Session 17 - Advanced oxidation processes

[CEST2019_00900] Elimination of relevant pharmaceuticals in hospital wastewater from Colombia by combination of a biological system with a sonochemical process
by Torres-Palma R., Serna-Galvis E., Hernández F., Botero-Coy A.M., Moncayo-Lasso A., Silva-Agredo J.

In this work conventional biological treatment was applied to raw HWW. After 36h, such process mainly removed biodegradable substances, but had a limited action on the pharmaceuticals. The resultant biotreated water was submitted to the sonochemical process (375 kHz and 88 W L-1, 1.5 h), which due to its chemical (i.e., radical attacks) and physical (i.e., suspended solids disaggregation) effects induced a considerable pharmaceuticals degradation (pondered removal: 58.82%), demonstrating the complementarity of the proposed combination. Afterwards, Fe2+ (5 ppm) and UVC light (4W) were added to the sonochemical system (generating sono-photo-Fenton process), which significantly increased up to 82.86% the pondered pharmaceuticals removal. Finally, it was found that 91.13% of the initial pharmaceuticals load in HWW was removed by the biological/sono-photo-Fenton combination.

Session: 17, Room: E, at Thu, 09/05/2019 - 15:45 to 16:00
Oral presentation in Advanced oxidation processes
[CEST2019_00665] Bacterial inactivation & study of damages in subcellular level during disinfection of aqueous samples
by Gounaki I., Lironi M.A., Venieri D.

The aims of the study were i) to investigate ozonation and UVA/TiO2 photocatalysis as water disinfection techniches & ii) to study damages in subcellular level, in terms of disinfection effects on cellular components (lipids, membrane and proteins). Disinfection experiments were conducted with the bacterial strains Escherichia coli, Pseudomonas aeruginosa and Bacillus cereus. Ozonation proved to be more effective for the disinfection of aqueous samples compared with UV-A photocatalysis, as for the Gram (-) bacteria a complete reduction was achieved within 15 min, whereas for the Gram (+) bacteria the same reduction was obtained within 30 min.
Regarding the subcellular level the lipid peroxidation progressed at an exponential rate in the course of treatment. The ONPG hydrolysis assay showed negligible alterations in teh course of treatment, indicating that the cell membrane may act as an effective barrier between the cytoplasm and the outer solution in each case.

Session: 17, Room: E, at Thu, 09/05/2019 - 16:09 to 16:12
Flash presentation in Advanced oxidation processes
[CEST2019_00637] A practical time discretization methodology for adjusting the dosage profile in photo-Fenton processes
by Xiangwei Y., Graells M., Pérez-Moya M.

This work is aimed at systematically determining conditions enhancing the performance of Photo-Fenton processes and improving the mineralization of aqueous solutions containing emergent pollutants. Current investigations cannot provide definitive solution approaches yet and optimizing H2O2 dosage is still a challenge. Thus, this work adopts recipe optimization concepts based on time discretization for experimentally addressing the optimization of the dosage profile. Results show the practicability of the solution, and discussion provides insight for the generalization of an optimization procedure.

Session: 17, Room: E, at Thu, 09/05/2019 - 16:03 to 16:06
Flash presentation in Advanced oxidation processes
[CEST2019_00639] 3D printed lab-scale raceway ponds reactors applied to photo-Fenton processes
by Nasr Esfahani K., Zandi M.D., Travieso-Rodriguez J.A., Graells M., Pérez-Moya M.

In this work, two different printable materials, PLA (polylactic acid) and Timberfill were evaluated in terms of chemical resistance to photo-Fenton reactants and viability for conducting the assays in raceway pond reactors (RPRs). The modeling and testing of chemical reactors, in particular their prototyping can benefit from additive manufacturing. However, the preparation of RPRs by 3D printing to study photo-Fenton reactions has not been investigated. First, these raw materials were exposed to H2O2/Fe(II) solutions at pH=3±0.2 under sunlight to simulate photo-Fenton environment. TOC analysis showed that PLA did not alter the concentration of TOC of the solution in the presence of H2O2 and iron. Furthermore, printed PLA and Timberfill lab-scale raceway ponds were examined under similar conditions in addition 30±0.5 mg·L-1 of caffeine as contaminant and involving the simultaneous exposition of the artificial UVA light. Through different assays in the PLA pond, TOC was not rised during operation, and no organic matter contaminated the solution from its container. However, in the case of Timberfill, the TOC of solution increased that represented the material destruction during contact time. This work shows the promising capability of PLA to be used as photo-Fenton reactor.

Session: 17, Room: E, at Thu, 09/05/2019 - 16:06 to 16:09
Flash presentation in Advanced oxidation processes
[CEST2019_00652] New evidence of accelerated elimination of an emergent water pollutant by TiO2 assisted photo-oxidation
by Favier L., Laslau A., Simion A.I., Sescu A.M., Harja M., Rusu L.

This study focuses on the photocatalytic degradation of a pharmaceutic compound essentially employed for the treatment of hypertension using TiO2 as catalyst and UV-A irradiation. An efficient elimination yield of 99% was obtained after 10 minutes of irradiation at initial pollutant concentration of 5 mg/L and 1.2 g/L of catalyst. A higher mineralization yield of 87% was reached in 2h of reaction. Results showed that under all studied process conditions the target molecule was degraded according to a pseudo first order kinetics. Obtained data clearly demonstrate the potential application of the investigated process for the remediation of polluted water.

Session: 17, Room: E, at Thu, 09/05/2019 - 15:30 to 15:45
Oral presentation in Advanced oxidation processes
[CEST2019_00596] Laboratory scale study of photolytic and photooxidative treatment for removal of pharmaceutical residues from water matrices
by Záray Gy., Dóbé S., Gombos E., Krakkó D., Mihucz V.G.

Photolytic and photooxidative degradations of diclofenac (DICL), naproxen (NAPR) and carbamazepine (CARB) were studied applying a batch photo-reactor containing low-pressure mercury lamp emitting at 185 and 254 nm. The drugs were added in concentration of 5×10-6 M to ultra-pure water (UPW) and biologically treated wastewater (BTWW). Almost complete photolytic and photooxidative degradations were observed by VUV irradiation for DICL, NAPR and CARB in UPW within 1.0, 1,0 and 1.5 min, respectively. But in the spiked BTWW matrix, the efficient degradation of DICL, NAPR and CARB were achieved within 1, 2 and 10 min, respectively. Several aromatic degradation products of DICL, NAPR and CARB were identified by quadrupole time-of-flight mass spectrometer hyphenated to an ultra-high performance liquid chromatograph after preconcentration with off-line solid phase extraction upon irradiation of the UPW matrix spiked with the selected drugs at 254 nm. For several degradation products, chemical structures differing from those previously reported have been proposed. Moreover, acridine has not yet been reported as photodegradation product for DICL. . Almost complete degradation of DICL, NAPR and CARB as well as their degradation products by VUV+PhO in BTWW took place in 5, 10 and 30 min, respectively applying only one 50 cm long photo-reactor and oxygen stream. The efficiency of this technology can be increased by simultaneous application of more photoreactors in a flowing system.

Session: 17, Room: E, at Thu, 09/05/2019 - 15:15 to 15:30
Oral presentation in Advanced oxidation processes
[CEST2019_00533] Fluoride-free Anodization of Titanium and the Photocatalytic Behaviour of the Produced TiO2 Nanostructures
by Taylor C.M., Mattia D., Wenk J.H.

Current methods for anodizing titania to produce immobilized titanium dioxide (TiO2) photocatalyst require the use of hazardous fluoride electrolytes. A fluoride-free electrolyte anodization method was developed. The electrolytes tested in this study were both bromide- and chloride-based and contained ethylene glycol as an additive. Under optimized anodization times and temperature conditions the alternative electrolytes led to growth of stable immobilized TiO2 layers. Crystal phases and topography of the produced TiO2 layers were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD) and photoelectron spectroscopy (XPS). Photocatalytic experiments showed that differences in the crystal phases had a strong effect on the degradation of the model aquatic contaminants carbamazepine and phenol. Nitrogen doping using urea made the photocatalyst more efficient by red shifting light absorption from UV into the visible region. The photocatalytic ability of fluoride-free anodized immobilized TiO2 photocatalysts has previously not been investigated. Using electrolytes without fluorine can be a more sustainable and a safer way to produce immobilized TiO2.

Session: 17, Room: E, at Thu, 09/05/2019 - 15:00 to 15:15
Oral presentation in Advanced oxidation processes
[CEST2019_00335] Wastewater treatment processes utilizing hydrodynamic cavitation
by Innocenzi V., Prisciandaro M., Veglio F.

In the present work, the potentiality of the hydrodynamic cavitation (HC) for the degradation of organic pollutants from industrial effluents has been studied. Cavitation is a phenomenon of formation, growth, collapse of microbubbles or cavities, in a few milli- to microseconds and releases large magnitude of energy in a short span of time. The main chemical effects of HC are the generation of highly reactive free radicals in the aqueous environment; it is possible to exploit these radicals for the intensification of chemical processes such as degradation of the water pollutants. HC represents an innovative advanced oxidation processes that can replace or be combined with the traditional oxidation processes. Lab experiments have been performed to remove pollutants as dyes (methyl orange) that can be present in textile effluents. In order to investigate the potentiality of HC, the effect of several operative conditions was investigated, as the presence of additivities (hydrogen peroxide and titanium oxides), contaminant concentration and cavitation device (venturi tube and orifice plate). The experiments showed the positive effect of hybrid treatment on pollutant degradation.

Session: 17, Room: E, at Thu, 09/05/2019 - 16:00 to 16:03
Flash presentation in Advanced oxidation processes