A structure adapted to be at least partially immersed in a liquid to be purified, in particular sewage, the structure comprising: a hollow body provided with at least one inlet opening and at least one outlet opening for the liquid; first dispensing means adapted to dispense an oxygen-containing gas, for example air, arranged so as to generate a flow of fluid, in particular a mixture of sewage and said gas, towards said at least one outlet opening; second dispensing means adapted to dispense an oxygen-containing gas, for example air, arranged so as to generate a flow of fluid, in particular a mixture of sewage and said gas, outside the hollow body.

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.

An ecosystem for deep water environment restoration includes: a light-collecting device; an underwater lighting system connected to the light-collecting device and configured to provide light to a deep water layer of a water body; a photocatalytic bionic net comprising a photocatalytic material and a fiber and placed in the deep water layer; and an aquatic plant. When the photocatalytic material receives the light, the photocatalytic material is able to adsorb organic pollutants of the water body to the photocatalytic bionic net and catalyze degradation of the organic pollutants of the water body, concentrate microorganisms to allow the microorganisms to decompose the organic pollutants into nutrients required for growth of the aquatic plant, and absorb the light to catalyze decomposition of water to produce oxygen. When the aquatic plant receives the light, the aquatic plant is able to perform photosynthesis to release oxygen.

A method for preparing an electron donor biofilm carrier includes proportioning organic polymer basic raw material and functional modifiers in a range of set-point, mixing the materials, feeding the mixtures into a screw extruder, processing them into a bar-type material, and then cut the bar-type material into granules with the cutting machine, and feeding the granules into the screw extruder, processing them into pipes of various shapes according to the selected screw extruder heads, and then cutting the pipes according to the required size. The electron donor biofilm carrier is mainly used in anaerobic or anoxic suspended carrier biofilm technologies. Electron donors with a standard electrode potential below 100 Mv are used as the functional material for preparation of electron donor biofilm carrier.

Methods, apparatus, and systems involving wastewater treatment systems are provided. Plastic grids, with first and second legs are provided. These first and second legs have distal ends separated from each other. Flat pipes are also provided for wastewater treatment systems.

Disclosed are an integrated dual circulation oxidization ditch apparatus for municipal wastewater and a treatment method. The apparatus comprises an anaerobic zone, an anoxic zone, an aerobic zone and a secondary sedimentation tank communicated in sequence. The anoxic zone comprises a first anoxic zone and a second anoxic zone. The aerobic zone comprises a first aerobic zone and a second aerobic zone, and a reflux pump is arranged between the anoxic zone and the aerobic zone. The anaerobic zone, the anoxic zone and the aerobic zone are internally provided with submersible mixers. Both the anoxic zone and the aerobic zone are internally provided with partition walls and guide walls, thereby forming circulation in each zone.

A total nitrogen (TN) removal device for sewage and its operation method. The TN removal device includes a denitrification tank, a supplementary reaction zone filled with aerobic granular sludge and a sedimentation and separation zone. The supplementary reaction zone and the sedimentation and separation zone are arranged inside the denitrification tank, and communicated through a three-phase separator. The sedimentation and separation zone is located above the supplementary reaction zone. A top of the sedimentation and separation zone is greater than its bottom. A membrane aerated biofilm reactor (MABR) assembly is arranged in a space formed by outer walls of the sedimentation and separation zone and supplementary reaction zone and an inner chamber of the denitrification tank. A side wall of the denitrification tank is provided with a chemical oxygen demand (COD) detector and a nitrate nitrogen detector.

This application relates to a system of treating wastewater wherein an oxygen infusion system is used to supersaturate wastewater before aerobic biological processes, wherein oxygen is transferred to the wastewater free of oxygen bubbles and achieves a reduction in power demand for the aeration process of wastewater.

A system for reducing total dissolved solids in wastewater can include a vertical reactor that can include a flexible sheet material, where the flexible sheet material can be configured to facilitate the growth and attachment of an algal biofilm. The vertical reactor can include a shaft, where the shaft can be associated with and can support the flexible sheet material, and a drive motor, where the drive motor can be coupled with the shaft such that the flexible sheet material can be selectively actuated. The system can include a fluid reservoir containing a portion of wastewater through which the flexible sheet material is configured to pass as well as a stressor operably configured to stimulate the algae to produce an extracellular polymeric substance. A method of reducing total dissolved solids in wastewater includes moving an algal biofilm through the wastewater and moving the algal biofilm through a gas.

A method and system for the nitrification and denitrification of septic effluent, e.g. from a domestic septic tank, is disclosed comprising a variable speed pump system for constant continuous flow and a recycle mechanism to increase efficacy in producing a final denitrified effluent suitable for discharge to ground or surface waters.