Method and apparatus for waste digestion using multiple biological processes
First Claim
1. A method of treating liquid-borne waste containing at least two different types of waste-digestive microorganism, the different types of microorganism requiring mutually incompatible chemical environments and comprising an aerobic and a non-aerobic species, the method comprising:
- a. introducing the waste into a treatment vessel having a bottom region;
b. continuously introducing a supply of micronized air bubbles into the bottom region of the waste-containing treatment vessel, the continuous supply of air bubbles corresponding to a quantity of introduced air thereby creating in the bottom region an aerobic zone compatible with and containing the aerobic species;
c. controlling the quantity of introduced air and the degree of agitation of the waste so as to produce in the waste at least one distinct non-aerobic zone vertically adjacent to the aerobic zone having a chemical environment compatible with and containing the non-aerobic species, thereby effecting biodegradation of the waste.
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Accused Products
Abstract
Methods and apparatus for treating waste streams utilize controlled introduction of microscopic gaseous bubbles to create, in a single vessel, as many as three separate biological environments in discrete, stratified zones. In preferred embodiments, bubbles of air are introduced at the bottom of the vessel, creating an aerobic zone in this vicinity. Depletion of oxygen by microorganisms resident in this layer creates an anoxic zone that drifts upward, establishing itself above the aerobic layer. The two layers remain segregated due to the intolerance of aerobic microorganisms for the overlying anoxic environment, the sharpness of the interface depending on the degree of intolerance. Preferably, the treatment vessel is used in conjunction with a clarifier in an internal recycle configuration; clear water from the top of the clarifier is conducted away from the system as treated effluent, while a portion of the biomass settling at the bottom of the clarifier is returned to the head of the treatment vessel through a hydrocyclone and screen arrangement to remove inert content, thereby substantially increasing the efficiency of biological waste-digestion processes.
176 Citations
24 Claims
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1. A method of treating liquid-borne waste containing at least two different types of waste-digestive microorganism, the different types of microorganism requiring mutually incompatible chemical environments and comprising an aerobic and a non-aerobic species, the method comprising:
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a. introducing the waste into a treatment vessel having a bottom region; b. continuously introducing a supply of micronized air bubbles into the bottom region of the waste-containing treatment vessel, the continuous supply of air bubbles corresponding to a quantity of introduced air thereby creating in the bottom region an aerobic zone compatible with and containing the aerobic species; c. controlling the quantity of introduced air and the degree of agitation of the waste so as to produce in the waste at least one distinct non-aerobic zone vertically adjacent to the aerobic zone having a chemical environment compatible with and containing the non-aerobic species, thereby effecting biodegradation of the waste. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. Apparatus of treating liquid-borne waste containing at least two different types of waste-digestive microorganism, the different types of microorganism requiring mutually incompatible chemical environments and comprising an aerobic and a non-aerobic species, the apparatus comprising:
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a. a treatment vessel having a bottom; b. means for introducing a supply of micronized air bubbles into the bottom of the waste-containing treatment vessel, the continuous supply of air bubbles corresponding to a quantity of introduced air thereby creating in the bottom region an aerobic zone compatible with and containing the aerobic species; c. means for imparting a degree of agitation of the waste; and d. control means, coupled to the bubble-introduction means, for controlling (i) the quantity of introduced air and (ii) the degree of agitation to produce in the waste at least one distinct non-aerobic zone vertically adjacent to the aerobic zone, the non-aerobic zone having a chemical environment compatible with and containing the non-aerobic species. - View Dependent Claims (16, 17, 18, 19, 20, 21, 22, 23, 24)
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Specification