An object of the present invention is to provide a method for producing PHA, which is capable of suppressing the cost of overall production equipment including a waste water treatment process in production of PHA using microorganisms. Provided is a method including: a production step of purifying or molding polyhydroxyalkanoic acid biosynthesized in bacterial cells of a microorganism; a discharge step of discharging waste water containing nitrogen-containing impurities from the production step; and a nitrogen removal step of biologically treating the waste water to remove the nitrogen-containing impurities from the waste water. In the method, the residual ratio of the polyhydroxyalkanoic acid in the production step is 99% by weight or less, and the waste water that is biologically treated in the nitrogen removal step contains the polyhydroxyalkanoic acid in addition to the nitrogen-containing impurities.

The invention relates to a method for the biological treatment of nitrogen in the form of ammonium in wastewater, by nitritation in a biological reactor, comprising: at least one step a of aerating the biological reactor containing the wastewater to be treated, at least one step b of eliminating at least part of the nitrites produced in step a, and a step c of extracting, from the reactor, a fraction of the sludge resulting from steps a and b. The invention also concerns a method for the biological treatment of nitrogen in wastewater, by nitritation/denitritation and/or deammonification, wherein the nitritation is implemented using the nitritation method according to the invention.

A self-circulating high-efficiency biological denitrification device includes a tank body, where an aerobic zone, an anoxic zone, a settling tank water distribution zone, a sludge zone, a sludge-water separation zone, and an effluent flow stabilization zone are arranged from bottom to top in the tank body; the settling tank water distribution zone includes a settling tank influent guide cylinder, and a circular butterfly jet water distributor is arranged between the settling tank influent guide cylinder and the aerobic zone; the settling tank influent guide cylinder is connected to a guide plate arranged in the aerobic zone, the anaerobic zone, and the sludge zone; the guide plate includes three sections; a nitrification liquid return gap and a sludge return gap are formed; a bottom of the aerobic zone is provided with an aerator; the aerator is connected to an air inlet pipe located outside the tank body.

The present invention discloses a tower-shape integrated ecological purification device for domestic sewage in a small town. The device includes a water storage and filter pond, a medium reverse osmosis pond, an amphibious biological reaction system, and an aquatic biological reaction system. The amphibious biological reaction system and the aquatic biological reaction system are alternately connected from the top down. The amphibious biological reaction system and the aquatic biological reaction system form an alternating dry and wet, oxidation-reduction compound environment. Plant absorption, biological substrate transformation, aeration, and strengthening medium adsorption are combined to form a multi-stage plant-microbe-animal integrated ecological purification treatment process/device. The present invention achieves the efficient purification and acceptable discharge of domestic sewage in small towns.

Water treatment structures may have at least a first geotextile fabric layer; a second geotextile fabric layer; a third geotextile fabric layer; a first filler layer with plastic particles, arranged between the first and second geotextile fabric layers; and a second filler layer with plastic particles, arranged between the second and third geotextile fabric layers, wherein the geotextile fabric layers and the filler layers are within a housing, and wherein the structure is configured such that contaminated water proceeds sequentially through the first geotextile fabric layer, the first filler layer, the second geotextile fabric layer, the second filler layer, and the third geotextile fabric layer. Methods of treating wastewater may involve passing wastewater, after optional oxygenating and pre-filtering, through such alternating layers of geotextile, preferably nonwoven, and polymer particles.

A water purification system for an ornamental aquarium is easily assembled as either a canister or a hang-on-back type model with a water tank or aquarium without compromising with an aesthetic appearance and low noise. The filtration element includes filtration blocks connectible in series for function and can be disassembled into a plurality of blocks that are reassembled to form the canister model and the hang-on-back model with a secure positioning feature.

An organic wastewater treatment apparatus is operated by switching between a first operation mode and a second operation mode. The first operation mode includes supplying organic wastewater to a dual-use tank and performing an anaerobic treatment process therein, performing a nitrification-denitrification process in a membrane bioreactor treatment tank, and extracting membrane-permeated water from a membrane separation device arranged in the membrane bioreactor treatment tank as treated water. The second operation mode includes supplying the organic wastewater to the dual-use tank and performing an aerobic treatment process therein, supplying mixed liquid containing activated sludge from the dual-use tank to both of the membrane bioreactor treatment tank and a sedimentation tank, performing a nitrification-denitrification process in the membrane bioreactor treatment tank, extracting membrane-permeated water from the membrane separation device arranged in the membrane bioreactor treatment tank as treated water, and also extracting solid-liquid separated liquid from the sedimentation tank as treated water.

A methodology, system and apparatus are provided that include anoxic biofilms to perform partial denitrification and anammox (PdNA) reactions. The PdNA reactions can facilitate process intensification and carbon efficient biological nitrogen removal. The anoxic biofilms can be placed in a pre-anoxic zone or a downstream anoxic zone, where the biofilm and reactions are managed, including using storage compounds, to overcome mass transfer limitations in the biofilm. The methodology, system and apparatus can, when compared to state-of-the art technologies, improve the concentration gradient or reduce mass transfer limitations to facilitate PdNA reactions.

A method of treating waste activated sludge. More specifically, the disclosure concerns treating waste activated sludge by a membrane aerated sludge digester to reduce of volatile soluble solids (VSS) concentration in the sludge to obtain aerobically treated sludge.

A method for treating dye wastewater includes: firstly, homogenizing the dye wastewater to balance the quality of the dye wastewater from different processes; then subjecting the homogenized dye wastewater to anaerobic treatment to remove most of chemical oxygen demand (COD) and total suspended solids (SS) in the wastewater; and finally subjecting the dye wastewater after the anaerobic treatment to circulating anaerobic-oxic treatment in a membrane bioreactor (MBR). In the present invention, the MBR is filled with a quinone-based hollow fiber membrane. The quinone acts as an electron mediator to accelerate an enzymatic reaction for dye decolorization during the anaerobic process, thereby achieving the purpose of efficient decolorization. The oxic treatment process further removes the COD and SS in the wastewater, so that the effluent meets a first-level discharge standard.