Patent US5681476A successfully refreshed from Google Patents.
US5681476A
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Process for the purification of groundwater
Assignee: Evonik Operations GmbH
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Filing: 1995-09-18
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Granted: 1997-10-28
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Expires: 2015-09-18
Abstract
Abstract Polluted groundwater is purified by separating off solids and adsorbing dissolved organic compounds to an adsorber resin. The adsorbed organic compounds are desorbed using steam and the adsorber resin is regenerated using an acid and an oxygen-containing gas. The process makes it possible to separate aromatic and halogenated hydrocarbons off of heavily polluted groundwater to the extent that the groundwater can be added to flowing surface water without reservation. The purified water can, if appropriate, be used as cooling water, or after further biological purification, as drinking water.
Inventors
- 👤 Gerda Grund
- 👤 John Kahsnitz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 20:41
CPC Classifications
B; B01; B01J; B01J20/00; B01J20/30; B01J20/34; C; C02; C02F; C02F1/00; C02F1/28; C02F1/285; C02F2103/00; C02F2103/06; Y; Y10; Y10S; Y10S210/00; Y10S210/902; Y10S210/908; Y10S210/909
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
72 words
A process for the purification of groundwater by removing aromatic hydrocarbons and halogenated hydrocarbons therefrom, comprising the steps of separating off solid constituents from said groundwater and then adsorbing said aromatic hydrocarbons and halogenated hydrocarbons to an adsorber resin, followed by desorbing the adsorbed aromatic hydrocarbons and halogenated hydrocarbons using steam and regenerating the adsorber resin using a 10 to 20 wt. % strength aqueous hydrochloric acid at 20° to 80° C.
Claim 2
Dependent Claim
72 words
A process for the purification of groundwater by removing aromatic hydrocarbons and halogenated hydrocarbons therefrom, comprising the steps of separating off solid constituents from said groundwater and then adsorbing said aromatic hydrocarbons and halogenated hydrocarbons to an adsorber resin, followed by desorbing the adsorbed aromatic hydrocarbons and halogenated hydrocarbons using steam and regenerating the adsorber resin using a 10 to 20 wt. % strength aqueous hydrochloric acid at 20° to 80° C.
Claim 3
Dependent Claim
23 words
The process according to claim 1, wherein the solid constituents are separated off from groundwater which has a pH of 1 to 8.
Claim 4
Dependent Claim
26 words
The process according to claim 1, wherein the adsorber resin is a divinylbenzene/styrene copolymer having a specific surface area of 600 to 1200 m 2 /g.
Claim 5
Dependent Claim
17 words
The process according to claim 1, wherein the desorbing is carried out at 100° to 150° C.
References Cited (Backward Citations)
DE249190C
Cited
US3275548A
Cited
US3531463A
Cited
US3520806A
Cited
US4042498A
Cited
US3985648A
Cited
AT392632B
Cited
DE4204573A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2000-10-27 | 2001-04-28 | 2001-10-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-10-27 | 2005-04-28 | 2005-10-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-10-27 | 2009-04-28 | 2009-10-28 | $7700.00 | Window Closed / Lapsed |