Leaching characteristics of heavy metals from solidified sludge under seawater conditions

Journal Article · · Hazardous Waste and Hazardous Materials; (USA)

OSTI ID:5764327

Hang-Sik, Shin; Ja-Kong, Koo; Jong-Oh, Kim; Yoon, Seok-Pyo ^[1]

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1. Korea Advanced Institute of Science and Technology, Seoul (Korea)

An attempts was made to investigate the leaching characteristics of solidified materials under sea-water condition. In leaching test, three different leachants, namely, sea water, acidic water, and distilled water were used. Final pH and metal concentration of leachate after 24-hr extraction were strongly affected by the nature of leachant. Addition of fly ash resulted in the decrease of leachate pH and the increase of leachate metal concentration. During 60-day leaching test periods, cumulative cadmium released under sea water was linearly increased, but other metals leached in decreasing rate with increasing number of leachant renewal. After 60 days of leaching periods, sample weights were decreased as lime and heavy metal components dissolved, and particle size of leached sample having no fly ash was especially decreased under the sea water leachant. Dissolved heavy metals were considerably reprecipitated under alkaline sea water condition. Microscopic study on surface change of solidified materials made with Scanning Electron Microscopy (SEM) and X-ray diffraction analysis (XRD) showed that lime dissolved out while C-S-H, ettringite, and gypsum crystals were formed.

• OSTI ID: 5764327
• Journal Information: Hazardous Waste and Hazardous Materials; (USA), Journal Name: Hazardous Waste and Hazardous Materials; (USA) Vol. 7:3; ISSN 0882-5696; ISSN HWHME
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
540320* -- Environment
Aquatic-- Chemicals Monitoring & Transport-- (1990-)
AEROSOL WASTES
ALKALINE EARTH METAL COMPOUNDS
ASHES
CALCIUM COMPOUNDS
CALCIUM OXIDES
CHALCOGENIDES
COHERENT SCATTERING
DIFFRACTION
DISSOLUTION
ECOLOGICAL CONCENTRATION
ELECTRON MICROSCOPY
ELEMENTS
FLY ASH
HYDROGEN COMPOUNDS
LEACHING
MANAGEMENT
METALS
MICROSCOPY
OXIDES
OXYGEN COMPOUNDS
PARTICLE SIZE
PH VALUE
POLLUTION
RESIDUES
SCANNING ELECTRON MICROSCOPY
SCATTERING
SEAWATER
SEPARATION PROCESSES
SIZE
WASTE DISPOSAL
WASTE MANAGEMENT
WASTES
WATER
WATER POLLUTION
X-RAY DIFFRACTION