Study On Preparation Of Attapulgite-based Heterogeneous Catalyst And Its Application In Methylene Blue Wastewater Treatment

Attapulgite clay?ATP?is widely used for the preparation of desulfurizers,adsorbents and catalysts due to its excellent properties.In recent years,attapulgite-based heterogeneous catalysts have been widely used in wastewater treatment.Since Fenton oxidation method was introduced,it has received extensive attention from researchers for its excellenet.In traditional Fenton oxidation processes the catalyst components is difficult to recycle,which limits its application in wastewater treatment.The large particle catalysts and magnetic catalysts,used in the field of wastewater treatment can effectively realize the separation,recovery and cyclic utilization of catalytic components.In order to separate and recycle,the magnetic catalysts,the strong magnetic must be used and which greatly increased the cost of wastewater treatment.At present,there are still few studies on large particle catalysts.It is of great practical significance to prepare large particle catalysts and apply to the removal of refractory organic pollutants in wastewater.In this article,a series of attapulgite-based heterogeneous catalysts were prepared and used for the treatment of wastewater which containing methylene blue?MB?.The main content of this article is as follows:?1?The attapulgite-based Heterogeneous Catalyst Fe₃O₄/ATP was prepared by Ultrasonic Impregnation method.The morphology structure of Fe₃O₄/ATP were analyzed by SEM,FT-IR and XRD.It was discussed that the influence of the preparation conditions of Fe₃O₄/ATP on its catalytic performance.The effect of operating conditions on the efficiency of Fe₃O₄/ATP/H₂O₂ removal of wastewater containing MB was studied.The reusability of Fe₃O₄/ATP was also investigated.Research indicates:The Fe₃O₄ spherical particles with a particle size of 43.31 nm are loaded on the surface of the ATP rod-like fiber structure.The optimal preparation conditions for Fe₃O₄/ATP are that the solvent was ethanol and n-hexane,the ultrasonic immersion time was 30 min,the ultrasonic frequency was 100 kHz,the immersion temperature was 25°C,and the immersion solution concentration was 30 mmol/L.The catalytic activity of Fe₃O₄/ATP is gradually activated during 10 cycles of utilization.After 10 times repeated cycles,the degradation of MB is still as high as 90%,which catalytic degradation by Fe₃O₄/ATP/H₂O₂ Heterogeneous Fenton process?2?The attapulgite-based heterogeneous catalyst of CuO-Fe₂O₃/ATP was also prepared by ultrasonic impregnation method.The morphology and structure of CuO-Fe₂O₃/ATP were analyzed by SEM,FT-IR and XRD.It was discussed that the effect of CuO-Fe₂O₃/ATP/H₂O₂ operating conditions on MB removal efficiency and the reusability of CuO-Fe₂O₃/ATP was inspected.The results showed that CuO-Fe₂O₃ spherical particles with a particle size of 27.13 nm were loaded on the surface of the ATP rod-like fiber structure.After10 recycles,the CuO-Fe₂O₃/ATP/H₂O₂ heterogeneous Fenton reaction system still has a high efficiency of removing efficiency of MB in wastewater,its remove rate as high as 97%,CuO-Fe₂O₃/ATP showed good catalytic performance and stability.?3?The attapulgite-based heterogeneous catalyst ofCuO-Fe₂O₃/?-Al₂O₃-ATP was also prepared by ultrasonic impregnation method.The morphology and structure of CuO-Fe₂O₃/?-Al₂O₃-ATP were analyzed by SEM,FT-IR and XRD.The influences of the operating conditions of CuO-Fe₂O₃/?-Al₂O₃-ATP/H₂O₂ heterogeneous Fenton reaction on MB removal efficiency were discussed and the recycling performance of CuO-Fe₂O₃/?-Al₂O₃-ATP was also studied in this part.After CuO-Fe₂O₃/?-Al₂O₃-ATP was used for 10 times,the removal efficiency of MB in wastewater was still as high as 98%which removed by CuO-Fe₂O₃/?-Al₂O₃-ATP/H₂O₂ heterogeneous Fenton process.CuO-Fe₂O₃/?-Al₂O₃-ATP showed good catalytic performance and stability.?4?The CuO-Fe₂O₃/ATP/H₂O₂ catalytic degradation MB model was established by the surface response method.The interaction effects between the operating conditions were discussed and the optimal operating conditions for CuO-Fe₂O₃/ATP/H₂O₂ Heterogeneous Fenton process were predicted.It was predicted that the optimal operating conditions of CuO-Fe₂O₃/ATP/H₂O₂ heterogeneous Fenton process for degradation of MB.The results show that the prediction model established in the experiment is scientific enough,and the reaction temperature,catalyst dosage,and pH have a significant effect on the catalytic degradation of MB by CuO-Fe₂O₃/ATP/H₂O₂ Heterogeneous Fenton process.The significant effect of H₂O₂ dosage on the catalytic degradation of MB depends on the operating conditions of CuO-Fe₂O₃/ATP/H₂O₂ Heterogeneous Fenton process.The predicted optimal catalytic conditions for degradation of MB by the model was that the reaction temperature was59.91°C,H₂O₂ dosage was 2 mL/L,catalyst dosage was 12 g/L,p H was 2.17 and MB removal rate up to 100%.?5?UV-Vis spectroscopy was used to analyze the change of UV-Vis absorption peak of MB during removed by CuO-Fe₂O₃/ATP/H₂O₂ Heterogeneous Fenton process.The amount of·OH produced by CuO-Fe₂O₃/ATP/H₂O₂ Heterogeneous Fenton process was analyzed by Spectrophotometric.It was disgusted that the degradation mechanism of MB by CuO-Fe₂O₃/ATP/H₂O₂ Heterogeneous Fenton process.The results show that the catalytic degradation of MB by CuO-Fe₂O₃/ATP/H₂O₂ is based on the oxidation of·OH,which is catalyzed by CuO-Fe₂O₃/ATP/H₂O₂ Heterogeneous Fenton process.The intensity of MB UV-visible absorption peaks at 664 nm,264 nm,and 292 nm was gradually decreased,due to the S-C and C=N in the MB molecular structure were destroyed by·OH.The final form of MB in CuO-Fe₂O₃/ATP/H₂O₂ Heterogeneous Fenton process is H₂O and CO₂.