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 submersible reverse osmosis desalination apparatus uses low temperature concentrate or brine from the desalination apparatus to provide a high volume cold liquid stream to an Ocean Thermal Energy Conversion (OTEC) heat engine. The OTEC engine also employs a warm liquid stream and uses the cold and warm liquid streams to obtain electrical power from a closed-cycle or open-cycle heat exchange and generator system. Use of the concentrate or brine stream provides a much greater liquid volume and much greater cold thermal energy content than would be obtained by using cold desalinated product water from the desalination apparatus in the OTEC heat engine.

A submersible water desalination apparatus includes an array of hot-swappable water separation membrane modules arrayed in an approximately polygonal configuration around a product water collection conduit that represents or is proximate to and generally aligned with a central axis of the array; a plurality of hot-swap product water valves connected to the conduit and detachably connected to generally radially-extending product water collection manifolds in fluid communication with a plurality of water separation membrane cartridges within the modules; the modules having in cross-section generally tapered module sides that converge towards the conduit and assist in underwater docking and attachment of a replacement module to a hot-swap product water valve.

A submersible water desalination apparatus includes a plurality of water separation membrane elements that when supplied with salinated water under pressure at a first depth will produce at least partially desalinated product water and concentrate or brine; a product water collector that receives product water from the membrane elements; and a permeate conduit that transports product water from the collector downwardly to a motorized submersible pump remotely located from the membrane elements and collector at a second depth greater than the first depth. The second depth is sufficiently greater than the first depth so that the height of a standing column of product water in the product water collector and permeate conduit between the membrane elements and the suction side of the pump maintains a net positive suction head that prevents inlet side cavitation during pump startup and operation.

The present invention provides a device and method for sulphur cycle-based advanced denitrification of wastewater coupling autotrophic denitrification and heterotrophic denitrification, and belongs to the technical field of wastewater treatment. The unit generating hydrogen sulfide during the wastewater treatment process adopts a lye to absorb hydrogen sulfide; the absorbed sulfide is introduced into an anoxic tank that removes nitrate nitrogen through sulfur-based autotrophic denitrification; and the remaining organic matters in the anaerobic methane-producing reaction tank are subjected to heterotrophic denitrification in the anoxic tank, and the anoxic unit combines the sulfur-based autotrophic denitrification with the heterotrophic denitrification of organic matters. The coupling of sulfur-based autotrophic denitrification and heterotrophic denitrification strengthens the removal of nitrate nitrogen. The biogas desulfurization process system only absorbs hydrogen sulfide and uses the absorbed sulfide in an anoxic system to realize the recovery and utilization of sulfur.

The present disclosure aims to move water between a plurality of devices and create a cycle for reusing treated water generated by each device. A water treatment system includes a plurality of wastewater treatment machines provided for each source; a plurality of sensors that at least detect and output the water volume and water quality of treated water; tanks that store treated water as recirculation water; an excess water tank/storage tank that store excess water; and a control device that drive-controls the wastewater treatment machines and manages the water volume and water quality of treatment water in each source tank on the basis of sensor data from the sensors. The control device controls replenish shortages by using recirculation water from another source or excess water from an excess water tank, if a determination has been made that there is a shortage of recirculation water in one source, using sensor data.

A water treatment apparatus includes a water receiver configured to receive an input of water; and an installation mechanism configured to include one or more slots in which a module for water treatment is installable. Among a plurality of types of modules available to be selected in accordance with a use of water treatment, at least one module includes a filter as a component, and the water treatment apparatus is configured to provide a water treatment function corresponding to the module to the water received at the water receiver by installing the module in one of the one or more slots.

A system and method for automatically controlling aeration and mixing processes are disclosed.

High levels of polyhydroxyalkanoates (PHA) can be produced from wastewater comprising Readily Biodegradable COD (RBCOD) using activated sludge comprising microorganisms capable of accumulating PHA by contacting the wastewater with the activated sludge in the presence of dissolved oxygen during a first period of time, to obtain PHA-loaded activated sludge, and then supplying elements essential for growth such as nitrogen and phosphorus and allowing up-take of these elements and limited growth during a second period of time, the supplied amount of at least of one of said essential elements compared to the amount of RBCOD supplied in step a) limiting the growth to an extent that not all PHA is used for growth, to obtain grown activated sludge; and removing or harvesting part of the PHA-loaded activated sludge and/or part of the grown activated sludge, so that the total average retention time of the sludge is less than 72 h.