Solar Photocatalysis for Urban and Industrial Waste Water Reclamation Sixto Malato Plataforma Solar de Almería (PSA-CIEMAT), Tabernas (Almería), Spain.

1 5 6 1. Central receiver technology 2. Parabolic dishes + Stirling engines 4 3. Parabolic-trough technology (thermal oil) 4. Parabolic-trough technology (DSG) 1 5. Parabolic-troughs (gas) + Molten Salt TES 6. Linear Fresnel Collector 7 9 7. Solar furnaces 2 8 8. Water desalination 3 9. Water photocatalysis 10. Passive architecture 10

Introduction 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” driven by solar energy 1/38

Introduction Wavelength, µm 2/38

Introduction CATALYSIS + SUN 3/38

Introduction 4/38

Introduction 1 Sun CPCs 5/38 Turbulent flow conditions No vaporization of volatile compounds No solar tracking No overheating Direct and Diffuse radiation Low cost Weatherproof (no contamination) 5/38

Introduction 6/38

Introduction The current lack of data for comparison of solar photocatalysis with other technologies definitely presents an obstacle towards an industrial application. Therefore, it is necessary: Give sound examples of techno-economic studies. Assessment of the environmental impact: life cycle analysis (LCA). To lead to industry application it will be critical that the processes can be developed up to a stage, where the process: can be compared to other processes. is robust, i.e. small to moderate changes to the wastewater stream do not affect the plant’s efficiency and operability strongly. is predictable, i.e. process design and up-scaling can be done reliably. gives additional benefit to the industry applying the process (e.g. giving the company the image of being “green”). 7/38

Examples of techno-economic studies Sound examples of techno-economic studies: AOP-BIO and BIO-AOP Lanfill leachate Treatment of Ecs Combination NF/AOPs 8/38

AOP-BIO and BIO-AOP 9/38

AOP-BIO and BIO-AOP WW characterization: TOC, COD, BOD, main inorganics, contaminants (LC-MS/GC-MS) TOXICITY Non-toxic or partially toxic (<50%) Toxic (>50%) EVALUATION OF BIODEGRADABILITY AOP EVALUATION OF BIODEGRADABILITY DURING AOP 2 1 1 TOC>500 mg/L TOC<500 mg/L DILUTION AND EVALUATION OF BIODEGRADABILITY 2 AOP EVALUATION OF BIODEGRADABILITY DURING AOP 1 2 BIOLOGICAL TREATMENT 1 AOP EVALUATION OF BIODEGRADABILITY DURING AOP BIOLOGICAL TREATMENT 2 BIOLOGICAL TREATMENT 1 2 COD and toxicity<Guideline DISCHARGE Biorecalcitrant compounds COD and toxicity<Guideline DISCHARGE AOP 1: Partially or not biodegradable 2: Biodegradable. COD>Guideline 10/38

Combined photo-Fenton and biotreatment AOP-BIO Combined photo-Fenton and biotreatment Non-biodegradable pesticides Biodegradable compounds Industrial wastewater DOC0: 480 mg/L Biological treatment (IBR) Decontaminated water DOC: 75 mg/L Solar Photo-Fenton 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 11/38

% Reduction combined system AOP-BIO Compound % Reduction combined system Final conc (g/L) Imidacloprid 96.4 25 Dimethoate 99.4 5 Pyrimethanil 81 161 Thiacloprid 84.2 88 Azoxystrobin 3 Malathion 100 < 0.1 Carbofuran Metalaxyl Spinosyn a Bupirimate Fenamiphos Tebufenozide 1. SPE extraction 1 2 3 4 2. LC-TOF-MS Oasis® HLB 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 12/38

BIO-AOP Real WW 13/38

BIO-AOP 14/38 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 14/38

AOP-BIO and BIO-AOP AOP  BIO BIO  AOP % TOC reduction 15/38 100 80 20 40 60 80 100 % TOC reduction AOP  BIO Biotr. time = 4 days BIO  AOP t30w = 350 min; H2O2 = 65 mM (elim.NXA) t30w = 21 min (elim. NXA) !!! H2O2 = 12 mM (elim. NXA) !!! 15/38

BIO-AOP LC-TOF-MS chromatograms No DPs Retention time (min) 16/38

3. Evaluation of toxicity Landfill leachate Landfill leachate (COD: 15615 mg/L; DQO: 42630 mg/L) Pre-treatment (Coagulation/floculation) 2. Photo-Fenton (Fe 1 mM) 3. Evaluation of toxicity and biodegradability 3.a Respirometry activated sludge 3.b Biodegradability by Zahn-Wellens 17/38

Landfill leachate Respirometry activated sludge 18/38

Landfill leachate Biodegradability by Zahn-Wellens 19/38

Pre-treatment (Coagulation/floculation) (<20 % mineralization) Landfill leachate TC= 15615 mg/L COD= 42630 mg/L DOC= 15610 mg/L Conduct.= 77.3 mS/cm Pre-treatment (Coagulation/floculation) 2. PHOTO-FENTON (<20 % mineralization) 3. BIOTREATMENT €/m3 % M1 M3 Chemicals (H202) 21.5 30.1 73 60 Electricity 0.1 1 Man power 1.4 5 CPC + facilities 6.4 11.7 22 27 Total (€/m3) 29.4 43.3 20/38

CONTINUOUS INTRODUCTION Treatment of ECs WWTPs NATURAL WATERS EMERGING CONTAMINANTS (ng-μg/L) Until recently unknown Commonly use Emerging risks (EDCs, antibiotics) Unregulated INCOMPLETE REMOVAL Photochemical transformations CONTINUOUS INTRODUCTION INTO THE ENVIRONMENT TRANSFORMATION PRODUCTS 21/38

Treatment of ECs 22/38

Treatment of ECs 23/38 CHARACTERIZATION LC-QLIT-MS/MS CHARACTERIZATION 29/62 Compounds with higher contribution in MWTP Effluent 23/38

Treatment of ECs 75 L, 4.1 m2, control T (35 ºC) 50 L, 0.69 g O3 h-1 24/38

Treatment of ECs Solar TiO2. Solar photo-Fenton Ozonation 25/38 1-Bisphenol A; 2-Ibuprofen; 3-Hydrochlorothiazide; 4-Diuron; 5-Atenolol; 6-4-AA; 7-Diclofenac; 8-Ofloxacin; 9-Trimethoprim; 10-Gemfibrozil; 11-4-MAA; 12-Naproxen; 13-4-FAA; 14-∑C; 15-4-AAA; 16-Caffeine; 17-Paraxanthine Contaminants > 1000 ng L-1. ∑C = rest of contaminants at less than 1000 ng L-1 25/38

Treatment of ECs 26/38 Solar TiO2 photo-Fenton Ozonation Treatment time, min 475 20 60 Accumulated solar Energy, kJ L-1 212 2.3 - Reagent Consumption H2O2 54 mg L-1 Fe(II) 5 mg L-1 O3 9.5 mg L-1 LC-MS chromatogram. Ozonation. t = 0 t = 60 min LC-MS chromatogram. Photo-Fenton. t = 0 t = 20 (t30W = 14) min Toxicity assays during ozonation and photo-Fenton showed < 10% inhibition on V. fisheri bioluminescence and in respirometric assays with municipal activated sludge 26/38

of micropollutants 5000 m3/day Treatment of ECs Calculation basis: 90% or 98% degradation of micropollutants 5000 m3/day H2O2 1.1 € kg-1 Fe(II) 0.72 € kg-1 H2SO4 0.20 € kg-1 NaOH 0.12 € Kg-1 Electricity 0.07 € Kwh-1 O2 0.15 € Kg-1 Labour 18.8 € h-1 23.1 € kg O3 Solar photo-Fenton Ozonation €m3 90% 98% Reagent 0.064 0.148 0.16 0.22 Labour 0.03 0.05 Electricity 0.004 0.010 0.020 Investment 0.09 0.15 0.23 0.27 Total 0.188 0.358 0.450 0.560 27/38

Combination NF/AOPs 28/38

Combination NF/AOPs NF in parallel (5.2 m2). 1.4 m3 h-1 29/38

Combination NF/AOPs Micropollutants at 15 µg L-1, each Ions Na+ K+ mg L-1 Na+ K+ Mg2+ Ca2+ SO42- Cl- HCO3- 380-440 5-7 37-60 85-100 250-280 290-350 813-915 Micropollutants at 15 µg L-1, each 30/38

Combination NF/AOPs 31/38 Inorganic ions Pharmaceuticals R (%) Ce, CF=4 (mg L-1) Ce, CF=10 (mg L-1) Na+ K+ Mg2+ Ca2+ SO42- Cl- HCO3- 76-87 77-82 91-97 88-93 96-99 67-84 72-88 1000-1100 15-19 140-180 90-105 840-890 770-860 1780-1930 2036-2156 31-31.1 592-731 70-105 2000-3600 1200-1260 2440-2500 Pharmaceuticals R (%) Ce, CF=4 (mg L-1) Ce, CF=10 (mg L-1) Carbamazepine Flumequine Ibuprofen Ofloxacin Sulfamethoxazole 93-96 97-100 96-100 97-99 92-95 47-52 58-63 55-61 58-62 52-59 138-141 148-152 150-154 140-145 144-146 Solar photocatalysis 31/38

r = kC Combination NF/AOPs 32/38 Fe (II), 0.1 mM H2O2, 25 mg L-1 Natural pH 32/38

Ethylenediamine-N,N'-disuccinic acid (EDDS) Combination NF/AOPs Fe (II), 0.1 mM 0.2 mM EDDS H2O2, 25 mg L-1 Natural pH Fe(III)-L + hν → [Fe(III)-L]* → Fe(II) + L• Ethylenediamine-N,N'-disuccinic acid (EDDS) 33/38

Combination NF/AOPs 34/38 CF 1 4 10 Solar photo-Fenton H2O2 consumed (gm-3) Quv (kJ L-1) t(min) / CPC surface(1) 17.0 22.5 90/100 4.4 5.1 120/22.6 1.9 2.8 110/12.4 photo-Fenton like Fe (III)-EDDS complex 24.9 2.7 14/15 6.2 0.6 10/3.3 2.5 0.5 19/2.7 Operational requirements for attaining 95% of pharmaceuticals degradation present in NF concentrates (CF=4 and 10) when solar photo-Fenton and photo-Fenton like Fe(III)-EDDS complex were applied. CF=1, no NF, only AOP. 34/38

Heterogeneous photocatalytic hydrogen generation in a solar pilot plant Flow rate 20 L/min. CPC with pyrex glass tubes, 1.375 m2. Irradiated volume 9.79 L. Total volume 25 L. Catalyst loading 0.2-1 g/L, Pt/(TiO2-N) or Pt/(CdS-ZnS) Sacrificial agents: formic acid (0.05 M), glycerol (0.001 M) and a municipal wastewater (97.7 mg/L of DOC). 35/38

Heterogeneous photocatalytic hydrogen generation in a solar pilot plant 36/38

Heterogeneous photocatalytic hydrogen generation in a solar pilot plant 0.05 M formic acid Real wastewater, 98 mg/L of DOC Reaction conditions: 5 g of catalyst, 25 L of aqueous solution. Data corresponding to 5 hours of irradiation. K. Villa, X. Domènech, S. Malato, M. I. Maldonado, J. Peral. Heterogeneous photocatalytic hydrogen generation in a solar pilot plant. Int. J. Hydrogen Energy, 38 (29), 2013, 12718-12724. 37/38

Acknowledgements Unidad de Tratamientos Solares de Agua (Solar Treatment of Water Research Group) . Plataforma Solar de Almería (CIEMAT). 38/38