UV-H2O2 ADVANCED OXIDATION OF ANIONIC SURFACTANT: REACTION KINETICS, EFFECTS OF INTERFERING SUBSTANCES AND OPERATING CONDITIONS

2019 ◽  
Vol 18 (6) ◽  
pp. 1245-1254
Author(s):  
Asok Adak ◽  
Bijoli Mondal ◽  
Pallab Datta
2021 ◽  
Author(s):  
Meutia Ermina Toif ◽  
Muslikhin Hidayat ◽  
Rochmadi Rochmadi ◽  
Arief Budiman

Abstract Glucose is the primary derivative of lignocellulosic biomass, which is abundantly available. Glucose has excellent potential to be converted into valuable compounds such as ethanol, sorbitol, gluconic acid, and levulinic acid (LA). Levulinic acid is a very promising green platform chemical. It is composed of two functional groups, ketone and carboxylate groups which can act as highly reactive electrophiles for nucleophilic attack so it has extensive applications, including fuel additives, raw materials for the pharmaceutical industry, and cosmetics. The reaction kinetics of LA synthesis from glucose using hydrochloric acid catalyst (bronsted acid) were studied in a wide range of operating conditions, i.e., temperature of 140-180 oC, catalyst concentration of 0.5-1.5 M, and initial glucose concentration of 0.1-0.5 M. The highest LA yield is 48.34 %wt at 0.1 M initial glucose concentration, 1 M HCl, and temperature of 180 oC. The experimental results show that the bronsted acid catalyst's reaction pathway consists of glucose decomposition to levoglucosan (LG), conversion of LG to 5-hydroxymethylfurfural (HMF), and rehydration of HMF to LA. The experimental data yields a good fitting by assuming a first-order reaction model.


2021 ◽  
Vol 16 (4) ◽  
pp. 904-915
Author(s):  
Meutia Ermina Toif ◽  
Muslikhin Hidayat ◽  
Rochmadi Rochmadi ◽  
Arief Budiman

Glucose is one of the primary derivative products from lignocellulosic biomass, which is abundantly available. Glucose has excellent potential to be converted into valuable compounds such as ethanol, sorbitol, gluconic acid, and levulinic acid (LA). Levulinic acid is an exceptionally promising green platform chemical. It comprises two functional groups, ketone and carboxylate, acting as highly reactive electrophiles for a nucleophilic attack. Therefore, it has extensive applications, including fuel additives, raw materials for the pharmaceutical industry, and cosmetics. This study reports the reaction kinetics of LA synthesis from glucose catalyzed by hydrochloric acid (HCl), a Bronsted acid, that was carried out under a wide range of operating conditions; i.e. the temperature of 140–180 °C, catalyst concentration of 0.5–1.5 M, and initial glucose concentration of 0.1–0.5 M. The highest LA yield of 48.34 % was able to be obtained from an initial glucose concentration of 0.1 M and by using 1 M HCl at 180 °C. The experimental results show that the Bronsted acid-catalyzed reaction pathway consists of glucose decomposition to levoglucosan (LG), conversion of LG to 5-hydroxymethylfurfural (HMF), and rehydration of HMF to LA. The experimental data yields a good fitting by assuming a first-order reaction model. 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). 


2021 ◽  
Vol 43 (7) ◽  
pp. 504-512
Author(s):  
Sri Martini ◽  
Sharmeen Afroze ◽  
Mira Setiawati

Objectives : This comparative study investigated various methods of advanced oxidation processes (AOPs) that were separately conducted for treating raw petroleum refinery effluent regarding chemical oxygen demand (COD) removal.Methods : Fenton, photo-Fenton, TiO2, ZnO, TiO2/Ultra violet (UV), and ZnO/UV were performed individually for measuring the effect of light irradiation, treatment time, pH, catalysts dosage, and light source on the profile of COD values.Results and Discussion : The experimental data of this work showed that the dependency on the light exposure in heterogeneous photo-catalytic reaction using TiO2 and ZnO is higher than that of homogeneous photo-Fenton technique. The optimum operating conditions in heterogeneous system occurred at 100 min of oxidation time, pH 5, and catalyst dosage 1 g/L that resulted in 21.8, 20.68, 60.9, and 55.17% of COD removal for TiO2, ZnO, TiO2/UV, and ZnO/UV, respectively. In contrast, both Fenton and photo-Fenton experienced their highest performance at pH 4 by obtaining 44.2 and 59.77% of COD removal, respectively. Eventually, kinetic study indicated that COD degradation can be well expressed by second-order pattern that reached higher correlation coefficient values by 0.999 and 0.998 for TiO2/UV and TiO2, respectively.Conclusions : Overall, it could be assumed that AOPs are reliable techniques to purify raw and complex raw industrial effluents.


Author(s):  
Hee-Jun Kim ◽  
Chan-Hee Won ◽  
Hyun-Woo Kim

This study investigates how the non-thermal plasma (NTP) process leads to advanced oxidation of sewage using response surface methodology. For environmentally viable and efficient operation of the NTP process, temperature and contact time were selected as two important independent variables. Their impacts on the performance were tested following an experimental design to figure out optimal operating conditions. Based on obtained treatment efficiency, statistically optimized conditions were derived by using an approach adapting the central composite design. Results show that coupling 40 °C of temperature and 4 h of contact time demonstrate optimal performance for total chemical oxygen demand (TCOD, 59%) and total suspended solids (85%), respectively. This implies that NTP may present efficient particulate destruction leading to organic solids dissolution. Statistical analysis reveals that the contact time shows more significant dependency than the temperature on the advanced oxidation of TCOD, possibly due to dissolved organic material. For total nitrogen removal, on the contrary, the optimal efficiency was strongly related to the higher temperature (~68 °C). This work provides an inroad to considering how NTP can optimally contribute to better oxidation of multiple pollutants.


2011 ◽  
Vol 11 (4) ◽  
pp. 460-467 ◽  
Author(s):  
C. H. M. Hofman-Caris ◽  
D. J. H. Harmsen ◽  
B. A. Wols ◽  
L. J. J. M. Janssen ◽  
E. F. Beerendonk ◽  
...  

Advanced oxidation processes, like UV/H2O2 oxidation, are important barriers against organic micro pollutants in drinking water treatment. In order to guarantee safe drinking water, it is important to be able to predict the reactors' performance to adjust the operating conditions to the actual influent water characteristics (like UV transmission) and lamp performance. Therefore, a design tool was developed, which is based on a kinetic model that describes and predicts the direct photolysis and oxidation of organic compounds in pilot experiments, using Low Pressure (LP) UV-lamps. This model has been combined with computational fluid dynamics (CFD), in order to be able to accurately predict the results of pilot and full scale installations, and also to design reactor systems. The model was applied to three model compounds (atrazine, ibuprofen and NDMA) in two different pilot reactors, and it has been shown that reactor performance can be fairly predicted by applying this ‘UVPerox’ model. The model takes into account the water quality and power of the lamps, and the properties of the compounds involved.


Catalysts ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 782
Author(s):  
Wamda Faisal Elmobarak ◽  
Bassim H. Hameed ◽  
Fares Almomani ◽  
Ahmad Zuhairi Abdullah

The petroleum industry is one of the most rapidly developing industries and is projected to grow faster in the coming years. The recent environmental activities and global requirements for cleaner methods are pushing the petroleum refining industries for the use of green techniques and industrial wastewater treatment. Petroleum industry wastewater contains a broad diversity of contaminants such as petroleum hydrocarbons, oil and grease, phenol, ammonia, sulfides, and other organic composites, etc. All of these compounds within discharged water from the petroleum industry exist in an extremely complicated form, which is unsafe for the environment. Conventional treatment systems treating refinery wastewater have shown major drawbacks including low efficiency, high capital and operating cost, and sensitivity to low biodegradability and toxicity. The advanced oxidation process (AOP) method is one of the methods applied for petroleum refinery wastewater treatment. The objective of this work is to review the current application of AOP technologies in the treatment of petroleum industry wastewater. The petroleum wastewater treatment using AOP methods includes Fenton and photo-Fenton, H2O2/UV, photocatalysis, ozonation, and biological processes. This review reports that the treatment efficiencies strongly depend on the chosen AOP type, the physical and chemical properties of target contaminants, and the operating conditions. It is reported that other mechanisms, as well as hydroxyl radical oxidation, might occur throughout the AOP treatment and donate to the decrease in target contaminants. Mainly, the recent advances in the AOP treatment of petroleum wastewater are discussed. Moreover, the review identifies scientific literature on knowledge gaps, and future research ways are provided to assess the effects of these technologies in the treatment of petroleum wastewater.


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