The present disclosure relates to a biocide generating system for inhibiting bio-fouling within a water system of a watercraft. The water system is configured to draw water from a body of water on which the watercraft is supported. The biocide generating system includes an electrode arrangement adapted to be incorporated as part of an electrolytic cell through which the water of the water system flows.

Self-cleaning electrochemical cells, systems including self-cleaning electrochemical cells, and methods of operating self-cleaning electrochemical cells are disclosed. The self-cleaning electrochemical cell can include a plurality of concentric electrodes disposed in a housing, for example, a cathode and an anode, a fluid channel defined between the concentric electrodes, a separator residing between the concentric electrodes, first and second end caps coupled to respective ends of the housing, and an inlet cone. The separators may be configured to localize the electrodes and dimensioned to minimize a zone of reduced velocity occurring downstream from the separator. The end caps and inlet cone may be dimensioned to maintain fully developed flow and minimize pressure drop across the electrochemical cell.

A hydrophobic biofilm membrane modified with a spiropolyurethane may be used for desalination of salt water to fresh water. The spiropolyurethane component of the membrane can produce a hydrophobic spin membrane boundary which attracts saline water, and where the hydrophobic spin membrane boundary can comprise a hinge-like motion for capture of salt molecules via a loose pore-gate spongy membrane surface texture while allowing desalinated water to flow through the porous membrane. The membrane is useful in both reverse osmosis (RO) and membrane distillation (MD) separations, including the desalination.

A seawater mineral extract derived from seawater having a salinity of from 3.4% Brix to 3.6% Brix, wherein the seawater mineral extract comprises a mineral salt content of at least 20% of the overall seawater extract.

A carbon negative clean fuel production system includes: a main platform; a heat collection device for capturing heat from a hydrothermal emissions from a hydrothermal vent on a floor of an ocean; a heat-driven electric generator; a heat distribution system including a heat absorbing material and a heat transporting pipe; anchor platforms tethered to the main platform; a mineral separator; a seawater filtration unit; a water splitting device; a sand refinery machine; a carbon removal system; and a chemical production system for producing hydrides, halides and silane. Also disclosed is a method for carbon negative clean fuel production, including: capturing heat; producing electric energy; separating minerals; filtering seawater; splitting water; refining sand; removing carbon dioxide; and producing hydrides, halides, and silane.

A system and method for producing from saline source water a product containing an increased ratio of multi-valent ions to mono-valent ions, which includes multiple nanofiltration units arranged to selectively remove mono-valent ions from the water fed into each nanofiltration stage in the nanofiltration permeate stream while retaining multi-valent ions in the nanofiltration reject stream. The rate at which the increase in the multi-valent ion- to mono-valent ion ratio is obtained may be enhanced by introduction of lower salinity water into the nanofiltration reject between stages, and by recirculating a portion of downstream nanofiltration reject flow into an upstream nanofiltration unit. The enhanced multi-valent ion product is suitable for multiple uses, including irrigation of plants and remineralization of desalinated water. The relative concentrations of the multi-valent ions in the product may be adjusted, for example by selection of nanofiltration membrane technologies which have higher or lower rejection for specific multi-valent ions.

A water intake and pretreatment system (10) comprising an inlet for delivering water from a natural source to a reservoir (12); said inlet to reservoir having a net screen (16) to prevent entry of organisms above a predetermined size and including a one-way gate (30) to allow organisms to exit the reservoir; said reservoir further comprising a granular filter media for water and algae filtration; and a drainage layer for removal of filtered water from the granular filter media to a drainage outlet. A local backwashing apparatus (40) is included for localized backwashing of the granular filter media.

A filtration apparatus includes a tubular casing having a longitudinal axis and first and second casing ends, a plurality of partition plates positioned in the casing and sealed thereto to thereby define a plurality of axially successive chambers within the casing, including an intake collection chamber between a first of the partition plates and the first casing end, a discharge collection chamber between a second of the partition plates and the second casing end, and a reject collection chamber opposite the second partition plate from the second casing end. A plurality of elongated filtration membrane stacks are positioned side-by-side in the casing generally parallel to the longitudinal axis. Each filtration membrane stack includes an intake end which is fluidly connected to the intake collection chamber, a discharge end which is fluidly connected to the reject collection chamber, and a permeate channel which extends between the intake and discharge ends and is fluidly connected to the discharge collection chamber, an end of the permeate channel located adjacent the intake end being sealed from the intake collection chamber. The filtration apparatus also includes an intake pipe having a first end fluidly connected to the intake collection chamber and a second end fluidly connected to a first connector located proximate the second casing end; a discharge pipe having a first end fluidly connected to the discharge collection chamber and a second end fluidly connected to a second connector located proximate the first connector; and a reject pipe having a first end fluidly connected to the reject collection chamber and a second end fluidly connected to a third connector located proximate the first and second connectors. Each filtration membrane stack includes a plurality of filtration membranes, and the plurality of filtration membrane stacks together define a plurality of axially successive sets of radially adjacent filtration membranes. Also, each filtration membrane of each of the sets of filtration membranes is sealed to a corresponding hole in a respective one of the partition plates.

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 hybrid system and a method for hybrid desalination and crystallization of seawater is provided. The hybrid system includes a reverse osmosis unit configured to separate the seawater from dissolved solids, generate a first quantity of purified water, and generate a second quantity of wastewater. The hybrid system also includes a pressure exchanger configured to lower a pressure of the second quantity of wastewater to atmospheric pressure. The hybrid system further includes a laser induced shock wave crystallizer configured to trigger nucleation of the dissolved salts in the second quantity of wastewater, expel a third quantity of wastewater having a second concentration of dissolved salts, and expel a fourth quantity of salt crystals. The hybrid system also includes a collection vat for receiving the salt crystals. The hybrid system further includes a high pressure pump configured to recycle the third quantity of wastewater back to the reverse osmosis unit.