One aspect of the present invention provides a method of treating ballast water, which includes: a first step of transporting a raw material from a first base to a second base where a vessel is configured to be anchored; a second step of inputting the raw material into an on-site treatment agent manufacturing facility located at the second base to manufacture a treatment agent; and a third step of supplying the treatment agent to the vessel anchored at the second base and treating ballast water using the treatment agent.

A reactor that operates with ultraviolet light emitting diodes (UV-LEDs) to attain UV photoreactions or UV photo-initiated reaction in a fluid flow for various applications, including water purification. The UV-LED reactor is comprised of a conduit means for passing fluid flow, an ultraviolet light emitting diode (UV-LED), and a radiation-focusing element to focus the UV-LED radiation to the fluid in the longitudinal direction of the conduit. The UV-LED reactor may include photocatalysts or chemical oxidants, which are activated by UV emitted by UV-LEDs for photocatalytic and photo-initiated reactions.

Per- and polyfluoroalkyl substances (PFAS) are destroyed by oxidation in supercritical conditions. PFAS in water can be concentrated and prepared for destruction in a pretreatment phase. Following annihilation of the PFAS in supercritical conditions to levels below 5 parts per trillion (ppt), the water effluent can be used to recover heat, returned to sub-critical conditions, and then released back into the environment.

Per- and polyfluoroalkyl substances (PFAS) are destroyed by oxidation in supercritical conditions. PFAS in water can be concentrated and prepared for destruction in a pretreatment phase. Following annihilation of the PFAS in supercritical conditions to levels below 5 parts per trillion (ppt), the water effluent can be used to recover heat, returned to sub-critical conditions, and then released back into the environment.

Per- and polyfluoroalkyl substances (PFAS) are destroyed by oxidation in supercritical conditions. PFAS in water is concentrated in a reverse osmosis step and salt from the resulting solution is removed in supercritical conditions prior to destruction of PFAS in supercritical conditions.

A method for electrolysis-ozone-corrosion inhibitor/electrolysis-ozone-hydrogen peroxide-corrosion inhibitor coupling treatment on toxic and refractory wastewater includes the following steps: adding toxic and refractory wastewater to be treated into a wastewater treatment reaction tank equipped with a plate anode and a plate cathode, and starting a direct current (DC) power supply connected to the plate anode and the plate cathode to treat the toxic and refractory wastewater at an appropriate current density under stirring, during which a corrosion inhibitor and hydrogen peroxide are added to the toxic and refractory wastewater to be treated and ozone is introduced into the toxic and refractory wastewater to be treated through an aeration device. The method can increase the production rate and production quantity of free radicals in a reaction system, effectively improve the treatment efficiency for toxic and refractory wastewater, and reduce the treatment cost.

Disclosed are a P—N heterojunction composite material supported on the surface of nickel foam, a preparation method therefor and the application thereof. The composite material is a supported catalyst which can be used to remove pollutants in water by means of photoelectrocatalysis. The method comprises firstly modifying, by means of a hydrothermal method, a layered nickel-iron bimetallic hydroxide nanosheet on the surface of clean nickel foam, and then modifying cobalt oxide nanowires on the surface of the layered nickel-iron bimetallic hydroxide nanosheet by means of a mixed solvent-thermal method, so as to obtain a P—N heterojunction catalyst composite material supported on the surface of nickel foam (Ni foam@NiFe-LDH/Co.sub.3O.sub.4). The composite material has a good response to visible light, which can greatly enhance the absorption and utilization of light, and is further beneficial to enhance the performance of the catalyst.

A two-stage treatment process for destroying per- and polyfluoroalkyl substances (PFAS) in an aqueous stream. The two-stage treatment process uses a combination of multifunctional crystalline molecular sieves, such as zeolites and zeotypes, to separate PFAS from the aqueous stream, catalytically decompose and defluorinate any PFAS molecules, and generate non-toxic waste products that are safe for disposal. The first stage includes adsorption of the PFAS within one of a pair of vessels containing porous, hydrophobic, hydrothermally stable molecular sieves, dehydration of the captured PFAS on the sieves, and catalytic ozonation of the captured PFAS molecules on the dried sieves. The second stage involves catalytic decomposition and neutralization of the ozonation results with one of a pair of vessels including a zeolite-supported CaO catalyst, catalytic oxidation of any toxic CO generated by the decomposition, and an acid wash for regeneration of the spent catalyst.

A method and system for water body algae control are provided. The method for water body algae control may include the steps of: withdrawing water from the water body; infusing a gas containing oxygen and/or ozone into the withdrawn water by generating nanobubbles of the gas within the water; and returning the infused water into the water body. The water body algae control system may include a nanobubble generator that may be configured to receive water that is withdrawn from a water body. An oxygen concentrator and an air compressor may be configured to provide a gas containing oxygen to the nanobubble generator and/or to an ozone generator, in which the nanobubble generator is configured to disperse nanobubbles of the gas containing oxygen and/or ozone into the water, and in which the nanobubble containing water is then directed back into the water body.

A method for removing contaminants from exhaust air and liquid using a disinfection device comprising a housing having a chamber and a top end. The chamber has a body and a reducing part. The reducing part comprises a first opening at the bottom end of the chamber and a floating body configured to seal the first opening at the bottom end. The disinfection device further comprises a spiral guiding channel having an inlet and an outlet connecting to the chamber; and an exhaust conduit having an expandable part at one end of the exhaust conduit. The exhaust conduit connects to the top end of the housing and partially extends through the body of the chamber. A nonluminous disinfection part is installed in the disinfection device interior so as to remove air contaminants when air is passing through the chamber from the spiral guiding channel to the exhaust conduit.