Preparation of Cu-MnOX/γ-Al2O3 by high gravity-assisted impregnation method for heterogeneous catalytic ozonation of nitrobenzene

It is of great practical significance to develop integrated processes with high efficiency, adaptability and stability to treat the dyeing wastewater with the feature of high organic matter, high-color and large ranges in water quality and quantity. In this paper, a novel catalyst MnOx+FexOy/AC was prepared by the impregnation method. The catalyst was used in the heterogeneous catalytic ozonation process to treat the dyeing wastewater. The results showed that the optimal Fe:Mn ratio of catalyst is 1:2. Under the optimized conditions of pH 5, ozone aeration rate 0.2L/min, catalyst dosage 20g and the reaction time 60min, the removal rate of COD, NH3-N, TP, Chromaticity were 81.7%, 90.2%, 93.4%, 99.1%, respectively. The heterogeneous catalytic ozonation is a promising process for the treatment of dyeing wastewater.

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Removal of Phenol From Wastewater by High-Gravity Intensified Heterogeneous Catalytic Ozonation With Activated Carbon

10.21203/rs.3.rs-750315/v1 ◽

2021 ◽

Author(s):

jingwen zhang ◽

shengjuan shao ◽

xin ding ◽

zhixing li ◽

jiaxin jing ◽

...

Keyword(s):

Activated Carbon ◽

Removal Rate ◽

Packed Bed ◽

Catalytic Ozonation ◽

High Gravity ◽

Paramagnetic Resonance ◽

Heterogeneous Catalytic ◽

Tertiary Butanol ◽

Rotating Packed Bed ◽

Initial Ph

Abstract In this study, the high-gravity technique is used to intensify the heterogeneous catalytic ozonation with activated carbon (AC) as the catalyst for removal of phenol from wastewater in a rotating packed bed (RPB), and the effects of high-gravity factor, inlet O3 concentration, liquid-gas ratio and initial pH on the degradation and mineralization of phenol at room temperature are investigated. It is revealed that the degradation rate of phenol reaches 100% at 10 min and the removal rate of total organic carbon (TOC) reaches 91% at 40 min under the conditions of high-gravity factor β=40, inlet O3 concentration =90 mg·L-1, liquid flow rate =80 L·h-1 and initial pH=11. Compared with the bubbling reactor (BR)/O3/AC and RPB/O3 systems, the mineralization rate of phenol by the RPB/O3/AC system is increased by 24.78% and 34.77%, respectively. Free radical quenching experiments are performed using tertiary butanol (TBA) and benzoquinone(BQ) as scavengers of ·OH and O2·−, respectively. It is shown that the degradation and mineralization of phenol are respectively attributed to the direct ozonation and the indirect oxidation by ·OH generated from the decomposition of O3 adsorbed on AC surface. •OH and O2•− are also detected by electron paramagnetic resonance (EPR). Thus, it is concluded that AC-catalyzed ozonation and high gravity technique had a synergistic effect on •OH initiation, which in turn can significantly improve the degradation and mineralization of organic wastewater.

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

Scientific Reports ◽

10.1038/s41598-021-85651-2 ◽

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.

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