Ameliorative effect of fly ashes

Thesis/Dissertation · Tue Jan 01 04:00:00 EST 1991

OSTI ID:5690875

Bhumbla, D K

Agronomic effectiveness and environmental impact of fly ashes used to reclaim pyritic acid mine spoils were investigated in the laboratory and field. Mine spoils at two abandoned sites were amended with three rates of fly ash, three rates of rock phosphate, and seeded with alfalfa and wheat. Application of fly ash decreased bulk density and increased moisture retention capacity of spoils. Fly ash application reduced cation exchange capacity, acidity, toxic levels of Al, Fe, and Mn in soils by buffering soil pH at 6.5, and retarded pyrite oxidation. The reduction in cation exchange capacity was compensated by release of plant nutrients through diffusion and dissolution of plerospheres in fly ash. Improvement of spoil physical, chemical and microbial properties resulted in higher yield, more nitrogen fixation, and utilization of P from rock phosphate by alfalfa. Laboratory investigations demonstrated that neutralization potential and the amounts of amorphous oxides of iron were more important for classifying fly ashes than the total elemental analysis presently used in a taxonomic classification system. Contamination of the food chain through plant removal of Mo and As in fly ash treated mine spoils was observed only for Mo and only for the first year of cropping. Plant available As and Mo decreased with time. Laboratory leaching and adsorption studies and a field experiment showed that trace metals do not leach from fly ashes at near neutral pH and more oxyanions will leach from fly ashes with low neutralization potential and low amounts of amorphous oxides of iron.

• Research Organization: West Virginia Univ., Morgantown, WV (United States)
• OSTI ID: 5690875
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
540220* -- Environment
Terrestrial-- Chemicals Monitoring & Transport-- (1990-)
560300 -- Chemicals Metabolism & Toxicology
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ABANDONED SITES
AEROSOL WASTES
AGRICULTURE
ALFALFA
ALUMINIUM
ASHES
BENCH-SCALE EXPERIMENTS
CEREALS
COMBUSTION PRODUCTS
CONTAMINATION
DISSOLUTION
ELEMENTS
ENVIRONMENTAL EFFECTS
FIELD TESTS
FLY ASH
FOOD CHAINS
GRAMINEAE
GROWTH
INDUSTRY
ION EXCHANGE
IRON
LAND RECLAMATION
LEACHING
LEGUMINOSAE
LILIOPSIDA
MAGNOLIOPHYTA
MAGNOLIOPSIDA
MANGANESE
METALS
MINERALS
PLANT GROWTH
PLANTS
PYRITE
RESIDUES
SEPARATION PROCESSES
SOILS
SPOIL BANKS
SULFIDE MINERALS
TESTING
TRANSITION ELEMENTS
WASTES
WHEAT