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LSRE-LCM SHAKING THE PRESENT

SHAPING THE FUTURE

Removal of Organic Micropollutants in Urban Wastewater by using UV-LEDs

Heterogeneous Photocatalysis

Introduction

F. Biancullo1,2,*, N.F.F. Moreira1, A.R. Ribeiro1, J.L. Faria1, S. Castro-Silva2, A.M.T. Silva1.

Experimental

Results and discussion

Conclusions References

Acknowledgments

1Laboratory of Separation and Reaction Engineering – Laboratory of Catalysis and Materials (LSRE-LCM), Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, Porto, 4200-465 Porto, Portugal 2Adventech-Advanced Environmental Technologies, Centro Empresarial e Tecnológico, Rua de Fundões 151, 3700-121, São João da Madeira, Portugal

Despite the positive contribution of urban wastewater (UWW) reuse practices for a

sustainable water management, crop irrigation with treated UWW is an environmental

and health concern within the European Union. Uptake of contaminants by plants and

crops has a negative effect on the food chain and increases the risk of antibiotic

resistance spread, which is presently considered serious concern to the public health [1].

Moreover, the most recent Watch List of European Decision 2015/495/EU identified a set

of substances, including macrolide antibiotics [2]. Current tertiary treatment technologies

are not able to mineralize many contaminants of emerging concern (CECs) occurring in

UWW [3]. The present study focuses on the application of light-emitting diodes (LEDs) for

a particular advanced oxidation process, heterogeneous photocatalysis, aiming the

removal of organic micropollutants from UWW, such as azithromycin (AZT), trimethoprim

(TMP), ofloxacin (OFL) and sulfamethoxazole (SMX).

This work was financially supported by Project POCI-01-0145-FEDER-006984 – Associate Laboratory LSRE-LCM funded by FEDER through

COMPETE2020 - Programa Operacional Competitividade e Internacionalização (POCI) – and by national funds through FCT - Fundaça ̃o para a

Cie ̂ncia e a Tecnologia. Part of the work presented in this poster is part of a project that has received funding from the European Union’s Horizon

2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 675530. The contribution of the EU in

supporting COST Action ES1403 is appreciated. ARR, NFFM and AMTS acknowledge FCT (SFRH/BPD/101703/2014, PD/BD/114318/2016 and

IF/01501/2013, respectively).

In general, the concentration of all detected CECs decreased

significantly after 10 min of photocatalytic treatment, which is not

due to physical removal since no significant adsorption of the CECs

over TiO2 could be found within 30 min of contact (data not shown).

In the view of process costs, it might be more convenient to use less

radiation (i.e., number of LEDs), extending the treatment time. The

biodegradability of the treated UWW has to be addressed.

[1] A. Christou, A. Agüera, J.M. Bayona, E. Cytryn, V. Fotopoulos, D. Lambropoulou, C.M. Manaia, C. Michael, M. Revitt, P. Schröder, D. Fatta-

Kassinos, Water Research, 123 (2017) 448-467.

[2] M.O. Barbosa, N.F.F. Moreira, A.R. Ribeiro, M.F.R. Pereira, A.M.T. Silva, Water Research, 94 (2016) 257-279.

[3] I. Michael, L. Rizzo, C.S. McArdell, C.M. Manaia, C. Merlin, T. Schwartz, C. Dagot, D. Fatta-Kassinos, Water Research, 47 (2012) 957-995.

Conditions

*f.biancullo@adventech.pt.

UV

A L

ED

s U

VA

LE

Ds

Sampling Air bubbling

Stirring

Spiked tests

Non-spiked tests

• UWW was collected after secondary treatment

from Northern Portugal (DOC0 = 20 mg L-1);

• 150 mL in continuous magnetic stirring and air

sparging (3.5 L min-1).

• UWW spiked with four antibiotics: AZT, TMP,

OFL and SMX (ca. 100 μg L-1 each);

• Several TiO2-P25 catalyst loads (0.10, 0.25,

0.50, 1.00, 1.50 and 2.00 g L-1) and different light

configurations (1, 2 and 4 UVA LEDs);

• Antibiotics removal monitored (UHPLC-MS/MS).

• UWW as collected;

• Selected TiO2-P25 catalyst load (1.50 g L-1) and

light configurations (4 UVA LEDs);

• CECs analyzed (UHPLC-MS/MS after SPE).

Figure 3: Apparent first-order reaction rate constants (k) as function of catalyst load.

1 LED 2 LEDs 4 LEDs

0.00 g L-1

Figure 4: Apparent first-order reaction rate constants (k) as function of number of LEDs.

0.25 g L-1 0.50 g L-1

1.50 g L-1 2.00 g L-1

1.00 g L-1

0.10 g L-1

Kinetic studies for the target antibiotics (spiked UWW)

Detected CECs Raw (ng L-1) TiO2-P25 + UV

(ng L-1) Removal

(%)

Atorvastatin 10.9 0.6 90.3

Azithromycin 35 7 69.6

Bezafibrate 29 8 70.4

Carbamazepine 41.1 12.6 70.5

Ciprofloxacin 50.4 6.2 81.1

Clothianidin 391 191 45.4

Diclofenac 93.3 20.7 77.3

Hydrochlorothiazide 116 45 62.5

Imidacloprid 22 20 9.1

Isoproturon 22.1 4.8 81.2

Ofloxacin 87.8 0.0 100.0

Tramadol 49.6 10.2 80.7

Venlafaxine 66.0 21.1 69.0

Table 1: Removal of CECs by 10 min TiO2 photocatalysis (1.5 g L-1 catalyst load and 4 LEDs).

Removal of CECs in non-spiked UWW

Figure 1: Batch apparatus used for photocatalysis tests.

No significant adsorption (< 30%)

was found at any catalyst load

(data not shown).

For catalyst loads > 1 g L-1, k

constants increases not linearly

with the catalyst load (4 LEDs).

Two perpendicular LEDs had

quite similar efficiency to four

LEDs (at the same catalyst

loading), specially for ofloxacin

and sulfamethoxazole

removals.

Figure 2: Normalized concentration of antibiotics

(1 g L-1 catalyst load and 4 LEDs).

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