scholarly journals Treatment of Bio-Treated Coking Wastewater by Catalytic Ozonation with Semi-Batch and Continuous Flow Reactors

Water ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2532
Author(s):  
Can He ◽  
Jianbing Wang ◽  
Heng Xu ◽  
Xiangyu Ji ◽  
Weiyi Wang ◽  
...  
Keyword(s):  
Chemical Oxygen Demand ◽  
Continuous Flow ◽  
Oxygen Demand ◽  
Catalytic Ozonation ◽  
Cod Removal ◽  
Utilization Efficiency ◽  
Coking Wastewater ◽  
Ozone Absorption ◽  
Flow Reactors ◽  
Continuous Flow Reactors

In this work, the treatment of bio-treated coking wastewater (BCW) by catalytic ozonation was conducted in semi-batch and continuous flow reactors. The kinetics of chemical oxygen demand (COD) removal were analyzed using BCWs from five coking plants. An integral reactor with catalytic ozonation stacked by ozone absorption (IR) was developed, and its efficiency was studied. The catalyst of MnxCe1-xO2/γ-Al2O3 was efficient in the catalytic ozonation process for the treatment of various BCWs. The chemical oxygen demand (COD) removal efficiencies after 120 min reaction were 64–74%. The overall apparent reaction rate constants were 0.0101–0.0117 min−1, which has no obvious relationship with the initial COD of BCW and pre-treatment biological process. The IR demonstrated the highest efficiency due to the enhancement of mass transfer and the utilization efficiency of ozone. Bypass internal circulation can further improve the reactor efficiency. The optimal results were obtained with the ozone absorption section accounting for 19% of the valid water depth in the reactor and 250% of circulation flow ratio. The long-term and full-scale application of the novel reactor in a continuous mode indicated stable removal of COD and polycyclic aromatic hydrocarbons (PAHs). The results showed that the system of IR is a promising reactor type for tertiary treatment of coking wastewater by catalytic ozonation.

scholarly journals Improved Ozonation Efficiency for Polymerization Mother Liquid from Polyvinyl Chloride Production Using Tandem Reactors

Molecules ◽  
2019 ◽  
Vol 24 (24) ◽  
pp. 4436 ◽  
Author(s):  
Zhiyong Yang ◽  
Penglei Wang ◽  
Yagang Zhang ◽  
Xingjie Zan ◽  
Wenjuan Zhu ◽  
...  
Keyword(s):  
Reaction Time ◽  
Chemical Oxygen Demand ◽  
Polyvinyl Chloride ◽  
Ozone Concentration ◽  
Degradation Rate ◽  
Oxygen Demand ◽  
Cod Removal ◽  
Utilization Efficiency ◽  
High Ozone Concentration ◽  
In Series

Polymerization mother liquid (PML) is one of the main sources of wastewater in the chlor-alkali industry. The effective degradation of the PML produced in PVC polymerization using three or five ozone reactors in tandem was designed with a focus on improving the ozonation efficiency. The ozonation efficiency of the tandem reactors for the degradation of PML, along with the effect of ozone concentration, the number of reactors utilized in series, and the reaction time on the chemical oxygen demand (COD) removal were investigated in detail. The results showed that the COD removal increased as the ozone concentration was increased from 10.6 to 60 mg·L−1, achieving 66.4% COD removal at ozone concentration of 80.6 mg·L−1. However, when the ozone concentration was increased from 60 mg·L−1 to 80 mg·L−1, the COD removal only increased very little. The COD decreased with increasing ozone concentration. During the initial degradation period, the degradation rate was the highest at both low and high ozone concentrations. The degradation rate decreased with reaction time. The rate at a low ozone concentration decreased more significantly than at high ozone concentration. Although high ozone concentration is desirable for COD removal and degradation rate, the utilization efficiency of ozone decreased with increasing ozone concentration. The ozone utilization efficiency of the five-reactor device was three times higher than that of three tandem reactors, demonstrating that ozonation utilization efficiency can be improved by increasing the number of tandem reactors. Ozonation in tandem reactors is a promising approach for PML treatment.

scholarly journals Chemical oxygen demand (COD) removal from bio-treated coking wastewater by hydroxyl radicals produced from a reduced clay mineral

2019 ◽  
Vol 180 ◽  
pp. 105199 ◽  
Author(s):  
Ziqi Zhou ◽  
Tian Yu ◽  
Hailiang Dong ◽  
Liuqin Huang ◽  
Rosalie K. Chu ◽  
...  
Keyword(s):  
Chemical Oxygen Demand ◽  
Clay Mineral ◽  
Hydroxyl Radicals ◽  
Oxygen Demand ◽  
Cod Removal ◽  
Coking Wastewater

Advanced Treatment of Coking Wastewater by Oxidation Process Using Pyrite and Hydrogen Peroxide

2013 ◽  
Vol 726-731 ◽  
pp. 2521-2525
Author(s):  
Zhi Yong Zhang ◽  
De Li Wu
Keyword(s):  
Hydrogen Peroxide ◽  
Oxidation Process ◽  
Low Cost ◽  
Oxygen Demand ◽  
Utilization Efficiency ◽  
Advanced Treatment ◽  
Coking Wastewater ◽  
Second Stage ◽  
Potential Alternative ◽  
High Utilization

Coking wastewater is a kind of recalcitrant wastewater including complicate compositions. Advanced treatment of coking wastewater by Fenton-Like reaction using pyrite as catalyst was investigated in this paper. The results show that the chemical oxygen demand (COD) of coking wastewater decreased significantly by method of coagulation combined with two-stage oxidation reaction. COD of wastewater can decrease from 250mg/l to 45mg/l after treatment, when 2g/L pyrite was used in each stage oxidation and the dosage of hydrogen peroxide (H2O2) is 0.2ml/l for first stage treatment, 0.1ml/l for second stage treatment respectively. The pyrite is effective to promote Fenton-Like reaction with low cost due to high utilization efficiency of H2O2, moreover, catalyst could be easily recovered and reused. The Fenton-Like reaction might be used as a potential alternative to advanced treatment of recalcitrant wastewater.

Continuous flow reactors: a perspective

2012 ◽  
Vol 14 (1) ◽  
pp. 38-54 ◽  
Author(s):  
Charlotte Wiles ◽  
Paul Watts
Keyword(s):  
Continuous Flow ◽  
Flow Reactors ◽  
Continuous Flow Reactors

scholarly journals Optimization and Modelling of Chemical Oxygen Demand Removal by ANAMMOX Process Using Response Surface Methodology

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Ali Jalilzadeh ◽  
Ramin Nabizadeh ◽  
Alireza Mesdaghinia ◽  
Aliakbar Azimi ◽  
Simin Nasseri ◽  
...  
Keyword(s):  
Chemical Oxygen Demand ◽  
Response Surface ◽  
Oxygen Demand ◽  
Cod Removal ◽  
Ammonium Concentration ◽  
Ammonium Oxidation ◽  
Optimum Conditions ◽  
Surface Method ◽  
Anammox Process ◽  
Modelling And Optimization

A systematic model for chemical oxygen demand (COD) removal using the ANAMMOX (Anaerobic AMMonium OXidation) process was provided based on an experimental design. At first, the experimental data was collected from a combined biological aerobic/anaerobic reactor. For modelling and optimization of COD removal, the main parameters were considered, such as COD loading, ammonium, pH, and temperature. From the models, the optimum conditions were determined as COD 97.5 mg/L, ammonium concentration equal to 28.75 mg-N/L, pH 7.72, and temperature 31.3°C. Finally, the analysis of the optimum conditions, performed by the response surface method, predicted COD removal efficiency of 81.07% at the optimum condition.

Synthesis of Tailored Segmented Polyurethanes Utilizing Continuous-Flow Reactors and Real-Time Process Monitoring

2021 ◽  
Author(s):  
Xabier Lopez de Pariza ◽  
Tim Erdmann ◽  
Pedro L. Arrechea ◽  
Leron Perez ◽  
Charles Dausse ◽  
...  
Keyword(s):  
Real Time ◽  
Process Monitoring ◽  
Continuous Flow ◽  
Time Process ◽  
Flow Reactors ◽  
Segmented Polyurethanes ◽  
Continuous Flow Reactors

Functional Group Interconversion Reactions in Continuous Flow Reactors

2021 ◽  
Vol 25 ◽  
Author(s):  
Alexander Leslie ◽  
Angel Maria Joseph ◽  
Marcus Baumann
Keyword(s):  
Continuous Flow ◽  
Functional Group ◽  
Modern Synthesis ◽  
Flow Reactors ◽  
Flow Synthesis ◽  
Specific Reaction ◽  
Solid Foundation ◽  
Continuous Flow Reactors ◽  
Flow Techniques

: An overview of the current uptake of continuous flow techniques for various functional group interconversion reactions is presented. Besides highlighting a variety of prominent examples and their main features, this review provides insights into specific reaction classes, such as oxidations, reductions, rearrangements as well as different C-H functionalization processes. While this review can only include key examples from the last decade, the reader will find a solid foundation of important transformations along with further references to inform and appreciate the opportunities arising from modern synthesis technologies such as flow synthesis.

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