Advanced Oxidation Techniques Research Articles

Characteristics of Fe/C catalysts based on pyrolysis of ferric citrate and its peroxymonosulfate activation performance to degrade sulfadiazine in water.

Advanced oxidation techniques based on peroxysulfate activation have been paid much attention owing to their excellent performance in degrading stubborn pollutants in water. In response to the current situation that requires more raw materials and higher costs and involves more complicated processes for the preparation of Fe/C catalysts to activate persulfates, novel catalysts (Fe/C-700, Fe/C-800, Fe/C-900 and Fe/C-1000) were prepared by a high-temperature carbonization method at different pyrolysis temperatures (700, 800, 900 and 1000 °C) using inexpensive and environmentally friendly ferric citrate as raw material. Fe/C catalysts were characterized using SEM, EDS, XRD, XPS, and VSM and were screened for the activation of peroxymonosulfate (PMS) to degrade sulfadiazine (SDZ) in water, where Fe/C-900 exhibited higher efficiency. Thus, its activation performance for PMS to degrade SDZ was comprehensively investigated and the mechanisms of activation degradation were analyzed. The results showed that the degradation rate of 98.7% can be achieved to 10 mg L-1 SDZ by 0.1 g L-1 Fe/C-900 and 0.5 mmol L-1 PMS within 60 min. A wide range of solution pH, low catalyst dosage and good recycling performance were found in the Fe/C-900 application and the amount of iron ions dissolved at the end of the reaction was low (0.350 mg L-1). It was shown that both free radical and non-free radical pathways existed in the reaction system, where 1O2, SO4-˙ and O2-˙ played dominant roles in the degradation process of SDZ. The results could provide new ideas for the preparation of Fe/C catalysts and their heterogeneous activation for PMS to degrade stubborn organic pollutants in water.

MOF-derived CuO@CB@CF cathode for O2 activation to generate ROSs for efficient electro-Fenton-catalysis

The generation of reactive radicals by molecular oxygen activation has become an important advanced oxidation technique. The combination of highly active carbon materials and stable transition metal oxides can activate molecular oxygen to produce hydrogen peroxide and further produce active free radicals at the same time, which is an efficient way for the removal of organic pollutants by heterogeneous electro-Fenton (HEF) system. In this study, a novel metal organic framework (MOF) derived CuO-carbon black-carbon felt (CuO@CB@CF) composite catalytic electrode has been prepared, which can generate H2O2 efficiently by selective O2 reduction through two-electron pathway with high pollutant removal efficiency. By optimizing the calcination temperature of MOF and loading capacity, the MOF-derived CuO@CB@CF has demonstrated excellent performance as a HEF catalytic electrode. Meanwhile, the effects of applied voltage, pH value, electrode area and aeration conditions have been studied. The excellent performance of MOF-derived CuO@CB@CF provides new insights into the removal of organic pollutants through electro-Fenton processes of transition metal oxide and carbon-based catalysts.

3D-honeycomb architectures evaporator toward mutual reinforcement of evaporation and catalysis for efficient freshwater harvesting

Solar-driven freshwater harvesting has emerged as an effective and sustainable technology to mitigate global water scarcity due to its high energy conversion efficiency. Nevertheless, achieving mutual reinforcement of photothermal and photocatalysis processes is in high demand because the contamination of harmful and highly concentrated volatile organic compounds (VOCs) will inevitably evaporate and condense alongside water. Herein, an integrated 3D-honeycomb fabric (NPPF) evaporator decorated with polydopamine (PDA), polypyrrole (PPy), and hydrotalcite (LDH) nanoflowers was designed innovatively by synergistically cooperating photothermal evaporation and advanced catalytic oxidation techniques. With periodically concave arrays, it can create the maximum level of light-trapping through multiple scattering and omnidirectional light absorption, thereby increasing its photothermal catalytic degradation ability. Meanwhile, introducing the LDH nanoflowers boosted the photothermal evaporation capacity of the NPPF evaporator. Therefore, it demonstrated high solar absorption efficiency of ∼98.02% and an evaporation rate of ∼2.02 kg m−2 h−1 under one sun. Furthermore, it can achieve superb degradation activity, especially for high-concentration VOCs, with efficiency of ∼93.99%, surpassing most of the other evaporators reported previously. Besides, the outdoor experiment demonstrated its practicability. More importantly, it can remove tetracycline and phenol with efficiency of ∼98.85% and ∼ 92.06%. The advantages make this evaporator a promising representative for cooperative freshwater production.

Effective discharge method of pulsed energy in industrial effluents by DBD and EHPD technique

This manuscript proposes a method for effective discharging method of pulsed energy in industrial effluents. The proposed approach is based on the dielectric barrier discharge (DBD) and Electro hydraulic Plasma Discharge (EHPD). The objective function of the proposed approach is minimizing the concentration of the ethylene blue (MB) dye in the industrial waste water. Using DBD and EHPD technique, treating such industrial effluents before mixing to the running water can effectively prevent polluting the water bodies and human health. It is one of the tertiary waste water treatments, which can also degrade biological substances. DBD technique is one of the advanced oxidation technique to de-color MB dye and the EHPD reactor is a strong and extremely efficient method for the degradation of MB. By then, the proposed model is implemented in the MATLAB platform and the implementation is calculated with the present procedure. The study concludes that the DBD and EHPD method outperforms other methods in terms of degradation efficiency. De-colorization of methylene blue (MB) took just 15 s using a 3 KV, 50μs pulse.

Enhanced degradation of tetracycline by TiO2@MXene with peroxydisulfate under visible light irradiation

Photocatalysis and peroxydisulfate (PS) based advanced oxidation techniques are promising technologies in the field of water treatment that can be used to destroy increasingly persistent organic contaminants. The current work used a simple hydrothermal approach to synthesize a catalyst made of composites of TiO2 nanospheres and multi-layer Ti3C2Tx sheets (TiO2@MXene). Tetracycline (TC) was then effectively degraded by the TiO2@MXene material integrated with PS activation (300 mg/L). Under simulated sunlight (AM 1.5G, P = 2.8 W) irradiation, the combination method dramatically increases TC degradation. Following a 30-min treatment with 300 mg/L TiO2@MXene (wt.10 %), the optimal efficiency can reach 100 %. As the reactive functional species, holes (h+), SO4-•, •OH, and •O2− dominate the catalytic process. Furthermore, investigation was conducted into significant factors such as catalyst dosage, PS dosage, common anions, and TiO2 loading dosage. The TiO2@MXene material was demonstrated to be a feasible and sustainable strategy worth taking into consideration in the mitigation of emerging water contaminants due to its ease of recovery, stability of surface properties, and recyclability. Furthermore, the proposed degradation mechanism further demonstrated the viability of TiO2@MXene with PS in TC degradation. This, this study provides insights into the design of effective photocatalyst coupling PS activation for the efficient degradation of organic pollutants.

Insight into the activation mechanism of sulfite over amorphous Fe1-xCoxS: Key role of Fe3+/Fe2+ self-cycling and oxysulfur radicals generation

Sulfite activation has been considered as a promising advanced oxidation technique for treating organic pollutants in water. In this work, a series of cobalt-doped FeS (Fe1-xCoxS) samples were synthesized via ultrasonic-assisted precipitation route and applied them in sulfite activation and Rhodamine B (RhB) removal in water at the same time, and their physical properties were characterized by XRD, SEM, TEM, XPS and electrochemical analysis. Benefiting from its high electron density, low corrosion voltage and impedance that beneficial to accelerate the electron transfer rate in the Fe1-xCoxS/sulfite system and the reducing sulfur species rich in electrons which beneficial to promote the self-cycling of Fe3+/Fe2+, the activity of Fe1-xCoxS for sulfite activation on the RhB removal was better than that of FeS in both acidic and neutral conditions. The redox cycle of metal ions on the surface of Fe1-xCoxS efficiently triggered sulfite activation. The hydroxyl radical (·OH), resulting from the conversion of oxysulfur radicals, plays a crucial role in the degradation of RhB. Additionally, a non-radical activation pathway of sulfite has been proposed. The present study provided a new idea and effective strategy for sulfite activation to environmental removal of organic matter in water.

In situ chemical oxidation of tinidazole in aqueous media by heat-activated persulfate: kinetics, thermodynamic, and mineralization studies

This study investigated the use of heat-activated persulfate (HAP) as a chemical oxidation technique for removing tinidazole (TNZ) antibiotic from aqueous solutions. The impact of various operating parameters, including TNZ initial concentration (20 μM), persulfate (PS) initial dose (0.2–2 mM), solution pH (3–11), solution temperature (20–60 °C), and reaction time (10–120 min), was examined. The results indicated that sulfate radicals were the primary species responsible for TNZ degradation. Higher temperatures and PS concentrations improved the process, while higher pH values and TNZ initial concentrations slowed it down. Additionally, chloride and bicarbonate ions reduced reaction rates, with chloride ions having a more significant effect. Under optimal conditions (including [TNZ]0 = 20 μM, pH = 7, [PS]0 = 1 mM, temperature = 60 °C, and reaction time = 120 min), the removal efficiency achieved was 91.15%, with a mineralization rate of 85.8%. These results suggest that the process is relatively safe. The degradation of TNZ was best described by the pseudo-first-order model compared to other models. Additionally, the process was found to be exothermic and spontaneous, with a negative Gibbs free energy change indicating that it is thermodynamically feasible. The study found HAP to be an effective and cost-efficient technique for removing TNZ antibiotic due to its ease of operation and the absence of the need for additional chemicals or waste handling. Based on these findings, HAP can be considered an advanced oxidation technique for treating antibiotic-contaminated water.

Technical–Economic Feasibility of a New Method of Adsorbent Materials and Advanced Oxidation Techniques to Remove Emerging Pollutants in Treated Wastewater

The focus on emerging contaminants (ECs) in wastewater has intensified due to the considerable risks they present to human health and wildlife. This paper presents the results of the technical–economic assessment of the Clean Up solution, carried out in the framework of the project entitled “Validation of Adsorbent Materials and Advanced Oxidation Techniques to Remove Emerging Pollutants in Treated Wastewater”. The viability of the Clean Up system is evaluated by being applied as an advanced treatment system for treated urban wastewater, that is, for the elimination of pathogens and emerging pollutants (EPs), while considering the established quality criteria by current regulations. In this sense, it is a technology that has been successfully validated at an experimental level, and that offers similar removal performance compared to that of the most efficient alternatives available on the market. The technical–economic assessment has been conducted through a systematic process. Initially, the estimation involved the calculation of treatment costs for the Clean Up system when applied at an industrial scale. Subsequently, the treatment costs were estimated for the most favorable technological alternative to the Clean Up system from a technical–economic standpoint, also applied at an industrial scale, within identical scenarios and conditions as those assumed for the Clean Up system. The final step involved a comprehensive comparison of treatment costs between both alternatives, implemented uniformly under analogous conditions and assumed similar performance across all cases.

Model Prediction and Optimization of Cefixime Trihydrate Removal from Simulated Wastewater through Advanced Plasma Technology

Plasma technology has received significant attention as an advanced oxidation technique for the efficient removal of pharmaceuticals from various wastewaters. In this study, cefixime trihydrate (CFX) was used as a typical pharmaceutical, and a stepwise optimization strategy was adopted to determine the experimental parameters that benefiting the generation of free radical. The removal rate of 20 mg/L CFX reached 94.8% after 60 min plasma treatment when the voltage was 12 kV, the discharge gap was 15 mm, and the number of needles was 5. Furthermore, through the prediction and optimization of the response surfaces mythology (RSM) and artificial neural networks (ANN) model, the removal rate of CFX increased to 95.8% when the voltage was 11.9 kV, discharge gap was 15 mm, the number of needles was 5, and treatment time was 60 min. Finally, based upon the change of solution absorbance before and after the UV-Vis scan for plasma treatment and free radical quenching experiments, ·OH, 1O2, and ·O2− mainly attacked the C=C of CFX and played an important role during the plasma treatment. Moreover, the toxicity of CFX solution after ·OH attack was reduced evidently compared with that of the initial CFX solution via further toxicity assessment.

Efficient and Sustainable Remediation of Refinery Wastewater using Electrocoagulation and Advanced Oxidation Techniques

Efficient and Sustainable Remediation of Refinery Wastewater using Electrocoagulation and Advanced Oxidation Techniques

Research Progress in the Treatment of High-Salinity Wastewater

The generation of high-salinity wastewater is closely associated with various industries, containing a plethora of dissolved salts such as chlorides, sulfates, and carbonates, which pose a significant threat to the environment and human health. Consequently, the treatment of high-salinity wastewater has emerged as a pivotal environmental challenge in contemporary society. This review aims to elucidate the sources and characteristics of high-salinity wastewater, as well as the current status and trends in the field of high-salinity wastewater treatment. First and foremost, we explore the means by which high-salinity wastewater is generated in different industries and the principal salt components it contains. We revisit conventional methods for high-salinity wastewater treatment, including chemical precipitation, ion exchange, evaporation-crystallization, and reverse osmosis, while emphasizing the application of biotechnological approaches. This includes the utilization of salt-tolerant microorganisms, biological adsorption, biodegradation processes, and various types of bioreactors. Advanced oxidation technologies also play a crucial role in high-salinity wastewater treatment. We introduce advanced oxidation techniques such as ozone oxidation, UV-catalyzed oxidation, and high-pressure water oxidation, emphasizing their potential in degrading organic compounds and reducing salt concentration. Furthermore, we discuss hybrid approaches, such as case studies combining biological treatment with advanced oxidation technologies, and the advantages and challenges associated with these integrated techniques. Finally, we provide an outlook on future trends, including research on novel and efficient biodegrading agents, advancements and innovations in advanced oxidation technologies, and the development of intelligent high-salinity wastewater treatment systems. Policy and industry trends will also influence the direction of high-salinity wastewater treatment field development. In summary, high-salinity wastewater treatment represents a complex and pressing environmental challenge. However, through the integration of diverse treatment technologies and ongoing research efforts, it is anticipated that more effective, cost-efficient, and environmentally friendly solutions can be developed to mitigate the impact of high-salinity wastewater on ecosystems and society.

The analytic hierarchy process method to design applicable decision making for the effective removal of 2-MIB and geosmin in water sources

Numerous utilities encounter issues with taste and odor that alter the public’s impression of the safety of drinking water. The creation of certain components in water naturally due to global climate change is another source of taste and odor components, in addition to industrial emissions. Geosmin and 2-methylisoborneol (2-MIB), both of which are generated by blue-green algae and actinomycetes, are two substances that contribute to the musty and earthy smells in drinking water sources. Unfortunately, current conventional treatment plants only partially remove 2-MIB and geosmin. Therefore, to protect the environment and public health, more up-to-date or optimized treatment methods should be applied to outdated treatment facilities. Best treatment practices, evaluation standards, and decision-making approaches, however, are still shrouded in mystery. The goal of this study was to identify the most effective treatment options for 2-MIB and geosmin. By using the analytical hierarchy process (AHP), a total of 22 assessment criteria were found and prioritized. A thorough literature search led to the identification of potential treatment options, and their effectiveness was evaluated. These options and priority rankings were decided upon using AHP in the decision-making process. Advanced oxidation techniques came out on top in the final priority ranking, followed by membrane filtering, adsorption, oxidation, hybrid processes, and traditional treatment methods. The applied analytical decision techniques may also be used to choose the optimal treatment options, even though the results are particular to 2-MIB and geosmin.

Tribocatalytic sterilization of BN2/CN Z-type heterojunctions

Considering advanced oxidation techniques offer new opportunities for microbial degradation and inactivation, in this study, Z-type heterojunctions of Ba1.4Sr3.6NdNb7Ti3O30-N2/g-C3N4 (BN2/CN) were successfully prepared using a solid-phase method and explored for their potential applications in tribocatalytic bactericidal inhibition. These results demonstrate that BN2/CN exhibits excellent inhibitory and inactivating effects on E. coli under tribocatalytic conditions. The UV–visible spectrum showed a gradual decrease in the survival rate of E. coli with the increase of tribocatalysis time, reaching an inactivation effect of 91% after 1 h, while fluorescence staining also confirmed that E. coli were essentially eliminated, with hardly any surviving bacteria observed under a laser confocal microscope. Hence, this study presents a novel catalytic approach for sterilization. Moreover, inhibition experiments demonstrated that the BN2/CN catalyst did not inhibit the growth of E. coli, tribocatalysis played a crucial role in the disinfection and sterilization processes. The inactivation of bacteria by BN2/CN catalyst was still above 90% after multiple cycles of sterilization experiments. Finally, we demonstrated that the production of •OH and •O2- during tribocatalysis is key to the inactivation of E. coli, thus achieving the desired effect of tribocatalytic sterilization.

Cu-Fe-Ni layered hydroxides / magnetic biochar composite as peroxymonosulfate activator for removal of enrofloxacin

In this research, an economical peroxymonosulfate (PMS) was employed as the oxidizing agent, while a sophisticated Cu-Fe-Ni layered hydroxides/magnetic biochar composite (MBC/CuFeNi LDHs, succinctly termed MC-1) functioned as a catalyst to mitigate the presence of enrofloxacin (ENR), a notably toxic contaminant discerned in water. The stratified architecture and intricate surface functional groups of the composite played pivotal roles in ENR's degradation. Metal oxides containing Cu, Fe, and Ni particularly exhibit excellent catalytic performance and oxygen storage capacity. The introduction of magnetic biochar (MBC) can reduce the aggregation of CuFeNi, and the rich functional groups on the surface of MBC can increase the content of functional groups on the surface of the composite, which helps to activate PMS. To be more precise, an impressive 91.6% of ENR was abated by the MC-1&PMS ensemble within a mere 20 min. Moreover, the catalytic dynamism of the MC-1&PMS synergy was predominantly ascribed to the production of hydroxyl (∙OH) radicals, complemented by sulfate (SO4∙-), singlet oxygen (1O2), and superoxide radicals (∙O2-). In the ensuing discourse, a conceivable degradation trajectory for ENR was postulated. Overall, this investigation furnishes novel perspectives in the conceptualization of heterogeneous carbon catalysts within the realm of advanced oxidation techniques.

Tocilizumab degradation via photo-catalytic ozonation process from aqueous

Following the advent of the coronavirus pandemic, tocilizumab has emerged as a potentially efficacious therapeutic intervention. The utilization of O3-Heterogeneous photocatalytic process (O3-HPCP) as a hybrid advanced oxidation technique has been employed for the degradation of pollutants. The present study employed a solvothermal technique for the synthesis of the BiOI-MOF composite. The utilization of FTIR, FESEM, EDAX, XRD, UV–vis, BET, TEM, and XPS analysis was employed to confirm the exceptional quality of the catalyst. the study employed an experimental design, subsequently followed by the analysis of collected data in order to forecast the most favorable conditions. The purpose of this study was to investigate the impact of several factors, including reaction time (30–60 min), catalyst dose (0.25–0.5 mg/L), pH levels (4–8), ozone concentration (20–40 mMol/L), and tocilizumab concentration (10–20 mg/L), on the performance of O3-HPCP. The best model was discovered by evaluating the F-value and P-value coefficients, which were found to be 0.0001 and 347.93, respectively. In the given experimental conditions, which include a catalyst dose of 0.46 mg/L, a reaction time of 59 min, a pH of 7.0, and an ozone concentration of 32 mMol/L, the removal efficiencies were found to be 92% for tocilizumab, 79.8% for COD, and 59% for TOC. The obtained R2 value of 0.98 suggests a strong correlation between the observed data and the predicted values, indicating that the reaction rate followed first-order kinetics. The coefficient of synergy for the degradation of tocilizumab was shown to be 1.22. The catalyst exhibited satisfactory outcomes, but with a marginal reduction in efficacy of approximately 3%. The sulfate ion (SO42−) exhibited no influence on process efficiency, whereas the nitrate ion (NO3−) exerted the most significant impact among the anions. The progress of the process was impeded by organic scavengers, with methanol exhibiting the most pronounced influence and sodium azide exerting the least significant impact. The efficacy of pure BiOI and NH2-MIL125 (Ti) was diminished when employed in their pure form state. The energy consumption per unit of degradation, denoted as EEO, was determined to be 161.8 KWh/m3-order.

Comparative study of naphthalene removal in different radicals-dominated systems: Kinetics, degradation intermediates, and pathways

The investigation on naphthalene (NAP) removal has been reported by increasing literatures due to its frequent detection in contaminated sites. However, the degradation intermediates of NAP in different radicals-dominated systems, as well as the estimation of their toxicities, have not been systematically illuminated. In this work, the degradation intermediates and pathways of NAP were thoroughly compared in hydroxyl radical (HO•) and sulfate radical (SO4−•) driven systems, and the radical addition was the dominant mechanism in both two systems. The toxicological assessment of 27 NAP degradation intermediates were performed, suggesting that the acute toxicity of intermediates produced by SO4−• addition could be weakened. Moreover, a kinetic model was established to simulate the kinetics of NAP degradation at various conditions, and the simulated results were in keeping with the experimental values. The effects of chemical concentration (NAP, oxidant, HCO3−, and Cl−) and solution pH on NAP removal were elucidated. The steady-state concentrations of radicals and their contribution to NAP removal were determined by the model. Finally, the performance of significant mineralization of NAP (96.9%) in SO4−•-driven system confirmed the superiority of SO4−•-based advanced oxidation technique in the remediation of NAP-contaminated site.

Photo Degradation of Solochrom Violet Dye by ZnO: Experimental and Theoretical Study

The present project involves photodegrading the dye solochrom violet under advanced oxidation techniques at (25 oC) temperature and UV light. Zinc Oxide (ZnO) and UV radiation at a wavelength of 580 nm were used to conduct the photocatalytic reaction of the solochrom violet dye. One of the factors looked into was the impact of the starting conditions. pH, the amount of original hydrogen peroxide, and the dye concentration time radiation were used. For hours, the kinetics and percentages of degradation were examined at various intervals. In general, it has been discovered that the photodegradation rates of the dye were greater when H2O2 and ZnO were combined with UV light. The best wavelength to use was determined. Modern oxidation techniques were proven to be very effective at degrading the majority of contaminants in wastewater. Using a spectrophotometer, the dye's photocatalytic browning was investigated. The theoretical calculation concentrated on the active site using the density functional theory technique and the Gaussian 09 program.

A critical review on the degradation mechanism of textile effluent during electrocatalytic oxidation: Removal optimization and degradation pathways

Industrial effluents containing synthetic dyes are responsible for significant non–aesthetic pollution and health-risk issues due to their release into the water bodies. Removal of these pollutants via biological, traditional physicochemical, and some advanced oxidation techniques is regularly scarce, expensive, or ineffective. Therefore, a more effective and economical approach to the degradation of dyes has received much attention over the last decade. Inside this framework, electrochemical oxidation treatment has found a place where it can be a leading technology in the near future, particularly for the removal of recalcitrant organic pollutants. In this review, the recent advancements in the mechanism of electrochemical oxidation (EO) of dye were explained. Most of the favorable electrochemical tools used for the dye effluent treatment were described with the following objectives: (1) to describe the fundamental facts of the EO process; (2) to deliberate the effect of operating parameters on the treatment performance; (3) to critically evaluate the benefits of various categories of the active and non–active anodes; (4) to determine the usability of various categories of the anode materials towards the dye degradation, kinetics controlled and process proficiency determination; (5) to determine the degradation mechanism of various dyes. Scale-up, techno-economic issues, and future research challenges were also discussed to encourage the practical applications of technology.

Ultrasound assisted Sono-Fenton process including FeMnO3 nanocatalysts for degradation of phenazopyridine

This study describes the synthesis of FeMnO3 magnetic nanocatalysts using a hydrothermal method. The nanocatalysts were used to degrade phenazopyridine hydrochloride (PhP) through the Sono-Fenton method, an advanced oxidation technique. The fabricated FeMnO3 nanocatalysts underwent various characterization techniques, including field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), fourier transform infrared spectroscopy (FT-IR), vibrating sample magnetometry (VSM), and Brunauer Emmett Teller (BET) analysis. Based on the XRD pattern and FE-SEM images, the cubic crystal structure and particle uniformity were confirmed. The catalytic performance of FeMnO3 nanocatalysts was examined in terms of their ability to remove PhP. Additionally, the impact of various parameters on the degradation rate of phenazopyridine was investigated. The optimal values for pH, nanocatalyst dosage, H2O2 concentration, and sonication time were found to be 10, 1 g/L, 1.2 mol/L, and 30 min, respectively. The degradation efficiency was eventually found to be 97 %. The most significant advantages of these nanocatalysts include their reusability without any significant decrease in reaction efficiency, rapid reaction time, ease of synthesis, and lack of requirement for complex systems.

Experimental Photodegradation of OPs and CBs by Advanced Oxidation Techniques in the Aqueous TiO2 Suspensions

The reaction of pesticides with the OH radical, is the most dominant annihilation reaction ofthe atmosphere. Phosmet, Azamethiphos, Coumaphos and Temephos were used as organophosphorouspesticides, and Methiocarb, Carbofuran and Pirimicarb compounds were used as carbamate pesticideswith the aim of investigating the kinetics of the reactions of Organophosphorous (OPs) and Carbamate(CBs) Pesticides with the OH radicals. In aqueous TiO2 suspensions, the degradation reactions viaphotocatalytic-effect of the seven pesticides selected as pollutants were analysed, and the impact of theinitial concentration was calculated. All experiments were conducted in the same photoreactor and underthe same conditions as three repetitions. The optimum amount of photocatalyst for the studied pesticidewas determined and TiO2 concentration for all experiments were taken as 0.2 g/100 mL. Considering thatorganic pollutants are present in water in trace amount, the initial concentrations for all organiccompounds were added so as to be1.0x10-4 molxL-1, into the suspensions and the solution containing theorganic pollutant. In this study, degradation speed of pesticides were determined experimentally, and thefastest degrading pesticide was tried to be found out.