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.
An apparatus for mixing and pumping manure from a reservoir including an elongated frame adapted to be pivoted from a vehicle bed from a lying position to an upright position within a reservoir to be pumped. Pump means are provided at the base of said elongated frame communicating with a conduit extending the length of the frame, a first slurry mixing impeller adjacent the pump at the base of the frame and driven by a common shaft with the pump, a second mixing means in the form of a screw having an axis of rotation parallel to the elongated frame and having a common drive shaft with the impeller and the pump and a third mixing device in the form of a jet nozzle communicating with the pump at the base thereof and being spaced from the second mixing means. The first and third mixing means have jet nozzles directed at right angles to the axis of the elongated frame.
The present invention relates to a method for the aerobic digestion of a fluid waste material, notably an aqueous sewage, in which at least part of the waste material and/or of the digestion mixture is comminuted to reduce the median particle size of biomass and other solid particles in the digestion mixture to less than 10 micrometres, for example using destructive cavitation with a pressure drop of from 2 to 7.5 Bar. The comminution produces particles which are preferentially ingested by predator organisms in the digestion stage so that they graze on the bacteria and biomass particles and thus reduce the amount of biomass and suspended solids produced in the digestion stage. The invention also relates to apparatus for use in the method of the invention.
An anaerobic digester for digesting animal manure and other biologically degradable material contains support media for enhancing the contact between the microbes in the digesting mass and the available nutrients. The digester includes a novel fluid circulation and distribution system. The distribution system prevents build up of heavy material in the bottom of the digester and prevents agglomeration of light material at the top of the digester. The digesting fluid travels over a floating weir into an intake and impeller assembly. The impeller drives the fluid through a conduit located adjacent the floor of the digester. Nozzles in the conduit project the fluid downwardly toward the floor thus causing a sweeping action on the floor. Fluid then flows upwardly past the support media. Risers are provided at the ends of the conduit, which terminate in nozzles at the surface of the digesting liquid. The nozzles direct the flow of digesting material back toward the fluid inlet and also sweep the corners of the digester to prevent material accumulation.
A method is provided for treating a waste stream by contacting the waste stream sequentially with a consortium of prokaryotic microorganisms, preferably purple non-sulfur bacteria, followed by a the green algae Chlorella. The consortium of prokaryotic microorganisms assimilate a first portion of the wastes, and the green algae assimilate the remaining portion of the wastes to produce a substantially purified effluent stream. Isolated microorganisms made by the above method are valuable commercial products.
The invention is a method for using periphyton to treat flowing water in a waterway. The periphyton reduces the quantity of undesirable chemicals polluting the water. Fish, in turn, control the density of periphyton by grazing on the periphyton and convert the undesirable chemicals associated with the periphyton into removable forms such as fish tissue or fish feces.
