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US 9,309,138 B2Granted
Fresh water production method
AssigneeToray Industries, Inc.
InventorsWakako Ogiwara, Hiroo Takabatake, Masahide Taniguchi
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AssigneeToray Industries, Inc.
InventorsWakako Ogiwara, Hiroo Takabatake, Masahide Taniguchi
Estimating the term…
Provided is a fresh water production method applying a combined water-treatment technology employing a plurality of semi-permeable membrane units, the method enabling prevention of problems caused by growth of a biofilm and allowing effective use of an injected chemical agent and an injected neutralizing agent. The fresh-water production method produces fresh water by treatment of source water by a semi-permeable membrane treatment device, the concentrated water resulting from the treatment by the semi-permeable membrane treatment device is mixed with other source water, and the water mixture is treated by a second semi-permeable membrane treatment device. A first chemical agent is injected continuously or intermittently into the source water and a second chemical agent is injected continuously or intermittently into the source water.
A fresh water production method comprising treating a first raw water, wherein the first raw water is sewage, industrial wastewater, lake water, groundwater, river water or a treatment water obtained by subjecting sewage, industrial wastewater, lake water, groundwater or river water to pre-treatment other than in accordance with the fresh water production method, using a first semipermeable membrane treatment apparatus to produce fresh water and concentrated water, mixing the concentrated water produced by the treatment in the first semipermeable membrane treatment apparatus with a second raw water, wherein the second raw water is seawater, salt lake water, brine water or a treatment water obtained by subjecting seawater, salt lake water or brine water to pre-treatment other than in accordance with the fresh water production method and has an osmotic pressure higher than the osmotic pressure of the first raw water, to produce a mixed water, and treating the mixed water using a second semipermeable membrane treatment apparatus to produce fresh water, wherein a first microbicide is continuously or intermittently injected into the first raw water and a second microbicide is continuously or intermittently injected into the second raw water and wherein a third microbicide is continuously or intermittently injected into the concentrated water and, optionally, a fourth microbicide is continuously or intermittently injected into the mixed water.
A fresh water production method comprising treating a first raw water, wherein the first raw water is sewage, industrial wastewater, lake water, groundwater, river water or a treatment water obtained by subjecting sewage, industrial wastewater, lake water, groundwater or river water to pre-treatment other than in accordance with the fresh water production method, using a first semipermeable membrane treatment apparatus to produce fresh water and concentrated water, mixing the concentrated water produced by the treatment in the first semipermeable membrane treatment apparatus with a second raw water, wherein the second raw water is seawater, salt lake water, brine water or a treatment water obtained by subjecting seawater, salt lake water or brine water to pre-treatment other than in accordance with the fresh water production method and has an osmotic pressure higher than the osmotic pressure of the first raw water, to produce a mixed water, and treating the mixed water using a second semipermeable membrane treatment apparatus to produce fresh water, wherein a first microbicide is continuously or intermittently injected into the first raw water and a second microbicide is continuously or intermittently injected into the second raw water, wherein the first microbicide is of a type identical to that of the second microbicide and wherein a third microbicide is continuously or intermittently injected into the concentrated water and, optionally, a fourth microbicide is continuously or intermittently injected into the mixed water.
A fresh water production method comprising treating a first raw water, wherein the first raw water is sewage, industrial wastewater, lake water, groundwater, river water or a treatment water obtained by subjecting sewage, industrial wastewater, lake water, groundwater or river water to pre-treatment other than in accordance with the fresh water production method, using a first semipermeable membrane treatment apparatus to produce fresh water and concentrated water, mixing the concentrated water produced by the treatment in the first semipermeable membrane treatment apparatus with a second raw water, wherein the second raw water is seawater, salt lake water, brine water or a treatment water obtained by subjecting seawater, salt lake water or brine water to pre-treatment other than in accordance with the fresh water production method and has an osmotic pressure higher than the osmotic pressure of the first raw water, to produce a mixed water, and treating the mixed water using a second semipermeable membrane treatment apparatus to produce fresh water, wherein a first microbicide is continuously or intermittently injected into the first raw water and a second microbicide is continuously or intermittently injected into the second raw water, wherein the first microbicide is of a type different from that of the second microbicide and the second microbicide is injected so that the second microbicide is not mixed with the first microbicide and wherein a third microbicide is continuously or intermittently injected into the concentrated water and, optionally, a fourth microbicide is continuously or intermittently injected into the mixed water.
Dependencies are inferred from the claim text.