Currently, the researches on pretilachlor are mainly concentrated on the fate of pretilachlor after it goes into the environment. However, there are few reports on removal of pretilachlor from the environment. Kim et al. had reported that the removal of the pretilachlor in solution was only 90% after 24 h reaction by adopted zero valent iron synthesized in the laboratory. Therefore, it is necessary to find an effective method to removal the pretilachlor in water. The main common methods to treatment the nonbiodegrad able pesticide wastewater are advanced oxidation processes, such as ozonation, Fenton oxidation, photocatalytic oxidation, electrocatalysis oxidation and so on. As one of effective methods for the nonbiodegradable organic compounds, eletro catalysis oxidation can transform the organic components into CO2 or biodegradable organic ones.

Because of its simplicity, easy con trol and no secondary pollution in the process of eletrocatalysis oxidation, it was called environment friendly technology. In the paper, we investigated the degradation process of preti 2 electrode doped Sb was as anode and stainless steel as cathode. The effect of current Pazopanib density on degradation of pretilachlor was studied in detail. Besides, the degradation pathways of pretilachlor were also stud ied by analyzing the intermediates from the degradation process. This will provide the basic research data for the practical treatment of the wastewater with pretilachlor. 2. Materials and methods 2. 1. Materials Pretilachlor was purchased from J&K chemical Co. Ltd..

Na 2SO 4, NaOH and hydrochloric acid were purchased from Bodi chemical company. Acetic acid, propionic acid, oxalic acid, monochloroacetic acid were obtained from Tianjin Chemical Reagent Factory. Sb doped Ti/SnO 2 electrode used in the experiments were prepared by ourselves. UV absorption spectra were obtained on a SHIMADZU UV visible spectrometer Pazopanib model UV 2550. Degradation solution was diluted to 10 times for absorption measurement. TOC measurement was obtained on a SHIMADZU TOC instru ment ASI 5000A. 3. Results and discussion 3. 1. Degradation effect of pretilachlor The initial pretilachlor concentration was 60 mg L 1, and 0. 1 mol L 1 Na 2SO 4 was used as supporting electrolyte. Current density was set as 10, 20 and 30 mA cm 2 for DC degradation. The degradation effect of pretilachlor at different current densities was shown in Fig.

1. Decay of pretilachlor was enhanced with the increase of cur rent density as shown in Fig. 1. After 60 min, the removal of pretilachlor at the current density of 10, 20 and 30 mA cm 2 was 78%, 98. 8% and 100%, respectively. The concentration of pretilachlor decreased exponentially with reaction time and the degradation rate could be expressed HDAC-42 by the following equation. 2. 2. 1. Electrochemical degradation of pretilachlor Electrochemical degradation of pretilachlor was carried out in the electrolysis cell with 100 mL glass beaker. For each cell, a 6 cm2 Sb doped Ti/SnO 2 electrode was used as anode and a stainless steel with the same dimension was used as cathode. The electrode gap was set as 2 cm. A DC potentiostat was used as the power supply for organic degradation studies.

Pretilachlor sample solution was placed in each cell with support ing electrolyte. Electrolysis was performed under galvanostatic control. Solution samples were took out from the cell after electrolysis for 30 min, 60 min, 90 min, 120 min and 180 min, respectively. Then the concentration of pretilachlor and Ponatinib small organic acids produced in degradation pretilachlor were ana lyzed by HPLC after samples were filtered through a filter with 0. 45 _m. At the same time, total organic carbon were also analyzed. where c was the concentration of pretilachlor at the reaction time t, c 0 was the initial concentration and k was the reaction rate constant. The degradation of pretilachlor was in accordance with pseudo first order kinetics as shown in Fig. 1.

The reaction rate constant NSCLC k is found to be 2. 39 ?? 10 2, 7. 67 ?? 10 2 and 9. 65 ?? 10 2 min 1 at the current density of 10, 20 and 30 mA cm 2 with regression coef ficient R 2 of 0. 9910, 0. 9969 and 0. 9840, respectively. On the other hand, the current density remarkably in uenced the mineralization of pretilachlor. At current density of 10, 20, 30 mA cm 2, removal of TOC was 24. 0%, 43. 1% and 59. 2% in 60 min and 56. 0%, 85. 1% and 100% in 180 min, as shown in Fig. 1. The removal of TOC was lower than that of pretilachlor, which indicated the formation of unmineralized products during the degradation of pretilachlor. Moreover, complete mineralization of pretileculor is possible with the increased current density and reaction time, such as the current density of 30 mA cm 2 of 180 min.

and the treatment time methanol at the ow rate of 1 mL min 1 dried over by anhydrous Na 2SO4 2. 2. 2. Solid phase extraction of degradation solution of pretilachlor Before analyzing and identifying the intermediates of preti lachlor degradation, degradation solution was processed with solid phase extraction by solid phase extraction column. SPE column was adjusted by methanol and then followed by distilled water.