Project/Area Number |
05680474
|
Research Category |
Grant-in-Aid for General Scientific Research (C)
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Allocation Type | Single-year Grants |
Research Field |
環境保全
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Research Institution | Hokkaido University |
Principal Investigator |
EMI Seijiro Hokkaido Univ., Fac. of Eng., Instructor, 工学部, 助手 (80111152)
|
Project Period (FY) |
1993 – 1994
|
Project Status |
Completed (Fiscal Year 1994)
|
Budget Amount *help |
¥1,600,000 (Direct Cost: ¥1,600,000)
Fiscal Year 1994: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1993: ¥900,000 (Direct Cost: ¥900,000)
|
Keywords | Fixation process for biological specimens / Wastewater / Osmium / Determination / Distilllation / Spectrophotometry / 1,5-Diphenyl-carbonohydrazide / Removal |
Research Abstract |
1. The sensitivity of the spectrophotometric determination method for osmium (Os) with thiourea is rather low, so 1,5-diphenylcarbonohydrazide (DPCI) was used instead of thiourea in the present work. 2. The analysis process of the method with DPCI is as follows. The sample solution involving osmium was distillled after adding of an oxidizing agent and the distrilled osmium tetroxide was absorbed in the absorbing solution. The absorbance of the solution was measured. 3. When sulfuric acid was used as the buffer solution, the Os-DPCI complex had maximum absorption at 305 nm. The calibration curve of Os in the range of Os concentration 0.4-8 mg/l was linear. The mole absorption coefficient of the complex was 2.25*10^4 1 mol^<-1> cm^<-1>. The coefficient was six times as large as that for thiourea. The optimum conditions for the determination was 1 mM of DPCI concentration, 1.18 of pH,temperature over 20゚C and 1h of standing time. The effect of co-existing substances to the Os determination was examined and ethanol interfered the determination. 4. When acetic acid was used as the buffer solution, the Os-DPCI complex had maximum absorption at 580 nm. The optimum conditions for the determination were 3.8 of pH and temperature over 25゚C.DPCI concentration and standing time were similar to case of sulfuric acid. The calibration curve of Os was nearly linear and the mole absorption coefficient of the complex was 1.81*10^4 1 mol^<-1> cm^<-1>. The interference of ethanol for Os determination was negligibly small. 5. Using the determination method that we proposed, the determination of Os in real wastewaters and the experiment of Os removal in wastewaters were carried out.
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