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Kinetics and Mechanism of the Redox Reaction of Naphthol Green B with Hydrazine Dihydrochloride in Aqueous Acidic Medium
B. Myek,
S. O. Idris,
J. F. Iyun
Issue:
Volume 5, Issue 6, December 2017
Pages:
76-79
Received:
7 March 2017
Accepted:
18 March 2017
Published:
22 November 2017
Abstract: The kinetics of the redox reaction between naphthol green B and hydrazine dihydrochloride has been studied in aqueous hydrochloric acid medium at an ionic strength, I = 0.50 mol dm-3(NaCl), [H+] = 1.0×10-4 moldm-3 (HCl) and T = 21±1°C. The redox reaction displayed a stoichiometry of 1:1 and obeys the rate law: -d[NGB3-]/dt=k2[NGB3-][N2H4.2HCl]. Change in hydrogen ion concentration of the reaction medium has no effect on the rate of the reaction. Added cations and anions inhibited the rate of the reaction. The redox reaction showed negative salt effect, with the rate decreasing with increase in ionic strength of the reaction medium. Results of the Michaelis–Menten’s plot show that an intermediate complex was not formed during the course of the reaction. The outersphere mechanism is proposed for this reaction.
Abstract: The kinetics of the redox reaction between naphthol green B and hydrazine dihydrochloride has been studied in aqueous hydrochloric acid medium at an ionic strength, I = 0.50 mol dm-3(NaCl), [H+] = 1.0×10-4 moldm-3 (HCl) and T = 21±1°C. The redox reaction displayed a stoichiometry of 1:1 and obeys the rate law: -d[NGB3-]/dt=k2[NGB3-][N2H4.2HCl]. Cha...
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Extraction and Spectrophotometric Assay of Yttrium (III) with TOPO, Application to Water Samples and Alloys
Salim Ali Mohammad,
Samiea Yaseen Sharaf Zeebaree
Issue:
Volume 5, Issue 6, December 2017
Pages:
80-86
Received:
18 October 2017
Accepted:
6 November 2017
Published:
29 November 2017
Abstract: An easy, accurate, selective and sensitive method for extraction and spectrophotometric determination of yttrium (III) in aqueous solution has been determined. The procedure is based on the extract of yttrium (III) with Trioctylphosphine oxide (TOPO) reagent from the aqueous medium followed reaction of extracted yttrium (III) in organic layer with alizarin red s (ARS) reagent at pH 4.9 to form a red carmine complex which has maximum absorption at 519 nm. Beer's law is obeyed over the concentration range 10-260 µg yttrium (III) /10 ml, (i. e., 1-26 ppm) with a determination coefficient of (0.991) and molar absorptivity of 0.53×104 l.mol-1.cm-1. The recoveries are obtained in the range of 98.7 - 100.01% and a relative standard deviation is better than ±2.33%. The method has been successfully applied to the determination of yttrium (III) in natural waters and magnesium alloys.
Abstract: An easy, accurate, selective and sensitive method for extraction and spectrophotometric determination of yttrium (III) in aqueous solution has been determined. The procedure is based on the extract of yttrium (III) with Trioctylphosphine oxide (TOPO) reagent from the aqueous medium followed reaction of extracted yttrium (III) in organic layer with ...
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Electrochemical Water Treatment Technology in Viet Nam: Achievement & Future Development
Tran Tan Tien,
Duong Hieu Linh,
Luong Tan Vu,
Pham Thi Thanh Hoa,
Nguyen Thi Thanh Phuong,
Tran Le Luu
Issue:
Volume 5, Issue 6, December 2017
Pages:
87-94
Received:
26 October 2017
Accepted:
9 November 2017
Published:
1 December 2017
Abstract: Electrochemical technology is a promising technique for water and wastewater treatment in the world. This technology has many advantages as compact model, saving area, highly removal efficient of non-biodegradable compounds, reduction of secondary by-products. There are some different electrochemical techniques such as electroflotation; electrocoagulation using sacrificial electrodes; direct or indirect electrochemical oxidation using Dimensionally Stable Anodes (DSA) and electrodialysis to separate ions in water. In Vietnam, some researches on water and wastewater treatment by electrochemical technology have been studied in the recently year. In this paper, notable results of studies in the application of water and wastewater treatment by electrochemical technology in Vietnam are reviewed in detail. The researching trends of the authors mainly focused on the laboratory scales and the simulated wastewater. Therefore, there are not enough scientific basis to apply for real treatment plants. In the future, electrochemical methods should be used to study the different types of wastewater at the pilot scales, especially difficult handling wastewater and toxics that biological methods cannot handle effectively.
Abstract: Electrochemical technology is a promising technique for water and wastewater treatment in the world. This technology has many advantages as compact model, saving area, highly removal efficient of non-biodegradable compounds, reduction of secondary by-products. There are some different electrochemical techniques such as electroflotation; electrocoag...
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Arsenic Treatment in Groundwater in Mekong Delta Using Laterite Absorbent
Nguyen Thi Thanh Phuong,
Duong Thi Kieu Trang,
Tran Le Luu
Issue:
Volume 5, Issue 6, December 2017
Pages:
95-100
Received:
12 October 2017
Accepted:
23 October 2017
Published:
12 December 2017
Abstract: Arsenic contamination in groundwater has led to pandemic influenza and many disease in Viet Nam and its neighbour country. It is estimated that about 57 million people in the world are affected by Arsenic contamination in drinking water. In Viet Nam, especially in Mekong River Delta, the Arsenic was detected in drinking water is up to 3000 μg/l, many times higher value allowed by the World Health Organization (WHO) of 10 μg/l. In this study, the laterite absorbent was used to treat Arsenic in groundwater in Mekong River Delta in Viet Nam. It is determined that laterite is a powerful absorbent for Arsenic removal in groundwater.
Abstract: Arsenic contamination in groundwater has led to pandemic influenza and many disease in Viet Nam and its neighbour country. It is estimated that about 57 million people in the world are affected by Arsenic contamination in drinking water. In Viet Nam, especially in Mekong River Delta, the Arsenic was detected in drinking water is up to 3000 μg/l, ma...
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