scholarly journals Heterogeneous Catalytic Ozonation of p-Chlorobenzoic Acid in Aqueous Solution by FeMnOOH and PET

Separations ◽  
2018 ◽  
Vol 5 (3) ◽  
pp. 42 ◽  
Author(s):  
Savvina Psaltou ◽  
Stylianos Stylianou ◽  
Manasis Mitrakas ◽  
Anastasios Zouboulis
Keyword(s):  
Organic Compound ◽  
Adsorption Capacity ◽  
Treatment Process ◽  
Catalyst Concentration ◽  
Catalytic Ozonation ◽  
Total Removal ◽  
Chlorobenzoic Acid ◽  
Heterogeneous Catalytic ◽  
Hydrophobically Modified ◽  
Typical Model

The oxidation of p-chlorobenzoic acid (p-CBA), used as a typical-model refractory organic compound, in aqueous solutions during the heterogeneous catalytic ozonation treatment process by applying the hydrophilic tetravalent manganese feroxyhyte (TMFx), as well as modified hydrophobic TMFx and the polyethylene terephthalate (PET) as solid (powdered) catalysts was examined in this study. TMFx was hydrophobically modified by using trichloromethylsilane (TriClMS) solutions in toluene at the concentration range 10–1000 mg/L. TMFx catalysts were characterized by the application of scanning electron microscopy (SEM), as well as by Brunauer-Emmet-Teller (BET) and surface charge density determinations. TMFx catalyst, which was modified by 50 mg/L trichloromethylsilane (TriClMS) solution (TMFx-50), was found to present the higher adsorption capacity of studied organic compound (250 μg p-CBA/g) when compared with all the other investigated catalysts, which in turn resulted in the higher removal of p-CBA (>99%) by the subsequent application of ozonation, as compared to hydrophilic TMFx (96.5%) and to single ozonation (96%) applications. PET-catalyst concentration in the range 0.5–10 g/L led to almost total removal of p-CBA within 15 min of reaction/oxidation time at pH 7. Conclusively, the experimental results for both catalysts indicated that hydrophobicity and adsorption capacity are crucial steps for the process of heterogeneous catalytic ozonation of refractory organic compounds.

scholarly journals Application of heterogeneous catalytic ozonation process for treatment of high toxic effluent from a pesticide manufacturing plant

2020 ◽  
Vol 7 (2) ◽  
pp. 79-88
Author(s):  
Mina Ghahrchi ◽  
Edris Bazrafshan ◽  
Behruz Adamiyat Badan ◽  
Yousef Dadban Shahamat ◽  
Fariba Gohari
Keyword(s):  
Reaction Time ◽  
Treatment Process ◽  
Catalyst Concentration ◽  
Oxygen Demand ◽  
Catalytic Ozonation ◽  
Cod Removal ◽  
Heterogeneous Catalytic ◽  
Removal Efficiencies ◽  
Ozonation Process ◽  
Maximum Removal

Background: The discharge of untreated wastewater containing toxic and resistant compounds into the environment is a serious threat for ecosystems. Therefore, this study was conducted to evaluate the treatment of poison production factory wastewater using heterogeneous catalytic ozonation process (COP). Methods: Magnetic carbon nanocomposite was used as a catalyst at concentrations of 1, 2, and 4 g/L. Its effect on improving the treatment process was evaluated at reaction time of 30, 60, 90, and 120 minutes. At the end of each experiment, parameters including total organic carbon (TOC), chemical oxygen demand (COD), biological oxygen demand (BOD5 ), pH, electrical conductivity (EC), and turbidity were measured. Results: It was revealed that in single ozonation process (SOP), the maximum removal efficiencies of TOC, COD, and BOD5 were achieved at reaction time of 120 minutes as 56%, 40%, and 11.7%, respectively. By adding the catalyst to the wastewater, the treatment process was improved, so that the maximum removal efficiencies of COD (91%), TOC (73%), and BOD5 (74%) were obtained at catalyst concentration of 4 g/L. Under this condition, BOD5 /COD ratio increased from 0.22 to 0.64. Also, the results of analysis of ozone consumption per each mg of reduced COD showed that its amount sharply decreased from 2.1 mgO3 / mg COD removal in the SOP, to 0.34 mgO3 /mg COD removal in the COP. The results of kinetic reaction analysis also revealed that the rate constant increased from 0.007 to 0.02 min-1. Conclusion: According to the results, it can be concluded that the COP at a catalyst concentration of 4 g/L, by decomposing resistant compounds and increasing the biodegradability, can be used as a suitable pretreatment method for biological processes.

Ozone catalysed with solids as an advanced oxidation process for landfill leachate treatment

2007 ◽  
Vol 55 (12) ◽  
pp. 237-243 ◽  
Author(s):  
C. Tizaoui ◽  
L. Mansouri ◽  
L. Bousselmi
Keyword(s):  
Advanced Oxidation Process ◽  
Catalyst Concentration ◽  
Oxidation Process ◽  
Advanced Oxidation ◽  
Catalytic Ozonation ◽  
Expanded Perlite ◽  
Landfill Leachates ◽  
Leachate Treatment ◽  
Gas Concentration ◽  
Heterogeneous Catalytic

Heterogeneous catalytic ozonation (HCO) of wastewater is gaining both research and industrial interests. It is proved to be an advanced oxidation process since it involves hydroxyl radicals as oxidation species. Few studies have been carried out to test HCO in the treatment of landfill leachates. This work has been carried out to test three types of catalysts: activated carbon (AC), expanded perlite (EP) and titanium dioxide (TiO2) combined with ozone at 80 g/m3 gas concentration for the treatment of a leachate generated by Jebel Chakir landfill site near Tunis–capital of Tunisia. The work has shown a reduction in COD of about 45% and an increase in biodegradability (BOD5/COD) from 0.1 to 0.34. A catalyst concentration of 0.7 g/L was found optimal for the treatment of the leachate.

scholarly journals Transition Metal Ions as Ozonation Catalysts: An Alternative Process of Heterogeneous Catalytic Ozonation

Catalysts ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1091
Author(s):  
Savvina Psaltou ◽  
Konstantina Sioumpoura ◽  
Efthimia Kaprara ◽  
Manassis Mitrakas ◽  
Anastasios Zouboulis
Keyword(s):  
Catalytic Activity ◽  
Metal Ions ◽  
Natural Water ◽  
Transition Metal Ions ◽  
Catalytic Ozonation ◽  
Experimental Conditions ◽  
Chlorobenzoic Acid ◽  
Heterogeneous Catalytic ◽  
Water Matrix ◽  
Phosphate Ions

The aim of this study is to elucidate the mechanism of micropollutants’ removal in drinking water by the application of catalytic ozonation, using transition metals as appropriate catalysts. For that purpose, the degradation of 500 μg/L of p-chlorobenzoic acid (p-CBA) and benzotriazole with the addition of 2 mg/L of ozone in the presence of 1 mg/L of Co(II) or Fe(II) and at pH 7.8 were examined. It was found that in distilled water experiments, both metal ions can be characterized as catalysts, enhancing the ozonation process; however, in the natural water matrix, only iron presented higher removal rates of examined organic pollutants, when compared to single ozonation. The metal ions present catalytic activity, when they can form precipitates, hence converting the initially homogeneous process of catalytic ozonation towards a heterogeneous one. However, when 2 mg/L of ozone was applied in natural water experiments, Co(II)—unlike Fe(II)—could not be oxidized into its trivalent form, hence it cannot precipitate as Co(OH)3. Therefore, under these experimental conditions, this metal was not found to present any catalytic activity. Nevertheless, the addition of phosphates (PO43−) in concentrations higher than 100 mg/L can increase the oxidation ability of the Co(II)/O3 system, due to the resulting sufficient formation of Co3(PO4)2 precipitates. Although cobalt can enhance the •OH production (and therefore, the ozonation procedure) under these conditions, the relatively highly added concentration of phosphate ions makes the treated water non-potable, resulting in the application of further treatment to remove the excess phosphates. Therefore, only Fe(II) can be considered as a sufficient catalyst to enhance the ozonation processes.

scholarly journals The Effect of Thermal Treatment on the Physicochemical Properties of Minerals Applied to Heterogeneous Catalytic Ozonation

2020 ◽  
Vol 12 (24) ◽  
pp. 10503
Author(s):  
Savvina Psaltou ◽  
Efthimia Kaprara ◽  
Kyriaki Kalaitzidou ◽  
Manassis Mitrakas ◽  
Anastasios Zouboulis
Keyword(s):  
Catalytic Activity ◽  
Thermal Treatment ◽  
Physicochemical Properties ◽  
Hydroxyl Radicals ◽  
Ph Value ◽  
Catalytic Ozonation ◽  
Point Of Zero Charge ◽  
Chlorobenzoic Acid ◽  
Positive Effects ◽  
Heterogeneous Catalytic

In order to enhance the efficiency of heterogeneous catalytic ozonation, the effect of thermal treatment on three commonly used and inexpensive minerals, i.e., zeolite, talc and kaolin (clay), which present different physicochemical properties as potential catalysts, has been examined for the removal of para-chlorobenzoic acid (p-CBA). p-CBA is considered a typical micro-pollutant, usually serving as an indicator (model compound) to evaluate the production of hydroxyl radicals in ozonation systems. The catalytic activity of selected solid catalysts was studied for different pH values (6, 7 and 8) and different temperatures (15 °C, 25 °C and 35 °C). The mechanism of radicals’ production was also verified by the addition of tert-butyl alcohol (TBA). The respective thermal behavior study showed that the point of zero charge (PZC) of these minerals increased with the increase of applied treatment temperature, as it removed crystalline water and hydroxyls, thus improving their hydrophobicity. Circa-neutral surface charge and the presence of hydrophobicity were found to favor the affinity of ozone with solid/catalytic surfaces and the subsequent production of hydroxyl radicals. Therefore, zeolite and talc, presenting PZC 7.2 and 6.5 respectively, showed higher catalytic activity after thermal treatment, while kaolin with PZC equal to 3.1 showed zero to moderate catalytic efficiency. The degradation level of p-CBA by oxidation was favored at 25 °C, while the pH value exerted positive effects when it was increased up to 8.

scholarly journals Heterogeneous Catalytic Ozonation of Micropollutants in a Pilot Scale Continuous Flow System

2020 ◽  
Vol 2 (1) ◽  
pp. 24
Author(s):  
Efthimia Kaprara ◽  
Chrysovalantou Koutsiantzi ◽  
Savvina Psaltou ◽  
Anastasios Zouboulis ◽  
Manassis Mitrakas
Keyword(s):  
Continuous Flow ◽  
Flow System ◽  
Pilot Scale ◽  
Catalytic Ozonation ◽  
Hydrophobic Membrane ◽  
Chlorobenzoic Acid ◽  
Heterogeneous Catalytic ◽  
Complete Degradation ◽  
Scale Unit ◽  
Micropollutant Removal

The present study evaluates micropollutant degradation from water by catalytic ozonation in a pilot scale unit comprising of a hydrophobic membrane for ozone dilution and a column filled with granules of the catalyst. The catalysts examined are alumina, calcite, dolomite, goethite, pearlite, polyethylene terephthalate (PET) and zeolite. Experimental results revealed zeolite as the most effective material achieving complete degradation of benzotriazole and carbamazepine, as well as 70% degradation of atrazine and about 50% of p-chlorobenzoic acid (p-CBA). The rest of the catalysts tested presented a moderate performance in micropollutant removal, reaching 30%–50% for atrazine, 25%–35% for p-CBA, more than 90% for benzotriazole and complete degradation of carbamazepine. Adsorption capacity of all materials examined did not exceed 5%.

scholarly journals Performance of Heterogeneous Catalytic Ozonation with Minerals in Degradation of p-Chlorobenzoic Acid (p-CBA) from Aqueous Solutions

Proceedings ◽  
2019 ◽  
Vol 48 (1) ◽  
pp. 12
Author(s):  
Savvina Psaltou ◽  
Efthimia Kaprara ◽  
Manassis Mitrakas ◽  
Anastasios I. Zouboulis
Keyword(s):  
Surface Charge ◽  
High Reactivity ◽  
Catalytic Ozonation ◽  
Treatment Technique ◽  
Solid Materials ◽  
Batch Mode ◽  
Chlorobenzoic Acid ◽  
Heterogeneous Catalytic ◽  
Low Concentrations ◽  
Negative Surface

Water pollution is a critical environmental issue nowadays. One major problem is the pollution of freshwaters by pollutants of low concentrations (ng/L–μg/L), known as micropollutants. The most promising techniques for micropollutants degradation are Advanced Oxidation Processes (AOPs). Heterogeneous catalytic ozonation is among them, and recent studies have shown that it can be an efficient water treatment technique. The aim of this study is to evaluate the catalytic activity of five minerals (anatase, dolomite, kaolin, talc and zeolite) on the ozonation of small concentrations of p-CBA at pH 7 by batch mode experiments. p-CBA was employed as a model compound for evaluation of single and catalytic ozonation performance, because it cannot be efficiently removed by direct ozonation (kO3 < 0.15 M−1s−1), while it has high reactivity with hydroxyl radicals (k·OH = 5×109 M−1s−1). It was found that all applied solid materials can be characterized as catalysts, except kaolin, theuse of which presented almost the same performance with single ozonation. The best results were obtained by zeolite and dolomite (>99.4%) within 15 min reaction/oxidation time. These materials were neutrally (PZC = 6.8) and positively (PZC = 8.9) charged, respectively, during the oxidation process (pH 7), favoring the contact of micropollutant and ozone with the catalysts’ surface. On the other hand, the addition of anatase and talc in the ozonation system resulted in 97.5% and 98.5% p-CBA degradation, respectively, due to their slightly negative surface charge throughout the reaction. Conclusively, the experimental results indicated that the performance of heterogeneous catalytic ozonation is strongly depending on the surface charge of the solid materials (catalysts).

scholarly journals Enhanced catalytic ozonation of ibuprofen using a 3D structured catalyst with MnO2 nanosheets on carbon microfibers

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Guhankumar Ponnusamy ◽  
Hajar Farzaneh ◽  
Yongfeng Tong ◽  
Jenny Lawler ◽  
Zhaoyang Liu ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Active Sites ◽  
Low Cost ◽  
Three Dimensional ◽  
Industrial Applications ◽  
Catalytic Ozonation ◽  
Heterogeneous Catalytic ◽  
Structured Catalyst ◽  
Dimensional Network ◽  
Carbon Microfibers

AbstractHeterogeneous catalytic ozonation is an effective approach to degrade refractory organic pollutants in water. However, ozonation catalysts with combined merits of high activity, good reusability and low cost for practical industrial applications are still rare. This study aims to develop an efficient, stable and economic ozonation catalyst for the degradation of Ibuprofen, a pharmaceutical compound frequently detected as a refractory pollutant in treated wastewaters. The novel three-dimensional network-structured catalyst, comprising of δ-MnO2 nanosheets grown on woven carbon microfibers (MnO2 nanosheets/carbon microfiber), was synthesized via a facile hydrothermal approach. Catalytic ozonation performance of Ibuprofen removal in water using the new catalyst proves a significant enhancement, where Ibuprofen removal efficiency of close to 90% was achieved with a catalyst loading of 1% (w/v). In contrast, conventional ozonation was only able to achieve 65% removal efficiency under the same operating condition. The enhanced performance with the new catalyst could be attributed to its significantly increased available surface active sites and improved mass transfer of reaction media, as a result of the special surface and structure properties of this new three-dimensional network-structured catalyst. Moreover, the new catalyst displays excellent stability and reusability for ibuprofen degradation over successive reaction cycles. The facile synthesis method and low-cost materials render the new catalyst high potential for industrial scaling up. With the combined advantages of high efficiency, high stability, and low cost, this study sheds new light for industrial applications of ozonation catalysts.

Heterogeneous catalytic ozonation of p-chloronitrobenzene (pCNB) in water with iron silicate doped hydroxylation iron as catalyst

2017 ◽  
Vol 89 ◽  
pp. 81-85 ◽  
Author(s):  
Yue Liu ◽  
Shiyuan Wang ◽  
Weijin Gong ◽  
Zhonglin Chen ◽  
Haifang Liu ◽  
...  
Keyword(s):  
Catalytic Ozonation ◽  
Iron Silicate ◽  
Heterogeneous Catalytic

Production of clinoptilolite nanorods by glow discharge plasma technique for heterogeneous catalytic ozonation of nalidixic acid

RSC Advances ◽  
2016 ◽  
Vol 6 (25) ◽  
pp. 20858-20866 ◽  
Author(s):  
Alireza Khataee ◽  
Tannaz Sadeghi Rad ◽  
Mehrangiz Fathinia ◽  
Sang Woo Joo
Keyword(s):  
Glow Discharge ◽  
Nalidixic Acid ◽  
Discharge Plasma ◽  
Catalytic Ozonation ◽  
Glow Discharge Plasma ◽  
Acid Degradation ◽  
Heterogeneous Catalytic ◽  
Plasma Technique

This study investigates nalidixic acid degradationviaheterogeneous catalytic ozonation using clinoptilolite nanorods (CNs) as a novel nanocatalyst.

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