Provided is a method for operating an RO-membrane treatment system that includes an energy recovery device that recovers energy from the concentrate of an RO-membrane device and the RO-membrane treatment system that reduce the occurrence of biofouling in not only the RO-membrane device but also the energy recovery device in order to increase the energy efficiency of the entire system and operate the RO-membrane treatment system with consistency. The method includes adding at least one slime-control agent selected from a combined-chlorine slime-control agent and a stabilized-bromine slime-control agent to water that is to be treated with the reverse-osmosis-membrane device such that a residual halogen concentration in the concentrate that is to be introduced into the energy recovery device is 0.1 to 10000 mg/L as total chlorine.

Provided are wastewater treatment processes that involves struvite precipitation and a microbial fuel cell for the recovery of nutrients and energy from a digester effluent.

Three embodiments of an invention are disclosed in which sea water undergoes a desalination process accompanied by production of salable energy of value greater than the cost of the fossil fuel required, and which discharges brine to the sea at a temperature and salinity harmless to sea life.

A plant for the disposal of wastes includes a supercritical water oxidation reactor, a supercritical water gasification reactor, and a feeding system configured for feeding at least two organic currents of wastes to the supercritical water oxidation reactor and supercritical water gasification reactor and configured for feeding at least one aqueous flow within said plant. The feeding system is configured for feeding the at least one aqueous current with a series flow through the supercritical water oxidation reactor and supercritical water gasification reactor. The feeding system is configured for feeding the at least two organic currents of wastes with a parallel flow through the supercritical water oxidation reactor and supercritical water gasification reactor and so as to selectively feed each of the organic currents of wastes to the supercritical water oxidation reactor or to the supercritical water gasification reactor.

A system for brine water desalinization includes a first heat exchanger having an inlet plenum and an outlet plenum for a first fluid comprising a concentrate in a liquid. The first heat exchanger includes a shell side fluid inlet and a shell side fluid outlet for a second fluid comprising a higher concentrated liquid than the first fluid. The system also comprises pipes configured to direct the first fluid from the outlet plenum to a shell side fluid inlet of a second heat exchanger and to direct the second fluid from the shell side fluid outlet to an inlet plenum of the second heat exchanger. The system further includes pipes configured to produce desalinized water by a serial distillation of multiple steams from an nth number of heat exchangers into respective distillates thereof and a parallel product of brine waste thereof from the heat exchangers.

System and method for micro-Super Critical Water Oxidation solids treatment of fecal waste are described. The system includes an injector vessel (112) and a reactor (114). The reactor can receive an injection of a slurry batch and an input of compressed air that is heated over time to a temperature at or above the critical point of water into the super critical fluid phase. A combined concentrator and phase separator (150)) can receive a treated output from the reactor and separate solid ash from liquid and gaseous effluent. A drying tunnel (170) can receive and dry the solid ash. The treatment process includes heating the slurry batch, within the reactor, to a temperature of at or above the critical point of water into the super critical fluid phase and maintaining the slurry batch a minimum temperature, within the reactor, for a predetermined treatment time to produce a treated output.

A reverse osmosis water production apparatus for use in a body of water includes a first section defining a buoyancy chamber and an elongate second section connected to the first section and configured to define an elongate chamber which extends downward beneath a waterline in use. The elongate chamber is provided with a plurality of elongate reverse osmosis membrane tubes, each tube containing a reverse osmosis membrane. A longitudinal axis of each reverse osmosis membrane tube is substantially parallel with a longitudinal axis of the elongate chamber and the reverse osmosis membrane tubes are arranged around a passage.

The invention produces pure fluids and transports fluids using renewable energy integrated into the purification process and maximize energy efficiency by utilizing simple machines, gravity, and buoyancy combined with different proven state of the art water purification and membrane systems.

The invention requires no real estate in some embodiments and in other embodiments can also locate in very dense populated areas on land to provide decentralized services.

A metal recovery system includes: a desalination apparatus obtaining freshwater with a reverse osmosis membrane from liquid to be processed pressurized by a pump; a metal recovery apparatus recovering metal ions from first drainage from the desalination apparatus, using a metal ion exchange membrane; and a control apparatus that includes: a pump control unit controlling energization of the pump so that an inflow flow rate of the liquid to be processed flowing into the desalination apparatus is a predetermined first flow rate when an exchange membrane temperature is within a temperature range determined in advance; and an exchange membrane control unit controlling energization of electrodes applying an electric field to a metal ion exchange membrane based on a first ion concentration that is a concentration of the metal ions in the first drainage when the exchange membrane temperature is within a temperature range determined in advance.

A charging system for charging a reactor with air used energy produced by the reactor and includes a vessel having a hollow interior cavity partially filled with a liquid slug, a first air pocket within the cavity on a first side of the liquid slug, and a second air pocket within the cavity on a second side of the liquid slug. The liquid slug forms a water trap seal in the cavity between the two pockets and moves within the vessel in a cycle in which gas is loaded into the first air pocket in a first stroke and gas in the first air pocket is compressed in a second stroke. Movement of the liquid slug during the second stroke is caused by an increasing pressure in the second air pocket due to introduction of high-pressure gas from the reactor into the second air pocket.