Photodegradation of direct yellow-12 using UV/H2O2/Fe2+

A detailed investigation of photodegradation of direct yellow-12 (DY12) using UV/H(2)O(2)/Fe(2+) has been carried out in a photochemical reactor. Experiments studied degradation as a function of concentration, decolorization and reduction in chemical oxygen demand (COD). The effect of operating parameters, such as UV, pH, amount of Fenton's reagent (H(2)O(2) and FeSO(4)), and amount of DY12 dye has also been determined. It has been observed that simultaneous utilization of UV irradiation with Fenton's reagent increases the degradation rate of DY12 dye. The dye quickly losses its color and there is an appreciable decrease in COD value, indicating that the dissolved organic have been oxidized. The kinetics of degradation of the dye in dilute aqueous solutions follows pseudo-first order kinetics. Final products detected at the end of the reaction include NO(3)(-), NO(2)(-), N(2)O, NO(2), SO(2), CO(2) and CO. Results indicate that dye degradation is dependent upon pH, UV-intensity, concentration of Fenton's reagent and dye. Acidic pH has been found to be more suitable in comparison to neutral and alkaline. The optimum concentration of Fenton's reagent (H(2)O(2)/Fe(2+)) was found as 1500/500 mg l(-1) for 50 mg l(-1) DY12 dye in water at pH 4. The results indicate that the treatment of DY12 dye wastewater with UV/Fe(2+)/H(2)O(2) system is efficient.     

Degradation of dyehouse effluent containing C.I. Direct Blue 199 by processes of ozonation, UV/H2O2 and in sequence of ozonation with UV/H2O2

The decolorization and mineralization of cotton dyeing effluent containing C.I. Direct Blue 199 (DB 199) by advanced oxidation processes (AOPs) such as ozonation, UV/H(2)O(2), and in sequence of ozonation with UV/H(2)O(2) processes were evaluated in this study. By ozonation alone, the color removal was almost 100% for DB 199 and greater than 80% for dye bath effluent rapidly within 5 and 15 min, respectively. Meanwhile, the reduction of total organic carbon (TOC) was about 60% for DB 199 and almost no change for dye bath effluent, respectively due to incomplete mineralization. On the other hand, by UV/H(2)O(2) alone, the color removing not only took longer time but obtained lower removal efficiencies for DB 199 and dye bath effluent about 80% and 95% in 30 and 120 min, respectively. Nevertheless, it was more effective than ozonation for TOC removal while about 75% and 80% in 30 and 120 min, respectively. As a result, this study conducted the combination with the above two processes in order to shorten time demand as well as the higher removal efficiencies of both color and TOC simultaneously. Thus, the sequence process was designed to begin with ozonation to rapidly remove color proficiently, following by UV/H(2)O(2) in order to promptly remove remaining TOC efficiently. The successful process design by sequence of ozonation with UV/H(2)O(2) has proved the significant improvement for the removal of both color and TOC in dye bath effluent shortly. Besides, the lab prepared dye solution was substantially much easier to be decolorized than field dye bath effluent so that the lab results were utilized to design the further applications of pilot or full scale.     

Photodegradation of methyl tert-butyl ether (MTBE) by UV/H2O2 and UV/TiO2

Two UV-based advanced oxidation processes (AOPs), UV/H2O2 and UV/TiO2, were tested in batch reactor systems to evaluate the removal efficiencies and optimal conditions for the photodegradation of methyl tert-butyl ether (MTBE). The optimal conditions at an initial MTBE concentration of 1 mM ([MTBE]0=1 mM) were acidic and 15 mM H2O2 in UV/H2O2 system, and pH 3.0 and 2.0 g/l TiO2 in UV/TiO2 suspended slurries system under 254-nm UV irradiation. Under the optimal conditions, MTBE photodegradation during the initial period of 60 min in UV/H2O2 and UV/TiO2 systems reached 98 and 80%, respectively. In both systems, MTBE photodegradation decreased with increasing [MTBE]0. While MTBE photodegradation rates increased with increasing dosage of H2O2 (5-15 mM) and TiO2 (0.5-3 g/l), further increase in the dosage of H2O2 (20 mM) or TiO2 (4 g/l) adversely reduced the MTBE photodegradation. Pseudo first-order kinetics with regard to [MTBE] can be used to describe the MTBE photodegradation in both systems. The pseudo first-order rate constants linearly increased with the increase in the molar ratio of [H2O2]0 to [MTBE]0 in UV/H2O2 system and linearly increased with the decrease in [MTBE]0 in UV/TiO2 system.     

Decolourization and mineralization of commercial reactive dyes by using homogeneous and heterogeneous Fenton and UV/Fenton processes

The oxidative decolourization and mineralization of three reactive dyes in separately prepared aqueous solutions C.I. Reactive Yellow 3 (RY3), C.I. Reactive Blue 2 (RB2) and C.I. Reactive Violet 2 (RV2) by using homogeneous and heterogeneous Fenton and UV/Fenton processes have been investigated. The effects of H(2)O(2), Fe(2+) and Fe(0) concentrations, Fe(2+)/H(2)O(2) and Fe(0)/H(2)O(2) molar ratios at pH 3 and T=23+/-1 degrees C have been studied. Optimal operational conditions for the efficient degradation of all three dye solutions (100 mg L(-1)) were found to be Fe(2+)/H(2)O(2)=0.5mM/20mM and Fe(0)/H(2)O(2)=2mM/1mM. The experimental results showed that the homogeneous Fenton process employing UV irradiation was the most effective. By using this process, the high levels of mineralization (78-84%) and decolourization (95-100%) were achieved. Pseudo-first-order degradation rate constants were obtained from the batch experimental data.     

Application of Box-Wilson experimental design method for the photodegradation of bakery's yeast industry with UV/H2O2 and UV/H2O2/Fe(II) process

Decolorization and mineralization of bakery's yeast industry effluent by photochemical advanced oxidation processes (AOPs) utilizing UV with hydrogen peroxide and Photo-Fenton, were investigated in a laboratory scale photo-reactor equipped with a 16 W low-pressure mercury vapor lamp. The Box-Wilson experimental design method was employed to evaluate the effects of major process variables (e.g. pH, oxidant dose, and irradiation time) on the decolorization efficiency. Response function coefficients were determined by regression analysis of the experimental data and prediction results agreed with the experimental results. The optimum hydrogen peroxide concentration and irradiation time were found to be 5 mM and 50 min at pH 3, respectively, for UV/H2O2 process. In the Photo-Fenton process application, maximum decolorization efficiency (96.4%) was obtained at the optimum reaction conditions that were 100 mM H2O2 and 1 mM Fe(II) doses at pH 3, and 10 min of irradiation time.     

Pre-ozonation coupled with UV/H2O2 process for the decolorization and mineralization of cotton dyeing effluent and synthesized C.I. Direct Black 22 wastewater

The decolorization and mineralization of cotton dyeing effluent containing C.I. Acid Black 22 as well as synthesized C.I. Acid Black 22 wastewater by means of advanced oxidation processes (AOPs), such as UV/H2O2, O3 and pre-ozonation coupled with UV/H2O2 processes, were evaluated in this study. It was observed that the UV/H2O2 process took longer retention time than ozonation for color removal of dye bath effluent. Reversely, the total organic carbon (TOC) removal showed different phenomena that ozonation and UV/H2O2 process obtained 33 and 90% of removal efficiency for 160 min of retention time, respectively. Additionally, laboratory synthesized dye wastewater was substantially more efficient in the decolorization process than dye bath effluent. Therefore, in this work, pre-ozonation coupled with UV/H2O2 process was employed to enhance the reduction of both color and TOC in dye bath effluent at the same time. At the same time, the retention time demand was reduced to less than 115 min for 90% removal of TOC and color by this combined process.     

Treatment of MSW landfill leachate by a thin gap annular UV/H2O2 photoreactor with multi-UV lamps

The treatment of leachate from landfills is a major disposal problem for municipal solid waste. The leachate is generally recalcitrant to be treated according to complicated characteristics and high color intensity resulting further threat for environment and human health. In this work, the designed thin gap annular photoreactor with 4-UV lamps in UV/H2O2 process was proposed to decolor and remove chemical oxygen demand (COD) from the landfill leachate for solving this environmental problem. Meanwhile, the operating parameters such as UV dosage, hydrogen peroxide concentration and leachate strength were evaluated. The landfill leachate treated with the maximum dosage of 4-UV lamps and 232.7 mM of hydrogen peroxide concentration achieved 72 and 65% of color and COD removal efficiencies in 300 min. As for less concentrated leachate of 20% strength, 91% of color and 87% of COD were removed within only 120 min. From the experimental results, the UV/H2O2 process in this work was an effective pre-treatment or treatment technology for landfill leachate.     

Kinetics of decolorization of an azo dye in UV alone and UV/H(2)O(2) processes

The decolorization of C.I. Acid Red 27 (AR27), a monoazo anionic dye, was studied in the ultraviolet radiation (UV) alone and UV plus hydrogen peroxide (UV/H(2)O(2)) processes. The experimental results indicated that the kinetics of both oxidation processes fit well by pseudo-first order kinetics. The reaction rate was sensitive to the operational parameters and increased with increasing H(2)O(2) concentration and light intensity. The reaction orders of H(2)O(2) concentration and light intensity in both processes were obtained with linear regression method. A regression model was developed for pseudo-first order rate constant (k(ap,UV/H(2)O(2))) as a function of the Cconcentration and UV light intensity. (k(ap,UV/H(2)O(2)))=(2 x 10(-4)I(0.75)(0) + k(3)I(1.38)(0)[H(2)O(2)](n)(0))phi(AR27). As a result of two opposing effects of H(2)O(2) concentration at low and high concentrations, n has a value of 0.49 and -0.39 and k(3) has a value of 3 x 10(-4) and 0.1 for the regions of 0 mg l(-1) < [H(2)O(2)](0) < 650 mg l(-1) and 650 mg l(-1) < [H(2)O(2)](0) < 1500 mg l(-1)1, respectively. PhiAR27 is the initial dye concentration correlation index for developing of model for different initial concentrations of AR27. This rate expression can be used for predicting k(ap,UV/H(2)O(2) at different conditions in UV alone and UV/H2O2 processes. The results show that UV alone cannot be an efficient method for decolorization of AR27 in comparison with UV/H(2)O(2) process, therefore the first term of the model can be neglected.     

Photochemical mineralization of di-n-butyl phthalate with H2O2/Fe3+

This study evaluated the performance of photo-Fenton reaction initiated by the UV irradiation with H(2)O(2)/Fe(3+), denoted as UV/H(2)O(2)/Fe(3+), to decompose di-n-butyl phthalate (DBP) in the aqueous solution. The concentration of total organic carbon (TOC) was chosen as a mineralization index of the decomposition of DBP by the UV/H(2)O(2)/Fe(3+) process. A second-order kinetic model with respect to TOC was adequately adopted to represent the mineralization of DBP by the UV/H(2)O(2)/Fe(3+) process. The experimental results of this study suggested that the dosages with 4.74 x 10(-5) mol min(-1)L(-1) H(2)O(2) and initial Fe(3+) loading concentration of 4.50 x 10(-4) mol L(-1) in the solution at pH 3.0 with 120 microW cm(-2) UV (312 nm) provided the optimal operation conditions for the mineralization of DBP (5 mg L(-1)) yielding a 92.4% mineralization efficiency at 90 min reaction time.     

Decolorization of alkaline TNT hydrolysis effluents using UV/H(2)O(2)

Effects of H(2)O(2) dosage (0, 10, 50, 100 and 300 mg/l), reaction pH (11.9, 6.5 and 2.5) and initial color intensity (85, 80 and 60 color unit) on decolorization of alkaline 2,4,6-trinitrotoluene (TNT) hydrolysis effluents were investigated at a fixed UV strength (40 W/m(2)). Results indicated that UV/H(2)O(2) oxidation could efficiently achieve decolorization and further mineralization. Pseudo first-order decolorization rate constants, k, ranged between 2.9 and 5.4 h(-1) with higher values for lower H(2)O(2) dosage (i.e., 10 mg/l H(2)O(2)) when the decolorization occurred at the reaction pH of 11.9, whereas a faster decolorization was achieved with increase in H(2)O(2) dosage at both pH 6.5 and 2.5, resulting in the values of k as fast as 15.4 and 26.6 h(-1) with 300 mg/l H(2)O(2) at pH 6.5 and 2.5, respectively. Difference in decolorization rates was attributed to the reaction pH rather than to the initial color intensity, resulting from the scavenging of hydroxyl radical by carbonate ion. About 40% of spontaneous mineralization was achieved with addition of 10 mg/l H(2)O(2) at pH 6.5. Efficient decolorization and extension of H(2)O(2) longevity were observed at pH 6.5 conditions. It is recommended that the colored effluents from alkaline TNT hydrolysis be neutralized prior to a decolorization step.     

Decolorization of C.I. Acid Blue 9 solution by UV/Nano-TiO(2), Fenton, Fenton-like, electro-Fenton and electrocoagulation processes: a comparative study

This study makes a comparison between UV/Nano-TiO(2), Fenton, Fenton-like, electro-Fenton (EF) and electrocoagulation (EC) treatment methods to investigate the removal of C.I. Acid Blue 9 (AB9), which was chosen as the model organic contaminant. Results indicated that the decolorization efficiency was in order of Fenton>EC>UV/Nano-TiO(2)>Fenton-like>EF. Desired concentrations of Fe(2+) and H(2)O(2) for the abatement of AB9 in the Fenton-based processes were found to be 10(-4)M and 2 x 10(-3) M, respectively. In the case of UV/Nano-TiO(2) process, we have studied the influence of the basic photocatalytic parameters such as the irradiation time, pH of the solution and amount of TiO(2) nanoparticles on the photocatalytic decolorization efficiency of AB9. Accordingly, it could be stated that the complete removal of color, after selecting desired operational parameters could be achieved in a relatively short time, about 25 min. Our results also revealed that the most effective decomposition of AB9 was observed with 150 mg/l of TiO(2) nanoparticles in acidic condition. The effect of operational parameters including current density, initial pH and time of electrolysis were studied in electrocoagulation process. The results indicated that for a solution of 20 mg/l AB9, almost 98% color were removed, when the pH was about 6, the time of electrolysis was 8 min and the current density was approximately 25 A/m(2) in electrocoagulation process.     

An integrated technique using zero-valent iron and UV/H2O2 sequential process for complete decolorization and mineralization of C.I. Acid Black 24 wastewater

The zero-valent iron (ZVI) reduction succeeds for decolorization, while UV/H(2)O(2) oxidation process results into mineralization, so that this study proposed an integrated technique by reduction coupling with oxidation process in order to acquire simultaneously complete both decolorization and mineralization of C.I. Acid Black 24. From the experimental data, the zero-valent iron addition alone can decolorize the dye wastewater yet it demanded longer time than ZVI coupled with UV/H(2)O(2) processes (Red-Ox). Moreover, it resulted into only about 30% removal of the total organic carbon (TOC), which was capable to be effectively mineralized by UV/H(2)O(2) process. The proposed sequential ZVI-UV/H(2)O(2) integration system cannot only effectively remove color and TOC in AB 24 wastewater simultaneously but also save irradiation power and time demand. Furthermore, the decolorization rate constants were about 3.77-4.0 times magnitude comparing with that by UV/H(2)O(2) process alone.     

Decolorization and mineralization of a phthalocyanine dye C.I. Direct Blue 199 using UV/H2O2 process

In this study, the successful decolorization and mineralization of phthalocyanine dye (C.I. Direct Blue 199, DB 199) by an advanced oxidation process (AOP), UV/H2O2, were observed while the experimental variables such as hydrogen peroxide dosage, UV dosage, initial dye concentration and pH were evaluated. The operating conditions for 90% decolorization of C.I. DB 199 and 74% removal of total organic carbon (TOC) were obtained for initial dye concentration of 20 mgl(-1), hydrogen peroxide dosage of 116.32 mM, UV dosage of 560 W and pH of 8.9 in 30 min. The pseudo-first order rate constant is a linear function of reverse of initial dye concentration. They linearly increased by incrementing UV dosage, yet were non-linear enhancement by increasing the hydrogen peroxide concentration. A higher pseudo-first order rate constant about 0.15 min(-1) was observed while hydrogen peroxide concentration within 5.82-116.32 mM. Moreover, the decolorization of C.I. DB 199 was observed to be more difficult than that of an azo dye, C.I. Acid Black 1, under the same operating conditions.     

A statistical experiment design approach for advanced oxidation of Direct Red azo-dye by photo-Fenton treatment

Advanced oxidation of an azo-dye, Direct Red 28 (DR 28) by photo-Fenton treatment was investigated in batch experiments using Box-Behnken statistical experiment design and the response surface analysis. Dyestuff (DR 28), H(2)O(2) and Fe(II) concentrations were selected as independent variables in Box-Behnken design while color and total organic carbon (TOC) removal (mineralization) were considered as the response functions. Color removal increased with increasing H(2)O(2) and Fe(II) concentrations up to a certain level. High concentrations of H(2)O(2) and Fe(II) adversely affected the color and TOC removals due to hydroxyl radical scavenging effects of high oxidant and catalyst concentrations. Both H(2)O(2) and Fe(II) concentration had profound effects on decolorization. Percent color removal was higher than TOC removal indicating formation of colorless organic intermediates. Complete color removal was achieved within 5min while complete mineralization took nearly 15min. The optimal reagent doses varied depending on the initial dyestuff dose. For the highest dyestuff concentration tested, the optimal H(2)O(2)/Fe(II)/dyestuff ratio resulting in the maximum color removal (100%) was predicted to be 715/71/250 (mgL(-1)), while this ratio was 1550/96.5/250 for maximum mineralization (97.5%).     

Ametryn degradation in the ultraviolet (UV) irradiation/hydrogen peroxide (H2O2) treatment

Ultraviolet (UV) irradiation (253.7nm) in the presence of hydrogen peroxide (H(2)O(2)) was used to decompose aqueous ametryn. The concentrations of ametryn were measured with time under various experiment conditions. The investigated factors included H(2)O(2) dosages, initial pH, initial ametryn concentrations, and a variety of inorganic anions. Results showed that ametryn degradation in UV/H(2)O(2) process was a pseudo-first-order reaction. Removal rates of ametryn were greatly affected by H(2)O(2) dosage and initial concentrations of ametryn, but appeared to be slightly influenced by initial pH. Furthermore, we investigated the effects of four anions (SO(4)(2-), Cl(-), HCO(3)(-), and CO(3)(2-)) on ametryn degradation by UV/H(2)O(2). The impact of SO(4)(2-) seemed to be insignificant; however, Cl(-), HCO(3)(-), and CO(3)(2-) considerably slowed down the degradation rate because they could strongly scavenge hydroxyl radicals (OH) produced during the UV/H(2)O(2) process. Finally, a preliminary cost analysis revealed that UV/H(2)O(2) process was more cost-effective than the UV alone in removal of ametryn from water.     

Effects of gap size and UV dosage on decolorization of C.I. Acid Blue 113 wastewater in the UV/H2O2 process

The wastewater from textile dyeing industry is difficult to be treated successfully according to both high variability of composition and color intensity. To investigate the effects of reactor gap size and UV dosage on the decolorization of dye wastewater, a commercially available azo dye C.I. Acid Blue 113 was chosen as a model compound. UV/H2O2 processes with various gap sizes and setups of plug flow reactor and recirculated batch reactor were proposed to deal with the dye wastewater in this study. The experimental parameters including the design of reactor configurations of annular gap size, and in batch system or plug flow reactors and hydrogen peroxide dosage, UV dosage were investigated. The gap size of reactor was adjusted by different diameter of reactor shells in order to optimize the reactor configuration. The color removal percentage was used to evaluate the treatment efficiency. An optimal hydrogen peroxide concentration of 46.53 mM was observed in this study for highest decolorization rate. Besides, the pseudo-first-order rate constant of 3.14 min(-1) was obtained by plug flow reactor with 0.5 cm gap size, 120.70 W/l of UV dosage and 23.27 mM of H2O2 dosage. The first-order rate constant, which was about 20 times less than that of plug flow reactor, was obtained 0.1422 min(-1) by recirculated batch reactor with 2.0 cm gap size, 7.0 W/l of UV and 23.27 mM of H2O2 dosages. Ultimately, we developed an effective pre-treatment or treatment technology for dye wastewater to provide the dyeing industries and dye manufacturers an alternative to meet the effluent standards.     

Photodegradation and toxicity changes of antibiotics in UV and UV/H(2)O(2) process

The photodegradation of three antibiotics, oxytetracycline (OTC), doxycycline (DTC), and ciprofloxacin (CIP) in UV and UV/H(2)O(2) process was investigated with a low-pressure UV lamp system. Experiments were performed in buffered ultrapure water (UW), local surface water (SW), and treated water from local municipal drinking water treatment plant (DW) and wastewater treatment plant (WW). The efficiency of UV/H(2)O(2) process was affected by water quality. For all of the three selected antibiotics, the fastest degradation was observed in DW, and the slowest degradation occurred in WW. This phenomenon can be explained by R(OH,UV), defined as the experimentally determined OH radical exposure per UV fluence. The R(OH,UV) values represent the background OH radical scavenging in water matrix, obtained by the degradation of para-chlorobenzoic acid (pCBA), a probe compound. In natural water, the indirect degradation of CIP did not significantly increase with the addition of H(2)O(2) due to its effective degradation by UV direct photolysis. Moreover, the formation of several photoproducts and oxidation products of antibiotics in UV/H(2)O(2) process was identified using GC-MS. Toxicity assessed by Vibrio fischer (V. fischer), was increased in UV photolysis, for the photoproducts still preserving the characteristic structure of the parent compounds. While in UV/H(2)O(2) process, toxicity increased first, and then decreased; nontoxic products were formed by the oxidation of OH radical. In this process, detoxification was much easier than mineralization for the tested antibiotics, and the optimal time for the degradation of pollutants in UV/H(2)O(2) process would be determined by parent compound degradation and toxicity changes.     

Degradation and by-product formation of diazinon in water during UV and UV/H(2)O(2) treatment

Kinetics and degradation products resulting from the application of UV and UV/H(2)O(2) to the US EPA Contaminant Candidate List pesticide diazinon were studied. Batch experiments were conducted with both monochromatic (low pressure [LP] UV 253.7 nm) and polychromatic (medium pressure [MP] UV 200-300 nm) UV sources alone or in the presence of up to 50 mg l(-1) H(2)O(2), in a quasi-collimated beam apparatus. Degradation of diazinon by both UV and UV/H(2)O(2) exhibited pseudo first order reaction kinetics, and quantum yield of 8.6 x 10(-2) and 5.8 x 10(-2) mol E(-1) for LP and MP lamps respectively. Photolysis studies under MP UV lamp showed 2-isopropyl-6-methyl-pyrimidin-4-ol (IMP) to be the main degradation product of diazinon at aqueous solution pH values of 4, 7 and 10. Trace levels up to 1.8 x 10(-3) microM of diazinon oxygen analogue diethyl 2-isopropyl-6-methylpyrimidin-4-yl phosphate (diazoxon) were detected only during the UV/H(2)O(2) reaction. Decay of both products was observed, as the UV/H(2)O(2) reaction prolonged, yet no mineralization was achieved over the UV fluence levels examined. Photolysis kinetics, quantum yield and UV/H(2)O(2) degradation of the reaction product IMP was determined using MP UV lamp at pH values of 4, 7 and 10.     

Inactivation of E. coli, B. subtilis spores, and MS2, T4, and T7 phage using UV/H2O2 advanced oxidation

The goal of this study was to evaluate the potential of an advanced oxidation process (AOP) for microbiocidal and virucidal inactivation. The viruses chosen for this study were bacteriophage MS2, T4, and T7. In addition, Bacillus subtilis spores and Escherichia coli were studied. By using H(2)O(2) in the presence of filtered ultraviolet (UV) irradiation (UV/H(2)O(2)) to generate wavelengths above 295nm, the direct UV photolysis disinfection mechanism was minimized, while disinfection by H(2)O(2) was also negligible. Virus T4 and E. coli in phosphate buffered saline (PBS) were sensitive to >295nm filtered UV irradiation (without H(2)O(2)), while MS2 was very resistant. Addition of H(2)O(2) at 25mg/l in the presence of filtered UV irradiation over a 15min reaction time did not result in any additional disinfection of virus T4, while an additional one log inactivation for T7 and 2.5 logs for MS2 were obtained. With E. coli, only a slight additional effect was observed when H(2)O(2) was added. B. subtilis spores did not show any inactivation at any of the conditions used in this study. The OH radical exposure (CT value) was calculated to present the relationship between the hydroxyl radical dose and microbial inactivation.     

Photochemical degradation of diethyl phthalate with UV/H2O2

The decomposition of diethyl phthalate (DEP) in water using UV-H2O2 process was investigated in this paper. DEP cannot be effectively removed by UV radiation and H2O2 oxidation alone, while UV-H2O2 combination process proved to be effective and could degrade this compound completely. With initial concentration about 1.0mg/L, more than 98.6% of DEP can be removed at time of 60 min under intensity of UV radiation of 133.9 microW/cm2 and H2O2 dosage of 20mg/L. The effects of applied H2O2 dose, UV radiation intensity, water temperature and initial concentration of DEP on the degradation of DEP have been examined in this study. Degradation mechanisms of DEP with hydroxyl radicals oxidation also have been discussed. Removal rate of DEP was sensitive to the operational parameters. A simple kinetic model is proposed which confirms to pseudo-first order reaction. There is a linear relationship between rate constant k and UV intensity and H2O2 concentration.