Preliminary Investigation of the Supply of Chemical Species to an Aqueous Solution Using a Hydrogen−Oxygen Flame

2005 ◽  
Vol 39 (15) ◽  
pp. 5851-5855
Author(s):  
Miho Uchida ◽  
Takahiro Sogabe ◽  
Tadaaki Ikoma ◽  
Akitsugu Okuwaki
Keyword(s):  
Aqueous Solution ◽  
Preliminary Investigation ◽  
Chemical Species ◽  
Oxygen Flame

scholarly journals HYDROXYLATION REACTION OF AROMATIC RINGS IN AQUEOUS SOLUTION INDUCED BY HYDROGEN–OXYGEN FLAME

1984 ◽  
Vol 13 (10) ◽  
pp. 1629-1632 ◽  
Author(s):  
Michiaki Takasaki ◽  
Shinya Nomoto ◽  
Kaoru Harada
Keyword(s):  
Aqueous Solution ◽  
Aromatic Rings ◽  
Hydroxylation Reaction ◽  
Oxygen Flame

Improvement of Inventory and Leaching Rate Measurements of C-14 in Hull Waste, and Separation of Organic Compounds for Chemical Species Identification

2014 ◽  
Vol 1665 ◽  
pp. 139-148 ◽  
Author(s):  
Ryota Takahashi ◽  
Michitaka Sasoh ◽  
Yu Yamashita ◽  
Hiromi Tanabe ◽  
Tomofumi Sakuragi
Keyword(s):  
Aqueous Solution ◽  
Organic Compounds ◽  
High Performance ◽  
Liquid Scintillation ◽  
Scintillation Counter ◽  
Chemical Species ◽  
Neutral Molecule ◽  
Leaching Rate ◽  
Oxidative Decomposition ◽  
Carbon Compounds

ABSTRACTIn order to analyze the C-14 inventory and leaching rate for safety evaluation of transuranic waste disposal, it is necessary to establish an analytical method that can measure C-14 with sufficient precision [1]. Oxidative decomposition of organic compounds containing C-14 is carried out to absorb carbon dioxide (CO2) in an alkaline solution, which is mixed with a liquid scintillation cocktail, and the amount C-14 is quantified by measuring a beta ray spectrum with a liquid scintillation counter. It has been difficult to completely decompose carbon compounds in a sample, even to CO2, by using conventional oxidizing agents. In the work described here, we improved the method of oxidative decomposition used to completely decompose carbon compounds using peroxydisulfuric acid (K2S2O8). When C-14 in the form of CO2 was absorbed in a sodium hydroxide (NaOH) aqueous solution, only 80% of the actually used quantity was detected. Total organic carbon measurements showed that the entire quantity of CO2 was absorbed by NaOH. When NaOH aqueous solution was used, it was found that only the analytical value was 80%. The entire quantity of the actually used carbon could be measured by absorbing the CO2 in Carbo-Sorb®. An anion form and a neutral molecule exist in the organic compound released from activated metals. In order to identify organic compounds efficiently, fractionation into an anion and a neutral molecule and separation by high performance liquid chromatography (HPLC) are necessary. Here, we propose the combined use of an ion exchange resin and HPLC as an improved technique for identification of the chemical species.

Photodegradation of amoxicillin in aqueous solution under simulated irradiation: influencing factors and mechanisms

2013 ◽  
Vol 67 (7) ◽  
pp. 1605-1611 ◽  
Author(s):  
Qian Zhao ◽  
Li Feng ◽  
Xiang Cheng ◽  
Chao Chen ◽  
Liqiu Zhang
Keyword(s):  
Aqueous Solution ◽  
Singlet Oxygen ◽  
Natural Waters ◽  
Pure Water ◽  
Chemical Species ◽  
Xenon Lamp ◽  
First Order ◽  
First Order Kinetics ◽  
Photodegradation Rate ◽  
Pseudo First Order

This paper investigated the effects of selected common chemical species in natural waters (HCO3−, NO3− and humic acids (HA)) on the photodegradation of amoxicillin (AMO) under simulated irradiation using a 300 W xenon lamp. Quenching experiments were carried out to explore the mechanisms of AMO photodegradation. The results indicated that AMO photodegradation followed pseudo-first-order kinetics. Increasing AMO concentration from 100 to 1,000 μg L−1 led to the decrease in the photodegradation rate constant from 0.2411 to 0.1912 min−1. The presence of NO3− and HA obviously inhibited the photodegradation rate of AMO because they can compete for photons with AMO. Bicarbonate, as a hydroxyl radical (·OH) scavenger, also adversely affected AMO photodegradation. Quenching experiments in pure water suggested that AMO could undergo self-sensitized photooxidation via ·OH and singlet oxygen (1O2), accounting for AMO removal of 34.86 and 8.26%, respectively. In HA solutions, the indirect photodegradation of AMO was mostly attributed to the produced ·OH (22.37%), 1O2 (24.12%) and 3HA* (20.80%), whereas the contribution of direct photodegradation was to some extent decreased.

scholarly journals A switchable sensor and scavenger: detection and removal of fluorinated chemical species by a luminescent metal–organic framework

2021 ◽  
Author(s):  
Hua-Qing Yin ◽  
Kui Tan ◽  
Stephanie Jensen ◽  
Simon J. Teat ◽  
Saif Ullah ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Metal Organic Framework ◽  
Chemical Species ◽  
Sensitive Detection ◽  
Luminescence Signal ◽  
Signal Change ◽  
Metal Organic ◽  
Organic Framework

A robust In-MOF, In(tcpp), demonstrates sensitive detection of the fluorinated chemical species F− and PFOA via distinctly different luminescence signal change, and effective adsorption and removal of both species from aqueous solution.

Aqueous Ammonia Equilibrium Calculations: Effect of pH and Temperature

1975 ◽  
Vol 32 (12) ◽  
pp. 2379-2383 ◽  
Author(s):  
Kenneth Emerson ◽  
Rosemarie C. Russo ◽  
Richard E. Lund ◽  
Robert V. Thurston
Keyword(s):  
Aqueous Solution ◽  
Aqueous Ammonia ◽  
Critical Evaluation ◽  
Chemical Species ◽  
Equilibrium System ◽  
Ammonia Water ◽  
Different Temperatures ◽  
Total Ammonia ◽  
Water Equilibrium ◽  
Equilibrium Calculations

The toxicity of ammonia to fishes has been attributed to the un-ionized ammonia chemical species present in aqueous solution. Because the percent of total ammonia present as un-ionized ammonia (NH3) is so dependent upon pH and temperature, an exact understanding of the aqueous ammonia equilibrium is important for toxicity studies. A critical evaluation of the literature data on the ammonia–water equilibrium system has been carried out. Results of calculations of values of pKa at different temperatures and of percent of NH3 in aqueous ammonia solutions of zero salinity as a function of pH and temperature are presented.

scholarly journals Removal of boron from aqueous solution using cryptocrystalline magnesite

2016 ◽  
Vol 7 (2) ◽  
pp. 205-213 ◽  
Author(s):  
Vhahangwele Masindi ◽  
Mugera W. Gitari
Keyword(s):  
Aqueous Solution ◽  
Adsorption Isotherms ◽  
Boron Concentration ◽  
Chemical Species ◽  
Aqueous System ◽  
World Health ◽  
Aqueous Systems ◽  
Ph Optimum ◽  
Boron Ions ◽  
Health Organization

The present study aimed to evaluate the efficiency of using cryptocrystalline magnesite to remove boron ions from aqueous systems. Batch experimental protocols were used to evaluate the adsorption capacity of magnesite for boron. Parameters optimized included: time, dosage, chemical species concentration and pH. Optimum conditions were observed to be 30 min of agitation, 1 g dosage of magnesite per 100 mL of aqueous solution and 20 mg/L initial boron concentration. Removal of boron from aqueous solution was observed to be independent of initial pH of the aqueous solution. The adsorption of boron onto magnesite was observed to fit better to pseudo-second-order kinetics than pseudo-first-order kinetics hence proving chemisorption. The intra-particle diffusion model revealed that the adsorption of boron from aqueous system occurs through multiple reaction phenomena. Adsorption isotherms proved that the removal of boron by magnesite fitted well to both Langmuir and Freundlich adsorption isotherms hence proving that both mono- and multi-site adsorption processes are taking place. Under optimized conditions, magnesite was able to attenuate the boron concentration to <0.01 mg/L which is below levels stipulated in World Health Organization guidelines. It was concluded that this comparative study will be helpful for further application of magnesite in remediation of boron-contaminated aqueous systems.

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