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US 10,093,568 B2Granted
Method for wastewater treatment by urine separation, seawater addition, and nitrification and in-sewer denitrification
AssigneeThe Hong Kong University of Science and Technology
InventorsGuanghao Chen, Hamish Robert Mackey, Feng Jiang, Ho Kwong Chui
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Abstract
A method for wastewater treatment which comprises (a) separating and/or collecting urine from the wastewater for pretreatment, (b) removing phosphorus from urine using seawater, (c) optionally oxidizing nitrogen from urine, and (d) discharging the phosphorus-removed and/or nitrogen-oxidized urine to a sewer.
Claims12
A method for wastewater treatment providing phosphorus recovery from urine, comprising:
- (a) collecting urine or urine mixed with flushwater, separate from wastewater not used for said collecting said urine or urine mixed with flushwater, for pretreatment,
- (b) introducing seawater to the collected urine or urine mixed with flushwater;
- (c) at least after introducing the seawater, using a biological hydrolysis reactor to biologically hydrolyze urea in the urine to release ammonia from the urine and increase pH, causing precipitation of phosphorus;
- (d) obtaining a low-phosphate ammonia-rich supernatant as an effluent from the biological hydrolysis reactor;
- (e) nitrifying the urine by nitrifying the ammonia hydrolyzed from the urine to nitrate and/or nitrite using a biological nitrification reactor;
- (f) removing nitrogen from the nitrified urine comprising discharging nitrified urine to a foul sewer to mix with the other wastewater for in-sewer denitrification and organic carbon removal;
- and
- (g) discharging the low-phosphate ammonia-rich supernatant to a foul sewer for further wastewater treatment and, after discharging to the foul sewer, applying wastewater treatment to the phosphorus-removed urine to mix with other wastewater, thereby reducing phosphorus loading of domestic sewage in the further wastewater treatment.
5 more elements
A method for wastewater treatment providing phosphorus recovery from urine, comprising:
- (a) collecting urine or urine mixed with flushwater, separate from wastewater not used for said collecting said urine or urine mixed with flushwater, for pretreatment,
- (b) introducing seawater to the collected urine or urine mixed with flushwater;
- (c) at least after introducing the seawater, using a biological hydrolysis reactor to biologically hydrolyze urea in the urine to release ammonia from the urine and increase pH, causing precipitation of phosphorus;
- (d) obtaining a low-phosphate ammonia-rich supernatant as an effluent from the biological hydrolysis reactor;
- (e) oxidizing nitrogen from the urine;
- (f) nitrifying the urine by nitrifying the ammonia hydrolyzed from the urine to nitrate and/or nitrite using a biological nitrification reactor;
- (g) removing nitrogen from the nitrified urine comprising discharging nitrified urine to a foul sewer to mix with the other wastewater for in-sewer denitrification and organic carbon removal;
- and
- (h) discharging the phosphorus-removed and the nitrogen-oxidized urine to a foul sewer, enabling further wastewater treatment and, after discharging to the foul sewer, applying wastewater treatment to the phosphorus-removed urine to mix with other wastewater to achieve organic carbon removal, thereby reducing phosphorus loading of domestic sewage in the further wastewater treatment.
6 more elements
A method for wastewater treatment providing phosphorus recovery from urine, comprising:
- (a) collecting urine or urine mixed with flushwater, separate from wastewater not used for said collecting said urine or urine mixed with flushwater, for pretreatment,
- (b) introducing seawater to the collected urine or urine mixed with flushwater;
- (c) at least after introducing the seawater, using a biological hydrolysis reactor to biologically hydrolyze urea in the urine to release ammonia from the urine and increasing pH, causing precipitation of phosphorus;
- (d) obtaining a low-phosphate ammonia-rich supernatant as an effluent from the biological hydrolysis reactor;
- and
- (e) discharging the phosphorus-removed urine to a foul sewer for further wastewater treatment and, after discharging to the foul sewer, applying wastewater treatment to the phosphorus-removed urine to mix with other wastewater to achieve in-sewer denitrification and organic carbon removal while reducing phosphorus loading of domestic sewage in the further wastewater treatment.
3 more elements
Dependencies are inferred from the claim text.