There is provided processes and uses of an inline saturator for maintaining fish in a cage in an open body of water, the process comprising: restricting movement of water into and out of a part of the cage and forming a portion of water within the part of the cage. The process also includes injecting oxygenated water produced by an inline saturator into the portion of water to raise a dissolved oxygen level and to lower a dissolved nitrogen gas level therein. A treatment process is also provided that includes the steps noted above and further including introducing a medicinal substance into the oxygenated water or the portion of the body of water.

An activated sludge process for the treatment of municipal wastewater, particularly applicable to oxidation ditch activated sludge treatment systems which utilize a conventional race track or continuous loop reactor basin configuration. The process removes phosphorus and nitrogen from an activated sludge wastewater treatment system, with an anoxic cycle followed by an aerobic cycle, and followed by a surface wasting cycle until a low flow diurnal period is reached in a diurnal or twenty-four hour period. Automated microprocessor control system using “oxidation-reduction potential” (ORP) and “dissolved oxygen” (DO) as process variable inputs automate aerated and anoxic cycles to optimize phosphorus and nitrogen removal using the available carbon in the influent wastewater resulting in an energy efficient dynamic dissolved oxygen control during the aerated periods.

Systems and methods are provided for nitrogen gas sparging assisted biological treatment of water. In one example, a denitrification system may include a media-packed column or bed through which nitrogen gas is sparged to remove dissolved oxygen from water. In some examples, an external carbon source and electron donor may be added to the media-packed column or bed to facilitate biological removal of the nitrate and/or other contaminants from the water. In this way, by relying on the sparged nitrogen gas to remove the dissolved oxygen, less of the external carbon source and electron donor may be employed as compared to denitrification systems not assisted by nitrogen gas sparging.

A copper integrated electrode with a convertible oxidation state, a preparation method and an application method are provided. The preparation process is based on an electrochemically induced self-growth method. Copper foam is used as a precursor, soaked in a graphene oxide solution, dried, calcined at high temperature and annealed, and then treated with an alkali solution to obtain the copper integrated electrode with the convertible oxidation state. The working electrode prepared by the nano-catalytic material of the present invention has good denitrification performance in the environmental field, which can achieve nearly 100% nitrate removal rate, nearly 100% nitrogen selectivity and long-term stability. These properties are due to the prepared working electrode having an oxidizable copper (I, II/0, I), oxygen vacancy (O) and a one-dimensional nanowire structure. The structure can regulate the adsorption and reduction of intermediate products, resulting in nearly 100% nitrate removal rate and nearly 100% nitrogen selectivity.

Wastewater is treated though primary treatment of the water by way of a micro-sieve to produce a primary effluent and primary sludge. There is secondary treatment of the primary effluent by way of a membrane bioreactor (MBR) or an integrated fixed film activated sludge (IFAS) reactor to produce a secondary effluent and a waste activated sludge. The micro-sieve may have openings of 250 microns or less, for example about 150 microns. In a process, a gas transfer membrane is immersed in water. Pressurized air flows into the gas transfer membrane. An exhaust gas is withdrawn from the gas transfer membrane and used to produce bubbles from an aerator immersed in the water.

The present disclosure provides devices and methods of using same for cleansing a solution (e.g., a salt or used dialysis solution) of urea via electrooxidation, and more specifically to cleansing a renal therapy solution/dialysis solution of urea via electrooxidation so that the renal therapy solution/dialysis solution can be used or reused for treatment of a patient. In an embodiment, a device for the removal of urea from a fluid having urea to produce a cleansed fluid includes a urea decomposition unit and an electrodialysis unit.

An anaerobic-AO-SACR combined advanced nitrogen removal system for high ammonia-nitrogen wastewater, in which high ammonia-nitrogen wastewater first enters an anaerobic reactor to remove most of organic matters from the wastewater, effluent water enters an AO reactor for nitrogen removal by pre-denitrification in an anoxic zone and for removal of the remaining organic matters and nitrification of ammonia nitrogen in an aerobic zone, and then the effluent water enters an intermediate pool. Meanwhile, under the control of a water quality testing device and a PLC controller, a part of raw water is introduced into the intermediate pool to adjust the carbon nitrogen ratio of the wastewater. Then, the effluent water enters an SACR reactor, and the wastewater undergoes pre-denitrification-nitrification-endogenous denitrification precisely by using the characteristics of denitrifying bacteria and through adjustment and control of PH/DO/ORP testers and the PLC controller on the SACR reactor so as to realize advanced nitrogen removal.

A deep denitrification treatment system for wastewater by A.sup.2O based on high-oxygen three-phase contact is provided, including an annular anaerobic treatment device, a uniform water distribution device, a high-oxygen three-phase contact biological oxidative degradation device, a nitrification liquid collecting and shunting device, an annular nitrification liquid anoxic nitrification device and a sludge sedimentation reflux clean water discharge device sequentially connected between a water inlet and a water outlet, where the annular anaerobic treatment device surrounds a periphery of the annular nitrification liquid anoxic nitrification device, the annular nitrification liquid anoxic nitrification device surrounds a periphery of the sludge sedimentation reflux clean water discharge device, and an upper part of the sludge sedimentation reflux clean water discharge device is sequentially provided with the nitrification liquid collecting and shunting device, the high-oxygen three-phase contact biological oxidative degradation device and the uniform water distribution device.

A wastewater treatment plant and related method comprise a treatment stage including a biological-process substage configured for growing unicellular organisms adapted to reduce contaminants in the wastewater which are dissolved, including at least one of organic matter and nitrogenous matter, by digestion thereof, and which are adapted to floc after digestion and a floc-removal substage downstream from the biological-process substage, relative to the flow of wastewater, and configured for substantially removing the unicellular organisms that have flocked. The treatment stage is configured to form majority and minority flows of treated wastewater, and the minority flow is configured to be recycled upstream of the biological-process treatment substage. The plant includes a heat transfer assembly configured for transferring heat from the majority flow of treated wastewater to the minority flow thereof to increase temperature of wastewater to be treated.

Filters comprising a Chlorella ellipsoidea by-product (lipid-free biomass) for aquaculture wastewater treatments and methods for removing ammonia, phosphorous, and organic matter from aquaculture wastewater using such filters. The filters have multiple layers of a compressed Chlorella ellipsoidea lipid free biomass by-product of Chlorella ellipsoidea biodiesel production, wherein each of the multiple layers is separately changeable.