scholarly journals Catalytic Ozonation for Effective Degradation of Coal Chemical Biochemical Tail Water by Mn/Ce@RM Catalyst

Water ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 206
Author(s):  
Yicheng Wang ◽  
Yingkun Wang ◽  
Xi Lu ◽  
Wenquan Sun ◽  
Yanhua Xu ◽  
...  

An Mn/Ce@red mud (RM) catalyst was prepared from RM via a doping–calcination method. Scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy were used to characterize the surface morphology, crystal morphology, and elemental composition of the Mn/Ce@RM catalyst, respectively. In addition, preparation and catalytic ozonation conditions were optimized, and the mechanism of catalytic ozonation was discussed. Lastly, a fuzzy analytic hierarchy process (FAHP) was adopted to evaluate the degradation of coal chemical biochemical tail water. The best preparation conditions for the Mn/Ce@RM catalyst were found to be as follows: (1) active component loading of 3%, (2) Mn/Ce doping ratio of 2:1, (3) calcination temperature of 550 °C, (4) calcination time of 240 min, and (5) fly ash floating bead doping of 10%. The chemical oxygen demand (COD) removal rate was 76.58% under this preparation condition. The characterization results suggested that the pore structure of the optimized Mn/Ce@RM catalyst was significantly improved. Mn and Ce were successfully loaded on the catalyst in the form of MnO2 and CeO2. The best operating conditions in the study were as follows: (1) reaction time of 80 min, (2) initial pH of 9, (3) ozone dosage of 2.0 g/h, (4) catalyst dosage of 62.5 g/L, and (5) COD removal rate of 84.96%. Mechanism analysis results showed that hydroxyl radicals (•OH) played a leading role in degrading organics in the biochemical tail water, and adsorption of RM and direct oxidation of ozone played a secondary role. FAHP was established on the basis of environmental impact, economic benefit, and energy consumption. Comprehensive evaluation by FAHP demonstrated that D3 (with an ozone dosage of 2.0 g/H, a catalyst dosage of 62.5 g/L, initial pH of 9, reaction time of 80 min, and a COD removal rate of 84.96%) was the best operating condition.

2011 ◽  
Vol 347-353 ◽  
pp. 1949-1952 ◽  
Author(s):  
Liang Li ◽  
Bing Zhe Xu ◽  
Chang Yu Lin ◽  
Xiao Min Hu

Zidovudine wastewater is difficult to biodegradation due to high COD and toxicity. The synergetic treatment of Zidovudine wastewater by Ultrasonic and iron-carbon micro-electrolysis technology was studied. The influence of initial pH, reaction time, mass ratio of iron and carbon and mass ratio of iron and water on degradation rate of COD was researched. The result showed that the COD removal rate was only about 54.3% and the degradation speed is very slow when iron-carbon micro-electrolysis treated Zidovudine wastewater separately. However, when ultrasonic synergy micro-electrolysis to treat Zidovudine wastewater, the COD removal rate could was up to 85% and the reaction time was also decreased. Moreover, the BOD5 / COD rose from 0.15 to 0.35, which meant the wastewater became easily biodegradable.


Author(s):  
Song Wang ◽  
Genwang Zhu ◽  
Zhongchen Yu ◽  
Chenxi Li ◽  
Dan Wang ◽  
...  

Abstract As porous crystal materials, metal-organic frameworks (MOFs) have attracted wide attention in the field of environmental remediation. In this study, a trivalent iron-tartaric acid metal-organic framework (T2-MOF) was successfully synthesized using the inexpensive raw materials ferric chloride (FeCl3.6H2O) and tartaric acid (C4H6O6). The physical and chemical properties of T2-MOF were studied by using X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy and Brunauer–Emmett–Teller. After that, T2-MOF was used as a catalyst for catalytic ozonation of succinonitrile. The results show that T2-MOF has obvious crystal characteristics and uniform structure. In addition, T2-MOF exhibits strong catalytic performance in ozonation of succinonitrile. The results indicate that the chemical oxygen demand (COD) removal rate is affected by various operating parameters including catalyst characteristics dosages and initial pH values. In the ozonation with 30 mg L−1 T2-MOF, the COD removal rate of 100 mg L−1 succinonitrile reached 73.1% (±4.6%) within 180 min, which was 67.3% (±4.4%) higher than that obtained in the process without catalyst. T2-MOF maintained strong catalytic performance with the pH range of 3.0–7.0. By monitoring the Fe2+ concentration at different reaction time, it was found that the homogeneous catalysis occurred simultaneously with the heterogeneous catalysis.


2020 ◽  
Vol 13 (1) ◽  
pp. 126
Author(s):  
Guozhen Zhang ◽  
Xingxing Huang ◽  
Jinye Ma ◽  
Fuping Wu ◽  
Tianhong Zhou

Electrochemical oxidation technology is an effective technique to treat high-concentration wastewater, which can directly oxidize refractory pollutants into simple inorganic compounds such as H2O and CO2. In this work, two-dimensionally stable anodes, Ti/RuO2-IrO2-SnO2, have been developed in order to degrade organic pollutants from pharmaceutical wastewater. Characterization by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD) showed that the oxide coating was successfully fabricated on the Ti plate surface. Electrocatalytic oxidation conditions of high concentration pharmaceutical wastewater was discussed and optimized, and the best results showed that the COD removal rate was 95.92% with the energy consumption was 58.09 kW·h/kgCOD under the electrode distance of 3 cm, current density of 8 mA/cm2, initial pH of 2, and air flow of 18 L/min.


2021 ◽  
Vol 16 (3) ◽  
pp. 673-685
Author(s):  
D. Hadj Bachir ◽  
Hocine Boutoumi ◽  
H. Khalaf ◽  
Pierre Eloy ◽  
J. Schnee ◽  
...  

TiO2 pillared clay was prepared by intercalation of titan polyoxocation into interlamelar space of an Algerian montmorillonite and used for the photocatalytic degradation of the linuron herbicide as a target pollutant in aqueous solution. The TiO2 pillared montmorillonite (Mont-TiO2) was characterized by X-ray photoelectron spectroscopy (XPS), X-Ray diffraction (XRD), X-Ray fluorescence (XRF), scanning electronic microscopy (SEM), thermogravimetry and differential thermal analysis (TG-DTA), Fourier transformed infra-red (FT-IR), specific area and porosity determinations. This physicochemical characterization pointed to successful TiO2 pillaring of the clay. The prepared material has porous structure and exhibit a good thermal stability as indicated by its surface area after calcination by microwave. The effects of operating parameters such as catalyst loading, initial pH of the solution and the pollutant concentration on the photocatalytic efficiency and COD removal  were evaluated. Under initial pH of the solution around seven, pollutant concentration of 10 mg/L and 2.5 g/L of catalyst at room temperature, the degradation efficiency and COD removal of linuron was best then the other operating conditions. It was observed that operational parameters play a major role in the photocatalytic degradation process. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0). 


Author(s):  
Yue Teng ◽  
Ke Yao ◽  
Wenbin Song ◽  
Yongjun Sun ◽  
Haoliang Liu ◽  
...  

Cu-Mn-Ce@γ-Al2O3 was prepared by incipient wetness impregnation and used to catalyze ozonation in a coal chemical wastewater-biotreated effluent. The preparation factors that considerably affected the catalytic performance of Cu-Mn-Ce@γ-Al2O3, specifically metal oxide loading percentage, calcination temperature, and calcination time, were examined. The catalyst was characterized by scanning electron microscopy, energy dispersive spectrometry, X-ray diffraction, and Brunauer-Emmett-Teller analysis. The optimal catalytic ozonation operating parameters, such as ozone dosage, catalyst dosage, pH, and reaction time, were also investigated. Results showed that an optimized catalyst consisted of 17.0% CuO, 3.0% MnO2, and 2.0% CeO2 (wt.%). The optimal calcination temperature and calcination time were 600 °C and 5 h. The optimal catalytic ozonation operating parameters, including ozone dosage, catalyst dosage, pH, and reaction time, were 7, 80.0 mg/L, 20.0 mg/L, 7 and 50 min, respectively. The COD removal of biotreated effluent increased to 61% under these optimal operating conditions. Meanwhile, ozonation alone resulted in only 20% removal. This work proposes the use of easily available Cu-Mn-Ce@γ-Al2O3 catalyst and might drive the advancement of catalytic ozonation for chemical wastewater purification.


2010 ◽  
Vol 62 (6) ◽  
pp. 1304-1311 ◽  
Author(s):  
Huaili Zheng ◽  
Huiqin Zhang ◽  
Xiaonan Sun ◽  
Peng Zhang ◽  
Tiroyaone Tshukudu ◽  
...  

Catalytic oxidation of malachite green using the microwave-Fenton process was investigated. 0% of malachite green de-colorization using the microwave process and 23.5% of malachite green de-colorization using the Fenton process were observed within 5 minutes. In contrast 95.4% of malachite green de-colorization using the microwave-Fenton was observed in 5 minutes. During the microwave-Fenton process, the optimum operating conditions for malachite green de-colorization were found to be 3.40 of initial pH, 0.08 mmol/L of Fe2 +  concentration and 12.5 mmol/L of H2O2 concentration. Confirmatory tests were carried out under the optimum conditions and the COD removal rate of 82.0% and the de-colorization rate of 99.0% were observed in 5 minutes. The apparent kinetics equation of −dC/dt = 0.0337 [malachite green]0.9860[Fe2 + ]0.8234[H2O2]0.1663 for malachite green de-colorization was calculated, which implied that malachite green was the dominant factor in determining the removal efficiency of malachite green based on microwave-Fenton process.


2012 ◽  
Vol 610-613 ◽  
pp. 2367-2371 ◽  
Author(s):  
Ming Zhong Hu ◽  
Zhen He Shi ◽  
Hong Yan Zhao

The effects of the oxidation of potassium ferrate and the flocculation on cresol wastewater water were evaluated. This research aimed at determining the optimum conditions for the COD removal rate duing cresol wastewater water process. The results showed that potassium ferrate dosage of 1.1g/L, the pH value of 5, reaction time 15min, m-cresol initial concentration of 200 mg/L were the optimum conditions. Under the optimum conditions, COD removal rate was over 67%.


2013 ◽  
Vol 295-298 ◽  
pp. 1307-1310
Author(s):  
Xi Tian ◽  
Ming Xin Huo ◽  
De Jun Bian ◽  
Sheng Shu Ai ◽  
Qing Kai Ren

The wastewater produced from the polytetrahydrofuran (PolyTHF) was treated with iron-carbon micro electrolysis process. This paper had studied the COD removal efficiency influences of primary PH value, reaction time, the quality ratio of the iron-carbon, the quality and volume ratio of Fe-wastewater. The results show that when pH value is 3, the quality ratio of the iron-carbon is 11 and the quality and volume ratio of Fe and wastewater is 17 with contact time of 90 min, the wastewater COD removal rate can reach as high as 95.0%.


2013 ◽  
Vol 807-809 ◽  
pp. 1473-1478
Author(s):  
Juan Xie ◽  
Xin Qiang Wang ◽  
Cheng Tun Qu

In this paper, aqueous methanol (methanol concentration 1000 mg·l-1) degradation was studied by using UV/Fenton, and effect of methanol degradation was evaluated with COD removal rate. When pH was determined, H2O2 dosage, Fe2+ dosage and reaction time were investigated by single factor test, respectively. In the orthogonal experiment, UV/Fenton was used to deal with wastewater of 1000 mg·l-1methanol, the order of the influent factors on COD removal was: H2O2 dosage > reaction time > Fe2+ content. Under the optimal condition (6%H2O250 ml·l-1, Fe2+ 0.9 g·l-1, reaction time 60 min), 95.77% COD removal rate was obtained. In addition, a comparison of UV, Fenton regent and UV/Fenton system indicated that UV and Fe2+ had synergistic effect on catalytic decomposition of H2O2, and reaction time to obtain the highest COD removal was shorted 10 min when UV/Fenton was used.


2019 ◽  
Vol 125 ◽  
pp. 03008
Author(s):  
Rachmad Ardhianto ◽  
Arseto Yekti Bagastyo

Personal care wastewater contains pharmaceuticals and personal care products (PPCPs). The compounds were in organic pollutants which have to be treated before water can be discharged. Electrochemical processes such as electro-coagulation and electro-oxidation were used to remove non-biodegradable in wastewater. Electro-coagulation as pretreatment using aluminum electrodes as anode and cathode. Electro-oxidation using Ti/Pt, and Ti/IrO2 as anode electrodes and variation of current 0,6 A, 0,7 A, 0,8 A and 1,0 A. Aluminum electrodes has effectiveness in removing COD, and TSS in electrocoagulation. Using aluminum electrodes remove COD, and TSS 76.1% (5.41 g) and 90.3% (6.10 g). Under initial pH, aluminum electrode does not cause a change in pH from initial pH (4.8-4.9). The removal efficiency of electrooxidation process using aluminum electrocoagulation effluent COD using Ti/Pt and Ti/IrO2 were 34,30% (1,55 g) and 39,71% (1,80 g). Increasing current when using Ti/IrO2 causes the COD removal rate to be more effective than using Ti/Pt. removal COD with 1.0 A gave the optimum COD removal were 34,30% (2,3 Ah/L; 1,55 g) with Ti/Pt, and 39,71% (2,3 Ah/L; 1,80 g) with Ti/IrO2 compared to 0,6 A (1,4 Ah/L), 0,7 A (1,6 Ah/L), and 0.8 A (1,9 Ah/L).


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