Ozone-based Advanced Oxidation Processes Research Articles

An Ozone-based Advanced Oxidation Process for an Integrated Air Pollution Control System

An Ozone-based Advanced Oxidation Process for an Integrated Air Pollution Control System

Removal of organic micropollutants from domestic wastewater: The effect of ozone-based advanced oxidation process on nanofiltration

The objective of this study was to develop an innovative and advanced integrated “membrane and oxidation” system for the treatment of domestic wastewater by coupling membrane bioreactor (MBR), nanofiltration (NF) and ozonation. Five contaminants were selected (acetaminophen, carbamazepin, sulfamethoxazole, tetracyclin and terbutryn). The MBR effluent samples have been fully characterized using conventional analysis (COD, TOC, UV254, ionic chromatography…) and advanced characterization analyses (3D fluorescence excitation–emission matrices (3DEEM)) before being spiked with 1 ppm of each of the selected pharmaceuticals. NF process experiments were carried out in batch and semi-batch mode using a flat sheet membrane system (NF-90). Selected OMPs were well rejected by NF (between 84 % and 98 %) and the main fouling mechanisms observed were pore blocking and gel layer formation. MBR effluent was then pre-treated in an ozonation pilot unit’s with ozone gas inlet fixed at 5 g.Nm−3.The complete degradation by ozonation of carbamazepine and sulfamethoxazole took 15–20 min and more than 30 min for terbutryn. Acetaminophen, tetracyclin and dissolved organic matter were almost totally ozonated in 5 min. The overall mineralization rate was low. The pre-ozonation enables the NF fouling resistance to be decreased by almost 40 %.

Bromate formation control by enhanced ozonation: A critical review

In the past two decades, ozone-based advanced oxidation processes, known as enhanced ozonation processes (EOPs), have been extensively investigated for the removal of emerging organic contaminants in water, such as pesticides, endocrine-disrupting compounds, and pharmaceuticals. EOPs offer an advantage by producing highly oxidizing radicals, such as hydroxyl radicals, to oxidize recalcitrant organic compounds. Although the EOPs are able to effectively remove emerging contaminants, several studies reported the formation of bromate, which has drawn significant attention because of its potential carcinogenicity. This issue becomes challenging for the utilization of EOPs on bromide containing water. Therefore, this work critically reviews and summarizes the mechanisms, influencing factors, advantages and disadvantages, and control strategies for bromate formation by four EOPs, i.e., peroxone and e-peroxone, photolytic ozonation, heterogeneous ozonation, and sonolytic ozonation. Various economic and technical characteristics of EOPs were also compared. Mathematical modeling, pilot and full-scale data, and secondary pollutant potential (toxic metals leaching from catalyst) have been identified as knowledge gaps, and future research should seek to address these issues.

Degradation and mineralization of the emerging pharmaceutical pollutant sildenafil by ozone and UV radiation using response surface methodology.

Pharmaceuticals and their degradation products which are present in wastewater and superficial waters are becoming an ecological issue. This research investigated the degradation and mineralization of synthetic solutions of the pharmaceutical compound sildenafil citrate (SC) by single ozonation and ozonation jointed with UV radiation (O3/UV). The effects of initial drug concentration (50-125mgL-1), inlet ozone concentration (35-125gNm-3), and UV radiation on SC degradation and decrease of total organic carbon (TOC) were investigated using response surface methodology based on a central composite experimental design. Through the RSM analysis, it was possible to confirm the removal of SC for the entire experimental range. Major intermediates of SC degradation were identified and a degradation pathway was proposed. The kinetics of SC degradation was modeled as a pseudo-first-order reaction with a rate constant ranging between 0.072 and 1.250min-1. The SC degradation and TOC removal were strongly enhanced by increasing the concentration of gaseous ozone at the inlet and incorporating UV radiation. The highest TOC removal reached at 60min was 75%, in the O3/UV system, with initial SC content of 50mgL-1 and inlet ozone concentration of 125gNm-3. The degradation rate of SC was increased 3 to 9 times in the presence of UV radiation. Ozone-based advanced oxidation processes appear as a suitable alternative for treatment of the emerging pollutant SC.

Comparison of the new Cl2/O3/UV process with different ozone- and UV-based AOPs for wastewater treatment at pilot scale: Removal of pharmaceuticals and changes in fluorescing organic matter

This work critically compared the removal of fluorescing PARAFAC components and selected pharmaceuticals (carbamazepine, fluoxetine, gemfibrozil, primidone, sulfamethoxazole, trimethoprim) from a tertiary wastewater effluent by different UV- and ozone-based advanced oxidation processes (AOPs) operated at pilot-scale. Investigated AOPs included UV/H2O2, UV/Cl2, O3, O3/UV, H2O2/O3/UV, and the new Cl2/O3/UV. AOPs comparison was accomplished using various ozone doses (0–9 mg/L), UV fluences (191–981 mJ/cm2) and radical promoter concentrations of Cl2 = 0.04 mM and H2O2 = 0.29 mM. Chlorine-based AOPs produced radical species that reacted more selectively with pharmaceuticals than radical species and oxidants generated by other AOPs. Tryptophan-like substances and humic-like fluorescing compounds were the most degraded components by all AOPs, which were better removed than microbial products and fulvic-like fluorescing substances. Removal of UV absorbance at 254 (UV254) nm was always low. Overall, chlorine-based AOPs were more effective to reduce fluorescence intensities than similar H2O2-based AOPs. The Cl2/O3/UV process was the most effective AOP to degrade all target micro-pollutants except primidone. On the other hand, the oxidation performance of pharmaceuticals by other ozone-based AOPs followed the order H2O2/O3/UV > O3/UV > O3. UV/Cl2 process outcompeted UV/H2O2 only for the removal of trimethoprim and sulfamethoxazole. Correlations between the removal of pharmaceuticals and spectroscopic indexes (PARAFAC components and UV254) had unique regression parameters for each compound, surrogate parameter and oxidation process. Particularly, a diverse PARAFAC component for each investigated AOP resulted to be the most sensitive surrogate parameter able to monitor small changes of pharmaceuticals removal.

The applications of ozone-based advanced oxidation processes for wastewater treatment: A review

The rise in population and industrialization accounts for the generation of a huge amount of wastewaters. The treatment of this wastewater is obligatory to safeguard the environment and various life forms. Conventional methods for high strength wastewater treatment coming out to be ineffective. Advanced oxidation processes (AOPs) for such wastewater treatment proved to be very effective particularly for the removal of various refractory compounds present in the wastewater. Ozone based AOPs with its high oxidizing power and excellent disinfectant properties is considered to be an attractive choice for the elimination of a large spectrum of refractory compounds. Furthermore, it enhances the biodegradability of wastewaters after treatment which favors subsequent biological treatments. In this review, a detailed overview of the AOPs (like the Fenton process, photocatalysis, Electrochemical oxidation, wet air oxidation, and Supercritical water oxidation process) has been discussed explicitly focusing on ozone-based AOPs (like O3, O3/H2O2, O3/UV, Ozone/Activated carbon process, Ozone/Ultrasound process, O3/UV/H2O2 process). This review also comprises the involved mechanisms and applications of various ozone-based AOPs for effective municipal/industrial wastewaters and landfill leachate treatment. Process limitations and rough economical analysis were also introduced. The conclusive remarks with future research directions also underlined. It was found that ozonation in combination with other effective AOPs and biological methods enhances treatment efficacies. This review will serve as a reference document for the researchers working in the AOPs field particularly focusing on ozone-based AOPs for wastewater treatment and management systems.

Removal of Cyanotoxins in Detroit River Water Using Ozone-Based Advanced Oxidation Processes

ABSTRACT The removal of cyanotoxins, microcystin-LR (MLR), anatoxin-a (ANA), and cylindrospermopsin (CYN) in Detroit River water (DRW) was investigated by ozone and advanced oxidation process (AOP). Enhanced removal of all cyanotoxins was observed with increasing applied ozone dose. The reactivity of cyanotoxins with ozone followed the order of MLR>CYN>ANA in DRW at its natural pH of 7.6, as indicated by the calculated pseudo first-order oxidation coefficients (kd) of 17.5, 7.41, and 2.03 L/mg, respectively. The most efficient oxidations of MLR, CYN, and ANA with ozone in DRW were obtained at pH 5, 7.6, and 10, respectively, with kd values of 29.5, 7.41, and 4.65 L/mg. Ozone-based AOP with hydrogen peroxide did not make a significant difference in the removal of cyanotoxins compared to the application of ozone alone.

Nano-Catalysts in Ozone-Based Advanced Oxidation Processes for Wastewater Treatment

Pollution is now being varied with huge contaminants in wastewater especially with kind of recalcitrants that are emerging pollutants needed new advanced resolutions to mineralize them completely. Thus, the investigation of technology and technique processes is very important for research and development. Moreover, these manual, research, and application of the advanced oxidation processes especially using ozone for water and wastewater are concentrated and appreciated in over the world. Recently, nanoparticles have researched into subjects to enhance new, advanced technology for many domains such as environment, biology, agriculture, and medicine. Hence, the purpose of this review is to summarize the important role of nano-particulars as nano-catalysts in ozone-based advanced oxidation processes for wastewater treatment and evaluate how to contribute into ozone-based advance oxidation processes by nano-catalysts for wastewater treatment. The advanced oxidation processes (AOPs) for wastewater treatment nowadays are being appreciated in the twenty-first century when economy development day by day is concentrated extremely in industry, agriculture, and pharmacy leading to various pollutants in the environment. According to these developments, amount of various contaminants is discharged in wastewater; thus, investigation of advance technology based on nano-catalysts combining the ozonation will meet the demands for wastewater treatment. This review found potentials and prospects of nano-catalysts applied in the catalytic ozonation process for wastewater treatment. Efficiency of some well-known nano-catalysts with analytical properties for catalytic ozonation is also evaluated. Mechanisms of this process are identified to easily approach the catalytic ozonation using nano-materials for wastewater treatment in the future.

Degradation of sulfonamide antibiotics using ozone-based advanced oxidation process: Experimental, modeling, transformation mechanism and DFT study

In this research, degradation of three sulfonamide antibiotic compounds (SNAs) such as Sulfasalazine (SSZ), Sulfamethoxazole (SMX) and Sulfamethazine (SMT) as well as Metronidazole (MNZ) were investigated for the first time using experimental, modeling and simulation data under O3, H2O2, and O3/H2O2 systems. The kinetic and synergistic study confirmed the pseudo-first-order reaction and highest performance of the O3/H2O2 process for the SNAs degradation process. Two modeling approach, central composite design (CCD) based on response surface methodology (RSM) and artificial neural network (ANN) were utilized to investigate the optimization and modeling of SSZ degradation as the response of O3/H2O2 system and results were compared. The individual and interactive effects of main operational parameters were also possessed by the main effect graphs, contour and response surface plots. The experimental results showed maximum degradation efficiency at the optimum condition for SSZ, SMX, SMT and MNZ were 98.10%, 89.34%, 86.29% and 58.70%, respectively in O3/H2O2 process. For proposed reaction mechanism of SNAs in O3/H2O2 process the influence of inorganic salts including Na2SO4, NaH2PO4, Na2CO3, NaCl and tert butanol (TBA) as organic OH scavenger was studied. Besides that, LC-MS/MS analysis and DFT calculation were employed to identify the intermediate molecules produced (31 species) during the SSZ degradation (as a SNAs model) and a probable degradation pathway was proposed. The results provided a new strategy by combination of experiment and computer simulation to evaluate the O3/H2O2 system for optimization of SNAs removal from wastewater.

Pretreatment of Secondary Effluents in View of Optimal Ozone-Based AOP Removal of Trace Organic Contaminants: Bench-Scale Comparison of Efficiency and Energy Consumption

This study compares the performance of several ozone-based advanced oxidation processes (AOPs), in combination with filtration, in terms of trace organic contaminant (TrOC) removal efficiency and energy and cost requirement. It was shown that the hydroxyl radical (•OH) scavenging rate of the secondary wastewater effluent decreased as a result of an additional pretreatment step, leading to an increase of ozone and •OH exposures at the same ozone dose. Adding filtration such as sand filtration or granular activated carbon filtration (GACF) as a pretreatment increased the removal efficiency of TrOCs by all tested ozone-based AOPs and reduced the minimum effective ozone dose for TrOC elimination. When the applied ozone dose is more than this minimum effective ozone dose, the elimination of TrOCs can be observed. For example, because of the use of anion resin filtration, 17α-ethinylestradiol elimination contributed by the process of ozone-based AOP increased from 34.6 to 42.1% at an ozone dose of 1.0 g O3/g dissolved organic carbon. Ozone-based AOPs coupled with filtration as a pretreatment were found to be more cost-efficient than the single AOPs at all ozone dose levels. The energy consumption of ozone-based AOPs was decreased by more than 25% when applying GACF as a pretreatment. In comparison with other filtration techniques, the pretreatment of secondary effluents by GACF before ozonation was proven to be the most cost-effective method for TrOC elimination.

Reuse and recycle solutions in refineries by ozone-based advanced oxidation processes: A statistical approach

Fresh water sources are under pressure globally by the increasing population and consequently increasing production, which increases the water demand day by day. Thus, decreasing the industrial fresh water demand and wastewater production became crucial both for the water availability in the future and for its impact to the environment. This study examined the ozone-based treatments as the possible solution to a refinery to treat the effluent already treated by the traditional techniques to reach the final requirements for reuse and recycle purposes. The screening tests performed by fractional factorial design revealed that the significant parameters for the treatment were ozone feed ratio, H2O2 amount and processing time while pH was found insignificant for this case. Based on the box-Behnken response surface methodology for effluent collected after biological treatment, the significant parameters were optimized as the ozone ratio of 0.9 g/h, H2O2 amount of 47 mg/L and 60 min duration. However, in case of increasing the H2O2 amount to 80 mg/L the duration can be minimized to 37.5 min decreasing the energy and reagent consumption costs by a 37%, reaching a final total organic carbon (TOC) under 4 mg/L, that is the target for reuse possibilities.

Kinetics and mechanism of thiamethoxam abatement by ozonation and ozone-based advanced oxidation processes

In this study, the abatement of neonicotinoid insecticide, thiamethoxam, by single ozonation, ozone/ultraviolet (O3/UV) and electro-peroxone (EP) process was evaluated. The second-order rate constants for the reaction of thiamethoxam with O3 and hydroxyl radical (OH) at pH 7 were determined to be 15.4 M–1 s–1 and 3.9 × 109 M–1 s–1, respectively. The degradation pathways of thiamethoxam were proposed based on quantum chemical calculations and transformation products were identified using chromatographic and mass-spectrometric techniques. The acute and chronic toxicity of thiamethoxam and its major TPs to various aquatic organisms were assessed. With typical ozone doses applied in water treatment (≤5 mg/L), thiamethoxam was abated by only ∼16–32 % in two real water matrices (groundwater and surface water) during single ozonation, but by ∼100 % and >70 % during the O3/UV and EP treatment, respectively. The energy demand to abate 90 % thiamethoxam in the two water matrices was generally comparable for single ozonation and the EP process (∼0.14 ± 0.03 kW h/m3), but higher for the O3/UV process (0.21–0.22 kW h/m3). These results suggest that single ozonation is unable to sufficiently abate thiamethoxam under typical conditions of water treatment. Therefore, ozone-based advanced oxidation processes are needed to enhance thiamethoxam abatement.

Decolorization of Azo Dye Solution by Ozone Based Advanced Oxidation Processes: Optimization Using Response Surface Methodology and Neural Network

ABSTRACT The decolorization of acid black azo dye by three ozone-based advanced oxidation processes, viz. O3, O3/UV, O3/Fe (II) were studied by developing prediction model using Response Surface Methodology (RSM) and Artificial Neural Network (ANN) techniques. The decolorization is determined through the absorbance wavelength of dye using UV-Vis spectrophotometer. The central composite design experiment was used to develop a mathematical correlation between four independent parameters such as ozone dose, initial pH, initial dye concentration, reaction time and decolorization efficiency as process response. The decolorization efficiency of 95.5% obtained at optimized conditions (ozone concentration = 70 mg L−1, initial dye concentration of 200 mg L−1, initial pH 6 and reaction time of 20 min) was comparable to 94.15% predicted by RSM. The predicted results obtained from both RSM and ANN were found to be in good agreement with experimental values (R2 = 0.982 for O3; 0.981 for O3/UV; 0.976 for O3/Fe (II) process for RSM modeling and R2 = 0.994 for O3; 0.992 for O3/UV; 0.991 for O3/Fe (II) for ANN modeling). Thus, both RSM and ANN would effectively predict the performance of O3, O3/UV, O3/Fe (II) processes while ANN predictions found to be better than RSM in statistical comparison. All the three AOPs studied found to be competent for the decolorization of acid black azo dye. UV promotes decolorization by ozone but it adds to initial cost. Fe (II) can enhance ozonation efficiency significantly and found to be more effective compared with O3 and O3/UV processes.

Optimization of H2O2 and ozone-based advanced oxidation processes as pretreatment of sanitary landfill leachate

Optimization of H2O2 and ozone-based advanced oxidation processes as pretreatment of sanitary landfill leachate

Advanced Oxidation Processes for the Removal of Antibiotics from Water. An Overview

In this work, the application of advanced oxidation processes (AOPs) for the removal of antibiotics from water has been reviewed. The present concern about water has been exposed, and the main problems derived from the presence of emerging pollutants have been analyzed. Photolysis processes, ozone-based AOPs including ozonation, O3/UV, O3/H2O2, and O3/H2O2/UV, hydrogen peroxide-based methods (i.e., H2O2/UV, Fenton, Fenton-like, hetero-Fenton, and photo-Fenton), heterogeneous photocatalysis (TiO2/UV and TiO2/H2O2/UV systems), and sonochemical and electrooxidative AOPs have been reviewed. The main challenges and prospects of AOPs, as well as some recommendations for the improvement of AOPs aimed at the removal of antibiotics from wastewaters, are pointed out.

Treatment of Diethyl Phthalate Leached from Plastic Products in Municipal Solid Waste Using an Ozone-Based Advanced Oxidation Process.

Plastic products in municipal solid waste result in the extraction of phthalates in leachate that also contains large amounts of organic matter, such as humic substances, ammonia, metals, chlorinated organics, phenolic compounds, and pesticide residues. Phthalate esters are endocrine disruptors, categorized as a priority pollutant by the US Environmental Protection Agency (USEPA). Biological processes are inefficient at degrading phthalates due to their stability and toxic characteristics. In this study, the peroxone (ozone/hydrogen peroxide) process (O3/H2O2), an O3-based advanced oxidation process (AOP), was demonstrated for the removal of diethyl phthalate (DEP) in synthetic leachate simulating solid-waste leachate from an open dump. The impact of the O3 dose during DEP degradation; the formation of ozonation intermediate by-products; and the effects of H2O2 dose, pH, and ultraviolet absorbance at 254 nm (UVC) were determined during ozonation. Removal of 99.9% of an initial 20 mg/L DEP was obtained via 120 min of ozonation (transferred O3 dose = 4971 mg/L) with 40 mg/L H2O2 in a semi-batch O3 system. Degradation mechanisms of DEP along with its intermediate products were also determined for the AOP treatment. Indirect OH radical exposure was determined by using a radical probe compound (pCBA) in the O3 treatment.

Comparison of emerging contaminant abatement by conventional ozonation, catalytic ozonation, O3/H2O2 and electro-peroxone processes

The abatement of several emerging contaminants (ECs) in groundwater by conventional ozonation and three ozone-based advanced oxidation processes (AOPs) - catalytic ozonation with manganese dioxide (MnO2), conventional peroxone (O3/H2O2), and electro-peroxone (EP) - was compared in this study. The addition of MnO2, H2O2, or electro-generation of H2O2 during ozonation enhanced ozone transformation to hydroxyl radicals to different extent. These changes did not considerably influence the abatement of ECs with moderate to high ozone reactivities (kO3≥500 M-1s-1), whose abatements were similar with >90 % during all four processes. In comparison, the abatements of ozone-refractory ECs (kO3< 15 M-1s-1) were lower during conventional ozonation (∼40–85 % abatement), but could be enhanced by ∼10–40 % during the three ozone-based AOPs. Besides enhancing ozone-refractory EC abatement, the three AOPs, especially the O3/H2O2 and EP processes, reduced considerably bromate formation compared to conventional ozonation. These results demonstrate that the EP process performs similarly as catalytic ozonation and O3/H2O2 processes in terms of EC abatement and bromate control. Considering its more convenient, flexible, and safer way of operation, the EP process may provide an attractive alternative to the two more traditional AOPs for water treatment.

Enhancement of Ozone Mass Transfer by Stainless Steel Wire Mesh and Its Effect on Hydroxyl Radical Generation

ABSTRACT In order to improve the mass transfer efficiency of ozone in water, stainless steel wire mesh (SSWM) corrugated structure was packed into a microbubble ozone reactor to enhance the mass transfer efficiency. The results showed that the SSWM/O3 system could effectively improve the mass transfer efficiency. When the concentration of ozone in the liquid phase reached a stable state, it was about 21 mg/L, which was about 14% higher than that of ozone alone; the apparent mass transfer coefficient (KLa) was 0.7255 min−1, which was about 51% higher than that by ozone alone systems. The hydroxyl radicals in the SSWM/O3 system were more generated than that of ozone alone. After 6 min of operation, the concentration of hydroxyl radicals increased by 60 µmol/L compared with that in ozone alone system. The Chemical Oxygen Demand (COD) removal efficiency of biologically treated leachate by SSWM/O3 system was about 10% higher than that of ozone alone system after 120 min of reaction. The effects of pressure, temperature, ozone inlet concentration, and flow rates on the ozone concentration in the liquid phase and the generation of hydroxyl radicals were also investigated. The results indicated that reactor pressure has little effect on ozone concentration in liquid phase, but increasing pressure helps to generate ·OH; ozone concentration and ·OH generation in liquid phase increase with the increase of inlet ozone concentration and flow rate; ozone concentration in the liquid phase decreases with the increase of temperature, but ·OH generation increases with the increase of temperature. Our results indicate that the system consisting of SSWM and microbubble column reactor is an efficient process for the intensification of ozone-based advanced oxidation processes.

Artificial neural network modeling on the prediction of mass transfer coefficient for ozone absorption in RPB

It has been proved that Higee technology can intensify the processes involving the multiphase mass transfer, and be applied to the ozone-based advanced oxidation processes. Modeling and prediction of mass transfer coefficient are rare in this field. A modeling approach based on artificial neural network (ANN) was developed in this work to predict mass transfer coefficient of ozone absorption process in rotating packed bed (RPB). Serial experiments were conducted to obtain data for the establishment of ANN model, which was then employed to predict the overall mass transfer coefficient (KLa) using dimensionless quantities such as Reynolds number of gas and liquid, Froude number and Weber number, calculated in terms of the geometry of RPB and operating conditions. To optimize the model structure and performance, random grid search for hyperparameters was adopted in this work. The final model exhibits a prediction ability with R2 of 0.9896 and 0.9877, RMSE of 0.01801 and 0.03085, and MAE of 0.01265 and 0.02219 on the training set and the test set, respectively.

Removal Characteristics of Steroid Estrogen in the Mixed System through an Ozone-Based Advanced Oxidation Process

In this work, the removal of estrone (E1), 17β-estradiol (E2), and 17α-ethinylestradiol (EE2) in their coexisting micro-polluted solution through an ozone-based oxidation process was studied in depth. The results showed that all of the estrogens in the mixed solution could be completely degraded and their degradation processes fitted the pseudo-first-order kinetic model well. As the initial concentration of the mixed solution increased from 50 to 300 μg L−1, the removal rate constants of E1, E2, and EE2 decreased by 65.9%, 66.5%, and 67.0%, respectively. However, when the initial solution pH increased from 2.0 to 7.0, the removal rate constant of E1, E2, and EE2 increased by 271.4%, 149.7%, and 152.4%, respectively. When the H2O2 or UV was introduced into the ozonation system, the removal efficiency of steroid estrogens in the mixed solution was substantially enhanced. Moreover, main intermediates of E1, E2, and EE2 were proposed. The synthetic estrogen EE2 was chosen as the representative compound to evaluate the estrogenic activities during O3, O3/H2O2, and O3/UV processes. In the O3/H2O2 and O3/UV processes, the degradation products still possessed certain estrogenic activities, which led to a hysteresis of the decrease of estrogenic activity compared with that of the estrogen concentration. These findings provided some reliable research data, alternative oxidants, and oxidation manners for the removal of steroid estrogens from the aquatic environment.