Pilot-scale Photoreactor Research Articles

Assessing the photo-activation efficiency of aminopolycarboxylate iron complex mixtures for effective sulfamethoxazole degradation in a pilot-scale UVA-LED photoreactor

This study focused on the degradation of antibiotic sulfamethoxazole (SMX), through the UVA-LED photo-activation of aminopolycarboxylate-based iron complexes in a pilot-scale photoreactor. Fe3+-EDDS, Fe3+-NTA, and a combination of both complexes Fe3+-EDDS and Fe3+-NTA were studied in simulated tap water (TW) and simulated secondary effluent (SE) from a municipal wastewater treatment plant (MWWTP). In TW, 40% SMX degradation was reached after 60 min, with different concentration profiles due to absorption characteristics of each complex. Combining Fe3+-EDDS and Fe3+-NTA an initial rapid SMX degradation was observed followed by a slower phase, improving SMX degradation with respect to each complex separately. In SE and despite presenting similar kinetics, SMX degradation was lower than in TW, due to the presence of organic matter in the water matrix. Moreover, the Fe3+-EDDS and Fe3+-NTA mixture improved SMX degradation with increasing iron concentration. This improvement was attributed to reduced dissolved organic carbon (DOC) from NTA and the lower molar absorption coefficient of Fe3+-NTA. Higher EDDS ratios led to faster complex degradation but did not significantly enhance SMX removal. Conversely, higher NTA ratios reduced SMX degradation. In summary, this study revealed a synergistic effect between Fe3+-EDDS and Fe3+-NTA in SMX degradation. Considering the cost difference between EDDS and NTA, using both compounds offers technical and economic advantages. All treatments reduced chronic toxicity in Selenastrum capricornutum.

Photo-catalytic and thermal-assisted air purification of VOC and NOx simultaneously by pilot-scale photo-reactor

Photo-catalytic and thermal-assisted air purification of VOC and NOx simultaneously by pilot-scale photo-reactor

Remediation of perchloroethylene contaminated groundwater using Fe0/ZnS embedded in a highly porous polymer: Experimental results on pilot-scale photoreactor and kinetic modeling analysis for industrial scale-up

Perchloroethylene (PCE) is a pollutant toxic to aquatic life and suspected of being a human carcinogen. It is also recalcitrant to degradation. Therefore remediation of PCE-contaminated groundwater is currently still a challenging task. In this work, the efficiency of a UV-assisted oxidation process exploiting a photocatalyst composed of zero-valent iron supported on commercial zinc sulfide (Fe/ZnS) and incorporated in a highly porous polymer, is investigated. The experimental studies were carried out, for about six months, on a pilot-scale photoreactor operating in continuous mode at the Solofra (Campania, Italy) wastewater plant, to evaluate the effectiveness and stability of the photocatalytic system. The results show that it is possible to reach a PCE degradation in natural groundwater in the range of 85–95%%. Furthermore, a kinetic model is developed and compared with collected experimental data. The mathematical model well describes the experimental data of the photocatalytic system operating both in batch and continuous mode and therefore it can be potentially used for further scale-up of photocatalytic systems devoted to PCE degradation, allowing to estimate the catalyst weight required for total PCE removal as a function of the liquid flow rate to be treated and inlet PCE concentration.

Microcontaminant removal in solar pilot scale photoreactors with commercial iron nanoparticles obtained from olive mill wastewater

This study assessed removal of microcontaminants (MCs) from natural water (NW) using iron nanoparticles extracted from olive mill wastewater (ZVI-OMW), an agro-industrial waste product, combined with oxidants under natural solar radiation. The specific effects of corrosion, adsorption and solar photolysis, and of H2O2, S2O82-, carbonates and ZVI-OMW concentrations on treatment efficiency were also evaluated. Lab tests demonstrated that the combination of 1 mM S2O82- with NW and 1 mM ZVI-OMW was the best treatment option. Process performance was evaluated under these operating conditions in pilot-scale raceway pond reactors (RPR) at three liquid depths (5, 10 and 15 cm), as well as in a compound parabolic collector (CPC) photo-reactor. The time required to achieve 50% removal of a MC mixture (atrazine, carbendazim, imidacloprid and thiamethoxam, at 100 µg/L each) increased with liquid depth, resulting in 164, 224, and 250 min for 5, 10, and 15 cm, respectively. MC mass removal rate increased with liquid depth, achieving 50% MC removal in the CPC (1 mM ZVI-OMW) in 120 min. Doubling ZVI-OMW concentration was detrimental to process efficiency in both photoreactors due to light obstruction. Partial sedimentation of ZVI-OMW in the RPR suggests that the use of this type of reactor for heterogeneous photocatalysis could present problems for large-size operation.

Performance of a C-containing Cu-based photocatalyst for the degradation of tartrazine: Comparison of performance in a slurry and CPC photoreactor under artificial and natural solar light

A carbon-containing Cu-based material (Cu@C) was used as photocatalyst for the degradation of a commonly food-industry azo-dye (tartrazine, also called Y5), under solar light at laboratory and pilot scale photoreactors. Important performance parameters such as dark adsorption capacity, catalyst́s loading and initial concentration of the dye were first optimized in a slurry photoreactor at laboratory scale under artificial solar light following the kinetics of degradation of the dye. Afterwards, the photocatalytic activity was investigated at pilot scale in a compound parabolic collector (CPC) photoreactor operating for 10 h of irradiation. The degradation of tartrazine is among the highest values reported for alternative metal oxide semiconductors, in both photoreactor configurations. Catalytic data revealed a 3 times faster degradation kinetics of tartrazine in the CPC photoreactor under natural solar light than in the slurry reactor under artificial solar light. This behavior indicates that a moderate photon flux in the CPC is more adequate to operate with the prepared photocatalyst, as it minimizes the recombination of charge carriers in the catalyst. This is important, since most of the photocatalytic tests designed to evaluate the activity of novel materials are frequently carried out under simulated solar light and disregard the impact of photon flux in outdoor conditions.

Evaluation of copper-doped TiO2 film supported on glass and LDPE with the design of a pilot-scale solar photoreactor

Synthesis of copper-doped TiO2 (Cu:TiO2) and undoped TiO2 were performed by the sol–gel method. These photocatalysts were characterized by Raman spectroscopy, XRD, and diffuse reflectance. The synthesized catalysts were fixed on glass by the Doctor Blade technique, and on low-density polyethylene (LDPE) by the liquid phase suspension method. The films were characterized by SEM-EDX. The use of doped and undoped photocatalysts fixed in two types of substrates was evaluated in a pilot scale photoreactor under solar radiation. The photoreactor consisted of a simple model designed based on the use of photocatalysts fixed on flat substrates. The adsorption, photodegradation and photolysis processes of methylene blue (MB) were evaluated separately in order to define the extent to which the photocatalyst degraded. The pilot scale system, with the method of fixing the catalyst on a glass substrate, degraded 72.8% of the dye in 6 h, studied under the Langmuir Hinshelwood pseudo-first-order mathematical model with a constant of 0.0024 min−1. With the method of fixing the catalyst on an LDPE substrate, it degraded 68.1% in 6 h, following the same mathematical model, with a constant of 0.0021 min−1.

Heterogeneous Photocatalysis Scalability for Environmental Remediation: Opportunities and Challenges

Heterogeneous photocatalysis is an ecofriendly technique for purifying organic pollutants in environmental systems. While pilot-scale photoreactors have explored photocatalytic system upscalibility, their practical implementation is restricted for various reasons. These include feed composition alteration, complicated photoreactor designs, high operation and synthesis costs, photocatalyst poisoning, low quantum yield under solar irradiation, fast exciton recombination, and low reuse or regeneration capabilities. In this paper, we highlight the photocatalyst scalability challenges for real-world applications. We also provide an in-depth discussion on photocatalyst opportunities for effective air and water pollution control. Lastly, we offer a contemporary perspective on photocatalysis scale-up for the real environmental treatment.

Enhancement of the oxidative removal of diclofenac and of the TiO2 rate of photon absorption in dye-sensitized solar pilot scale CPC photocatalytic reactors

The sensitization of rate of photon absorption of a TiO2 photocatalyst irradiated by natural solar radiation in pi- lot scale compound parabolic collectors (CPC’s) photoreactors was investigated. Methyl red (MR) dye was used as a photo-sensitizer to increase the rate of photon absorption of a TiO2 photocatalyst and the oxidative removal of the common pharmaceutical diclofenac (DCF) in solar, pilot scale, compound parabolic collectors (CPC’s) pho-toreactors. The impact of the concentrations of TiO2 and MR were investigated and tuned to determine the most effective operational conditions. The results show that the dye-sensitization process of the catalyst and the degra- dation of DCF were favored at catalyst concentrations close to the optimum. Complete degradation and min- eralization of DCF DCF were achieved under most effective operational conditions. The mineralization of DCF and dye increased by up to 65% in the presence of the MR sensitizer compared to the results without sensitizer. The oxidation by-products formed during the process were identified by gas chromatography–mass spectrometry (GC–MS). A detailed mechanism of the dye-sensitization process was proposed, and a kinetic model for the simul- taneous degradation of diclofenac and the dye was derived using the pseudo-stationary state method. This study demonstrates the positive impact of dye sensitizers on the photocatalytic degradation of pharmaceuticals in pilot scale photoreactors irradiated by natural sunlight.

Degradation of tetracycline by solar photo‐Fenton: Optimization and application in pilot photoreactor

AbstractThe objective of this study is to analyze the photodegradation of the antibiotic tetracycline by the solar photo‐Fenton process. The optimal conditions were obtained in a 2² (2 × 2) factorial design with the following input variables: reaction time and catalyst concentration (ferrous ion [Fe2+]). After statistical analysis using the Statistica 7.0 software, the optimal conditions determined, time = 120 min and Fe2+ = 166.81 mg/L, were applied in a pilot scale photoreactor, resulting in an 88.7% removal of the drug. In addition, in this stage we studied the reaction kinetics, biodegradability, and phytotoxicity of the products generated by the process. In the kinetic study, a constant of 1.82 × 10−2 min−1 was obtained. For this constant, a reaction time of 38.16 min is required for the initial tetracycline concentration to be reduced by 50%. The biodegradability tests indicated a gradual increase in the five‐day biological oxygen demand/chemical oxygen demand ratio over time. The phytotoxicity tests showed an 18.5% decrease in the inhibition rate of the root growth of lettuce seedlings, indicating that the treatment applied reduces the toxicity of the substance.

Solar treatment (H2O2, TiO2-P25 and GO-TiO2 photocatalysis, photo-Fenton) of organic micropollutants, human pathogen indicators, antibiotic resistant bacteria and related genes in urban wastewater

Solar-driven advanced oxidation processes were studied in a pilot-scale photoreactor, as tertiary treatments of effluents from an urban wastewater treatment plant. Solar-H2O2, heterogeneous photocatalysis (with and/or without the addition of H2O2 and employing three different photocatalysts) and the photo-Fenton process were investigated. Chemical (sulfamethoxazole, carbamazepine, and diclofenac) and biological contaminants (faecal contamination indicators, their antibiotic resistant counterparts, 16S rRNA and antibiotic resistance genes), as well as the whole bacterial community, were characterized.Heterogeneous photocatalysis using TiO2-P25 and assisted with H2O2 (P25/H2O2) was the most efficient process on the degradation of the chemical organic micropollutants, attaining levels below the limits of quantification in less than 4 h of treatment (corresponding to QUV < 40 kJ L−1). This performance was followed by the same process without H2O2, using TiO2-P25 or a composite material based on graphene oxide and TiO2.Regarding the biological indicators, total faecal coliforms and enterococci and their antibiotic resistant (tetracycline and ciprofloxacin) counterparts were reduced to values close, or beneath, the detection limit (1 CFU 100 mL−1) for all treatments employing H2O2, even upon storage of the treated wastewater for 3-days. Moreover, P25/H2O2 and solar-H2O2 were the most efficient processes in the reduction of the abundance (gene copy number per volume of wastewater) of the analysed genes. However, this reduction was transient for 16S rRNA, intI1 and sul1 genes, since after 3-days storage of the treated wastewater their abundance increased to values close to pre-treatment levels. Similar behaviour was observed for the genes qnrS (using TiO2-P25), blaCTX-M and blaTEM (using TiO2-P25 and TiO2-P25/H2O2). Interestingly, higher proportions of sequence reads affiliated to the phylum Proteobacteria (Beta- and Gammaproteobacteria) were found after 3-days storage of treated wastewater than before its treatment. Members of the genera Pseudomonas, Rheinheimera and Methylotenera were among those with overgrowth.

Development of TiO2-C photocatalysts for solar treatment of polluted water

Two different types of Carbon-containing TiO2 photocatalysts were studied in depth. A hybrid TiO2-C spherical material was prepared by solvothermal synthesis from furfural and titanium isopropoxide and compared to a binary TiO2-activated carbon composite prepared using the slurry method. A systematic study of the catalyst concentration, type of pollutant molecule, the concentration of H2O2 and the type of irradiation (simulated solar irradiation and pilot-scale photoreactors) was performed. The influence of catalyst weight and H2O2 concentration was verified by following the kinetics of phenol (PH), imidacloprid (IM) and dichloroacetic acid (DCA) photodegradation. It may be concluded from the results that activated carbon promotes higher efficiency in the photoactivity of TiO2 than the hybrid TiO2-C photocatalyst. The basic surface chemistry and significant contribution of micropores in the binary TiO2-AC composite seem to be responsible for their higher TiO2 photoactivity than the TiO2-C hybrid materials which are characterized by a mesopore structure and an acid surface pH. This study shows the advantage of using a solar simulator to elucidate the efficiency of carbon materials in a thorough comparison including various photocatalytic reactions with several different substrates before testing at pilot scale.

NOx abatement from stationary emission sources by photo-assisted SCR: Lab-scale to pilot-scale studies

In developing a higher activity for NOx abatement from stationary emission sources, photo-assisted selective catalytic reduction (photo-SCR) was systematically investigated over TiO2 supported on a spherical α-Al2O3/γ-Al2O3. The formation of NO2 was virtually suppressed in the reaction temperature range of 110–200°C. The NOx removal efficiencies of TiO2/γ-Al2O3 photocatalyst at 120°C for real flue gas (in pilot-scale photoreactor) and simulated flue gas (in lab-scale photoreactor) were 68–75% and 43.5%, respectively, in the presence of reducing reagent (C4H10). SEM and XPS techniques revealed that sulfur temporarily occupied the active sites of the photocatalyst, causing deactivation. Spent TiO2/γ-Al2O3 photocatalyst was regenerated via desulfurization by either air or hydrogen at 400–500°C. The effects of regeneration temperature and regeneration time on the photocatalytic activity are methodically investigated, demonstrating that using hydrogen at 500°C in 1h could completely regenerate the spent photocatalyst.

Insights into solar photo-Fenton process using iron(III)–organic ligand complexes applied to real textile wastewater treatment

The treatment of a real textile wastewater was accomplished using a conventional photo-Fenton reaction and mediated by different ferric–organic ligand complexes, performed in lab and pilot scale photoreactors irradiated by simulated and natural solar radiation, respectively. The textile wastewater presents a dark-blue colour, alkaline pH, a high organic content (COD=1239mgO2L−1; DOC=408mgCL−1) and moderate biodegradability (BOD5/COD=0.16). The conventional solar-photo-Fenton reaction showed limited efficiency in the mineralization of the textile wastewater, which is characterized by a fast initial dissolved organic carbon decay in the absence of light, mainly attributed to the formation of iron–organic pollutants complexes with a low solubility at acidic pH values, leading to iron precipitation, followed by a very slow reaction rate under UV–visible light associated to (i) low amounts of dissolved iron and (ii) low photoactivity of the iron precipitates. The addition of the organic ligands, such as oxalic acid, citric acid and EDDS, enhanced significantly the photo-Fenton reaction, avoiding the formation of iron–organic pollutants complexes, and consequently increase of the quantum yield for ferrous ions production through the photodecarboxylation of ferric–organic ligands complexes. The catalytic activity of the iron–organic ligand complexes increased in the following order: Fe(III)–EDDS<Fe(III)–citrate<Fe(III)–oxalate. All the tested processes mediated by ferric–organic ligands complexes contributed to an effective decolourization and mineralization, but the most efficient system was the photo-Fenton-ferrioxalate reaction with an optimum catalyst concentration of 100mgFe3+L−1, pH 2.8, temperature of 30°C leading to complete decolourization and 69.1% mineralization after less than 8.8kJUVL−1. An enhancement of the wastewater biodegradability was observed during the photo-Fenton-ferrioxalate reaction.

Assessment of a multistage system based on electrocoagulation, solar photo-Fenton and biological oxidation processes for real textile wastewater treatment

Abstract The performance of a multistage treatment system for textile wastewater was investigated in this study. The processes of electrocoagulation (EC), photo-Fenton oxidation, and activated sludge biological degradation were integrated in batch mode. The integrated treatment system performance was assessed according to three response variables: dissolved organic carbon (DOC), chemical oxygen demand (COD) and biodegradability index. Based on preliminary tests, the EC-based wastewater treatment was suitable as the first stage of the integrated treatment system, followed by the photo-Fenton process. A lab photo-reactor was used to assess the influence of photo-Fenton variables on the process performance. Based on the better lab photo-Fenton reactor conditions, the improvement of some biological indicators related to the organics biodegradability of treated wastewater was investigated in a pilot-scale photoreactor. An activated sludge-based biological reactor at lab-scale was used as a final treatment stage, in order to achieve the legislated limits for discharge into water bodies. Partial degradation of the organic pollutants was achieved by the EC process, with a 36% reduction in COD. In the second treatment stage, a 70% biodegradability index was attained by setting the photo-Fenton reaction conditions at 100 mg Fe 2+ L −1 , pH 2.8, 12 mM H 2 O 2 and 6.9 kJ L −1 accumulated energy. Finally, a residual COD of 139 mg O 2 L −1 was achieved at the outlet of the biological process, which is below the maximum limit established by the Portuguese legislation.

Photoreactor scale-up for degradation of aqueous poly(vinyl alcohol) using UV/H2O2 process

Although advanced oxidation technologies (AOTs) are effective methods of degradation for recalcitrant pollutants in wastewater, the photoreactor scale-up is still a major challenge in photochemical reaction engineering. In this study, a methodology for the photoreactor scale-up, including all reaction mechanisms for the binary degradation of aqueous polyvinyl alcohol (PVA) by UV/H2O2 process is proposed. In this procedure, intrinsic kinetic parameters are determined using experimental data obtained in a laboratory-scale batch recirculating photoreactor. The obtained kinetic parameters are used to predict the performance of a pilot-scale continuous flow photoreactor without any adjustable parameter. Three compulsory conditions are necessary in this approach: (1) to have a validated kinetic scheme including the binary degradation of the polymer; (2) to have a validated intrinsic reaction kinetic expression considering continuous distribution kinetics to describe the dynamics of the polymer degradation; and (3) to apply and appropriately solve a rigorous mathematical model for the pilot-scale photoreactors using the computational fluid dynamics (CFD) model development. The CFD model for the scaling-up methodology is validated experimentally in a pilot-scale photoreactor.

Assessment of solar driven TiO2-assisted photocatalysis efficiency on amoxicillin degradation

The objective of this work was to evaluate the efficiency of a solar TiO2-assisted photocatalytic process on amoxicillin (AMX) degradation, an antibiotic widely used in human and veterinary medicine. Firstly, solar photolysis of AMX was compared with solar photocatalysis in a compound parabolic collectors pilot scale photoreactor to assess the amount of accumulated UV energy in the system (Q UV) necessary to remove 20 mg L(-1) AMX from aqueous solution and mineralize the intermediary by-products. Another experiment was also carried out to accurately follow the antibacterial activity against Escherichia coli DSM 1103 and Staphylococcus aureus DSM 1104 and mineralization of AMX by tracing the contents of dissolved organic carbon (DOC), low molecular weight carboxylate anions, and inorganic anions. Finally, the influence of individual inorganic ions on AMX photocatalytic degradation efficiency and the involvement of some reactive oxygen species were also assessed. Photolysis was shown to be completely ineffective, while only 3.1 kJUV L(-1) was sufficient to fully degrade 20 mg L(-1) AMX and remove 61% of initial DOC content in the presence of the photocatalyst and sunlight. In the experiment with an initial AMX concentration of 40 mg L(-1), antibacterial activity of the solution was considerably reduced after elimination of AMX to levels below the respective detection limit. After 11.7 kJUV L(-1), DOC decreased by 71%; 30% of the AMX nitrogen was converted into ammonium and all sulfur compounds were converted into sulfate. A large percentage of the remaining DOC was in the form of low molecular weight carboxylic acids. Presence of phosphate ions promoted the removal of AMX from solution, while no sizeable effects on the kinetics were found for other inorganic ions. Although the AMX degradation was mainly attributed to hydroxyl radicals, singlet oxygen also plays an important role in AMX self-photosensitization under UV/visible solar light.

Desulfurization of Real and Model Liquid Fuels Using Light: Photocatalysis and Photochemistry

Ultra-deep desulfurization of liquid fuels is crucial for the environment, longer lifetime of combustion engines, and emerging “green,” sustainable, carbon-neutral fuels for fuel cell applications. Current interest is towards photocatalysis and photochemistry for production of clean fuels and valuable chemicals. This critical Review provides systematization and analysis of studies on photocatalytic, photosensitized, and photochemical desulfurization of liquid fuels in the recent approximately 20 years. Zeolites, single-site photocatalysts, TiO2, and photosensitizers are discussed with their characterization and photocatalytic, photosensitized, and photochemical reaction networks. Pilot-scale photoreactors, kinetics of fuel desulfurization using sunlight, and uses of by-products of photodesulfurization of liquid fuels are covered (181 references).

Photocatalysts and Photoreactors for Treatment of Industrial Effluents

Development of photocatalysts and photoreactors for treatment of industrial effluents is considered important to harness solar energy for environmental clean up. The photocatalytic method of decolorization of textile dyes utilizes UV component of sunlight (3-5%) and the only solid phase (TiO2catalyst) can be recycled on a technical scale. Moreover, the method does not produce any sludge unlike adsorption and coagulation methods. These attributes of the photocatalytic method are attractive for possible application in industry. Our group is presently working on pilot scale photoreactors and exploring feasibility of industrial application of this technique. We have developed a few TiO2based photocatalysts (P-25 TiO2, ZnO, TiO2(bulk) and rare earth metal (In2O3, Nd2O3, Yb2O3and Sm2O3) doped TiO2), photo catalyst bearing supports (e.g., acrylic sheet) and photoreactors (annular immersion well type, falling film type and shallow slurry photoreactors) for use with UV &amp; sunlight. We have carried out a few tests with Solar Slurry Photoreactor (SSPR) in field using actual textile wastewater with encouraging results. The SSPR developed under this study was capable of decolorizing textile wastewater under specified conditions approximately with a treatment rate of 9.0 Lh-1. The reactor area exposed to sunlight was approximately 1 m2. Thus, a reactor having 18-20 m2exposed area would treat about 1.0 m3textile wastewater at a rate approximately equal to180 Lh-1. The present data suggest that it may be possible to apply this technique initially for the color treatment of textile wastewater from small dyeing operations. However, the details of techno-economic feasibility need to be assessed beforehand. The proposed book chapter would present details of all the above-mentioned efforts. It would be targeted to bring out inadequacies associated with the photocatalytic technology for wastewater treatment.

Removal of gaseous toluene by using TiO2 film doped of Ru-dye/Pt in a pilot scale photoreactor

The photodegradation efficiency (PE) of gaseous toluene was investigated by using titanium dioxide (TiO2) film doped of ruthenium (Ru)-dye/platinum (Pt) in a 3,600 L pilot reactor. Ru-dye was applied as a sensitizer to enhance PE of toluene in both UV and visible wavelength range since its major peaks are 225 nm, 325 nm, 375 nm, and 525 nm. PE by using Pt/TiO2 was more enhanced since Pt plays a role as an electron trapper in UV light range. The 3.2 μm thickness of TiO2 film was optimized for the highest PE. The highest PE was 75%, 85%, and 90% by TiO2, Pt/TiO2, and Ru-dye/Pt/TiO2 film, respectively.

Investigation of a jet mixing photo-reactor device for rapid dye discoloration and aromatic degradation via UV/H2O2 process

Jet mixing is a device which is used to homogenize liquids in short operating times. In this work, a pilot scale photo-reactor, equipped with two internal mixing jets and two immersed UV-C lamps (each with incident photon flux of 6.1×10−6einstein/s) was used for discoloration and aromatic degradation of 30mg/L of Direct Red 23, as a model pollutant in water, by UV/H2O2 process. Effects of physical and chemical parameters were investigated, and optimum conditions were obtained as: nozzles diameter of 1.6mm, nozzles direction angle of 45° directed to the walls of the reactor, flow-rate of 1.7L/min, initial H2O2 concentration of about 200mg/L and natural initial pH of 6.6. Under these conditions 96% discoloration and 86% aromatic degradation efficiencies were obtained after 60min treatment. Furthermore, the kinetic investigation revealed pseudo-first order reactions for discoloration with different H2O2 initial concentrations. Accordingly, as a figure-of-merit, the “electrical energy per order” was determined within 2.44–6.04kWh/m3/order, showing promising low electrical energy consumption and high economical benefit in comparison with similar treating photo-reactors.