (ca 300 compounds in 20 minutes)


Compound % Reduction

combined system

Final conc

(g/L)

Imidacloprid 96.4 25

Dimethoate 99.4 5

Pyrimethanil 81 161

Thiacloprid 84.2 88

Azoxystrobin 99.4 3

Malathion 100 < 0.1

Carbofuran 100 < 0.1

Metalaxyl 100 < 0.1

Spinosyn a 100 < 0.1

Bupirimate 100 < 0.1

Fenamiphos 100 < 0.1

Tebufenozide 100 < 0.1

Concentration of all pesticides decreased gradually throughout

the process (mainly during the photo-Fenton process).

After the combined system: totally removed, except

pyrimethanil and thiacloprid, found in range of g/L

1. SPE extraction

Oasis® HLB

1 2 3 4

2. LC-TOF-MS

AOP-BIO

Chemical Engineering Journal, 160, 447–456, 2010.


Parameter Amount

pH 3.98

Conductivity 7 mS.cm-1

TOC 775 mg.L-1

COD 3420 mg.L-1

Nalidixic acid 45 mg.L-1

TSS 0.407 g.L-1

Cl- 2.8 g.L-1

PO43- 0.01 g.L-1

SO42- 0.16 g.L-1

Na+ 2 g.L-1

Ca2+ 0.02 g.L-1

Real WW

N N

O

OH

O

BIO-AOP


0 50 100 150 200 250 3000

150

300

450

600

750

900

TOC

H2O

2 consumed

t30W

(min)

TO

C (

mg

/L)

0

10

20

30

40

50

60

70

H2O

2 c

on

su

med

(m

M)

0 50 100 150 200 250 300

0

10

20

30

40

50

Na

lid

ixic

acid

(m

g/L

)

t30W

(min)

0 50 100 150 200 250 3000

150

300

450

600

750

900

TOC

H2O

2 consumed

t30W

(min)

TO

C (

mg

/L)

0

10

20

30

40

50

60

70

H2O

2 c

on

su

med

(m

M)

0 50 100 150 200 250 300

0

10

20

30

40

50

Na

lid

ixic

acid

(m

g/L

)

t30W

(min)

INITIAL CONDITIONS (photo-Fenton)

• Nalidixic acid: 39 mg/L

• Initial TOC: 822 mg/L

• [NaCl] : 6.5 g/L

• Total degradation of the nalidixic acid

at 350 minutes (illumination time)

(65 mM H2O2)

• 28% of the initial TOC was removed

• Nalidixic acid: 38 mg/L

• Initial TOC: 725 mg/L

• [NaCl] : 4.3 g/L

INITIAL CONDITIONS (Biotreatment)

• NH4+ : <0.1 mg/L

• NO3- : <0.1 mg/L

• pH: 6.6

• 96% of the initial TOC was removed

• Nalidixic acid persists after biological treatment (~15 mg/L)

0 1 2 3 40

100

200

300

400

500

600

700

800

TOC

Nalidixic acid

Time (days)

TO

C (

mg

/L)

0

10

20

30

40

50

Na

lid

ixic

acid

(m

g/L

)

BIO-AOP

photo-Fenton


AOP-BIO versus BIO-AOP

0

20

40

60

80

100

% T

OC r

educ

tion

AO

P

BIO

Biotr.

time =

4 days Biotr.

time =

4 days

BIO

A

OP

t30w = 350

min; H2O2

= 65 mM (elim.NXA)

t30w = 21 min (elim. NXA) !!!

H2O2 = 12 mM (elim. NXA) !!!

Wat. Res., 45, 1736-1744, 2011.


LC-TOF-MS chromatograms

10 20 30 40 50

Initial wastewater

IBR

IBR + photo-Fenton

Time (min)Retention time (min)

N N

O

O

OH

O

O

P34

N N

OH

OO

OH

P2

N N

OH

OO

NXA

N N

O

O

O

OH

OH

P3

N ON

O

O OH

P4

N N

OH

OO

P5

N N

OH

OO

OH

P9

N NH

OH

OO

P6

N N

OH

OH

P14

N N

OH

OHP1

N N

OH

O

O

O

HO

P11

N NH

O

O

OH

OH

P12

N NH

OH

O

P15

N NH

O

P13

N N

OH

O

O

P7

N N

HO

OO

OH

ClP17

N N

OH

O

H

O

OHP22

N N

OH

O

OH

O

P27

No DPs

BIO-AOP


37

Solar reactors for water disinfection (PSA)


38

Design of solar reactor for water disinfection

(i) maximizing the collection of solar energy dose

(ii) enhancing the disinfecting efficacy especially against resistant pathogens

(iii) increasing the output of treated water in given solar exposure time

(iv) reducing the treatment time

(v) reducing the user dependence of the process

(vi) finding cheap and robust disinfection systems, which may also be

constructed with local materials without sophisticated technological needs

(this is especially important for developing countries)

(vii)optimizing photoreactor design taking into account the disinfection

mechanisms and previous knowledge based on practical experiences on

disinfection of real contaminated waters and wastewaters.


39

Damage of solar radiation on cells

39

Malato et al. Catalysis

Today. 147 (2009) 1-59.


40

The challenge: to improve SODIS

What is SODIS?

Transparent containers are filled with contaminated water and placed in

direct sunlight for at least 6 hours, after which time it is safe to drink.

55 countries where, in 2009, SODIS was in daily use by more

than 4.5 million people (Meierhofer and Landolt, 2009).


SODIS for drinking water disinfection

The positives: • Low cost, since usually only the poorest communities tend to be affected. • Easy to use. Compliance will suffer if the protocol is overly complicated. • Sustainable. The technique must not require consumables that are difficult or too expensive to obtain. The negatives: • Undesirable bacterial re-growth may occur. • Some water pathogens are very resistant. • Small water outputs and large treatment times. • Strongly dependantg on weather conditions.


42

The challenge: to improve SODIS

Water being treated by SODIS at a primary school in Southern Uganda. Students fill their bottles at home

and expose them to the sun while they are in class (McGuigan et al., 2012).


43

CPC enhancement for SODIS

Navntoft et al., J. Photochem. Photobiol. B: Biology, 93, 155-161, 2008.

Cloudy days

11:00 12:00 13:00 14:00 15:0010

0

101

102

103

104

105

106

107

0

10

20

30

40

50

60

Ba

cte

ria

Co

nc.

(CF

U/m

l)

Local time(hh:mm)

Old CPC

Controls

DL

UV IrradianceNo CPC

UV

Irr

ad

ian

ce

(W

/m2)

New CPC

Clear days

11:00 12:00 13:00 14:00 15:00 10

0

10 1

10 2

10 3

10 4

10 5

10 6

10 7

0

10

20

30

40

50

60

Ba

cte

ria

Co

nc. (C

FU

/ml)

Local time(hh:mm)

Tube+CPC

DL

Controls

UV Irradiance

Dark

Bottle U

V I

rra

dia

nce

(W

/m

2 )

Tube


44

Solar energy distribution in the CPC reactor

1. Solar radiation is

applied for

inactivation of

microorganisms

2. Ray tracing

model in a

CPC+tube system

0I

IT

)(log10 TlCA l

lll

E. coli absorption

E. coli extinction


45

Local volumetric adsorption energy (LVAE, W m-2) in the CPC photo-reactor • UVAave.= 30 w/m2. Incidence angle = 45º.

• Isotropic dispersion of E. coli Glass transmission = 90 %

• Loses (surface, shape, etc.) = 10%.

De tube LVAE efficiency (%)

20 cm 0.62 0.32 0.04

5 cm 0.51 0.11 0.01

108 CFU mL-1 107 CFU mL-1 106 CFU mL-1

Solar energy distribution in the CPC reactor


46

11:00 12:00 13:00 14:00 15:0010

0

101

102

103

104

105

106

107

0

10

20

30

40

50

60

0 l/min

UV

irr

ad

ian

ce

(W

/m2)

10 l/min

2 l/min

Ba

cte

ria

Co

nc.

(CF

U/m

l)Local time (hh:mm)

DL

Controls

How is the solar energy delivered?

Increasing flow rate has a negative effect on inactivation of bacteria, irrespective of the

long exposure time of 5 hours.

At a given time point there needs to be maximum exposure of bacteria to UV to ensure

inactivation as compared with having bacteria exposed to sub-lethal doses over a long

period of time.

1.E+00

1.E+01

1.E+02

1.E+03

1.E+04

1.E+05

1.E+06

1.E+07

1.E+08

0 10 20 30 40 50 60 70 80 90 100

Time (min)

Bacte

ria

l surv

ival (C

FU

/ml)

30 minutes of

continuous irradiation

30 minutes of interrumped

illumination


47

Bactericidal (lethal) solar dose

It was observed that bacterial inactivation depends on UVA dose instead of UVA

irradiance (for 14 - 40 W·m-2). There is a minimum and uninterrupted UVA dose

needed for a complete inactivation of bacteria; this dose was defined as the

“uninterrupted lethal UVA dose".

10 15 20 25 30 35 60 70

100

101

102

103

104

105

106

107

100

101

102

103

104

105

106

107

Final bacteria concentration

Ba

cte

ria

Co

nce

ntr

atio

n (

CF

U/m

l)

UV Energy (Wh/m2) (0,295-0,385 um)

Detection Limit:

4 CFU/ml

Average C0

Exposure to different uninterrupted UV dose


48 25l CPC-SODIS batch reactor

Static batch reactors

CPC reflector

Glass tube

CPC tube – 2.5 l

1.5l PET-bottles


49

Sequential batch reactor

C=1.89

Aperture=29.70cm

19

.37

cm

- decreasing the treatment time required

- increasing the total volume of water treated per day

- reducing user dependency.


50

Electronic dosimetric

control system CPC reflector

Borosilicate tube

Storage tank with

treated water

Platform titled 37ºC

Sequential batch reactor


51 Fontán-Sainz et al., Am. J. Trop. Med. Hyg. 2012, 86 (2) 223-228

10:00 11:00 12:00 13:00 14:00 15:00 16:00 17:00 18:00

0

20

40

60

80

100

0

20

40

60

80

100

Pa

ram

ete

r

Pa

ram

ete

r

Local time (hh:mm)

% Excystation

% PI-positive

% Global viability

0 NTU

10:00 11:00 12:00 13:00 14:00 15:00 16:00 17:00 18:00

0

20

40

60

80

100

0

20

40

60

80

100

Para

me

ter

Para

me

ter

Local time (hh:mm)

5 NTU

10:00 11:00 12:00 13:00 14:00 15:00 16:00 17:00 18:00

0

20

40

60

80

100

0

20

40

60

80

100

Para

me

ter

Para

me

ter

Local time (hh:mm)

30 NTU

C. parvum photo-inactivation in well water


52

Recirculated batch reactors


53

glass tube

water

catalyst

PP-support

matrix with

immobilized

catalyst

tubular PP-

support

glass tube

CPC reflector

Cross section

Immobilized TiO2


54

Comparison of solar AOPs for real WW effluent disinfection

P25 (100 mg L-1 ) + solar

11:00 12:00 13:00 14:00 15:00 16:00

101

102

103

104

105

0

10

20

30

40

50

DL Co

nc

en

tra

tio

n (

CF

U o

r P

FU

/10

0m

L)

Local Time (HH:MM)

UV

A irr

ad

ian

ce

(W

m-2)

Te

mp

era

ture

(ºC

)

Escherichia coli (——)

SRC: Sulphite reducing clostridia (——)

SOMCPH: somatic coliphages (——)

FRNA: F specific RNA bacteriophages

infecting Salmonella strain WG49 (—▲—)

Photo – Fenton pH3 photo-Fenton at natural pH (8)

11:00 12:00 13:00 14:00 15:00 16:00

101

102

103

104

105

0

10

20

30

40

50

DL Co

nc

en

tra

tio

n (

CF

U o

r P

FU

/10

0m

L)

Time (HH:mm)

U

VA

irr

ad

ian

ce

(W

m-2)

Te

mp

era

ture

(ºC

)

11:00 12:00 13:00 14:00 15:00 16:00

101

102

103

104

105

0

10

20

30

40

50

DL Co

nc

en

tra

tio

n (

CF

U o

r P

FU

/10

0m

L)

Time (HH:mm)

U

VA

irr

ad

ian

ce

(W

m-2)

Te

mp

era

ture

(ºC

)


Crops irrigation using treated MWW

http://newsimg.bbc.co.uk/media/images/

htt

p:/

/ww

w.iw

mi.cgia

r.o

rg/

• Wastewater (WW) reuse in agriculture is difficult to assess, but it is a widespread

practice in many areas around the globe, largely in arid and wet environments. -Hanoi, Viet Nam: 80% of vegetables irrigation with mixed WW.

-Kumasi, Ghana: irrigation with WW covers 11,900 hectares (1/3 of the irrigated area of the country)

• Planned: policies to minimise health risks and environmental pollution by collection &

treatment using proper processes & infrastructure.

• Unplanned: poor sanitation & high health risks.

• For agricultural irrigation in developing countries, it is

important to select WW treatments that both:

reduce pathogen numbers & retain the nutrients.

http://newsimg.bbc.co.uk/media/images/

http://www.iwmi.cgiar.org/


Areas of water scarcity

Source: Comprehensive Assessment of Water Management in Agriculture, 2007 (http://www.fao.org/nr/water/)

Physical water scarcity More than 75% of the river flows

are withdrawn for agriculture and

domestic purposes.

Approaching physical

water scarcity. More than

60% of the river flows are

withdrawn.

Little or no water scarcity Abundant water resources with less

than 25% of the waters form rivers

are withdrawn.

Not estimated

Economic water scarcity Water resources are abundant

relative to water use, less than 25%

of the waters form rivers are

withdrawn, but malnutrition exists.

http://www.fao.org/nr/water/


Source: FAO-AQUASTAT, 2008 (http://www.fao.org/nr/water/)

Water withdrawal for agriculture

Proportion of total water withdrawal for agricultural, domestic and industrial purposes (2001)

http://www.fao.org/nr/water/


Wastewater reuse for irrigation Benefits

– Reliable constant source of water.

– Nutrient content for better crop yields reducing the chemical fertilizers use.

– Low-cost WW treatment to prevent pollution of water bodies.

Disadvantages – Short term risks: health risk from water pathogens.

– Long term risks: heavy metals and organic toxic compounds with cumulative health effects.

E Coli — Germany Outbreak 2011 […] As of

June 20, along with the 39 fatalities, there

were more than 3,400 cases reported,

including 810 involving kidney failure. […]


…WW reclamation and reuse for crops irrigation for human consumption

• Italy (2003): E. coli & Total Coliforms < 10 CFU/100 mL

DM (185/2003) Regolamento recante norme tecniche per il riutilizzo delle acque.

• USEPA (2004): E. coli & Total Coliforms < 1 CFU/100 mL USEPA, Guidelines for Water Reuse, U.S. Environmental Protection Agency, 2004.

• Australia (2005): E. coli & Total Coliforms < 1 CFU/100 mL

Queensland Water recycling Guidelines. Queensland Government, Enviromental Protection Agency.

• WHO (2006): Faecal coliforms < 1 000 CFU/100mL WHO Guidelines for the safe use of wastewater, excreta and greywater. Wastewater use in agriculture.

• Spain (2007): E. coli < 100 CFU/100mL Spanish Official Bulletin, RD, 1620/2007.

• FAO (2008): Total coliforms < 1-200 CFU/mL. FAO, 2008.Valentina Lazarova Akiçca Bahri; Water Reuse for irrigation: agriculture, landscapes, and

turf grass; CRC Press.

Guidelines and recommendations for…


Objective of this study … to assess the performance of solar disinfection processes (with/

without H2O2), as a WW treatment to enhance microbial safety of treated

real WWTP effluents to be used for irrigation.

• E. coli K-12 (ATCC 23631) for control tests, and naturally present E. coli in real

WWTPE (typ.103 CFU mL-1).

• Distilled, Natural well water, and simulated and real WWTPE.

• Lettuce: Fast growing, leaves directly exposed to water, eaten raw.

• Risk associated to leafy greens was reported for E. coli by Solomon et al. 2002,

Berger et al. 2010, Habteselassie et al. 2010, Luo et al. 2010, Niemira et al. 2010.

• Solar treatment in low cost solar reactors with direct sunlight and sunlight/H2O2.


SODIS & Sunlight + added H2O2 (<10ppm) in solar CPC reactors

• Solar photo-assisted treatment with H2O2 induces accelerated inactivation of

several types of microorganisms in water due to photo-chemical and photo-

biological processes that occur when solar photons and non-toxic amounts of

hydrogen peroxide interact with living cells. Source: Anathaswamy, 1976, 1977, 1979; Sichel, 2009; Polo-Lopez, 2011; Agulló-Barceló, 2013;

Rodríguez-Chueca, 2014.

• Mechanism of action is based on the stressing effect produced by H2O2 and

solar photons due to internal photo-Fenton reactions with the available iron

inside the microbial cells.

Source: Sphüler, et al. (2010); Polo-López, et al. (2012)

Solar treatments proposed

OHOHFeOHFe 3

22

2

OHHFeOHFe 2h

2

3 0 5 10 15 20 25 30 35 40 45 50

100

101

102

103

F.

eq

uis

eti

(C

FU

/mL

)

QUV

(kJ/L)

DL

H2O2: 10mg/L



Solar reactors for water disinfection

CPC tube – 2.5 litres

SODIS-CPC reactor – 25 litres CPC Prototypes 7 – 70 litres

Continuous flow reactors Batch static reactors

300 NTU 100 NTU

5 NTU 0 NTU

PET containers – 1-2 litres


Solar CPC batch reactor – 25L

0NTU 5NTU 30NTU

0

10

20

30

40

50

60

Te

mp

era

ture

(ºC

)

Turbidity

inicial

2h

4h

6h

8h

Thermal behavior E. coli (well water -Spain)

10:00 11:00 12:00 13:00 14:00 15:00 16:00 17:00 18:00

0

20

40

60

80

100

0

20

40

60

80

100

Pa

ram

ete

r

Pa

ram

ete

r

Local time (hh:mm)

% Excystation

% PI-positive

% Global viability

Cryptosporidium parvum

E. coli (well water - Uganda)

Source: Nalwanga et al. Sol. En. 100 (2014) 195–202.

Ubomba-Jaswa et al., JCTB 85 (2010) 1028-37.

Fontán-Sainz at a., Amer. J. Tropic. Med. 86 (2012) 223-228.


Experimental design

1. Solar disin-

fection of water.

2. Watering of

lettuce with

treated water.

3. Detection of

E. coli on

lettuce leaves.


• Batch CPC reactors

– Borosilicate glass

– 20 L irradiated volume

– CPC 1.

– 4 types of water: DW, WW, simulated and

real WWTPE.

• Classical SODIS reactors

– PET bottles

– 1.5 L

– Tested for real effluents.

• Solar radiation vs Solar + H2O2 disinfection

– H2O2 adding: low amounts, low cost, no pH

adjustment, decomposition into water and

oxygen; < 50 mg/L non toxic for crops.

Experimental details


R2

R1

b2

b1


Water types

• Distilled Water spiked with a strain E. coli K-12

• Natural Well Water spiked with a strain of E. coli K-12

• Simulated WWTPE spiked with a strain of E. coli K-12

– DOC = 25 mg L-1

– Inorganic ions, Urea (6 mg L−1), peptone (32 mg L−1) meat extract (22 mgL−1)

(Klamert et al., 2010).

• Real WWTPE with naturally present E. coli

– freshly collected real secondary effluent water from the municipal wastewater

treatment plant of Almería (Spain).

– DOC = 15.9 - 17.1 mg/L, DIC = 66.4 - 77.8 mg/L, Turbidity = 7-9 NTU, pH=

7.4 – 7.8, Conductivity = 1739 and 1819 μS cm-1.

• Mineral water for positive (with spiked E. coli) and negative controls.


Watering of lettuce crops

with solar treated water


www.seward.co.uk

E. coli presence/absence method


E. coli detection on Chromocult plates

RE

(untreated)

EC1E6

(Control +) PW

(Control -)

b1-b2

(SODIS)

What does a “+” mean?

≥ 1 CFU/ 0.3 g lettuce

ie. ≥ 100 CFU/ 30 g lettuce

(one serving)


Recovery of E. coli bacteria after blending treatment

1,0E+00

1,0E+01

1,0E+02

1,0E+03

1,0E+04

1,0E+05

1,0E+06

1,0E+07

1,0E+00 1,0E+02 1,0E+04 1,0E+06

Conc. inicial (cfu/ml)

Co

nc

. d

es

pu

és

de

ba

tir

4*1

5s

eg

sin lechuga

con lechuga

C0 (CFU mL-1)

C a

fter

ble

nd

ing (

CF

U m

L-1

)

○ With lettuce

■ Without lettuce


E. coli presence/absence method • Lettuce leaves sample collection 24h after irrigation.

• 3 x ~0.1-g sample of lettuce leaves (duplicate).

• 24-hr incubation at 37ºC in 15 ml LB.

• 10-fold diluted in PBS: spreading in Chromocult-agar plates.


40


0 100 200 300 400 500 600 700

100

101

102

103

104

105

106

107

Time (h)E

. c

oli (

CF

U m

L-1)

DoseUV

(kJ m-2)

Distilled water

Well water

Simulated WWTPE

Real WWTPE

DL

0 1 2 3 4 5

100

101

102

103

104

105

106

107

Solar disinfection in solar CPC reactors

34-

40°C 39-

47°C

33-

34°C

35-

41°C

Total volume: 20L

Bichai et al., Wat. Res. 40 (2012) 6040-50.


0 100 200 300 400 500 600 700

100

101

102

103

104

105

106

107

E. c

oli (

CF

U m

L-1)

DoseUV

(kJ m-2)

Distiled water

Well water

Simulated WWTPE

Real WWTPE

5 mg/L-1 H

2O

2(open symbols)

10 mg/L-1 H

2O

2(solid symbols)

DL

0 1 2 3 4 5

100

101

102

103

104

105

106

107

Time (h)

H2O2/sunlight disinfection in solar CPC reactors

49°C

48°C

39-

41°C

46°C

Total volume: 20L



Solar disinfection of real WWTPE in PET bottles

0 100 200 300 400 500 600 700 800

100

101

102

103

104 Solar light/H

2O

2

10 mgL-1

5 mgL-1

SODIS

Time (h)

E. c

oli (

CF

U m

L-1)

DoseUV

(kJ m-2)

DL

0 1 2 3 4 5

100

101

102

103

104

Max. T in SODIS bottles 40.2 - 43.4°C Total volume: 1.5L



Irrigation results (presence/absence of E. coli)

Before treatment Initial conc. of E. coli (CFU

mL-1) of 4 real WWTPE 2.4 x 103 1.3 x 104 3.8 x 103 3.1 x 103

Untreated real

WWTPE

+ + + + + + + +

‒ + + + + ‒ + +

After solar treatment SODIS H2O2-solar

SODIS1 SODIS2 10mg L-1 5mg L-1

CPC experiment-R1 ‒ ‒ + ‒ ‒ ‒ ‒ ‒

CPC experiment-R2 ‒ ‒ ‒ ‒ ‒ ‒ ‒ ‒

Bottle test-b1 ‒ ‒ ‒ ‒ ‒ ‒ ‒ ‒

Bottle test-b2 ‒ ‒ ‒ ‒ ‒ ‒ ‒ +

Controls Mineral water

(negative control) ‒ ‒ ‒ ‒ ‒ ‒ ‒ ‒

Mineral water + E. coli K-12

(positive control; 106 CFUmL-1) + + + + + + + +

+/- indicate the presence/absence of E. coli in ~0.3 g of lettuce leaves samples.

For each water, 2 crops (2 leaves samples) were evaluated.

What does a “+” mean?

≥ 1 CFU/ 0.3 g lettuce

ie. ≥ 100 CFU/ 30 g lettuce

(one serving)


Summary – solar treated WW reuse

• Characterizing 20-L batch SODIS reactors.

• Using real wastewater effluents and describing E. coli inactivation in

solar and solar-H2O2 disinfection assays.

• Using SODIS simple PET-bottle technique for improving the microbial

safety of wastewater irrigation in developing communities.

• ‘Closing the loop’ by measuring E. coli contamination on crops

(lettuce) irrigated with the solar-disinfected or untreated wastewater.

• More detailed and large scale

research on WW reuse for irrigation

and its Implications for health risk

analysis is still needed.


79

Sunlight/H2O

2 treated wastewater reused for

lettuce irrigation: micropollutants and antibiotic

resistant bacteria contamination

To assess chemical and microbial cross contamination on crops irrigated

with real urban wastewater treatment plant (UWTP) effluents after a H2O

2

(20 mg L-1

)/sunlight treatment at pilot-scale by a solar compound

parabolic collector (CPC) system, in terms of:

transfer of multi-drug resistant (MDR) bacteria to both lettuce

leaves and top soil;

uptake of CECs by lettuce leaves and top soil.

Ferro, et al., Env. Sci. Technol. 2015, DOI: 10.1021/acs.est.5b02613.


H2O2

(20 mg L-1)

Experimental design

MDR E. coli

MDR E. faecalis

(105 CFU mL-1)

Carbamazepine

Flumequine

Thiabendazole

(100 g L-1)

MDR E. coli ?

MDR E. faecalis ?

Crop irrigation

CECs?


Disinfection/oxidation experiments

Solar CPC photo-reactor (V=8.5 L)

Flow rate: 16 L min-1

Real autoclaved wastewater spiked with MDR E. coli and MDR E. faecalis

(ca 105 CFU mL

-1) and carbamazepine (CBZ), flumequine (FLU) and

thiabendazole (TBZ) (ca 100 g L-1

)

Two treatment time for irrigation tests: 300 min (R1) and 90 min (R2).


Irrigation experiments

Lettuce leaves.

5 weeks irrigation experiments.

Drip irrigation and sprinkling irrigation (50 mL) were simulated.

Plated counting method was used for MDR bacteria enumeration.

CECs were extracted by application of QuEChERS method.


Inactivation of MDR E. coli and MDR E. faecalis strains by

H2O2/sunlight disinfection in solar CPC reactor


Degradation of CECs by H2O2/sunlight disinfection in solar CPC

reactor


Transfer of MDR bacteria to lettuce leaves and top soil

All negative controls samples were detected as negative;

During the first two weeks of drip irrigation, positive control samples

were detected as positive just for top soil samples;

During the sprinkling irrigation weeks, all positive control samples were

detected as positive;

Through all irrigation experiments using wastewater treated with

H2O

2/sunlight process for 300 min, all samples (both lettuce leaves and top

soil) were detected as negative for the presence of both MDR bacteria

strains;

In the 5th

sampling week, MDR E. faecalis was detected on one lettuce

leaves sample (6.4x103 CFU 100 mL

-1) and MDR E. coli was detected on one

top soil sample (2.5x101 CFU 100 g

d

-1), when wastewater treated with

H2O

2/sunlight process for 90 min was used.


CECs uptake by lettuce leaves

R1 refers to UWTP effluent treated within 5 h of H2O

2/sunlight and then used as irrigation

water; R2 refers to UWTP effluent treated within 90 min of H2O

2/sunlight and then used as

irrigation water.

0

20

40

60

80

100

120

I week III week V week

EC

s c

oncentr

atio

n [

ng g

-1]

CBZ (R1)

TBZ (R1)

CBZ (R2)

TBZ (R2)


CECs uptake by top soil

R1 refers to UWTP effluent treated within 5 h of H2O

2/sunlight and then used as irrigation

water; R2 refers to UWTP effluent treated within 90 min of H2O

2/sunlight and then used as

irrigation water.

0

50

100

150

200

250

300

350

400

450

500

550

I week II week III week IV week V week

EC

s c

on

ce

ntr

atio

n [

ng

g-1

]

CBZ (R1)

TBZ (R1)

CBZ (R2)

TBZ (R2)


Conclusions (treated WW reuse)

When the effluents are treated and the final MDR bacterial concentration is below the detection limit (for both E. coli and E. faecalis), non-cross contamination of pathogens in lettuce leaves and top soil was observed.

When MDR bacterial load was as high as 102 CFU mL-1 in the treated effluent, the complete absence of cross contamination in crops was not achieved.

For the first time, a new developed analytical methodology, adapted from QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) method, permitted to extract, detect and quantify CECs at nano-range in solid samples like lettuce leaves and soil.

Partial removal of selected CECs leads to chemical contamination in both lettuce and soil.

H2O2/sunlight process should be properly operated to effectively inactivate MDR bacteria as well as to minimize CECs residual concentration in order to reduce their subsequent uptake in crops irrigated with the treated wastewater.


89

Concluding remarks - CPC photoreactors have been demonstrated at pilot and full scale to be

effective for solar treatment of water for removing hazardous chemical

compounds and disinfect contaminated water.

- The removing of emerging contaminants from real wastewater has also

been demonstrated.

- New photocatalysts able to work with the visible component of the solar

spectrum are needed.

- Improvements in reactor design utilising immobilized photocatalyst are

required to increase efficiencies.

- More work is needed to assess photocatalyst longevity and fouling under

real working conditions.

-Cost-benefit and life cycle analysis are required before these technologies

will be deployed on a wide scale.

aops for wastewater treatment (reuse and...

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