Degradation Of Sodium Dodecyl Benzene Sulfonate Research Articles

Degradation of sodium dodecylbenzene sulfonate (SDBS) and high efficiency treatment of real grey water by TiO2-loaded stainless steel mesh under VUV irradiation

Reusing treated greywater indoors in buildings is an advanced strategy to increase the utilization of limited water resources, but currently there is a lack of feasible technologies for efficiently purifying greywater indoors. In this study, we construct the heterogeneous TiO2-stainless steel mesh (SSM) interface with photocatalytic degradation of sodium dodecylbenzene sulfonate (SDBS) by under vacuum ultraviolet (VUV) irradiation. At the initial SDBS of 10 mg/L, the degradation rates of SDBS with UV/TiO2-SSM and VUV/TiO2-SSM process were 53 % and 74 % respectively within 50 min. The results of specific scavengers experiments and EPR analysis revealed that the ·OH, h+ and direct photolysis contributed to SDBS degradation and mineralization. The degradation rate of SDBS in VUV/TiO2-SSM process was higher at weak acid or weak alkali conditions, while the performance of UV/TiO2-SSM process was better at alkaline conditions. Both Cl− and HCO3− could inhibit SDBS degradation, while SO42− slightly promoted the degradation. Active oxygen species mainly degrade SDBS in two ways: by attacking the α carbon, β carbon, or branched chain carbon on the alkane chain; or by attacking the adjacent carbon on the alkane chain, resulting in the formation of three branch forms of products. The toxicity of the intermediate products shows a decreasing or stable trend. The experiment shows that UV or VUV photocatalytic TiO2-SSM has a good prospect of removing anionic surfactant in the real greywater. This study provides strategies for the development and design of indoor water reuse technologies and devices in buildings.

Efficient treatment of surfactant containing wastewater by photocatalytic ozonation with BiPO4 nanorods

In this study, monoclinic BiPO4 nanorods were fabricated by one-pot solvothermal method. Its catalytic capability in photocatalytic ozonation process was tested by degradation and mineralization of sodium dodecyl benzene sulfonate (SDBS) solution. The results demonstrated that the TOC removal rate was dramatically improved to 90.0% at 75 min for UV/O3/BiPO4 process, which was 4.9 and 3.8 times more than that of UV/BiPO4 and O3. Moreover, the pseudo-first-order kinetic constant (0.337 min−1) and mineralization rate (90.0%) for SDBS degradation using BiPO4 in UV/O3 process were 1.6 and 1.3 times as great as that of conventional TiO2 photocatalyst (0.206 min−1, 67.3%). The influence of BiPO4 dosage, O3 concentration initial pH and coexisted ions on SDBS degradation in UV/O3/BiPO4 process were also investigated. The outcome of quenching studies illustrated both ·OH and h+ contributed prominently to SDBS degradation in UV/O3/BiPO4 process, implying that high valence band position of BiPO4 could promote the synergism between photocatalysis and ozonation. The degradation pathway of SBDS was proposed by combination of intermediates analysis and DFT calculation. Real carwash wastewater was chosen as typical surfactant containing wastewater to explore the practical application of UV/O3/BiPO4 technology. During 30 min, COD and LAS removal efficiency reached 59.7% and 70.6%, respectively. The quality indices of effluent could meet the requirements for reuse of carwash water in Water Quality Standard for Urban Miscellaneous Use in China. Energy consumption in the process was calculated as 13.9 kW h m−3, which was about 3.6 and 2.2 times less than that of UV/BiPO4 and O3 process, respectively. The results suggest that UV/O3/BiPO4 system has an application potential for surfactant containing wastewater treatment or recycle.

Remediation of Surfactants Used by VUV/O3 Techniques: Degradation Efficiency, Pathway and Toxicological Analysis.

Surfactants are increasingly used in systems that come into contact with the human body, such as food, pharmaceuticals, cosmetics and personal hygiene products. Increasing attention is being devoted to the toxic effects of surfactants in various human contact formulations, as well as the removal of residual surfactants. In the presence of ozone (O3), anion surfactants-a characteristic micro-pollutant-such as sodium dodecylbenzene sulfonate (SDBS) in greywater, can be removed using radical advanced oxidation. Herein, we report a systematic study of the SDBS degradation effect of O3 activated by vacuum ultraviolet (VUV) irradiation and the influence of water composition on VUV/O3, and determined the contribution of radical species. We show a synergistic effect of VUV and O3, while VUV/O3 reached a higher mineralization (50.37%) than that of VUV (10.63%) and O3 (29.60%) alone. The main reactive radicals of VUV/O3 were HO•. VUV/O3 had an optimal pH of 9. The addition of SO42- had almost no effect on the degradation of SDBS by VUV/O3, Cl- and HCO3- slightly reduced the reaction rate, and NO3- had a significant inhibition on the degradation. In total, SDBS had three isomers, with which the three degradation pathways were very comparable. Compared with SDBS, the toxicity and harmfulness of the degradation by-products of the VUV/O3 process decreased. Additionally, VUV/O3 could degrade synthetic anion surfactants from laundry greywater effectively. Overall, the results show the potential of VUV/O3 in safeguarding humans from residual surfactant hazards.

Accelerated transformation of sodium dodecylbenzene sulfonate surfactant in the UV/chlorine process: Kinetics and formation of chlorinated disinfection by-products

The degradation kinetics of Sodium dodecylbenzene sulfonate (SDBS) surfactant in the UV/chlorine process was comprehensively investigated, and the formation of chlorinated disinfection by-products (Cl-DBPs) were determined. Results showed that the degradation of SDBS by UV, chlorine and UV/chlorine all followed pseudo-first-order kinetics. The rate constant by UV/chlorine in ultrapure water was approximately 3 times higher than the sum of those by UV and chlorine, and decreased from 0.297 to 0.063 min−1 with pH increasing from 5.0 to 9.0. Water matrices such as NO3−, HCO3− and natural organic matter (NOM) inhibited the degradation efficiency to a certain extent. The second-order rate constant of SDBS with HO• was determined as 2.84 × 109 M−1 s−1. Through using different probes, the main contributors to SDBS degradation were found to be UV, HO• and reactive chlorine species (RCS). Meanwhile, 64.0 μg L−1 trichloromethane (TCM) and 8.7 μg L−1 chloral hydrate (CH) were simultaneously formed within 30 min of UV/chlorine treatment. The concentration of total organic chlorine (TOCl) (424.0 μg L−1) was obviously higher than those of TCM and CH. In addition, 414 unknown by-products formed during UV/chlorine treatment were detected by mass spectrometry at a high confidence level, including 64 monochloro-DBPs and 2 dichloro-DBPs. Although UV/chlorine process accelerated SDBS degradation, the associated DBP formation deserves enough attention.

Degradation of sodium dodecyl benzenesulfonate by vacuum ultraviolet irradiation

Sodium dodecyl benzenesulfonate (SDBS) is a common anionic surfactant used in detergents, and a major household pollutant. SDBS released with bathing and laundry wastewater causes eutrophication of water bodies and toxicity in aquatic organisms. We compared the degradation of SDBS in aqueous solution, by vacuum ultraviolet (VUV, 254 nm and 185 nm) and ultraviolet irradiation (UV, 254 nm). Using lab-scale reactors, VUV degraded SDBS more efficiently than UV, also achieving a higher mineralization rate. HO was the main reactive oxygen species produced by VUV. SDBS concentration affected the distribution of absorbed VUV and UV photons, and influenced the reaction triggered. VUV was more efficient at lower concentrations, when indirect oxidation by HO was prevalent. The UV process, relied mostly on direct photolysis, and was affected slightly by initial concentration. VUV was more efficient at solution pH of 5 and 9, while UV performed better at alkaline conditions. Temperature increased the degradation rates for both processes. The addition of SO42− slightly promoted SDBS degradation in the VUV process, while Cl− and HCO3− inhibited it. For UV, SO42− and Cl− illustrated no significant difference on the degradation, while HCO3− had a positive impact on the system. We identified the four photoproducts of SDBS degradation by VUV, and proposed a degradation pathway. Finally, the fact the VUV could be efficiently used to remove anionic surfactant from real wastewater, proved that it can be applied efficiently with low energetic consumption.

Sequential vertical flow trickling filter and horizontal flow multi-soil-layering reactor for treatment of decentralized domestic wastewater with sodium dodecyl benzene sulfonate

Sequential vertical flow trickling filter and horizontal flow multi-soil-layering bioreactor were investigated for the treatment of decentralized domestic wastewater at various concentrations of sodium dodecyl benzene sulfonate (SDBS). Results have shown that the removal rate of COD could reach 92.1% at initial COD concentration of 960 mg/L (800 mg/L was provided by SDBS). NH4+-N concentration could be reduced from 52.4 to 9.71 mg/L without aeration. Besides, a quadratic function model was fit to describe the relationship between the relative activity of amylase and the protein content in extracellular polymer substance. SDBS could inhibit the transport and metabolisms of amino acids, lipids and carbohydrates in biofilms. The analysis of three-dimensional fluorescence diagram indicated that the peak in excitation/emission wavelengths = 310–340/370–430 nm was the characteristic peaks of some active substances such as some enzymes in EPS. Only Microbacterium could totally offset the toxicity of SDBS degradation products.

Microwave assisted persulfate induced degradation of sodium dodecyl benzene sulfonate

Microwave assisted persulfate induced degradation of sodium dodecyl benzene sulfonate (SDBS) was investigated, focusing on establishing the best conditions for maximum degradation. The study involving different persulfate based oxidants, such as potassium persulfate (KPS), ammonium persulfate (NH3PS) and sodium persulfate (NaPS), revealed that the extent of degradation as 98.3, 82.2 and 68.2% was obtained for the use of KPS, NH3PS and NaPS, respectively. The study of the effect of SDBS concentration (25–100 mg/L), oxidant loading (0–3 g/L) and power (140–350 W) established that degradation decreased with an increase in the operating parameter beyond the optimum condition. Under optimized conditions using potassium persulfate (KPS) as an oxidant, 51.6% and 98.3% degradation of 50 mg/L SDBS solution was obtained by conventional and microwave assisted chemical oxidation approach, respectively, under optimized conditions of power, oxidant loading, volume and time maintained as 280 W, 2 g/L, 250 mL and 28 min, respectively. Extending the conventional approach for 120 min resulted in degradation of 92.5%, which establishes that microwave helps in reducing the treatment time significantly. Kinetic study revealed pseudo-first-order behavior for degradation of SDBS. Energy per order (EEO) for conventional and microwave assisted degradation was observed to be 840 and 317.33 kWh/m3, respectively. Overall, microwave assisted persulfate induced degradation of SDBS has been established to be promising method giving rapid degradation and better economics.

Degradation of SDBS in water solutions using plasma in gas-liquid interface discharge: Performance, byproduct formation and toxicity evaluation

Sodium Dodecyl Benzene Sulfonate (SDBS) is a major anionic surfactant and is widely used in the detergent industry. The large amount of SDBS discharged into water bodies can cause eutrophication of water bodies and produce toxic effects in aquatic organisms. In this study, the degradation of SDBS and variation in toxicity during the plasma treatment process were evaluated using gas-liquid interface discharge. The experimental results showed that SDBS could be removed effectively after discharge for 8 min at an initial concentration of 30 mg/L. The SDBS removal could be fitted by the first-order kinetic model. The plasma voltage and initial pH had great effects on the removal of SDBS. At the same voltage, SDBS could be removed faster under alkaline conditions. Compared to ozonation, much higher SDBS and TOC removal performance was achieved by plasma treatment. HO, which was mainly derived from the reaction of H2O2 and ozone in the solutions, played a major role in the oxidation process. The toxicity evaluation showed that plasma treatment could reduce the acute toxicity effectively initially, and also indicated that the formed intermediates of formate, oxalate, malonate and sulfate had no negative effects. However, further treatment caused an increase in toxicity, which was mainly correlated with the excessive residual H2O2 formed during the plasma process. This study indicated that while applying plasma treatment, the conditions should be optimized comprehensively to maintain a low H2O2 residual in the effluent.

Resolving the Thermoinduced Electrochemistry for an In-Depth Understanding of the STEP Degradation of SDBS.

The solar thermal electrochemical process (STEP) has sustainably accounted for the solar thermo- and electrochemical oxidation of sodium dodecyl benzene sulfonate (SDBS) fully driven by solar energy, gaining a high efficiency with a fast rate by the combination of thermochemistry and electrochemistry. In this article, thermoinduced electrochemistry was resolved for an in-depth understanding of the STEP degradation of SDBS. We employed thermodependent cyclic voltammetry, temperature-dependent fluorescence-electrochemical spectroscopy, and time-dependent electrochemical current spectroscopy for studying the electrochemistry, including the reaction, pathway, and mechanism. First, thermodependent cyclic voltammetric spectra indicated that the SDBS in sodium chloride solution is oxidized via an indirect process initialized by active chlorine, substantially accelerating and completing the oxidation process. Second, temperature-dependent fluorescence-electrochemical spectra displayed the pathway and kinetics by finding the initial desulfonation and the subsequent breaking of the alkyl side chain and benzene ring. Finally, time-dependent electrochemical current spectra demonstrated that the initial desulfonation is the fast step by generating the high current and the subsequent breaking is the slow one by a low current response, which is in agreement with the temperature-dependent fluorescence-electrochemical spectra. A panoramic view is proposed and schemed for fully understanding the process and mechanism of the STEP degradation of SDBS. Moreover, the efficiency and effectiveness of SDBS degradation were proven to be significantly enhanced by using the STEP in outdoor and indoor tests. It is a novel and energy-free route for wastewater treatment, accomplished by the synergistic use of solar energy without any other input of energy.

Optimized Removal of Sodium Dodecylbenzenesulfonate by Fenton-Like Oxidation Using Response Surface Methodology

This study investigates the degradation of sodium dodecylbenzenesulfonate (SDBS) in aqueous solution by the Fenton-like oxidation process. The effects of different parameters such as concentrations of ferric chloride and hydrogen peroxide, pH and reaction time on the SDBS removal and Chemical Oxygen Demand (COD) reduction were evaluated. Response Surface Methodology (RSM) with Central Composite Design (CCD) was used to study and optimize the oxidation process. A quadratic polynomial equation could accurately model the SDBS removal with an R2 of 0.98. The results showed that pH and time were the most significant parameters affecting SDBS removal and COD reduction, respectively. A high SDBS (90.5%) and COD (70.7%) reduction efficiency were obtained at the optimal conditions of 60 min, pH 4 and 8.82 mM of H2O2 and 3.67mM of Fe+3. In this work, the effects of some organic compounds on the degradation of SDBS by the Fenton-like process were examined. The results showed that 50 mgL-1of oxalic acid slightly enhanced the SDBS degradation efficiency while acetic acid and Ethylenediaminetetraacetic acid (EDTA) reduced it.

Microwave-induced carbon nanotubes catalytic degradation of organic pollutants in aqueous solution

In this study, a new catalytic degradation technology using microwave induced carbon nanotubes (MW/CNTs) was proposed and applied in the treatment of organic pollutants in aqueous solution. The catalytic activity of three CNTs of 10–20nm, 20–40nm, and 40–60nm diameters were compared. The results showed that organic pollutants such as methyl orange (MO), methyl parathion (MP), sodium dodecyl benzene sulfonate (SDBS), bisphenol A (BPA), and methylene blue (MB) in aqueous solution could be degraded effectively and rapidly in MW/CNTs system. CNTs with diameter of 10–20nm exhibited the highest catalytic activity of the three CNTs under MW irradiation. Further, complete degradation was obtained using 10–20nm CNTs within 7.0min irradiation when 25mL MO solution (25mg/L), 1.2g/L catalyst dose, 450W, 2450MHz, and pH=6.0 were applied. The rate constants (k) for the degradation of SDBS, MB, MP, MO and BPA using 10–20nm CNTs/MW system were 0.726, 0.679, 0.463, 0.334 and 0.168min−1, respectively. Therefore, this technology may have potential application for the treatment of targeted organic pollutants in wastewaters.

Application of Taguchi Method for Electro-Fenton Degradation of SDBS Anionic Surfactant

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 <p>In this work, the effectiveness of electro-Fenton process degradation of sodium dodecylbenzene sulfonate (SDBS) anionic surfactant in acidic wastewater was investigated. Taguchi method was applied to study the effect of process parameters on oxidation of SDBS pollutant. An orthogonal array L<sub>9 </sub>experimental design that allows investigating the simultaneous variation of current density, initial acidity of wastewater, and the initial SDBS concentration was employed to evaluate the effect of these parameters as control factors. Taguchi experimental design in dynamic sense was carried out with electrolysis time chosen as signal factor. Each experiment comprises the addition of peroxide (170 mg l<sup>-1</sup>; 0.005M) as a fixed component of Fenton's reagent and NaCl (1.5 mg l<sup>-1</sup>) as supportive electrolyte. The results revealed that SDBS degradation in acidic aqueous phase, can reached high values by the electro-Fenton process. The estimation of linear model coefficients for S/N (signal to noise) ratios expression has acceptable fitness of 93.5% with the selected control and signal factors. Main effects and analysis of variance (ANOVA) indicates that the current density and the acidity have high impact on electro-Fenton degradation of SDBS process with high sum of squares and low p-values that signifies the 0.05 α-level. Moreover, Taguchi optimal analysis indicates that high S/N ratio of response can be obtained with 0.3 mA cm<sup>-2</sup> current density,<br />
 pH=2 initial acidity of wastewater, and 10 mg l<sup>-1</sup> initial SDBS surfactant concentration.</p>
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Zinc Oxide Nanoparticles-Immobilized Mesoporous Hollow Silica Spheres for Photodegradation of Sodium Dodecylbenzenesulfonate

ZnO-Immobilized mesoporous hollow silica spheres (ZnO/xMHSS; x = 15, 30, 50 molar ratio of Zn/Si) were synthesized and examined as photocatalysts toward the degradation of sodium dodecylbenzenesulfonate (SDBS). The hollow structures of MHSS and ZnO-immobilized MHSS composite were evidenced by transmission electron microscopy analysis. X-ray diffraction results confirmed the presence of ZnO and a mesoporous structure in the synthesized materials. N2 adsorption–desorption analysis also depicted the formation of a mesoporous structure and the increased surface area for the ZnO/xMHSS materials. Fourier transform infrared spectroscopy analysis revealed the formation of Si–O–Zn bonds due to interaction between ZnO and MHSS. The photocatalytic testing results indicated that all the ZnO/xMHSS materials showed improved efficiencies of 10–21 % toward the photodegradation of SDBS when compared with bare ZnO. Among the prepared materials, ZnO/15MHSS was the best photocatalyst, which photodegraded 68 % SDBS after 1 h reaction. The kinetic study demonstrated that the photocatalytic reaction followed the second-order model.

Effects of Different Acids and pH on the Degradation of Sodium Dodecyl Benzene Sulfonate by TiO<sub>2</sub>-Bentonite

Five types of TiO2-bentonite catalyst, #1, #2, #3, #4, and #5, were prepared separately using hydrochloric acid, nitric acid and perchloric acid by the sol-gel method. The original concentration of sodium dodecyl benzene sulfonate (SDBS) in the aqueous solutions was 20 mg/L. The amounts of SDBS degraded by #1, #2, #3, #4 and #5 under a 6 W ultraviolet lamp were compared, the influences of #1 and #2 on the chemical oxygen demand (COD) of the aqueous solutions studied. And the influences of the initial pH on the degradation of SDBS and on the COD of aqueous solutions were investigated. The results showed as the following. (1) When the catalyst input was 0.5‰ and the solutions were irradiated with a 6 W ultraviolet lamp, 81.0%, 90.5% 47.5%, 39.5% and 26.5% of the SDBS in the aqueous solutions was degraded within 2 hours by catalysts #1, #2, #3, #4 and #5, respectively. The COD was reduced by 8.81% and 50.84%by catalysts #1 and #2, respectively. (2) Under an ultraviolet lamp, 94.5% and 99.3% of the SDBS in the aqueous solutions was degraded and 33.59% and 96.93% of the COD was reduced within 6 hours by catalysts #1 and #2, respectively. TiO2-bentonite catalyst #2 was the best based on the effects on the degradation of SDBS and on the reduction of the COD of aqueous solutions. Using nitric acid was better than using hydrochloric acid or perchloric acid for the preparation of TiO2-bentonite. (3) Under the same conditions (20 mg/L SDBS, 20°C, ultraviolet light irradiation time of 2 h, electromagnetic mixing, 0.5‰ input of TiO2-bentonite #2 ), 90.3% and 90.5% of SDBS was degraded by TiO2-bentonite #2 at pHs 6 and 8, respectively. The optimal pH range for SDBS degradation was 6~8. The COD was reduced by 59.5% and 63.5% pHs 4 and 6, respectively. The optimal pH range for the COD reduction was 4 ~ 6. The pH had a clear effect on SDBS degradation and the COD of the aqueous solutions.

SDBS Degradation by a Heterogeneous Fenton-Like Reaction on Three Types of Catalysts

Two kinds of attapulgite (ATP)-based catalysts (Fe (III)/ATP and Fe2O3/ATP) were prepared and their heterogeneous Fenton-like reactions were investigated for the degradation of Sodium dodecyl benzene sulfonate (SDBS) and contrast with that of Fe2O3 catalyst. Compared with the Fe2O3 catalyst, the two new ATP-based catalysts exhibited a higher activity and stability in SDBS mineralization. The effects of pH, H2O2 dosage, catalyst dosage and temperature were investigated. With incorporating ATP, the degradation ratio was more than that of Fe2O3 catalyst. And an enhancement of H2O2 utilization ratio was achieved.

Complete mineralization of surfactant from aqueous solution by a novel sono-synthesized nanocomposite (TiO2–Cu2O) under sunlight irradiation

In this study, a new method has developed for the synthesis of TiO2–Cu2O nano-composite with high optical absorption in the visible range and high photocatalytic activity in mineralization of sodium dodecyl-benzenesulfonate (SDBS) in an ultrasonic bath with low intensity at 40kHz. The results of EDAX, TEM and XRD confirmed the purity, crystallinity and the structure of the nanocomposite particles with the size less than 10nm. Ultrasound played a key role in the formation of nanocomposite with highest photocatalytic activity in mineralization of SDBS under sunlight. The degradation of SDBS by sunlight irradiation showed that the extent of mineralization depends on the operating conditions. In addition, the TiO2–Cu2O that contained 5% (mole ratio) TiO2 exhibited better photocatalytic activity than either Cu2O or TiO2 alone or other composites with different mole ratios. So that, the mineralization percentage of SDBS in the solution reached to 100% after 90min and the mineralization on the surface of the catalyst was completed after 240min. The data obtained from the degradation experiments fit the first-order kinetics and the adsorption obeyed the Langmuir model.

小型光催化滤池降解SDBS的实验研究<br>Experimental Study on the Degradation of SDBS Using a Small Photocatalytic Filter

利用小型光催化滤池对十二烷基苯磺酸钠（SDBS）进行了光催化氧化降解实验。结果表明，在中性及酸性条件下，SDBS降解率保持在70%左右；当pH ＞ 9.0时，SDBS降解率随pH的升高而下降；当水体温度为50℃时，SDBS的降解效率最高。光电催化测试结果表明，预吸附时间为700 s时，水和SDBS分子在TiO2膜表面的吸附达到饱和，此时的积分电量分别为235 μC和91 μC；SDBS吸附较快，为多分子层吸附。从微观角度探讨了光催化膜表面吸附降解SDBS的过程和机理。 The degradation experiments of sodium dodecyl benzene sulfonate (SDBS) were performed in this work by catalytic oxidation using a small photocatalytic filter. The results show that the degradation rate of SDBS keeps the value of about 70% when pH ≤ 9.0 while the value can decrease with the increase of pH once pH > 9.0, and the efficient degradation of SDBS can be received at 50℃. The test results of photoelectrochemistry also indicate that the adsorption of both water and SDBS molecules on the surface of nano TiO2 film would be saturated when the pre-adsorption time is 700 s with the integral electricity quantity of 235 μC and 91 μC, respectively. It is proved that the adsorption of SDBS molecules is a fast process with multiple layers on the surface of film. Furthermore, we discussed the adsorption process and mechanism of photocatalytic degradation about SDBS molecules in microcosmic level.

Study of Fe<sub>2</sub>O<sub>3</sub>/H<sub>2</sub>O<sub>2</sub> Fenton-Like Oxidation and Mineralization of Anion Surfactant

Fe2O3/H2O2, a kind of Fenton-like agent, was used to degrade an anion surfactant, sodium dodecyl benzene sulfonate(SDBS)，in an aqueous solution. Through a number of batch degradation experiments under various conditions, it was found that the reactivity of the system increased by increasing temperature. The SDBS degradation ratio will increase by, respectively, increasing H2O2 concentration and Fe2O3 dosage at some extent, but too high H2O2 concentration or Fe2O3 dosage will decrease the degradation efficiency. pH value has some influences on the reactivity of the system; from 2 to 10, the system maintains high efficiencies all the time. It also can be seen that Fe2O3/H2O2 Fenton-like reaction almost has the same efficiency as homogeneous Fenton reaction, while the former has a widely pH range (2-10), and Fe2O3 can be separated easily and has no secondary pollutants.

Characterization and Catalytic Activity of Fenton-Like Catalyst: Fe<sub>2</sub>O<sub>3</sub>/Attapulgite

Fe2O3/attapulgite(ATP) catalyst was successfully prepared for Fenton reaction to degrade an anion surfactant, sodium dodecyl benzene sulfonate(SDBS)，in an aqueous solution. BET, SEM, FT-IR were performed to characterize Fe2O3/ ATP catalyst. Comparative studies indicated that the SDBS degradation ratios were much higher in presence of Fe2O3/ATP and H2O2 than those in presence of Fe2O3/ATP or H2O2 only, which suggested that the Fe2O3/ATP-catalyzed Fenton-like reaction governed the SDBS removal process. It also can be seen that Fe2O3/ATP-catalyzed Fenton-like reaction almost has the same efficiency as homogeneous Fenton reaction, while the former can be reused and has no secondary pollutants.

Fenton-Like Mineralization of Anion Surfactant by Fe<sub>2</sub>O<sub>3</sub>/Attapulgite Catalyst

Fe2O3/attapulgite(ATP) catalyst was successfully prepared for Fenton reaction to degrade anion an surfactant, Sodium dodecyl benzene sulfonate(SDBS). Through a number of batch degradation experiments under various conditions, it was found that the reactivity of the system increased by increasing Fe2O3/ATP dosage and temperature. The SDBS degradation ratio will increase with increasing H2O2 concentration at some extent. But too high H2O2 concentration will make degradation efficiency decrease. The system maintains high efficiencies all experimental pH value(2-10).