1/19 Biodegradability and toxicity of intermediates produced by TiO 2 photocatalytic oxidation of aqueous solution of Naprelan (NPX) Fabiola Méndez-Arriaga, Jaime Gimenez, Santi Esplugas Chemical Engineering Department. University of Barcelona. Marti i Franques, Barcelona, Spain. The Thirteenth International Conference on TiO 2 Photocatalysis: Fundamentals & Applications San Diego, California September 22-25, 2008

IntroductionAimsExperimental SectionResultsConclusions OUTLINE San Diego, CA., September /18

INTRODUCTION “Pharmaceuticals and Personal Care Products as Pollutants (PPCPs) refers, in general, to any product used by individuals for personal health or cosmetic reasons or used by agribusiness to enhance growth or health of livestock”… EPA, Incomplete Removal San Diego, CA., September /18

INTRODUCTION  Prozac has been found in drinking water in London.  Scientists now have evidence that pharmaceuticals, in high enough quantities, can lead problems to prevent wildlife from reproducing.  Recent evidence indicates that a drug, diclofenac, is causing large-scale deaths of vultures in Pakistan. San Diego, CA., September /18

5/18 INTRODUCTION Used pharmaceutical ~ 3000 NSAID Anti-inflammatory NSAID Antibiotics Anti-diabetics Beta-blockers Contraceptives Lipids regulators Antidepressants Anti-neoplastics Tranquilizers impotence drugs Cytostatic agents Used pharmaceutical ~ 3000 NSAID Anti-inflammatory NSAID Antibiotics Anti-diabetics Beta-blockers Contraceptives Lipids regulators Antidepressants Anti-neoplastics Tranquilizers impotence drugs Cytostatic agents NAPRELAN (NPX) (Naproxen, Aleve, Apranax, Naprosyn) frequently One of most frequently found as recalcitrant in surface waters Widely prescribed for the skeleton-muscle pain Aromatic compound characterized for its 2- arylpropionic acid group Detected in WWTP influents into the range of 250 ng/L to 1.5 mg/L. Its presence has already shown harmful toxicological consequences and adverse ecological impact on the microbiological aquatic systems. San Diego, CA., September /18

INTRODUCTION Although some degradation processes of NPX have been developed (O 3, sludge-absorption, etc), a study aiming the biodegradability of byproducts from photo­catalysis irradiated treatment is still lacking. Advanced Oxidation Process “near ambient temperature and pressure water treatment process which involve the generation of hydroxyl radicals in sufficient quantity to effective water purification” Glaze and col Hydroxyl Radical ·OH Wet Oxidation And more... UV/H2O2TiO2Fe/H2O2O3/H2O 2 Sonolysis San Diego, CA., September /18 TiO 2 + hv → TiO 2 * (h + vb /e - cb ) e - + O 2 → · O 2 - h + + H 2 O → · OH + H +

The objective of this investigation is to undertake a study of the heterogeneous photocatalytic degradation of NPX in aqueous suspension with TiO2 in order: i) to identify the main byproducts remained after photocatalytic treatment and ii) to evaluate the biodegradability and toxicity of the treated dissolution. AIM San Diego, CA., September /18

NPX -Na (Sigma) TiO 2 Degussa P25 (70/30 anatase-rutile, surface area 55 m 2 /g ) Reagents HPLC (ACN-0.05 mM phosphate dyhidrogen ammonium 80/20) TOC (Shimadzu TOC-V CNS) BOD5/COD (Standards Methods) EC 50 Microtox test (inhibition of bioluminescence of Vibro fisheri ) LC/ESI-TOF-MS (Jasco AS-2050 IS -MS) Analytical Solarbox (Xe lamp, Duran photoreactor) Equipments EXPERIMENTAL PROCEDURE San Diego, CA., September /18

EXPERIMENTAL PROCEDURE ºC - O 2 Xe lamp 6.2  Eins/min Tubular Duran Photoreactor L Bath Temperature-control 20-40ºC Stirrer Sample Point pH and temperature display San Diego, CA., September /18 Peristaltic Pump O 2 sparing Batch Tank 1.5 L Switch on ºC Batch operation mode

RESULTS Previous non-photocatalytic effects: Thermodegadability Adsorption into TiO 2 Previous non-photocatalytic effects: Thermodegadability Adsorption into TiO 2 San Diego, CA., September /18

RESULTS NPX is degraded by UV-Vis irradiation Wavelength(nm) A NPX A A 200nm <Emitted from Xe lamp < 2600nm 300nm < TiO 2 Employed < 380nm 350nm < Abs NPX Photolysis of NPX causes a reduction of more than 80% of its initial concentration after 3 hours of treatment. San Diego, CA., September /18

RESULTS After 3 hours TiO 2 photocatalysis leads a removal of 40% of NPX with a mineralization of 20%. San Diego, CA., September /18

RESULTS  Photocatalysis proved more degradation efficiency in DOC removal than photolysis. San Diego, CA., September /18

RESULTS Temperature effect San Diego, CA., September /18 ■ NPX 3 h ■ TOC 3 h ■ NPX 4 h ■ TOC 4 h

RESULTS Identification of byproducts has shown that demethylation and decarboxylation are the principal initial processes in the degradation of NPX. Photocatalytic process Photolysis process San Diego, CA., September /18

RESULTS Identification of byproducts has shown that demethylation and decarboxylation are the principal initial processes in the degradation of NPL. San Diego, CA., September /18

RESULTS The production of demethylated by-product is strong dependent on the ·OH radical attack while the decarboxilated derivatives are mainly produced by photolysis process. San Diego, CA., September /18

RESULTS BOD5o= 0 ppm BOD5 at 180 and 240 min = <1 ppm 1.In O 2 saturated media, an improvement in the transformation of NPX is reached, due to lesser hole-electron re­combination, but no enhancement in mineralization is observed. 2. Intermediate products can represent worst biodegradability conditions for the treated effluent. 3. The toxicity of the treated solution is not reduced during photocatalytic process. San Diego, CA., September /18

1.- Photolysis: strong degradation effect on NPX 2.- TiO 2 increase the mineralization degree 3.- Oxygen promotes higher NPX and TOC removal 4.- Intermediates follow two principal pathways: decarboxylation and demetilation 5.- Intermediates result of the ·OH attack and the photoreactive species under irradiated conditions CONCLUSIONS San Diego, CA., September /18

6.- Intermediates are more toxic than the original NPX 7.- Biodegradability did not enhance at the final treatment 8.- No coupling for detoxification with a biological system can be assured before optimization CONCLUSIONES San Diego, CA., September /18

Generous support by the Spanish Ministry of Education and Science (CICYT projects CTQ /PPQ and CTQ /PPQ) and University of Barcelona (predoctoral fellowship) is gratefully acknowledged. AKNOWLEDGMENTS

INTRODUCTION Elemental Particle e-e-e-e- Conduction Band Photon hv Electronic excitation Valence Band O 2 -. Reduction H2OH2O Oxidation OH. Adsorbed Pollutant Degradation Products Reactive specie h+h+h+h+ O2O2 Heterogeneous photocatalysis: TiO 2 San Diego, CA., September /18