Two-sludge water reuse process
OwnerEugenio Giraldo, Barbara Winglerinventors
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Abstract
Systems and methods for cost efficiently producing water for reuse using a two-sludge process are described. Savings are realized compared to current art while producing reuse water and recovering nutrients. Savings are due to decreases in both alkalinity chemicals for nitrogen removal and energy for nitrification, as well as elimination of added carbon and decreased biosolids disposal needs for denitrification. In some cases, fertilizer that meets the requirements of the USDA National Organic Program can be produced using the described systems and methods.
Claims20
A method for treating wastewater by:
- a. treating wastewater in a two-sludge process where the second bioreactor is conducting nitrification reactions,
- b. measuring the concentration of at least one of ammonia, ammonium, nitrite or nitrate in the first bioreactor, or the second bioreactor, or both bioreactors, obtaining a nitrogen measurement,
- c. controlling the influent flow rate to at least one of the first or the second bioreactor based on said nitrogen measurement to keep said nitrogen measurement within a set point, or a range with no addition of alkalinity other than that contained in influent wastewater,
- d. optionally adding alkalinity other than that contained in influent wastewater to the second bioreactor if the fraction of influent total nitrogen that is nitrified is larger than 50%,
- e. collecting the treated effluent.
A method to control ammonia toxicity and nitrification in a nitrifying bioreactor by:
- a. measuring the concentration of at least one of ammonia, ammonium, nitrite, or nitrate in said bioreactor obtaining a nitrogen measurement,
- b. controlling the influent flow rate to said bioreactor based on said nitrogen measurement to keep said nitrogen measurement within a set point or a range with no addition of alkalinity other than that contained in the influent wastewater,
- c. adding dilution water to the bioreactor as needed to reduce ammonia concentration,
- d. optionally adding alkalinity if the fraction of influent ammonia that is nitrified is larger than 50%.
A system for treating wastewater comprising:
- a wastewater source, a two-sludge subsystem where the second bioreactor is a nitrifying bioreactor, one or more nitrogen measurement and control subsystem(s) measuring at least one of an ammonia sensor, or an ammonium sensor, or a nitrite sensor, or a nitrate sensor, means for controlling the influent wastewater flow to the bioreactors, an optional source of alkalinity, and pipes, valves, fittings, connectors, pumps and appurtenances to fluidly connect the above-mentioned parts of the system, and whereby:
- a. the wastewater source is fluidly connected to at least one inlet to the two-sludge subsystem,
- b. the nitrogen measurement and control subsystem is connected to at least one of the first bioreactor or the nitrifying bioreactor and configured to measure at least one of the influent ammonia to the bioreactor or at least one of bioreactor concentration of ammonia, ammonium, nitrate or nitrite, forming a nitrogen measurement,
- c. the influent flow to the first bioreactor, the nitrifying bioreactor or both bioreactors is controlled by the nitrogen measurement and control subsystem to keep the nitrogen measurement within a set point or a range with no addition of alkalinity other than that contained in the influent wastewater,
- d. the source of alkalinity is fluidly connected to either of the two bioreactors and alkalinity is optionally added when the conversion of nitrogen is higher than 50% as measured,
- e. the treated effluent is collected.
Dependencies are inferred from the claim text.