Various embodiments relate to denitrification of water using bacteria. A method of denitrification of water includes deoxygenated water including a water-soluble form of nitrogen. The method includes exposing the deoxygenated water to denitrifying bacteria to convert the water-soluble form of nitrogen in the water to nitrogen gas that is removed and to form a denitrified water. The method also includes reoxygenating the denitrified water. Denitrifying bacterial substrates and methods of making the same are also provided.

The present application provides a system and method for realizing partial anammox advanced nitrogen and phosphorus removal through mainstream and sidestream biofilm cyclic alternating for a municipal wastewater treatment plant. The system includes three main component units: a mainstream zone (a), an advanced treatment zone (b) and a side stream zone (c). Advanced nitrogen and phosphorus removal of the entire system is realized through cyclic alternating of biofilms. In the mainstream zone (a), the main function of an anaerobic/anoxic zone is to perform heterotrophic denitrification nitrogen removal, and partial denitrification/anammox autotrophic nitrogen removal, and the main function of an oxic zone is to remove organic matter, perform aerobic phosphorus uptake, and complete a nitrification reaction. In a denitrification fluidized bed (8) in the advanced treatment zone (b), advanced treatment is performed for a mixed solution of effluent and raw water in the mainstream zone to achieve heterotrophic denitrification, and partial denitrification/anammox autotrophic nitrogen removal. A high-ammonia nitrogen anammox nitrogen removal zone (7) in the sidestream zone (c) enriches anammox bacteria based on biofilms, realizing autotrophic nitrogen removal of sidestream high-ammonia nitrogen wastewater.

The disclosure discloses a method for enhancing denitrification of sewage with a low carbon-to-nitrogen ratio by using an electrode biocarrier, and relates to the field of sewage treatment. The disclosure uses a conductive material as a microbial carrier and a potentiostat to induce a micro-electric field for directional acclimation and enrichment of electroactive denitrification microorganisms, and realizes a high-efficiency denitrification of the sewage with a low carbon-to-nitrogen ratio. The disclosure aims to provide a technical method for solving the problem of deep denitrification of municipal sewage with a low carbon-to-nitrogen ratio.

A woven fabric formed of fabric fibers or threads coated with a hydrogel, wherein said hydrogel is not crosslinked or is partially crosslinked to the fabric fibers or thread, wherein the hydrogel has a number of excess reactive molecules that are available for a reaction with one or more molecules solvated in an aqueous solution, and wherein the reactive molecules of the hydrogel can reversibly bond with the molecules solvated in an aqueous solution, such that the reactive molecules of the hydrogel attract the molecules solvated in aqueous solution when the hydrogel coated fabric substrate is exposed to an aqueous solution.

The present disclosure provides compositions and methods of use for effectively treating aquarium water in long term. The compositions include various components functioning to improve water quality, reduce or remove inorganic nitrogen and phosphorus, stabilize buffer capacity, and provide other advantages to aquarium water. Methods of using the compositions to improve the efficiency of treating aquarium water are also provided. The compositions and methods of the present disclosure can improve prophylaxis against unfavorable aquatic plant such as algae and extend life of animals in aquarium water.

A method as described herein may include contacting a fluid with a single resin to cause the single resin to bond to nitrates and perchlorates contained in the fluid. The method may regenerate the single resin by a regeneration process comprising contacting the single resin with a salt solution, wherein regenerating removes a substantial portion of the nitrates contained within the single resin but does not remove a substantial portion of the perchlorates contained within the single resin, wherein the single resin comprises a nitrate-specific resin and does not comprise a perchlorate-specific resin.

A method of treating a liquid by creating nanobubbles of a desired gas within a target liquid and allowing the desired gas to react with a target component of the target liquid. The desired gas can be selected to be reactive with the target component, and a desired liquid can be formed after the desired gas reacts with the target component.

Various embodiments relate to denitrification of water using bacteria. A method of denitrification of water includes deoxygenated water including a water-soluble form of nitrogen. The method includes exposing the deoxygenated water to denitrifying bacteria to convert the water-soluble form of nitrogen in the water to nitrogen gas that is removed and to form a denitrified water. The method also includes reoxygenating the denitrified water. Denitrifying bacterial substrates and methods of making the same are also provided.

A method for preparing urea ammonium nitrate solution from waste nitric acid after stripping tin from circuit board includes: causing the waste nitric acid after stripping tin and the ammonia water to undergo neutralizing and precipitating reaction through acid-base neutralization, filtering, thereby obtaining tin-containing filter mud and a primary filtrate; adding iron powders into to the primary filtrate to initiate copper-iron replacement reaction, filtering, thereby obtaining iron-containing coarse copper powders and a secondary filtrate; adding hydrogen peroxide to the secondary filtrate, filtering, thereby obtaining an iron-containing sludge and a tertiary filtrate; adding a heavy metal capturing agent to the tertiary filtrate, filtering, thereby obtaining a heavy metal sludge and an ammonium nitrate solution; measuring a concentration of the ammonium nitrate solution, adding urea and liquid fertilizer corrosion inhibitor to obtain a urea/ammonium nitrate dilute solution, evaporating and concentrating the urea/ammonium nitrate dilute solution, thereby obtaining the urea ammonium nitrate solution.

An apparatus and method for extracting nitrogen including compounds from wastewater is disclosed herein. The methods and apparatus use molecularly designed selective electrocatalysts, electrolytes, and separation reactors to enable automated, distributed ammonia manufacturing with minimal environmental impacts. In some embodiments, a method of nitrogen reduction of wastewater is provided. The method includes: providing an apparatus including: a first chamber comprising a salt solution; a second chamber comprising a wastewater source; a third chamber comprising a salt solution and a third electrode, wherein the second chamber is positioned between the first chamber and the third chamber; an anion exchange membrane positioned between the first chamber and the second chamber; and a cation exchange membrane positioned between the second chamber and the third chamber; applying a potential bias between any two of the first chamber, the second chamber, and the third chamber.