A composition for treating swimming pool water comprises sodium bisulphate and aluminium sulphate. The aluminium sulphate in the composition minimizes the precipitation of sodium bisulphate at temperatures lower than about 5 degrees Celsius for a time period to maintain a concentrated form of acid to control the pH level of the water. In some embodiments, the composition includes 30 to 40% sodium bisulphate (NaHSO4) wt/wt %, 0.2% to 5% aluminium sulphate Al2(SO4)3 wt/wt %, 0.1% to 1% copper sulphate/chelating agent wt/wt %, 0.01% to 0.02% sodium hydroxide, and balance water.

A water treatment membrane washing apparatus includes two ozone dissolving tanks for storing filtrate generated by filtering raw water through a water treatment membrane and gas aspirators provided for the respective ozone dissolving tanks, for mixing the filtrate with ozone gas supplied from an ozone supply unit to generate ozone gas containing filtrate, and is configured such that waste ozone gas generated in one of the ozone dissolving tanks is aspirated by the gas aspirator provided for the other ozone dissolving tank. After the filtrate from the raw water is pretreated by being mixed with the waste ozone gas in the aspirator, the pretreated filtrate is mixed with the ozone gas in the other ozone dissolving tank until it reaches a predetermined concentration. The ozone gas containing filtrate is supplied from the secondary side of the water treatment membrane to the primary side thereof to wash the eater treatment membrane.

A ballast water treatment apparatus and a ballast water treatment system having a ballast water treatment apparatus are provided. The ballast water treatment apparatus includes a ballast water transport line configured to transport ballast water between a first location and a second location, the transported ballast water being passed through at least one injector, and a plasma generation device configured to be fed with a feed gas optionally comprising oxygen, and configured to generate a feed gas plasma by a streamer type discharge in a discharge area to provide a treated gas at a treated-gas outlet. The injector includes a liquid passage having an area constructed such as to increase a velocity of the passed-through water in a region of increased velocity, and an injector gas inlet provided in the region of increased velocity. The treated-gas outlet is in gaseous connection with the injector gas inlet.

A ballast water treatment apparatus and a ballast water treatment system having a ballast water treatment apparatus are provided. The ballast water treatment apparatus includes a ballast water transport line configured to transport ballast water between a first location and a second location, the transported ballast water being passed through at least one injector, and a plasma generation device configured to be fed with a feed gas optionally comprising oxygen, and configured to generate a feed gas plasma by a streamer type discharge in a discharge area to provide a treated gas at a treated-gas outlet. The injector includes a liquid passage having an area constructed such as to increase a velocity of the passed-through water in a region of increased velocity, and an injector gas inlet provided in the region of increased velocity. The treated-gas outlet is in gaseous connection with the injector gas inlet.

A wastewater management system includes a series of water treatment modules to treat wastewater and produce reusable and/or potable water and other beneficial byproducts of the wastewater treatment process. A pretreatment module, a filtration module, an evaporator module, an odor control module, a UV-light module, an autoclave module, a sonolysis module, an ozone module and a chlorination module are combined in multiple combinations along with holding tanks, condensers, flash tanks and other components to address water purification and reclamation needs based upon specific wastewater conditions. The system captures condensate from AC systems and rainwater from rainwater gutter systems processes the water to produce reusable and/or potable water with or without re-mineralization. Any CO.sub.2 produced by the water treatment system is captured and processed using naturally-occurring flora. The wastewater treatment system includes multiple closed-loop subsystems to minimize energy usage and maximize water purification and reclamation for reuse.

A water delivery control system operates to selectively deliver water from a water source to water use devices. The system includes at least one controller that wirelessly communicates messages with a portable user device. The system includes a water control valve and a motor that is operative to selectively move at least one valve element of the valve. A water meter is operative to measure water flow that corresponds to flow through the valve. The controller is operable to cause the valve to enable or prevent flow through the valve responsive at least in part to water flow data. The controller is operative to determine a water use condition responsive to a water usage pattern, and to cause at least one message to be sent to the portable user device responsive to the determined water use condition.

A water delivery control system operates to selectively deliver water from a water source to water use devices. The system includes at least one controller that wirelessly communicates messages with a portable user device. The system includes a water control valve and a motor that is operative to selectively move at least one valve element of the valve. A water meter is operative to measure water flow that corresponds to flow through the valve. The controller is operable to cause the valve to enable or prevent flow through the valve responsive at least in part to water flow data. The controller is operative to determine a water use condition responsive to a water usage pattern, and to cause at least one message to be sent to the portable user device responsive to the determined water use condition.

In an ozone generating device including a discharge unit for discharging a material gas that flows through a discharge space formed between two electrodes to generate ozone and a cooling unit for radiating heat which is generated by the discharging, wherein the material gas is obtained by vaporizing a liquefied raw material, the cooling unit includes a first cooling unit through which a first refrigerant flows in contact with one of the two electrodes and a second cooling unit which is provided further to the downstream side of flow of the material gas in the discharge unit than the first cooling unit, and in which the cold heat source is the liquefied raw material and the temperature of the second refrigerant introduced to the second cooling unit is set to be lower than the temperature of the first refrigerant introduced to the first cooling unit.

In an ozone generating device including a discharge unit for discharging a material gas that flows through a discharge space formed between two electrodes to generate ozone and a cooling unit for radiating heat which is generated by the discharging, wherein the material gas is obtained by vaporizing a liquefied raw material, the cooling unit includes a first cooling unit through which a first refrigerant flows in contact with one of the two electrodes and a second cooling unit which is provided further to the downstream side of flow of the material gas in the discharge unit than the first cooling unit, and in which the cold heat source is the liquefied raw material and the temperature of the second refrigerant introduced to the second cooling unit is set to be lower than the temperature of the first refrigerant introduced to the first cooling unit.

A pulsed voltage is repeatedly applied between a first electrode and a second electrode to which a gas is supplied, a plasma is generated between the first electrode and the second electrode, and an active species is produced in the plasma. The energy necessary for plasma generation is set to a value greater than or equal to 1.8 W/cm.sup.3 and less than or equal to 8.5 W/cm.sup.3.