Reducing the formation of adsorbable organic halides using an ammonium thiosulfate chlorine dioxide bleaching process

Reducing the formation of adsorbable organic halides during chlorine dioxide bleaching (the first stage chlorine dioxide bleaching, D0) is necessary to obtain clean bleaching processes. A new bleaching agent, ammonium thiosulfate (AT), was investigated to determine its potential for reducing the amount of adsorbable organic halides (AOX). Upon investigating the optimal reaction conditions for an effective reduction in AOX, the authors determined that adding 0.20% of AT 10 min after the beginning of the bleaching reaction, while maintaining a pH of 4 and a temperature of 70°C, yielded the best results. Under these conditions, AOX formation decreased by 22.0%. The bleaching effluent after the addition of AT was analyzed via gas chromatography-mass spectrometry, which showed an inhibited production rate of chlorobenzene and chlorophenol, which are both highly toxic and difficult-to-degrade compounds. Therefore, AT not only reduces AOX formation during the bleaching process, but also minimizes the difficulty of treating bleaching effluent. The results of this study provided a new, clean method for reducing AOX formation during chlorine dioxide bleaching.

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Hydrothermal Liquefaction of Wheat Straws for Bio-Oil and Related Analyses

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.347-353.2419 ◽

2011 ◽

Vol 347-353 ◽

pp. 2419-2422 ◽

Cited By ~ 1

Author(s):

Hui Wang ◽

Xiao Juan Liu ◽

Yan Xing Liu ◽

Peng Chen ◽

Jian Sun

Keyword(s):

Mass Spectrometry ◽

Gas Chromatography ◽

Fourier Transform ◽

Hydrothermal Liquefaction ◽

Gas Chromatography Mass Spectrometry ◽

Reaction Conditions ◽

Heating Value ◽

Bio Oil ◽

The Fourier Transform ◽

Optimal Reaction

The liquefaction of wheat straws in sub-critical water to obtain bio-oil was investigated in this paper. We observed that the reaction temperature (300-374 °C) and reaction time (1-15 min) played important roles in the yield of bio-oil and found the optimal reaction conditions (340 °C, 5 min). The bio-oil was analyzed by elemental analysis, the Fourier transform infrared spectroscopy (FTIR) and gas chromatography-mass spectrometry (GC-MS). Results indicated that the heating value of bio-oil product was 32-38 MJ/kg, higher than that of the bio-oil obtained from microalgae, and the product was composed of ketones, phenol and its derivatives, aromatics and small amount of aldehydes and ethers.

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Kandungan Hexenuronic Acid pada Pulp serta Pengaruhnya terhadap Kualitas Pulp dan Air Limbah: Tinjauan

JURNAL SELULOSA ◽

10.25269/jsel.v8i02.238 ◽

2018 ◽

Vol 8 (02) ◽

pp. 61

Author(s):

Andri Taufick Rizaluddin ◽

Krisna Septiningrum

Keyword(s):

Paper Industry ◽

Kappa Number ◽

Pulp And Paper ◽

Bleaching Process ◽

Adsorbable Organic Halides ◽

Organic Halides ◽

Cooking Process ◽

Hydrolysis Process ◽

Organic Chlorine ◽

Hexenuronic Acid

Proses pemasakan kayu dengan cara alkali aktif akan menghasilkan hexenuronic acid (HexA) yang berasal dari grup glucuronoxylan, tepatnya 4-O-methylglucuronoxylan pada hemiselulosa. Proses hidrolisis HexA menghasilkan dua jenis senyawa furan, yaitu 2-furancarboxylic acid (FA) dan 5-formyl-2-furancarboxylic acid (FFA). Proses hidrolisis HexA hasil proses pemasakan dan terkandung dalam pulp dan kertas merupakan salah satu penyebab proses penguningan pada kertas akibat adanya paparan kelembapan dan panas dari lingkungan. Selain itu, kandungan HexA pada pulp juga dapat meningkatkan konsumsi bahan kimia pada proses produksi pulp dan kertas, terutama pada proses pemutihan dan pengujian parameter bilangan Kappa, serta dapat berkontribusi pada kandungan senyawa organik klorin terlarut dalam air limbah industri pulp dan kertas. Metode untuk menurunkan kandungan HexA dari pulp dan kertas antara lain dengan mengaplikasikan proses oksidatif kimia pada proses pemutihan atau dengan menggunakan proses enzimatis. Kandungan HexA yang rendah, akan dapat mempertahankan pulp dan kertas dari terjadinya proses penguningan, menghemat konsumsi bahan kimia serta menurunkan kandungan adsorbable organic halides (AOX) pada air limbah.Kata kunci: hexenuronic acid, pemasakan kayu, bilangan Kappa, AOX, enzimatis Hexenuronic Acid Content on Pulp and its Effects on Pulp Quality and Wastewater: a ReviewAbstractThe wood active alkali cooking process will produce hexenuronic acid (HexA) originating from 4-O-methylglucuronoxylan of the glucuronoxylan group in hemicellulose. Hydrolysis process of HexA produces two types of furan compounds, namely 2-furancarboxylic acid (FA) and 5-formyl-2-furancarboxylic acid (FFA). The HexA hydrolysis process contained in pulp and paper resulting from the cooking process is one of the causes of the yellowing process on paper due to exposure to moisture and heat from the environment. In addition, the HexA content of pulp can also increase the consumption of chemicals in the pulp and paper production process, especially in the bleaching process and testing of Kappa number parameters, and can also contribute to the content of organic chlorine soluble compounds in the waste water of the pulp and paper industry. There are several methods for reducing the HexA content of pulp and paper including by applying the oxidative chemical process to the bleaching process or by using an enzymatic process. Low HexA content, will be able to maintain pulp and paper from the occurrence of the pulp yellowing process, save on chemical consumption and reduce the adsorbable organic halides (AOX) content in wastewater.Keywords: hexenuronic acid, wood cooking, Kappa number, AOX, enzymatic

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Removal of hexenuronic acid by xylanase to reduce adsorbable organic halides formation in chlorine dioxide bleaching of bagasse pulp

Bioresource Technology ◽

10.1016/j.biortech.2015.07.115 ◽

2015 ◽

Vol 196 ◽

pp. 413-417 ◽

Cited By ~ 46

Author(s):

Shuangxi Nie ◽

Shuangfei Wang ◽

Chengrong Qin ◽

Shuangquan Yao ◽

Johnbull Friday Ebonka ◽

...

Keyword(s):

Chlorine Dioxide ◽

Adsorbable Organic Halides ◽

Organic Halides ◽

Hexenuronic Acid ◽

Bagasse Pulp

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Lab-Scale Study on Removal of Phenol from Contaminated Groundwater by Chlorine Dioxide Oxidation Technology

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.599.363 ◽

2012 ◽

Vol 599 ◽

pp. 363-366

Author(s):

Qi Shan Wang ◽

Ze Xu ◽

You Wen Zeng ◽

Shang Chao Yue ◽

Yi Ran Zhang

Keyword(s):

Chlorine Dioxide ◽

Removal Rate ◽

Contaminated Groundwater ◽

Phenol Removal ◽

Reaction Conditions ◽

Technical Parameters ◽

Oxidation Technology ◽

Series Of Experiments ◽

High Level ◽

Optimal Reaction

A series of experiments were conducted to investigate the optimal technical parameters for phenol removal by chlorine dioxide (ClO2) oxidation. Results demonstrated that ClO2 could removal phenol effectively, both for simulated phenol contaminated groundwater and practical phenol contaminated groundwater. ClO2 dosage and reaction time were found to have a significant impact on phenol removal, while pH only affected slightly between 6.5 to 7.0 . Under optimal reaction conditions, the removal rate could reach an extremely high level of 97.5% within 30 min at a ClO2 dosage of 0.6 mg/L for the simulated phenol contaminated groundwater with initial phenol concentration of 0.2 mg/L. For the practical phenol contaminated groundwater the removal rate could reach 96% within 60 min at a ClO2 dosage 1.0 mg/L. This study provides a feasible chemical method to removal phenol from contaminated groundwater.

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Kinetics of Adsorbable Organic Halides (AOX) Reduction in Laccase-Aided Chlorine Dioxide Bleaching of Bagasse Pulp

BioResources ◽

10.15376/biores.11.3.7462-7475 ◽

2016 ◽

Vol 11 (3) ◽

Cited By ~ 1

Author(s):

Xueping Song ◽

Yong Pei ◽

Jingjing Su ◽

Chengrong Qin ◽

Shuangfei Wang ◽

...

Keyword(s):

Chlorine Dioxide ◽

Adsorbable Organic Halides ◽

Organic Halides ◽

Kinetics Of ◽

Bagasse Pulp

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Synthesis of Phosphonates via Michaelis-Arbuzov Reaction

Current Organic Synthesis ◽

10.2174/1570179414666161230144455 ◽

2017 ◽

Vol 14 (6) ◽

pp. 883-903 ◽

Cited By ~ 4

Author(s):

Boppudi Hari Babu ◽

Gandavaram Syam Prasad ◽

Chamarthi Naga Raju ◽

Mandava Venkata Basaveswara Rao

Keyword(s):

Reaction Times ◽

Biologically Active ◽

Fine Tuning ◽

Arbuzov Reaction ◽

Reaction Conditions ◽

Solvent Type ◽

Potential Applications ◽

Synthetic Methodologies ◽

Optimal Reaction ◽

The Arbuzov Reaction

Background: Michaelis–Arbuzov reaction has played a key role for the synthesis of dialkyl or diaryl phosphonates by reacting various alkyl or aryl halides with trialkyl or triaryl phosphite. This reaction is very versatile in the formation of P-C bond from the reaction of aliphatic halides with phosphinites or phosphites to yield phosphonates, phosphinates, phosphine oxides. The Arbuzov reaction developed some methodologies, possible mechanistic pathways, selectivity, potential applications and biologically active various phosphonates. Objective: The synthesis of phosphonates via Michaelis–Arbuzov reaction with many new and fascinating methodologies were developed and disclosed in the literature, and these are explored in this review. Conclusion: This review has discussed past developments and vast potential applications of Arbuzov reaction in the synthesis of organophosphonates. As presented in this review, various synthetic methodologies were developed to prepare a large variety of phosphonates. Improvements in the reaction conditions of Lewis-acid mediated Arbuzov rearrangement as well as the development of MW-assisted Arbuzov rearrangement were discussed. Finally, to achieve high selectivities and yields, fine-tuning of reaction conditions including solvent type, temperature, and optimal reaction times to be considered.

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Amperometric assay of vitamin C using an ascorbate oxidase enzyme electrode

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19793395 ◽

1979 ◽

Vol 44 (11) ◽

pp. 3395-3404 ◽

Cited By ~ 16

Author(s):

Pavel Posádka ◽

Lumír Macholán

Keyword(s):

Ascorbic Acid ◽

Vitamin C ◽

Oxygen Electrode ◽

Ascorbate Oxidase ◽

Current Response ◽

Reaction Conditions ◽

Long Term Storage ◽

Oxidase Enzyme ◽

Optimal Reaction

An oxygen electrode of the Clark type, coated by a thin, active layer of chemically insolubilized ascorbate oxidase from squash peelings specifically detects by measuring oxygen uptake 10 to 400 μg of ascorbic acid in 3 ml of phosphate buffer. The record of current response to substrate addition lasts 1-2 min. The ascorbic acid values determined in various samples of fruit juices are in good agreement with the data obtained by titration and polarography. The suitable composition of the membrane and its lifetime and stability during long-term storage are described; optimal reaction conditions of vitamin C determination and the possibilities of interference of other compounds are also examined. Of the 35 phenols, aromatic amines and acids tested chlorogenic acid only can cause a positive error provided that the enzyme membrane has been prepared from ascorbate oxidase of high purity.

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A Novel Pseudomonas geniculata AGE Family Epimerase/Isomerase and Its Application in d-Mannose Synthesis

Foods ◽

10.3390/foods9121809 ◽

2020 ◽

Vol 9 (12) ◽

pp. 1809

Author(s):

Zhanzhi Liu ◽

Ying Li ◽

Jing Wu ◽

Sheng Chen

Keyword(s):

3D Structure ◽

Three Dimensional ◽

Optimal Temperature ◽

Reaction Conditions ◽

Enzymatic Production ◽

Physiological Properties ◽

Potential Applications ◽

Kinetics Of ◽

Optimal Reaction ◽

Gene Age

d-mannose has exhibited excellent physiological properties in the food, pharmaceutical, and feed industries. Therefore, emerging attention has been applied to enzymatic production of d-mannose due to its advantage over chemical synthesis. The gene age of N-acetyl-d-glucosamine 2-epimerase family epimerase/isomerase (AGEase) derived from Pseudomonas geniculata was amplified, and the recombinant P. geniculata AGEase was characterized. The optimal temperature and pH of P. geniculata AGEase were 60 °C and 7.5, respectively. The Km, kcat, and kcat/Km of P. geniculata AGEase for d-mannose were 49.2 ± 8.5 mM, 476.3 ± 4.0 s−1, and 9.7 ± 0.5 s−1·mM−1, respectively. The recombinant P. geniculata AGEase was classified into the YihS enzyme subfamily in the AGE enzyme family by analyzing its substrate specificity and active center of the three-dimensional (3D) structure. Further studies on the kinetics of different substrates showed that the P. geniculata AGEase belongs to the d-mannose isomerase of the YihS enzyme. The P. geniculata AGEase catalyzed the synthesis of d-mannose with d-fructose as a substrate, and the conversion rate was as high as 39.3% with the d-mannose yield of 78.6 g·L−1 under optimal reaction conditions of 200 g·L−1d-fructose and 2.5 U·mL−1P. geniculata AGEase. This novel P. geniculata AGEase has potential applications in the industrial production of d-mannose.

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Efficient Degradation of Mordant Blue 9 Using the Fenton-Activated Persulfate System

Water ◽

10.3390/w11122532 ◽

2019 ◽

Vol 11 (12) ◽

pp. 2532 ◽

Cited By ~ 3

Author(s):

Md. Nahid Pervez ◽

Felix Y. Telegin ◽

Yingjie Cai ◽

Dongsheng Xia ◽

Tiziano Zarra ◽

...

Keyword(s):

Butyl Alcohol ◽

Textile Dye ◽

Oh Radicals ◽

Operational Parameters ◽

Reaction Conditions ◽

Tert Butyl Alcohol ◽

Initial Ph ◽

Fe Complex ◽

Optimal Reaction ◽

Activated Persulfate

In this study, a Fenton-activated persulfate (Fe2+/PS) system was introduced for the efficient degradation of Mordant Blue 9 (MB 9) as a textile dye in an aqueous solution. Results showed that the degradation of MB 9 was markedly influenced by operational parameters, such as initial pH, PS concentration, Fe2+ concentration, and initial dye concentration. Optimal reaction conditions were then determined. Inorganic anions, such as Cl− and HCO3−, enhanced the degradation efficiency of MB 9 under optimal conditions. Addition of HCO3− reduced the degradation performance of MB 9, whereas the addition of Cl− increased the degradation percentage of MB 9. In addition, quenching experiments were conducted using methanol and tert-butyl alcohol as scavengers, and methanol was identified as an effective scavenger. Thus, the degradation of MB 9 was attributed to S O 4 • − and •OH radicals. The degradation and mineralization efficiency of MB 9 was significantly reduced using the conventional Fenton process i.e., Fe2+/ hydrogen peroxide (HP) because of the formation of a Fe complex during degradation. Meanwhile, the Fe2+/persulfate (PS) system improved the degradation and mineralization performance.

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Software-guided microscale flow calorimeter for efficient acquisition of thermokinetic data

Journal of Flow Chemistry ◽

10.1007/s41981-021-00145-6 ◽

2021 ◽

Author(s):

Timothy Aljoscha Frede ◽

Marlene Dietz ◽

Norbert Kockmann

Keyword(s):

Design Of Experiments ◽

Process Development ◽

Reaction Conditions ◽

Experimental Conditions ◽

Flow Calorimeter ◽

Microscale Flow ◽

Increased Sensitivity ◽

Important Time ◽

Optimal Reaction

AbstractFast chemical process development is inevitably linked to an optimized determination of thermokinetic data of chemical reactions. A miniaturized flow calorimeter enables increased sensitivity when examining small amounts of reactants in a short time compared to traditional batch equipment. Therefore, a methodology to determine optimal reaction conditions for calorimetric measurement experiments was developed and is presented in this contribution. Within the methodology, short-cut calculations are supplemented by computational fluid dynamics (CFD) simulations for a better representation of the hydrodynamics within the microreactor. This approach leads to the effective design of experiments. Unfavourable experimental conditions for kinetics experiments are determined in advance and therefore, need not to be considered during design of experiments. The methodology is tested for an instantaneous acid-base reaction. Good agreement of simulations was obtained with experimental data. Thus, the prediction of the hydrodynamics is enabled and the first steps towards a digital twin of the calorimeter are performed. The flow rates proposed by the methodology are tested for the determination of reaction enthalpy and showed that reasonable experimental settings resulted. Graphical abstract A methodology is suggested to evaluate optimal reaction conditions for efficientacquisition of kinetic data. The experimental design space is limited by thestepwise determination of important time scales based on specified input data.

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