Types Of Advanced Oxidation Processes Research Articles

Degradation of phenol and sulfamethoxazole with persulfate and ozone with nano‐MnO2–biochar composites

AbstractBACKGROUNDIn this study, nano‐MnO2–biochar composites were synthesized as catalysts to promote the oxidation of recalcitrant organic contaminants. MnO2 nanoparticles coated on biochar were hypothesized to enhance the oxidation of phenol and sulfamethoxazole (SMX) using ozone and/or persulfate.RESULTSThe optimal percentage of MnO2 coating on the surface of biochar was determined, and the synthesis of nano‐MnO2‐coated biochar was confirmed via scanning electron microscopy–energy‐dispersive X‐ray spectroscopy (EDS), X‐ray diffraction and EDS line mapping analyses. Compared with oxidation using ozone or persulfate in the presence of either nano‐MnO2 or biochar, the synthesized nano‐MnO2–biochar composite markedly enhanced the oxidation of phenol and SMX. This was probably due to the spreading of MnO2 nanorods on the surface of biochar and the synergistic involvement of nano‐MnO2 and biochar as catalysts. X‐ray photoelectron spectroscopy analysis confirmed the involvement of Mn3+ in MnO2 to promote oxidation using ozone or persulfate. The coexistence of ozone and persulfate could also promote oxidation. Hydroxyl radicals (OH•) and persulfate radicals (SO4−•) were major reactive oxygen species for ozone and persulfate systems, respectively.CONCLUSIONResults suggest that the synthesized nano‐MnO2–biochar composites may be effective catalysts for various types of advanced oxidation processes in environmental remediation. © 2024 Society of Chemical Industry (SCI).

Insight into the adsorption behaviors and bioaccessibility of three altered microplastics through three types of advanced oxidation processes

Advanced oxidation processes (AOPs) can significantly alter the structural properties, environmental behaviors and human exposure level of microplastics in aquatic environments. Three typical microplastics (Polyethylene (PE), polypropylene (PP), and polystyrene (PS)) and three AOPs (Heat-K2S2O8 (PDS), UV-H2O2, UV-peracetic acid (PAA)) were adopted to simulate the process when microplastics exposed to the sewage disposal system. 2-Nitrofluorene (2-NFlu) adsorption experiments found the equilibrium time decreased to 24 hours and the capacity increased up to 610 μg g−1, which means the adsorption efficiency has been greatly improved. The fitting results indicate the adsorption mechanism shifted from the partition dominant on pristine microplastic to the physical adsorption (pore filling) dominant. The alteration of specific surface area (21 to 152 m2 g−1), pore volume (0.003 to 0.148 cm3 g−1) and the particle size (123 to 16 μm) of microplastics after AOPs are implying the improvement for pore filling. Besides, the investigation of bioaccessibility is more complex, AOPs alter microplastic with more oxygen-containing functional groups and lower hydrophobicity detected by XPS and water contact angle, those modifications have increased the sorption concentration, especially in the human intestinal tract. Therefore, this indicates the actual exposure of organic compounds loaded in microplastic may be higher than in the pristine microplastic. This study can help to assess the human health risk of microplastic pollution in actual environments.

Removal of persistent organic pollutants and disinfection of pathogens from secondary treated municipal wastewater using advanced oxidation processes.

An affordable and sustainable tertiary treatment is imperative to solve the secondary contamination issues related to wastewater reuse. To decontaminate and disinfect the actual secondary treated wastewater, various types of advanced oxidation processes (AOPs) have been studied. The optimization of the oxidant and catalyst is carried out to identify the best-performing system. Under selected experimental conditions, UV/peroxymonosulfate (PMS), O3/PMS, UV/MnO2, O3/MnO2, UV/O3/H2O2, O3/MnO2/H2O2, UV/MnO2/H2O2, and UV/O3/MnO2 has been identified as an efficient treatment option for simultaneous decontamination (>90% COD removal) and disinfection (100% inactivation of the total viable count of bacteria). The techno-economic assessment revealed that UV/MnO2 (23.5 $ kg-1 of COD) UV/O3/MnO2 (37.4 $ kg-1 of COD), UV/H2O2/MnO2 (36.4 $ kg-1 of COD), and O3/MnO2/H2O2 (32.5 $ kg-1 of COD) are comparatively low-cost treatment processes. Overall, UV/MnO2, UV/H2O2/MnO2, and O3/MnO2/H2O2 are the three best treatments. Nevertheless, further investigation on by-product and catalyst toxicity/recovery is needed. The results showed that AOPs are a technologically feasible treatment for simultaneously removing persistent organic pollutants and pathogens from secondary treated wastewater.

A review of microplastics pollution and its remediation methods: Current scenario and future aspects

Global plastic production and its use have been omnipresent since the early 19th century. The disposal of plastics undergoes breakdown due to various physicochemical and biological factors that trigger the formation of microplastics (MPs). Due to their hydrophobic properties, structural stability, and functional groups, it is difficult to degrade in natural habitat. The presence of their large surface area also helps to resist the decay of MPs. This review summarizes the recent trends and development of MPs degradation. The method includes biodegradation, various types of advanced oxidation processes (AOPs) such as photocatalytic oxidation, photo-degradation, and electrochemical oxidation, and also discussed the potential health risk factors of MPs and their degradation products. Most of the methods achieved nearly satisfactory performance that degraded the MPs into CO2, H20, and also secondary microplastic particles with persistent organic pollutants (POPs) under laboratory conditions, which have been studied by various researchers. It is also evident that the degradation of MPs has many challenges, therefore finding a sustainable approach is an urgent need to deal with the issue of global microplastic pollution. Some suggestions have been highlighted such as toxicity detection of remaining MPs particles after degradation, and analysis of secondary metabolites of microbes secreted during bioremediation that may have a negative impact on the environment. The selective and specific implementation of microbes and photo-catalyst that degrade MPs into useful and nontoxic components.

Advanced oxidation processes for microplastics degradation: A recent trend

Recently, microplastics (MPs) became a big name in the world since their presence in bodies of different species, environmental media, and even in bottled drinking water was frequently reported. Several studies reported MPs’ potential threat to health of humans, animals and the ecosystem. Therefore, it is of great importance to develop reliable technologies for removing MPs in the environment. Advanced oxidation processes (AOPs) are widely studied and applied for the decomposition of different refractory contaminants in the environment. Because reactive oxygen species produced in AOPs could effectively degrade many pollutants, several AOPs were applied for MPs decomposition. Homogeneous and heterogeneous AOPs, including UV photolysis, UV/H2O2, O3, UV/visible light-induced photocatalysis, heat activated PS and PMS, and plasma, could effectively decompose various types of MPs with different sizes. However, the decomposition mostly occurred on the surface of MPs even though several studies reported complete removal of MPs. Interestingly, several studies demonstrated that treated MPs could become pollutant carriers for animals and human beings by adsorbing contaminants in the environment. However, a limited number of studies on MPs removal by AOPs are available and only few types of AOPs are recently studied even though current studies demonstrated the potential of AOPs for complete MPs removal. Therefore, more effort must be put into investigating different AOPs for complete removal of MPs in the environment. AOPs will play a key role for MPs removal in the environment in the near future, definitely.

Advances in the Application of Nanocatalysts in Photocatalytic Processes for the Treatment of Food Dyes: A Review

The use of food additives (such as dyes, which improve the appearance of the products) has become more prominent, due to the rapid population growth and the increase in demand for beverages and processed foods. The dyes are usually found in effluents that are discharged into the environment without previous treatment; this promotes mass contamination and alters the aquatic environment. In recent years, advanced oxidation processes (AOPs) have proven to be effective technologies used for wastewater treatment through the destruction of the total organic content of toxic contaminants, including food dyes. Studies have shown that the introduction of catalysts in AOPs improve treatment efficiency (i.e., complete decomposition without secondary contamination). The present review offers a quick reference for researchers, regarding the treatment of wastewater containing food dyes and the different types of AOPs, with different catalyst and nanocatalyst materials obtained from traditional and green chemical syntheses.

Organometallic modified montmorillonite application in the wastewater purification: Pollutant photodegradation and antibacterial efficiencies

The ability of peptides to form stable complexes with metal ions offers a remarkable starting point for elaborating catalysts and antibacterial agents.This paper reports the synthesis and characterization of a new inexpensive organometallic-montmorillonite as highly active catalyst and antibacterial agent. An Fe(II)-Glycylglycylglycine (Fe-3Gly) complex was covalently anchored to montmorillonite K10 (K10) previously grafted with 3-aminopropyl-trietoxisilane (APTES). Multiple techniques were used to investigate the different steps of functionalization, to name FTIR, TGA, XRD, N2 adsorption–desorption technique, RD/UV–Vis, and SEM-EDS. The catalytic activity of the prepared catalyst was determined in terms of decolorization efficiency percentages of Congo Red dye (CR) in an aqueous solution using three types of Advanced Oxidation Processes (AOPs) that are the heterogeneous Fenton, the photocatalysis and photo-Fenton processes. A full factorial design of experiment was established in the photo-Fenton process in order to i) identify the most influential parameters and their interactions, and ii) determine the experimental conditions most favorable to the degradation. Thus, five factors were considered: catalyst weight (X1), H2O2 volume (X2), pH (X3), CR concentration (X4) and time (X5). From the statistical analysis, the correlation coefficient for the model was R2 = 0.90 and the most effective factor in the photo-Fenton degradation efficiency was the pH. The experimental values fitted with the predicted ones, thereby indicating the appropriateness of the established model. Furthermore, the prepared material showed good antibacterial activities.

Comparison of hydrogen peroxide-based advanced oxidation processes for the treatment of azole-containing industrial wastewater

In this study the effectiveness of three types of advanced oxidation processes (AOPs), namely the Fenton, UV/Fenton and UV/H2O2 processes, were compared for the treatment of a lab-prepared wastewater containing five-membered heterocyclic pyrazole, 2-(2-aminoethoxy) ethanol (also known as diglycolamine or DGA), hydrogen peroxide, and inorganic fluoride which are common components of semiconductor wastewater. The Fenton, UV/Fenton (at acidic and near neutral pH) and UV/H2O2 processes with same iron (or no iron) and H2O2 dosing were compared and the results show the three AOPs can remove pyrazole and DGA from the synthetic wastewater rapidly with a simultaneous reduction of total organic carbon (TOC). The UV/Fenton process at initial pH of 8.3 outperformed the other AOPs in terms of overall removal rate due to the synergistic effects of pH-dependent speciation of pyrazole and DGA, direct photolysis of hydrogen peroxide, iron-peroxide complexation and iron-oxalate complexation. The UV/Fenton process at initial pH = 3.0 had the slowest kinetics and the UV/H2O2 process (at pH = 8.3) had the lowest TOC removal efficiency. The successive oxidation of both pyrazole and DGA resulted in the production of formic acid, acetic acid, oxalic acid, nitrate ions and ammonium ions. Actual semiconductor industrial wastewater containing the same principal components as the lab-prepared water along with co-contaminants was treated with the three AOPs and the presence of co-contaminants lowered the removal rate constants of pyrazole and DGA for the Fenton and UV/H2O2 processes but increased those in the UV/Fenton process. Acute and chronic toxicity tests employing ceriodaphnia dubia indicated the wastewater after AOPs treatment showed no toxicity.

Recirculation of reject water in deep-dewatering process to influent of wastewater treatment plant and dewaterability of sludge conditioned with Fe2+/H2O2, Fe2+/Ca(ClO)2, and Fe2+/Na2S2O8: From bench to pilot-scale study

Deep dewatering of sewage sludge pretreated with advanced oxidation processes (AOPs) is a strategy for efficient sludge reduction and subsequent disposal. The pretreatment and dewatering performance of sludge conditioned with three types of AOPs (Fe2+/H2O2, Fe2+/Ca(ClO)2, and Fe2+/Na2S2O8), compared with sludge conditioned with traditional conditioner (Fe3+/CaO), were investigated in both bench and pilot-scale tests. All of those conditioner systems could reduce the water content of dewatered sludge cake to below 60 wt% in bench-scale (about 16 kg raw sludge per round) and pilot-scale (approximate 800 kg raw sludge per round) diaphragm filter press dewatering. Compared with raw sludge, the deep-dewatering filtrate after different conditioning and dewatering processes had higher ammonia nitrogen (NH4+-N) and chemical oxygen demand (COD) contents due to the degradation of organic matter, and much lower total phosphorus (TP) content due to the formation of iron phosphate precipitate. A better biodegradability (i.e. higher BOD5/COD ratio) was found in the deep-dewatering filtrate of sludge conditioned with Fe2+/H2O2 (25.2 %) and Fe2+/Ca(ClO)2 (17.4 %). Most of the heavy metals (Cr, Cu, Ni, and Pb) (>79 wt%) have remained in the dewatered sludge cake, and most of the Cl element (>90 wt%) in the sludge pretreated by Fe2+/Ca(ClO)2 and Fe3+/CaO was kept in the filtrate, rather than the dewatered sludge cake. Based on the pilot-scale experimental results, if all the filtrate in the deep-dewatering process returned to the influent of WWTP, the loading ratios of TP, NH4+-N, COD in the four conditioner systems were less than 3 wt%. The above results proved that the AOPs conditioned sludge could achieve deep-dewatering in pilot-scale and the direct recirculation of deep-dewatering filtrate to the influent of wastewater treatment plant was feasible.

Investigation of TNT red wastewater treatment technology using the combination of advanced oxidation processes

Different types of advanced oxidation processes and their combinations such as O3/H2O2/UV, O3/Fenton/UV, O3/TiO2/UV, Fenton/H2O2/UV, Fenton/TiO2/UV, TiO2/H2O2/UV, TiO2/H2O2/O3/UV, TiO2/O3/Fenton/UV, TiO2/H2O2/Fenton/UV and O3/H2O2/Fenton/UV were studied for the treatment of undiluted red wastewater from Z113 Factory. The treatment efficiency was evaluated by analyzing chemical oxygen demand (COD) reduction, % degradation of α-TNT, 2,4-DNT, 2,6-DNT, 2,4-DNT-3-SO3Na and 2,4-DNT-5-SO3Na. Among studied processes Fenton/TiO2/O3/UV was the most effective technology to treat red wastewater. It allows to reduce >99% of COD, α-TNT, 2,4-DNT, 2,6-DNT, 2,4-DNT-3-SO3Na and 2,4-DNT-5-SO3Na after 30 h of treatment with optimum operating conditions: rotation speed of 600 rpm, pH of 4 and temperature of 40 °C. According to the chromatograms obtained by gas chromatograph/mass spectrometer (GC/MS), intermediates of the decomposition of pollutants in red wastewater were identified. GC/MS, HPLC, UV–vis and Bacterial Toxicity test were used to assess effluent quality changes before and after treatment. By economic analysis, the studied process had the potential to apply in practice to treat real wastewater at the Z113 Factory.

A Review on Advanced Oxidation Processes (AOPs) for Wastewater Remediation

In 21st century, organic and domestic wastes and discharges from varied chemical and manufacturing industries to water bodies become a critical issue and challenge for the researchers, engineers and policy makers. Advanced oxidation processes (AOPs) are efficient, sustainable, economically viable and green techniques to elimination on-degradable organic pollutants by biological and traditional processes. A number of research articles have been published from the past two decades on the wastewater treatment using various advanced oxidation processes. The main objective of this review paper is to provide the quick view for researchers, academicians and scientists in the area of wastewater treatment using various types of AOPs, which incorporate green principles involves in the processes for removal of different pollutants and contaminants including dyes, phenols, pesticides, herbicides etc. from wastewaters, with emphasis on the degradation efficiency of various photocatalysts. The formation reactions of •OH radical and the mechanisms of degradation of various organic pollutants in the wastewater is also discussed. This review covers various types of advanced oxidation processes, viz., ozone-based processes, photocatalysis and Fenton-based reactions.

Effect of Cr doping in CeO2 nanostructures on photocatalysis and H2O2 assisted methylene blue dye degradation

Optimization of Advanced Oxidation Processes (AOPs) is key for the demand in green and sustainable method for degradation of organic contaminants in aqueous solution. In this study, the effect of Cr doping on CeO2 nanostructure was investigated to evaluate the catalytic performances of the Cr doped CeO2 nanocomposites with Methylene Blue (MB) used as model contaminant. Two types of AOPs were also explored; photocatalysis and H2O2 assisted. The Cr-doped CeO2 samples were prepared by deposition precipitation method and characterized with XRD, FE-SEM-EDX, UV–vis Spectroscopy and TPR. Generally, increase in Cr doping improved the catalytic activity in MB degradation efficiency for photocatalysis and H2O2-assisted methods, where with 3% weight of Cr-doping achieved 41 % and 59 % of MB degradation across 100 min respectively. The improvement of catalytic activity was attributed to the effects on Cr doping, which lowers the CeO2 band gap and also the Cr species serving as electron trapping centers to slow down the recombination of the charge carriers. The MB degradation results also showed that for Cr-doped CeO2 system, H2O2-assisted was the more effective catalytic method compared to photocatalysis. Isopropanol has been found explicitly feasible to demonstrate a plausible scavenging properties toward hydroxyl radical by suppressing the MB degradation in the reaction media, thus, suggesting that, the MB degradation mechanism proceeds via hydroxyl radical species.

Pilot scale degradation study of 16 selected volatile organic compounds by hydroxyl and sulfate radical based advanced oxidation processes

The studies of effective technologies for complete degradation of the volatile organic compounds (VOCs), are very important due to the high biotoxicity of the VOCs which makes the biological technologies ineffective. It also increases the risk of VOCs emission instead of their treatment when using open air biological technologies. In the present study, different types of Advanced Oxidation Processes (AOPs) were investigated for the degradation of several VOCs in a model pilot scale effluent, simulating effluents from bitumen production. The goal of this paper is to reach effective VOCs and wastewater degradation to make the bitumen production a cleaner process. O3, H2O2, O3/H2O2 (the so called peroxone), persulfate (PS) and peroxymonosulfate (PMS) were processes chosen for this work. Heat activation enhanced the total VOCs degradation in PS and PMS technologies, which achieved higher effectiveness than H2O2. Peroxone process at 40 °C achieved the highest efficiency of all processes studied needing only 60 min to completely degrade all compounds without any oxidation by-products. Sulfur containing VOCs (VSCs) were completely degraded in a shorter treatment time and nitrogen containing VOCs (VNCs) needed more time of treatment in all technologies studied. The preference of the hydroxyl and sulfate radicals for degradation of oxygen containing VOCs (OVOCs) had different behavior depending on the group of compounds and should be considered in future research for combined radical processes.

Catalytic oxidative degradation of phenol using iron oxide promoted sulfonated-ZrO2 by Advanced Oxidation Processes (AOPs)

Abstract In this paper, we report the efficiency of iron impregnated on both ZrO2 and sulfonated-ZrO2 catalysts for the catalytic oxidative degradation and mineralization of phenol (as a model organic pollutant) in the Fenton-like process and catalytic ozonation. Fe-impregnated on ZrO2 and sulfonated-ZrO2 catalysts were prepared, characterized, and used as an effective and reusable heterogeneous catalyst for the first time for phenol degradation and mineralization in both types of Advanced Oxidation Processes (AOPs). Among the studied catalysts, 4%Fe/sulfonated-ZrO2 exhibited superior performance in ozonation, achieving a total conversion of phenol within 15 min and high mineralization efficiency of 88% in 6 h. And in Fenton-like process, achieving a total conversion of phenol in an hour and 64% of mineralization in 6 h. The sulfonation of zirconia followed by Fe impregnation has shown a positive effect on oxidative degradation and mineralization of phenol. The catalyst sustained its activity even after four cycles of regeneration and reuse. Overall, the present study offers Fe/sulfonated-ZrO2 as an attractive catalytic material with high activity and stability for the abatement of phenol.

Treatment of Groundwater Contaminated with 1,4-Dioxane, Tetrahydrofuran, and Chlorinated Volatile Organic Compounds Using Advanced Oxidation Processes

ABSTRACTOzonation and four types of advanced oxidation processes, including O3/H2O2, O3/UV, O3/H2O2/UV, and UV/H2O2, were evaluated for the treatment of contaminated groundwater at a Superfund site in Simpsonville, South Carolina using bench-scale, batch ozone and UV apparatuses. Although the contaminants of concern were 1,4-dioxane, 1,1-dichloroethene, and trichloroethene, several other chlorinated organics as well as tetrahydrofuran were found in the groundwater samples. The O3/H2O2 treatment with O3 and H2O2 doses of 6 and 1.5 mg/L, respectively, and the UV/H2O2 treatment with UV and H2O2 doses of 1,000 mJ/cm and 20 mg/L, respectively, were sufficient to degrade 200 µg/L of 1,4-dioxane, 110 µg/L of 1,1-dichloroethene, and 10 µg/L of trichloroethene below their performance standards of 10, 7, and 4 µg/L, respectively. Due to a high bromide concentration (0.35 mg/L) in the groundwater sample, bromate formation was found to be significant in ozone-based treatment, including O3/H2O2.

Comprehensive study on effects of water matrices on removal of pharmaceuticals by three different kinds of advanced oxidation processes

Simple semi-theoretical models were developed to estimate the performance of three different kinds of advanced oxidation processes (AOPs) in the degradation of pharmaceuticals. The AOPs included the photo-Fenton process as an example of a liquid-liquid reaction, the TiO2 photocatalytic oxidation process as a solid-liquid reaction, and the combined ozone and hydrogen peroxide oxidation process as a gas-liquid reaction; the effects of the aqueous matrices (CESs: co-existing substances) of actual wastewater on the removal of pharmaceuticals (carbamazepine and diclofenac) was taken into account. By comparing the characteristic parameters of the models, obtained from the experiments using pure water and actual wastewater, the effects of CESs on the respective removal mechanisms could be separately and quantitatively evaluated. As a general tendency, the AOPs proceeded less effectively (were inhibited) in the matrices containing CESs, as observed with the use of a lower initial concentration of pharmaceuticals. The inhibition mechanisms differed for the three types of AOPs. In the photo-Fenton process, the Fenton reaction was improved by the incorporation of CESs, while the photo-reduction reaction was significantly inhibited. In the TiO2 photocatalytic oxidation process, competition between the pharmaceuticals and CESs for adsorption on the catalyst surface was a less significant inhibitory factor than the scavenger effects of the CESs. The combined ozone and hydrogen peroxide oxidation process was most strongly inhibited by CESs among the AOPs investigated in this study.

Comparison of various advanced oxidation processes for the degradation of phenylurea herbicides

ABSTRACTVarious types of advanced oxidation processes (AOPs), such as UV photolysis, ozonation, heterogeneous photocatalysis and their combinations were comparatively examined at the same energy input in a home-made reactor. The oxidative transformations of the phenylurea herbicides fenuron, monuron and diuron were investigated. The initial rates of transformation demonstrated that UV photolysis was highly efficient in the cases of diuron and monuron. Ozonation proved to be much more effective in the transformation of fenuron than in those of the chlorine containing monuron and diuron. In heterogeneous photocatalysis, the rate of decomposition decreased with increase of the number of chlorine atoms in the target molecule. Addition of ozone to UV-irradiated solutions and/or TiO2-containing suspensions markedly increased the initial rates of degradation. Dehalogenation of monuron and diuron showed that each of these procedures is suitable for the simultaneous removal of chlorinated pesticides and their chlorinated intermediates. Heterogeneous photocatalysis was found to be effective in the mineralization.

Advanced Oxidation Processes for Wastewater Treatment: Formation of Hydroxyl Radical and Application

Advanced oxidation processes (AOPs), defined as those technologies that utilize the hydroxyl radical (·OH) for oxidation, have received increasing attention in the research and development of wastewater treatment technologies in the last decades. These processes have been applied successfully for the removal or degradation of toxic pollutants or used as pretreatment to convert recalcitrant pollutants into biodegradable compounds that can then be treated by conventional biological methods. The efficacy of AOPs depends on the generation of reactive free radicals, the most important of which is the hydroxyl radical (·OH). The authors summarize the formation reactions of ·OH and the mechanisms of pollutants degradation. They cover six types of advanced oxidation processes, including radiation, photolysis and photocatalysis, sonolysis, electrochemical oxidation technologies, Fenton-based reactions, and ozone-based processes. Controversial issues in pollutants degradation mechanism were discussed. They review the application of these processes for removal of different kinds of toxic pollutants from wastewater, including aromatic compounds, dyes, pharmaceutical compounds, and pesticides, with emphasis on the parameters assessed, removal effectiveness, and the degradation mechanisms of pollutants. The authors discuss issues associated with practical wastewater treatment and offer suggestions for the direction for future researches.

Advanced Oxidation Processes for Wastewater Treatment: State of the Art

The protection and conservation of natural resources is one of the main priorities of modern society. Water is perhaps our most valuable resource, and thus should be recycled. Many of the current recycling techniques for polluted water only concentrate the pollutant without degrading it or eliminating it. In this sense, advanced oxidation processes are possibly one of the most effective methods for the treatment of wastewater containing organic products (effluents from chemical and agrochemical industries, the textile industry, paints, dyes, etc.). More conventional techniques cannot be used to treat such compounds because of their high chemical stability and/or low biodegradability. This article describes, classifies, and analyzes different types of advanced oxidation processes and their application to the treatment of polluted wastewater.

Advanced oxidation processes (AOPs) assisted by excimer lamp

The several types of advanced oxidation processes (AOPs) utilizing UV light, ozone and hydrogen peroxide have been studied to remove both organic and inorganic compounds from water and air. One of the AOPs, UV-ozonation process utilizing the excimer lamp was developed for water purification. The UV light emitted from KrCl excimer with the wavelength of 222 nm that destructs the hydrogen peroxide to hydroxyl radical realizes the AOPs. The ability of the AOPs with the excimer lamp was confirmed by the treatment of the humic acid solution.