Abstract: Purification of liquid agricultural wastes, such as, in particular, liquid anure, 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.degree. 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.degree. 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.

Abstract: Purification of liquid agricultural wastes, such as, in particular, liquid anure, 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.degree. 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.degree. C. A waste water treatment plant or system for the foregoing includes at least one algae/bacteria mixture culture reservoir and at least one rotifer reactor.