Patent application number | Description | Published |
20080257820 | Apparatus and Method for Treating Fgd Blowdown or Similar Liquids - A process has steps of one or more of aerobic treatment to remove COD and nitrify a waste stream, anoxic treatment to denitrify a waste stream, anoxic treatment to remove selenium and anaerobic treatment to remove heavy metals and sulphur. The process may be used to treat, for example, FGD blow down water. The process may further include one or more of (a) membrane separation of the waste stream upstream of the anoxic digestion to remove selenium, (b) dilution upstream of the biological treatment step, (c) physical/chemical pretreatment upstream of the biological processes or dilution step to remove TSS and soften the waste stream, or (d) ammonia stripping upstream of the biological treatment steps or dilutions step. These processes may be provided in a variety of suspended growth or fixed film reactors, for example a membrane bioreactor or a fixed film reactor having a GAC bed. Processes for biological treatment of inorganic compounds in a fixed medium reactor is described including steps of one or more of maintaining desired ORP levels, optionally by controlling nutrient addition, and removing solids or gas bubbles from the medium bed. | 10-23-2008 |
20100300963 | APPARATUS AND METHOD FOR TREATING FGD BLOWDOWN OR SIMILAR LIQUIDS - A process has steps of one or more of aerobic treatment to remove COD and nitrify a waste stream, anoxic treatment to denitrify a waste stream, anoxic treatment to remove selenium and anaerobic treatment to remove heavy metals and sulphur. The process may be used to treat, for example, FGD blow down water. The process may further include one or more of (a) membrane separation of the waste stream upstream of the anoxic digestion to remove selenium, (b) dilution upstream of the biological treatment step, (c) physical/chemical pretreatment upstream of the biological processes or dilution step to remove TSS and soften the waste stream, or (d) ammonia stripping upstream of the biological treatment steps or dilutions step. These processes may be provided in a variety of suspended growth or fixed film reactors, for example a membrane bioreactor or a fixed film reactor having a GAC bed. Processes for biological treatment of inorganic compounds in a fixed medium reactor is described including steps of one or more of maintaining desired ORP levels, optionally by controlling nutrient addition, and removing solids or gas bubbles from the medium bed. | 12-02-2010 |
20110186489 | GASIFICATION GREY WATER TREATMENT SYSTEMS - In one embodiment, a grey water treatment system includes an oxidation reactor for oxidizing grey water. The grey water treatment system also includes a biological reduction and precipitation system with microbes designed to remove one or more target components from the oxidized grey water. | 08-04-2011 |
20120024798 | Selenium Removal Using Chemical Oxidation and Biological Reduction - Selenium in the form of a reduced species such as selenocyanate is oxidized to produce an oxidized selenium species such as selenate or selenite, and then a biological reduction process is used to remove selenium from the oxidized selenium species. In an example, a chemical oxidant is added to a wastewater containing selenocyanate to produce selenate and selenite. The partially treated wastewater is then fed to a reactor containing a fixed media supporting a biofilm with selenium reducing organisms. The selenium in the selenate and selenite is reduced to an insoluble form of selenium, such as elemental selenium, which precipitates from the wastewater. | 02-02-2012 |
20120152761 | SELENIUM SEPARATION AND RECOVERY FROM BIOREACTOR SLUDGE - Wastewater containing soluble selenium is treated in a bioreactor. Microorganisms in the reactor reduce the selenium to elemental selenium, which is insoluble. The elemental selenium is discharged from the reactor in waste sludge. The sludge is treated to recover selenium. In one method, the sludge is washed with chemicals, for example surfactants, and agitated to disrupt the adhesion of the selenium particles to the cells. The selenium particles are then separated from the cells using a physical separation process such as a centrifuge or differential filtration. In another method, the sludge is de-watered or dried to a very high solids content. The selenium particles are dissolved using an oxidizer under high pH conditions. A solids fraction is removed from the resulting slurry. A resulting selenium brine is further refined to recover the selenium. | 06-21-2012 |
20130270181 | SELENIUM REMOVAL USING CHEMICAL OXIDATION AND BIOLOGICAL REDUCTION - Selenium in the form of a reduced species such as selenocyanate is oxidized to produce an oxidized selenium species such as selenate or selenite, and then a biological reduction process is used to remove selenium from the oxidized selenium species. In an example, a chemical oxidant is added to a wastewater containing selenocyanate to produce selenate and selenite. The partially treated wastewater is then fed to a reactor containing a fixed media supporting a biofilm with selenium reducing organisms. The selenium in the selenate and selenite is reduced to an insoluble form of selenium, such as elemental selenium, which precipitates from the wastewater. | 10-17-2013 |
20150034552 | Water Treatment System and Method for Removal of Contaminants Using Biological Systems - A novel biologically active water treatment system for removing contaminant from industrial effluent and method thereof is provided. A novel upflow bioreactor system having an expanded bed configuration and method for creating an expanded bed for release of gas without release of substantial precipitate is also provided. A novel downflow bioreactor system having an automated degas and backwash system is also provided. | 02-05-2015 |
20150151995 | Water Treatment System and Method for Removal of Contaminants Using Biological Systems - A novel biologically active water treatment system for removing contaminant from industrial effluent and method thereof is provided. A novel upflow bioreactor system having an expanded bed configuration and method for creating an expanded bed for release of gas without release of substantial precipitate is also provided. A novel downflow bioreactor system having an automated degas and backwash system is also provided. | 06-04-2015 |