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US4432869A Expired / Lapsed US ⏱️ 0.0 years remaining

Method of treating agricultural wastes

Assignee: Forschungszentrum Jülich
•
Filing: 1982-08-31
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Granted: 1984-02-21
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Expires: 2002-08-31
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Abstract

Abstract Purification of liquid agricultural wastes, such as, in particular, liquidanure, by means of an algae/bacteria mixture culture and a subsequent rotifer culture in a separate stage. The pH-value of the algae/bacteria mixture culture is controlled, especially by the waste water charging thereof, in such a way that a multiplication of rotifers in this stage is inhibited or precluded. The algae/bacteria mixture culture preferably occurs in shallow open air ponds for a period of time which depends upon the temperature and can amount to three to six days at a mean temperature of approximately 18° C. The hold time of the algae/bacteria suspension which is in the rotifer container and is adjusted to a pH of 6 to 8 can range from two to four days at a temperature of approximately 20° C. A waste water treatment plant or system for the foregoing includes at least one algae/bacteria mixture culture reservior and at least one rotifer reactor.

Inventors

  • 👤 Joost Groeneweg
  • 👤 Manfred Schluter

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-08 15:30
CPC Classifications
C; C02; C02F; C02F3/00; C02F3/02; C02F3/12; C02F3/1205; C02F3/121; C02F3/32; C02F3/34; Y; Y02; Y02W; Y02W10/00; Y02W10/10; Y02W10/30; Y02W10/37

Claims Analysis

Total Claims: 5
Claim 1
Independent Claim 121 words
A method of treating liquid agricultural waste water which includes the following sequential steps of: subjecting said waste water to an algae/bacteria mixture culture in a shallow open air pond for an effective period of time and temperature to obtain an algae/bacteria suspension, while controlling and maintaining the pH of said waste water to prevent any multiplication of rotifers; subsequently moving said algae/bacteria suspension to an aerated rotifer breeding container for removal of the algae/bacteria, and subjecting said algae/bacteria suspension to a rotifer culture for an effective period of time and temperature, while controlling and maintaining the pH of said algae/bacteria suspension to allow for rotifer multiplication; and separating said rotifers from the thusly treated suspension to obtain a purified water.
Claim 2
Independent Claim 121 words
A method of treating liquid agricultural waste water which includes the following sequential steps of: subjecting said waste water to an algae/bacteria mixture culture in a shallow open air pond for an effective period of time and temperature to obtain an algae/bacteria suspension, while controlling and maintaining the pH of said waste water to prevent any multiplication of rotifers; subsequently moving said algae/bacteria suspension to an aerated rotifer breeding container for removal of the algae/bacteria, and subjecting said algae/bacteria suspension to a rotifer culture for an effective period of time and temperature, while controlling and maintaining the pH of said algae/bacteria suspension to allow for rotifer multiplication; and separating said rotifers from the thusly treated suspension to obtain a purified water.
Claim 3
Dependent Claim 24 words
A method according to claim 1, in which the pH of said waste water subjected to said algae/bacteria mixture culture is at least 8.5.
Claim 4
Dependent Claim 24 words
A method according to claim 1, in which the pH of said algae/bacteria suspension subjected to said rotifer culture is approximately 6 to 8.
Claim 5
Dependent Claim 21 words
A method according to claim 1, wherein the waste water is anaerobically pretreated prior to being subjected to the algae/bacteria mixture.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1987-02-20 1987-08-22 1988-02-21 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1991-02-20 1991-08-22 1992-02-21 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1995-02-20 1995-08-22 1996-02-21 $7700.00 Window Closed / Lapsed

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