Identification and reactions of cyanide and thiocyanate in coal gasification wastewaters. Sixth quarterly report
This report discusses: (i) procedures for preservation and identification of cyanide and thiocyanate in coal gasification wastewaters, (ii) possible pathways for aqueous phase formation of thiocyanate in these waste-waters, and (iii) reaction of cyanide and polysulfide-sulfur to produce thiocyanate. Cyanide preservation procedures require the removal of sulfide and high levels of carbonate. An analytical procedure for thiocyanate determination based on a copper-pyridine colorimetric method with pre-extraction has been tested successfully on most samples. Kinetic studies on the reaction of cyanide with polysulfide-sulfur showed that the reaction was of order 1.54 +- 0.25 with a rate constant of about 0.24 (M/l) /sup -0/ /sup 54//min. Results of this work may help predict interrelationships among cyanide, sulfur and thiocyanate during oxidation of coal gasification wastewaters. Control of cyanide-polysulfide reaction requires selective control of sulfide oxidation kinetics.
- Research Organization:
- Carnegie-Mellon Univ., Pittsburgh, PA (USA). Environmental Studies Inst.
- DOE Contract Number:
- EX-76-S-01-2496
- OSTI ID:
- 6532290
- Report Number(s):
- FE-2496-23
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
COAL GASIFICATION PLANTS
WASTE WATER
CYANIDES
CHEMICAL ANALYSIS
THIOCYANATES
ABSORPTION SPECTROSCOPY
CHEMICAL REACTIONS
OXIDATION
PRESERVATION
SULFATES
SULFIDES
CARBONIC ACID DERIVATIVES
CHALCOGENIDES
HYDROGEN COMPOUNDS
INDUSTRIAL PLANTS
LIQUID WASTES
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
OXYGEN COMPOUNDS
SPECTROSCOPY
SULFUR COMPOUNDS
WASTES
WATER
010404* - Coal
Lignite
& Peat- Gasification
010800 - Coal
Lignite
& Peat- Waste Management
010900 - Coal
Lignite
& Peat- Environmental Aspects