Process for removing heavy metals from water

Details Process for removing heavy metals from water Process for removing heavy metals from water

1992-04-15

1993-11-30

Hruskoci, Peter

Liquid purification or separation

Processes

Making an insoluble substance or accreting suspended...

210724, 210725, 210726, 210727, 210912, C02F 162

Patent

active

052662101

ABSTRACT:
Wastewater contaminated with heavy metals is treated in a multi-stage process. In a first stage, wastewater is treated with an effective amount of calcium oxide and/or calcium hydroxide in the form of lime to adjust the pH so that various metals in the water become insoluble. Gypsum formation may also occur if sulfate ions are present in the wastewater. In a second stage, an effective amount of sodium carbonate is added in the form of soda ash to allow formation of calcium carbonate. In a third stage, a coagulant, preferably a polymer, is added to facilitate the formation of a sludge comprising heavy metals, gypsum and calcium carbonate. In a final stage, the pH of the resulting effluent may be adjusted with a suitable acid, such as hydrochloric acid, to attain acceptable discharge requirements. The sludge formed is substantially stable and dewatered and has low toxic metal leaching characteristics.

REFERENCES:
patent: Re29783 (1978-09-01), Smith et al.
patent: 3345288 (1967-10-01), Sontheimer
patent: 3575853 (1971-04-01), Gaughan et al.
patent: 3617560 (1971-11-01), Deul et al.
patent: 3720609 (1973-03-01), Smith et al.
patent: 3738932 (1973-06-01), Kostenbader
patent: 3833463 (1974-09-01), Croom
patent: 3846293 (1974-11-01), Campbell
patent: 3947350 (1974-03-01), Cardinal, Jr.
patent: 3997438 (1976-12-01), Weiland et al.
patent: 4025430 (1977-05-01), Pagel
patent: 4059513 (1977-11-01), Zadera
patent: 4343706 (1982-08-01), Etzel et al.
patent: 4415467 (1983-11-01), Piepho
patent: 4419246 (1983-12-01), Jayawant
patent: 4465597 (1984-08-01), Herman et al.
patent: 4610792 (1986-09-01), Van Gils et al.
patent: 4698163 (1987-10-01), Zibrida
patent: 4802993 (1989-02-01), Katoh
patent: 5000858 (1991-03-01), Manning et al.
patent: 5028272 (1991-07-01), Bonee

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