Methods and systems are provided herein for treating wastewater, such as wastewater from oil and natural gas production. Distilled water may be treated with bacteria and other micro-organisms to remove nitrogen compounds from the distilled water. The distilled water may be produced from pretreating and distilling wastewater. The treatment steps of the distilled water include subjecting the water to microbial action under both anoxic and aerobic conditions and employing a membrane bioreactor to further purify the water. The purified water is still further purified by either reverse osmosis or ion exchange systems.

This disclosure relates to nitrogen removal with carbon addition, including for wastewater treatment. The denitrification reaction may be terminated at an intermediate nitrite product which is supplied to the anammox reaction. Nitrogen may be removed by use of an electron donor source including, but not limited to, acetate or glycerol at a specific zone. The electron donor may be used to convert nitrate to nitrite through appropriate dosing, anoxic SRT and/or maintenance of a nitrate residual in isolation or in combination. The subsequent supply of nitrite and ammonia for anammox reactions is also proposed. The slower growing anammox may be selectively retained on media or using other physical approaches. The overall intent of the present disclosure is to minimize the use of electron donor by maximizing denitratation and anammox reactions. Test results for selective retention of anammox in biofilm, granular or suspended growth system or nitrate residual control are provided.

A method for deep treatment of household waste leachate by a biochemical process is provided, including: arranging one anoxic tank and two aerobic tanks in series; introducing the household waste leachate into the primary anoxic reactor, and diluting the household waste leachate to an concentration acceptable to microorganisms; introducing the diluted household waste leachate into the primary aerobic reactor, and subjecting the diluted household waste leachate to an pre-nitrification reaction to obtain a reactant; introducing the reactant into the secondary aerobic reactor, and subjecting the reactant to a main nitrification reaction to convert ammonia nitrogen into nitrate nitrogen and nitrite nitrogen by nitrification of nitrobacteria; refluxing the nitrification liquid to the primary anoxic reactor, converting the nitrate nitrogen and nitrite nitrogen into nitrogen gas by denitrobacteria in the primary anoxic reactor, and discharging the nitrogen gas into atmosphere, thereby finishing an denitrification process.

A wastewater treatment system includes two or more wastewater treatment reactors selected from an anoxic wastewater treatment reactor, a flex wastewater treatment reactor, and a hydroponic wastewater treatment reactor in fluid communication with and connecting a wastewater system inlet and a treated wastewater system outlet, each of the anoxic reactor, the flex reactor, or the hydroponic reactor including a reactor inlet for receiving wastewater to be treated and a reactor outlet directing treated wastewater from the anoxic reactor, the flex reactor, or the hydroponic reactor. The system also includes: (i) either but not both of the anoxic reactor or the flex reactor, (ii) a hydroponic reactor if the anoxic reactor is included, and (iii) at least two flex reactors if the hydroponic reactor is absent, and wherein at least one of the flex reactor or the hydroponic reactor includes an intermittent or pulsed aeration device and/or a submerged membrane or submerged root zone that achieves a natural gradient of oxidative states that is similar to oxidative states achieved using the intermittent or pulsed aeration device.

A method for collaborative optimization control method for organic nitrogen and inorganic nitrogen in a denitrification process is provided. The method includes: establishing ASM-mDON-DIN models for simultaneous simulation of microbial dissolved organic nitrogen (mDON) and inorganic nitrogen (DIN) in denitrification processes; and selecting a corresponding ASM-mDON-DIN model according to a set carbon/nitrogen ratio to collaboratively optimize the concentration values of mDON and DIN in the effluent in the denitrification process, to obtain best process operation parameter values.

Relatively greater capillarity material layers and relatively lesser capillarity material layers are provided. These layers can be used to promote capillary wetting in capillary wetting zones to promote prolonged periods of water retention. Carbon sources present in the capillary wetting zones may exhibit prolonged use provided by limited drying and wetting cycles experienced in the capillary wetting zones. Carbon sources positioned between saturated layers may exhibit prolonged use provided by anoxic conditions created by upper and lower water seals of the saturated layers. Capillarity layers can be employed in infiltration systems handling water, such as residential wastewater.

A cooperative fuzzy-neural control method is designed in this present invention. Due to the difficulty for cooperatively controlling the concentrations of the dissolved oxygen and nitrate nitrogen in wastewater treatment process, a cooperative fuzzy-neural control method is investigated. In this proposed method, firstly, a interval type-2 fuzzy neural network is employed to construct the cooperative fuzzy-neural controller. Secondly, a parameter cooperative strategy is proposed to cooperatively optimize the global and local parameters of the cooperative fuzzy-neural controller to meet the control requirements. This proposed cooperative fuzzy-neural control method can cooperatively control the concentrations of the dissolved oxygen and nitrate nitrogen in wastewater treatment process. The results illustrate that the proposed cooperative fuzzy-neural control method can achieve the high control accuracy and guarantee the normal operations of wastewater treatment process under the different operation conditions.

The application relates to a method for remediation and/or restoration of an anoxic body of water (10), wherein a calcium nitrate solution (3) is added to the anoxic body of water (10), and wherein the method comprises the steps of mixing water having a percent of oxygen saturation of between 50% and 150% with the calcium nitrate solution (3), resulting in a mixture, and pumping the mixture into the anoxic body of water (10), wherein the final concentration of nitrate-N in the remedied and/or restored anoxic body of water (10) is between 1 and 20 mg/l. The application furthermore relates to a system (1) for remediation and/or restoration of an anoxic body of water (10), wherein the system (1) is provided with means to add a calcium nitrate solution (3) to the anoxic body of water (10), wherein the means to add the calcium nitrate solution (3) to the anoxic body of water (10) consists of a mixing device (2) arranged to mix the calcium nitrate solution (3) with water having a percent of oxygen saturation of between 50% and 150%, resulting in a mixture, and wherein the system (1) comprises first pumping means (5) for pumping the mixture into the anoxic body of water (10).

A synergetic system for waste treatment is provided. The synergetic system includes a waste treatment system configured to perform biological treatment of waste. Additionally, the synergetic system includes a gas purification system configured to purify exhaust gas generated during the biological treatment of the waste. The synergetic system further includes a feeding system configured to feed excess heat from the gas purification system back to the waste treatment system. The waste treatment system is further configured to use the fed back excess heat for the biological treatment of the waste.

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.